WO2021199082A1

WO2021199082A1 - Antimicrobial compounds and uses thereof

Info

Publication number: WO2021199082A1
Application number: PCT/IN2021/050329
Authority: WO
Inventors: Jayanta Haldar; Sreyan GHOSH; Riya MUKHERJEE
Original assignee: Jawaharial Nehru Centre for Advanced Scientific Research
Current assignee: Jawaharial Nehru Centre for Advanced Scientific Research
Priority date: 2020-04-03
Filing date: 2021-04-01
Publication date: 2021-10-07
Anticipated expiration: 2022-10-03

Abstract

The present disclosure relates to compounds of Formula I, II, III or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof. The present disclosure relates to a process of preparing the compounds of Formula I, II or III. The present disclosure further relates to an antimicrobial composition comprising the compounds of Formula I, II or III and method of forming an antimicrobial composition thereof. The present disclosure also relates to a method of treating a microbial infection.

Description

ANTIMICROBIAL COMPOUNDS AND USES THEREOF

TECHNICAL FIELD

[0001] The subject matter described herein in general relates to the field of biomaterials and more particularly to the development of antimicrobial coatings to prevent the surface- mediated spread of infections, wherein the coatings are efficacious against different drug- resistant bacteria, fungi, and virus.

BACKGROUND OF INVENTION

[0002] Almost 80% of human infections result from microbe-contaminated surfaces. Adherence followed subsequent colonization of microbes onto various surfaces of everyday objects result in the spread of notorious community-acquired and nosocomial infections. Inhibition of microbial colonization on surfaces thus remains the crucial step to prevent infections arising from bacteria, fungi, and viruses. This can be accomplished by attaching different types of antimicrobials (e.g., antibiotics, antimicrobial peptides, quaternary ammonium compounds, etc.) to the surfaces. However, tethering antibiotics or antimicrobial peptides to a surface suffer from induction of resistance or short term stability. Therefore, there is an increasing interest in the development of cationic polymer based coating formulations which can avert the problem of resistance development by inactivating pathogens in a membrane bursting fashion. Cationic polymers can be employed on a surface either by non-covalent, physical adherence or by covalent immobilization. The basis of the covalent approach is painting of water-insoluble and organo-soluble antimicrobial polymers on various surfaces. Even though a robust technique, in certain cases the stability of the coating becomes precarious. On the other hand, covalent/irreversible immobilization of the cationic polymers to the surfaces imparts chemically crosslinked, durable coating. Researchers have developed a wide number of antimicrobial coatings by covalently attaching cationic polymers to different surfaces either by grafting from or in grafting onto approach.

[0003] However, a major challenge with cationic surfaces is the accumulation of dead microbes remaining on antimicrobial coatings, which block its antimicrobial functional groups thereby greatly diminishing its efficiency. Various groups have constructed coatings based on anti-adhesive polymers such as polyethylene glycol, polyzwitterionic compounds, etc. which however lack intrinsic antibacterial activity. To address this issue, switchable smart coatings have been engineered which can repeatedly switch between bactericidal and bacteria repellant states. [0004] The polymeric coating designs discussed till now have shown promising results but many of them associate synthetic complexity, batch-to-batch variation or complicated coating techniques. Thus, there is still a need for a simpler design that can be synthesized with ease and can be coated employing versatile coating techniques.

SUMMARY OF THE INVENTION [0005] In an aspect of the present invention, there is provided a compound of Formula

I

Formula I or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein

Y is hydrogen or

; n is 2 to 12;

X is independently selected from -O- or -NH-;

R is substituted or unsubstituted C₃-C₂₀ aliphatic radical; and Z- is a negatively charged counter anion.

[0006] In another aspect of the present disclosure, there is provided a compound of Formula II

Formula II or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12;

X is independently selected from -O- or -NH-;

R is substituted or unsubstituted C₃-C₂₀ aliphatic radical; and Z- is a negatively charged counter anion selected from Br-, Cl-, or G.

[0007] In yet another aspect of the present disclosure, there is provided a compound of Formula III

Formula III or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12;

X is independently selected from -O- or -NH-;

R is independently substituted or unsubstituted C₃-C₂₀ aliphatic radical;

Z- is a negatively charged counter anion selected from Br-, Cl-, or G.

[0008] In a further aspect of the present disclosure, there is provided a process of preparing the compound of Formula I, Formula II, and Formula III.

[0009] In another aspect of the present disclosure, there is provided a compound of Formula I, Formula II, Formula III, or their stereoisomers, polymorphs, solvates, hydrates, intermediates, or pharmaceutically active derivatives thereof for use in the treatment of microbial infection.

[0010] In an aspect of the present disclosure, there is provided a compound of Formula I, Formula II, Formula III, or their stereoisomers, polymorphs, solvates, hydrates, intermediates, or pharmaceutically active derivatives thereof for use in killing or inhibiting the growth of a microorganism selected from the group consisting of bacteria, vims, and fungi.

[0011] In an aspect of the present disclosure, there is provided a pharmaceutical composition comprising a compound of Formula I, Formula II, Formula III, or their stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically acceptable derivatives thereof together with a pharmaceutically acceptable carrier. [0012] In an aspect of the present disclosure, there is provided a use of the compound of Formula I, Formula II, Formula III, or their stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically acceptable derivatives thereof, in killing or inhibiting the growth of a microorganism selected from the group consisting of bacteria, vims, and fungi.

[0013] In an aspect of the present disclosure, there is provided a method for treatment of microbial infection in a subject comprising: administering to the subject an effective amount of the compound of Formula I, Formula II, Formula III, or their stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically acceptable derivatives thereof.

[0014] In an aspect of the present disclosure, there is provided an antimicrobial coating composition comprising the compound of Formula I, Formula II, Formula III, or their stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically acceptable derivatives thereof.

[0015] In an aspect of the present disclosure, there is provided a zwitterionic compound obtained by the hydrolysis of the compound of Formula I, Formula II, Formula III, or their stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically acceptable derivatives thereof.

[0016] In an aspect of the present disclosure, there is provided an antimicrobial coating comprising the zwitterionic compound of the present disclosure. [0017] In an aspect of the present disclosure, there is provided an antimicrobial composition coated substrate comprising the antimicrobial coating composition of the present disclosure.

[0018] In an aspect of the present disclosure, there is provided a method of killing microbes comprising providing the coating of the present disclosure.

[0019] In an aspect of the present disclosure, there is provided a method of forming an antimicrobial coating on a substrate, the method comprising: (a) preparing a coating composition with the compound of Formula I, Formula II, Formula III, or their stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically acceptable derivatives thereof; (b) applying the coating composition to a surface of a substrate; and (c) curing the substrate by UV irradiation to obtain an antimicrobial coated substrate.

[0020] These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES [0021] In order that the disclosure may be readily understood and put into practical effect, reference will now be made to exemplary embodiments as illustrated with reference to the accompanying figures. The figures together with a detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, in accordance with the present disclosure wherein:

[0022] Figure 1 illustrates the bactericidal kinetics of QSM 1 and QSM 2 against MRSA ATCC33591, in accordance with an embodiment of the present subject matter.

[0023] Figure 2 illustrates surface immobilization and characterization of the coated surfaces. (A) Schematic representation of coating of different surfaces from aqueous and organo- solutions of QSM 1 or QSM 2. (B) Infra-red spectrum of QSM 1 and QSM 2 coated polypropylene (PPE) surface. (C) X-ray photoelectron spectrum of polypropylene surface coated with QSM 2, in accordance with an embodiment of the present disclosure. [0024] Figure 3 depicts scanning electron microscopic images of cotton surfaces coated with (A) QSM 1 and (B) QSM 2. The inset images represent the color mapping of bromine (green) and nitrogen (red) of the same cotton surfaces subsequent to energy dispersive X-ray analysis. Scale bar = 250 μm. Atomic force microscopic images of polyurethane surfaces coated with QSM 2 in (C) tapping mode and (D) height phase, in accordance with an embodiment of the present disclosure.

[0025] Figure 4 illustrates the antibacterial activity of coated surfaces against i) planktonic cells and ii) stationary phase cells of MRS A ATCC33591 , in accordance with an embodiment of the present disclosure.

[0026] Figure 5 illustrates the (i) bactericidal kinetics and (ii) antifungal activity of coated cotton surfaces, in accordance with an embodiment of the present disclosure. [0027] Figure 6 illustrates (A) reduction in the bacterial count of MRSA ATCC33591 cells after 2 hrs treatment with coated and uncoated polyurethane surfaces. (*) indicates bacterial count <50 CFU/mF. (B)-(D) Observation of bacterial killing through scanning electron microscopic images of MRSA ATCC33591 cells harvested after incubation with (B) uncoated polystyrene surface, (C) polystyrene surface coated with QSM 1, and (D) surface coated with QSM 2, in accordance with an embodiment of the present disclosure. [0028] Figure 7 illustrates (i) bacterial adhesion assay for (A) uncoated surface, (B) QSM

1 coated surface, (C) QSM 2 coated surface and (D) hydrolyzed surface by dipping in MRSA ATCC33591. (ii) Antiviral assay of the coated substrates using plaque assay the washings of A/NWS/33 strain from (A) a noncoated PU (polyurethane) surface (well 1) and its twofold serial dilutions (wells 2-6); (B) and (C) from PU surfaces coated with QSM 1 and QSM 2 respectively (well 1) and its two fold serial dilutions (wells 2-6); against A/PR/8/34 strain, plaque assay was performed with washings from (D) a noncoated PU surface (well 1) and its twofold serial dilutions (wells 2-6); (E) and (F) PU surfaces coated with QSM 1 and QSM 2 respectively (well 1) and its twofold serial dilutions, in accordance with an embodiment of the present disclosure. [0029] Figure 8 illustrates ESI spectra of hydrolyzed zwitterionic product. (A) Hydrolysis of QSM 1 in TFA:H₂0 (1:1); (B) hydrolysis of QSM 2 in IN HC1, in accordance with an embodiment of the present disclosure.

[0030] Figure 9 shows the SEM images of the coated surgical mask and polyethylene surfaces, in accordance with an embodiment of the present disclosure.

[0031] Figure 10 depicts the antibacterial activity of QSM 2 coated (A) nylon, PMMA, polyethylene, rubber, (B) head-cap, paper, leather and surgical mask surfaces against drug-resistant strains of MRSA and VRSA, in accordance with an embodiment of the present disclosure.

[0032] Figure 11 depicts the antifungal activity of QSM 2 coated surfaces against C. albicans ATCC 10231, in accordance with an embodiment of the present disclosure. [0033] Figure 12 depicts the anti-influenza (antiviral) activity of QSM 2-coated and uncoated surgical mask and polyethylene surfaces against human influenza virus A/NWS/33(H1N1), in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0034] Those skilled in the art will be aware that the present disclosure is subject to variations and modifications other than those specifically described. It is to be understood that the present disclosure includes all such variations and modifications. The disclosure also includes all such steps, features, compositions, and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any or more of such steps or features.

Definitions

[0035] For convenience, before further description of the present disclosure, certain terms employed in the specification, and examples are delineated here. These definitions should be read in the light of the remainder of the disclosure and understood as by a person of skill in the art. The terms used herein have the meanings recognized and known to those of skill in the art, however, for convenience and completeness, particular terms and their meanings are set forth below.

[0036] The articles “a”, “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. [0037] The terms “comprise” and “comprising” are used in the inclusive, open sense, meaning that additional elements may be included. It is not intended to be construed as “consists of only”.

[0038] Throughout this specification, unless the context requires otherwise the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated element or step or group of element or steps but not the exclusion of any other element or step or group of element or steps.

[0039] The term “including” is used to mean “including but not limited to”. “Including” and “including but not limited to” are used interchangeably.

[0040] In the structural formulae given herein and throughout the present disclosure, the following terms have been indicated meaning, unless specifically stated otherwise. [0041] The term “at least one” is used to mean one or more and thus includes individual components as well as mixtures/combinations.

[0042] The compounds of Formula (I), Formula (II), and Formula (III) and their stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof can also be referred as “compounds of the present disclosure” or “compounds”.

[0043] The term “polymorphs” refers to crystal forms of the same molecule, and different polymorphs may have different physical properties such as, for example, melting temperatures, heats of fusion, solubilities, dissolution rates and/or vibrational spectra as a result of the arrangement or conformation of the molecules in the crystal lattice. It will be further appreciated that certain compounds of the invention that exist in crystalline form, including the various solvates thereof, may exhibit polymorphism (i.e. the capacity to occur in different crystalline structures). These different crystalline forms are typically known as 'polymorphs'. The invention includes such polymorphs. Polymorphs have the same chemical composition but differ in packing, geometrical arrangement, and other descriptive properties of the crystalline solid state. Polymorphs, therefore, may have different physical properties such as shape, density, hardness, deformability, stability, and dissolution properties. Polymorphs typically exhibit different melting points, IR spectra, and X-ray powder diffraction patterns, which may be used for identification. It will be appreciated that different polymorphs may be produced, for example, by changing or adjusting the reaction conditions or reagents, used in making the compound. For example, changes in temperature, pressure, or solvent may result in polymorphs. In addition, one polymorph may spontaneously convert to another polymorph under certain conditions.

[0044] The compounds described herein may contain one or more chiral centers and/or double bonds and therefore, may exist as stereoisomers, such as double-bond isomers (i.e., geometric isomers), regioisomers, enantiomers or diastereomers. Accordingly, the chemical structures depicted herein encompass all possible enantiomers and stereoisomers of the illustrated or identified compounds including the stereoisomerically pure form (e.g., geometrically pure, enantiomerically pure or diastereomerically pure) and enantiomeric and stereoisomeric mixtures. Enantiomeric and stereoisomeric mixtures can be resolved into their component enantiomers or stereoisomers using separation techniques or chiral synthesis techniques well known to the person skilled in the art. The compounds may also exist in several tautomeric forms including the enol form, the keto form and mixtures thereof. Accordingly, the chemical structures depicted herein encompass all possible tautomeric forms of the illustrated or identified compounds. It is also understood that some isomeric form such as diastereomers, enantiomers and geometrical isomers can be separated by physical and/or chemical methods and by those skilled in the art. Pharmaceutically acceptable solvates may be hydrates or comprising of other solvents of crystallization such as alcohols, ether, and the like.

[0045] As used herein, the term "substituted" is contemplated to include all permissible substituents of organic compounds. In a broad aspect, the permissible substituents include acyclic and cyclic, branched and unbranched, carbocyclic and heterocyclic, aromatic and nonaromatic substituents of organic compounds. Illustrative substituents include, for example, those described hereinabove. The permissible substituents can be one or more and the same or different for appropriate organic compounds. For purposes of this disclosure, the heteroatoms such as nitrogen may have hydrogen substituents, and/or any permissible substituents of organic compounds described herein which satisfy the valences of the heteroatoms. [0046] The term “solvate”, as used herein, refers to a crystal form of a substance which contains solvent.

[0047] The term “hydrate” refers to a solvate wherein the solvent is water.

[0048] The term “intermediate” refers to the compounds with same core structure of the compounds of the Formula I varying at specific allowed positions.

[0049] The term “pharmaceutically active derivative” refer to derivatives of Formula I which can be administered to a subject in physiologically compatible form which exhibit the pharmaceutical activity as disclosed herein.

[0050] The term “acceptable carrier” refer to vehicles of the Formula I which can deliver the Formula I without affecting the physical, chemical, physiological and pharmacological properties of Formula I.

[0051] The term “carrier” refers to the excipient which is combined with Formula I to form the antimicrobial coating composition. The carrier of the present disclosure refers to solvent which includes but not limited to ethanol, water and so on.

[0052] The term “antibiotic” refers to compounds or chemical substance produced by a microorganism, that inhibit or destroy the growth of microorganisms. Antibiotics include but not limited to penicillin, streptomycin, erythromycin and so on.

[0053] The term "effective amount" means an amount of a compound or composition which is sufficient enough to significantly and positively modify the symptoms and/or conditions to be treated (e.g., provide a positive clinical response). The effective amount of an active ingredient for use in a pharmaceutical composition will vary with the particular condition being treated, the severity of the condition, the duration of the treatment, the nature of concurrent therapy, the particular active ingredient(s) being employed, the particular pharmaceutically-acceptable excipient(s)/carrier(s) utilized, the route of administration, and like factors within the knowledge and expertise of the attending physician.

[0054] In this specification, the prefix C_x-y as used in terms such as C_x-y alkyl and the like (where x and y are integers) indicates the numerical range of carbon atoms that are present in the group; for example, C3-2oalkyl includes Chalky 1 (propyl and isopropyl), C4alkyl (butyl, 1-methylpropyl, 2-methylpropyl, and /-butyl), and the like. Unless specifically stated, the bonding atom of a group may be any suitable atom of that group; for example, propyl includes prop-l-yl and prop-2-yl.

[0055] The term “aliphatic radicals” as used herein refers to optionally mono- or polysubstituted and may be branched or unbranched, saturated or unsaturated. The term “aliphatic radical” and “aliphatic groups” may be interchangeably used. Aliphatic radicals, as defined in the present invention, include alkyl, alkenyl and alkynyl radicals. Unsaturated aliphatic radicals, as defined in the present disclosure, include alkenyl and alkynyl radicals. Preferred aliphatic radicals according to the present disclosure include but are not restricted to methyl, ethyl, vinyl (ethenyl), ethinyl, propyl, n-propyl, isopropyl, allyl (2-propenyl), 1-propinyl, methylethyl, butyl, n-butyl, iso-butyl, sec- butyl, tert-butyl butenyl, butynyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, pentyl, n-pentyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, hexyl, 1- methylpentyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, and n-dodecyl.

[0056] The term “C₃-C₂₀ alkyl” as used herein refers to a radical or group containing 3 to 20 carbon atoms, which are saturated, linear or branched hydrocarbons, unsubstituted or mono- or polysubstituted.

[0057] The term “C₃-C₂₀ alkenyl” as used herein refers to a radical or group containing 3 to 20 carbon atoms, which are unsaturated with at least one carbon carbon double bond in its structure, which are linear or branched, unsubstituted or mono- or polysubstituted. [0058] The term “C₃-C₂₀ alkynyl” as used herein refers to a radical or group containing 3 to 20 carbon atoms, which are unsaturated with at least one carbon carbon triple bond in its structure, which may be linear or branched, unsubstituted or mono- or polysubstituted.

[0059] A term once described, the same meaning applies for it, throughout the disclosure. [0060] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the preferred methods, and materials are now described. All publications mentioned herein are incorporated herein by reference. [0061] As mentioned above, currently, to avoid surface-associated infections, release- based systems are available in the healthcare settings. Different types of antimicrobials (e.g., antibiotics, antimicrobial peptides, quaternary ammonium compounds, etc.) are attached to the surfaces or loaded onto the surface. This antimicrobial (s) over the time leaches out from the surface and tackles the infection. This strategy suffers from exhaustion of the reservoir. Also, tethering antimicrobials such as antibiotics or antimicrobial peptides to a surface suffer from induction of resistance or short-term stability of the coating. Therefore, it is indeed necessary to have an easy coating strategy that can tackle a wide range of pathogens.

[0062] The present disclosure thus provides compound of Formula I, Formula II, and Formula III. These compounds are benzophenone-based small molecules, i.e., Quaternary Benzophenone -based Ester (QBEst; QSM 1) and Quaternary Benzophenone -based Amide (QBAm; QSM 2). Without being bound by theory, triggered by UV light, benzophenone can abstract a hydrogen atom from a neighboring aliphatic C-H group to form a new C-C bond. This approach helps to achieve the coating in an easy, one-step manner similar to painting or spraying but comprises of covalent conjugation with the surface. The molecules comprised of a quaternary nitrogen atom and decyl aliphatic chains conjugated through an ester (QBEst; QSM 1) or an amide (QBAm; QSM 2) functionality rendering them membrane-active as well as susceptible to degradation upon which the molecules can adapt a zwitterionic structure thereby attaining a non-fouling state. A major problem associated with the preparation of antimicrobial coatings on an industrial scale is the usage of volatile organic solvents posing serious health risks. On the other hand, the coating of different hydrophobic polymeric surfaces requires the use of organic solvents for improved film formation. Therefore, an optimum aliphatic chain of ten carbon atoms was incorporated in the designs to obtain solubility in both polar and non-polar solvents. Different surfaces were coated using aqueous or organo-solutions of QSM 1 and QSM 2. These coatings were characterized by different spectroscopic and microscopic techniques including AFM, SEM and XPS. The antimicrobial efficacies of the coated surfaces were investigated against human pathogenic bacteria, fungi and influenza virus including drug-resistant strains and various clinical isolates. The activity of the coated surfaces was examined against stationary phase cells of bacteria which are difficult to treat with traditional antibiotics. The non-leaching activity of the surfaces was tested to examine the covalent nature of the coating. The surfaces were subjected to hydrolytic degradation followed by the evaluation of bacterial adherence. [0063] According to an embodiment, the present disclosure relates to a compound of

Formula I

Formula I or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically

active derivatives thereof, wherein Y is hydrogen or ; n is 2 to

12; X is independently selected from -O- or -NH-; R is substituted or unsubstituted C₃- C₂₀ aliphatic radical; and Z- is a negatively charged counter anion.

[0064] According to an embodiment, the present disclosure relates to a compound of Formula I or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein Y is hydrogen; n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; R is independently selected from a group consisting of C₃-C₂₀ alkyl, C₃-C₂₀ alkenyl, and C₃-C₂₀ alkynyl; wherein C₃-C₂₀ alkyl, C₃-C₂₀ alkenyl, and C₃-C₂₀ alkynyl are independently unsubstituted or substituted and Z- is a negatively charged counter anion. [0065] According to an embodiment, the present disclosure relates to a compound of

Formula I or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein Y is

is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; R is independently selected from a group consisting of C₃-C₂₀ alkyl, C₃-C₂₀ alkenyl, and C₃-C₂₀ alkynyl; wherein alkyl, alkenyl, and alkynyl are independently unsubstituted or substituted; and Z- is a negatively charged counter anion.

[0066] According to an embodiment, the present disclosure relates to a compound of Formula I or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein Y is

is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; R is independently selected from a group consisting of C₃-C₂₀ alkyl, C₃-C₂₀ alkenyl, and C₃-C₂₀ alkynyl; wherein alkyl, alkenyl, and alkynyl are independently unsubstituted or substituted; and Z- is a negatively charged counter anion selected from Br-, Cl-, or G.

[0067] According to an embodiment, the present disclosure relates to a compound of Formula I, wherein Y is hydrogen; n is 2 to 12; X is independently selected from -O- or -NH-; R is substituted or unsubstituted C10 aliphatic radical; and Z- is Br-.

[0068] According to an embodiment, the present disclosure relates to a compound of Formula II

Formula II or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; X is independently selected from -O- or -NH-; R is substituted or unsubstituted C₃-C₂₀ aliphatic radical; and Z- is a negatively charged counter anion selected from Br-, Cl-, or

I-.

[0069] According to an embodiment, the present disclosure relates to a compound of Formula II

G.

[0070] According to an embodiment, the present disclosure relates to a compound of Formula II or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; X is -NH-; R is unsaturated or saturated C₃-C₂₀ aliphatic radical, wherein the aliphatic radical is unsubstituted or substituted; and Z is Br-.

[0071] According to an embodiment, the present disclosure relates to a compound of Formula II or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein n is 6; X is -NH-; R is C10H₂1 aliphatic radical; and Z- is Br-.

[0072] According to an embodiment, the present disclosure relates to a compound of Formula II or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; X is -O-; R is unsaturated or saturated C₃-C₂₀ aliphatic radical, wherein the aliphatic radical is unsubstituted or substituted; and Z- is Br-. [0073] According to an embodiment, the present disclosure relates to a compound of Formula II or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein n is 6; X is -O-; R is C₁₀H₂₁ aliphatic radical; and Z- is Br-. [0074] According to an embodiment, the present disclosure relates to a compound of

Formula III

Formula III or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; X is independently selected from -O- or -NH-; R is independently substituted or unsubstituted C₃-C₂₀ aliphatic radical; and Z is selected from Br-, Cl-, or G.

[0075] According to an embodiment, the present disclosure relates to a compound of Formula III or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; X is -NH-; R is independently unsaturated or saturated C₃-C₂₀ aliphatic radical; Z- is Br .

[0076] According to an embodiment, the present disclosure relates to a compound of Formula III or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; X is -O-; R is independently unsaturated or saturated C₃-C₂₀ aliphatic radical; and Z- is Br-.

[0077] According to an embodiment, the present disclosure relates to a process of preparing the compound of Formula I or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, the process comprising: reacting compound of Formula IV and Formula V to obtain a compound of Formula I.

[0078] According to an embodiment, the present disclosure relates to a process of preparing the compound of Formula I or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, the process comprising: reacting compound of Formula IV and Formula V is carried out in the presence of solvent at a temperature in the range of 40 to 80°C for a time period in the range of 20 to 50 hours to obtain a compound of Formula I.

[0079] According to an embodiment, the present disclosure relates to a process of preparing the compound of Formula I or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, the process comprising: reacting compound of Formula IV and Formula V is carried out in the presence of solvent at a temperature in the range of 55°C to 65 °C for a time period of 36 hours to obtain a compound of Formula I.

[0080] According to an embodiment, the present disclosure relates to a process of preparing the compound of Formula I or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, the process comprising: reacting compound of Formula IV and Formula V is carried out in the presence of solvent at a temperature in the range of 55°C to 65 °C for a time period of 36 hours to obtain a compound of Formula I and wherein the solvent is chloroform, or dichloromethane.

[0081] According to an embodiment, the present disclosure relates to compounds for use in the treatment of microbial infection.

[0082] According to an embodiment, the present disclosure relates to compounds, for use in killing or inhibiting the growth of a microorganism selected from the group consisting of bacteria, virus, and fungi. [0083] According to an embodiment, the present disclosure relates to a pharmaceutical composition comprising the compounds, together with a pharmaceutically acceptable carrier.

[0084] According to an embodiment, the present disclosure relates to a pharmaceutical composition comprising the compounds, together with a pharmaceutically acceptable carrier, and in combination with at least one antibiotic.

[0085] According to an embodiment, the present disclosure relates to the use of the compounds, in killing or inhibiting the growth of a microorganism selected from the group consisting of bacteria, vims, and fungi.

[0086] According to an embodiment, the present disclosure relates to a method for treatment of microbial infection in a subject comprising: administering to the subject an effective amount of the compounds.

[0087] According to an embodiment, the present disclosure relates to a method for treatment of microbial infection in a subject comprising: administering to the subject an effective amount of the compounds as described herein, wherein the microbial infection is caused a bacteria, vims, or fungi. The subject can be a mammal. In an embodiment, the subject is human or animal.

[0088] According to an embodiment, the present disclosure relates to an antimicrobial coating comprising the compounds as described herein.

[0089] According to an embodiment, the present disclosure relates to a zwitterionic compound obtained by the hydrolysis of the compounds as described herein.

[0090] According to an embodiment, the present disclosure relates to a zwitterionic compound obtained by the hydrolysis of the compounds as described herein for use in preventing a microbial infection.

[0091] According to an embodiment, the present disclosure relates to a zwitterionic compound obtained by the hydrolysis of the compounds as described herein for use in preventing a microbial infection, wherein the microbial infection is caused a bacteria, vims, or fungi.

[0092] According to an embodiment, the present disclosure relates to an antimicrobial coating composition comprising the zwitterionic compound as described herein. [0093] According to an embodiment, the present disclosure relates to an antimicrobial coating comprising the compounds as described herein in the form of a zwitterion. [0094] According to an embodiment, the present disclosure relates to an antimicrobial coating comprising the compounds as described herein in the form of a zwitterion wherein the zwitterionic form is obtained by the hydrolysis of the compounds of the present disclosure.

[0095] According to an embodiment, the present disclosure relates to an antimicrobial coating composition comprising the compounds of Formula I, Formula II or Formula III, or a zwitterionic form thereof with a carrier.

[0096] According to an embodiment, the present disclosure relates to an antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, wherein the zwitterionic form is obtained by hydrolysis of the compound of Formula I, Formula II or Formula III as disclosed herein with a carrier.

[0097] According to an embodiment, the present disclosure relates to an antimicrobial coating composition comprising the compounds as described herein, wherein the composition comprises the compounds of Formula I, Formula II or Formula III, or a zwitterionic form thereof with a solvent selected from water, ethanol, methanol, dimethylsulphoxide, dimethyl formamide, dichloromethane or chloroform.

[0098] According to an embodiment, the present disclosure relates to an antimicrobial coating composition comprising the compounds as described herein, wherein the composition comprises the compounds of Formula I, Formula II or Formula III, or a zwitterionic form thereof with water.

[0099] According to an embodiment, the present disclosure relates to an antimicrobial coating composition comprising the compounds as described herein, wherein the composition comprises the compounds of Formula I, Formula II or Formula III, or a zwitterionic form thereof with ethanol.

[00100] According to an embodiment, the present disclosure relates to an antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, wherein the antimicrobial coating composition is applied on a surface of a substrate by dipping, drop-casting, spraying, or brushing. [00101] According to an embodiment, the present disclosure relates to an antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, wherein the antimicrobial coating composition associates with the substrate via covalent interactions.

[00102] According to an embodiment, the present disclosure relates to an antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, wherein the substrate is selected from the group consisting of natural fibers, synthetic fibers, plastics, polymers, metals, glass, ceramics, and combinations thereof. [00103] According to an embodiment, the present disclosure relates to an antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, wherein the substrate is a biomedical device, implant, surgical instrument, fabric, tubing, gauze, air filter, protective mask, face shield, gloves, hand railing, tabletop, door handle, door, window, wall, glass, or bathroom fitting.

[00104] According to an embodiment, the present disclosure relates to an antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, wherein the substrate is selected from a group consisting of nylon, PMMA (polymethylmethacrylate), polyethylene, rubber, paper, leather, head cap, surgical mask and combinations thereof.

[00105] According to an embodiment, the present disclosure relates to an antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, for use in preventing a microbial infection.

[00106] According to an embodiment, the present disclosure relates to an antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, for use in preventing a microbial infection, wherein the microbial infection is caused a bacteria, virus, or fungi.

[00107] According to an embodiment, the present disclosure relates to an antimicrobial composition coated substrate comprising the antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof.

[00108] According to an embodiment, the present disclosure relates to an antimicrobial composition coated substrate comprising the antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, wherein the antimicrobial composition coated substrate has antimicrobial properties.

[00109] According to an embodiment, the present disclosure relates to an antimicrobial composition coated substrate comprising the antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, wherein the antimicrobial composition coated substrate has antimicrobial properties, wherein the antimicrobial composition coated substrate has antibacterial, antifungal, and antiviral properties.

[00110] According to an embodiment, the present disclosure relates to a method of killing microbes comprising providing the antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof.

[00111] According to an embodiment, the present disclosure relates to a method of killing microbes comprising providing the antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, wherein the microbe is a bacterium.

[00112] According to an embodiment, the present disclosure relates to a method of killing microbes comprising providing the antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, wherein the microbe is a fungus.

[00113] According to an embodiment, the present disclosure relates to a method of killing microbes comprising providing the antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, wherein the microbe is a virus.

[00114] According to an embodiment, the present disclosure relates to a method of killing microbes comprising providing the antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, wherein the microbe is a virus, wherein the microbe is an enveloped or non-enveloped virus.

[00115] According to an embodiment, the present disclosure relates to a method of killing microbes comprising providing the antimicrobial coating composition comprising the compounds as described herein, or a zwitterionic form thereof, wherein the microbe is a virus, wherein the enveloped virus is influenza virus, Covid-19, SARS, or MARS. [00116] According to an embodiment, the present disclosure relates to a method of forming an antimicrobial composition coated substrate, the method comprising: (a) preparing an antimicrobial coating composition comprising the compound as described herein or a zwitterionic form thereof; (b) applying the antimicrobial coating composition to a surface of a substrate; and (c) curing the substrate by UV irradiation to obtain an antimicrobial composition coated substrate.

[00117] According to an embodiment, the present disclosure relates to a method of forming an antimicrobial composition coated substrate, the method comprising: (a) preparing an antimicrobial coating composition comprising the compound as described herein or a zwitterionic form thereof; (b) applying the antimicrobial coating composition to a surface of a substrate; and (c) curing the substrate by UV irradiation to obtain an antimicrobial composition coated substrate, wherein the antimicrobial coating composition is applied by dipping, drop-casting, spraying, or brushing.

[00118] According to an embodiment, the present disclosure relates to a method of forming an antimicrobial composition coated substrate, the method comprising: (a) preparing an antimicrobial coating composition comprising the compound as described herein or a zwitterionic form thereof; (b) applying the antimicrobial coating composition to a surface of a substrate; (c) curing the substrate by UV irradiation to obtain an antimicrobial composition coated substrate; (d) treating the antimicrobial composition coated substrate after step (c) to hydrolyze the antimicrobial coating composition comprising the compound as described herein.

[00119] According to an embodiment, the present disclosure relates to an antimicrobial ultraviolet (UV) curable coating comprising a UV curable composition comprising the compounds as described herein.

[00120] According to an embodiment, the present disclosure relates to a coating as described herein, wherein the coating associates with a substrate surface via covalent interactions.

[00121] According to an embodiment, the present disclosure relates to an antimicrobial ultraviolet (UV) curable coating as described herein, wherein the coating associates with a substrate surface via covalent interactions. [00122] According to an embodiment, the present disclosure relates to a coating as described herein, wherein the coating is applied by dipping, drop-casting, spraying, or brushing.

[00123] According to an embodiment, the present disclosure relates to a coating as described herein, wherein the substrate is selected from the group consisting of natural fibers, synthetic fibers, plastics, polymers, metals, glass, ceramics, and combinations thereof.

[00124] According to an embodiment, the present disclosure relates to a coating as described herein, wherein the substrate is a biomedical device, implant, surgical instrument, fabric, tubing, gauze, air filter, protective mask, face shield, gloves, hand railing, tabletop, door handle, door, window, wall, glass, or bathroom fitting.

[00125] According to an embodiment, the present disclosure relates to a coating as described herein, wherein the substrate is a nylon, PMMA, polyethylene, rubber, paper, leather, head cap, or surgical mask.

[00126] According to an embodiment, the present disclosure relates to a coating as described herein, for use in preventing a microbial infection.

[00127] According to an embodiment, the present disclosure relates to a coating as described herein, for use in preventing a microbial infection, wherein the microbial infection is caused a bacteria, virus, or fungi.

[00128] According to an embodiment, the present disclosure relates to a method of forming an antimicrobial coating on a substrate, the method comprising: (a) preparing a coating composition with the compound as described herein; (b) applying the coating composition to a surface of a substrate; and (c) curing the substrate by UV irradiation to obtain an antimicrobial coated substrate.

[00129] According to an embodiment, the present disclosure relates to a method of forming an antimicrobial coating on a substrate, the method comprising: (a) preparing a coating composition with the compound as described herein; (b) applying the coating composition to a surface of a substrate; and (c) curing the substrate by UV irradiation to obtain an antimicrobial coated substrate, wherein the coating composition is applied by dipping, drop-casting, spraying, or brushing. [00130] According to an embodiment, the present disclosure relates to an article having the antimicrobial coating as described herein.

[00131] According to an embodiment, the present disclosure relates to an article having the antimicrobial coating as described herein, wherein the coating is associated with the article via covalent interactions.

[00132] According to an embodiment, the present disclosure relates to an article having the antimicrobial coating as described herein, wherein the article has antimicrobial properties.

[00133] According to an embodiment, the present disclosure relates to an article having the antimicrobial coating as described herein, wherein the article has antibacterial, antifungal, and antiviral properties.

[00134] According to an embodiment, the present disclosure relates to a method of killing microbes comprising providing the coating of the present disclosure.

[00135] According to an embodiment, the present disclosure relates to a method of killing microbes comprising providing the coating of the present disclosure, wherein the microbe is a bacterium.

[00136] According to an embodiment, the present disclosure relates to a method of killing microbes comprising providing the coating of the present disclosure, wherein the microbe is a fungus. [00137] According to an embodiment, the present disclosure relates to a method of killing microbes comprising providing the coating of the present disclosure, wherein the microbe is a virus.

[00138] According to an embodiment, the present disclosure relates to a method of killing microbes comprising providing the coating of the present disclosure, wherein the microbe is an enveloped or non-enveloped vims.

[00139] According to an embodiment, the present disclosure relates to a method of killing microbes comprising providing the coating of the present disclosure, wherein the microbe is an enveloped or non-enveloped vims, wherein the enveloped is influenza vims, Covid-19, SARS, or MARS. [00140] According to an embodiment, the present disclosure relates to a coating obtained by hydrolysis of the ester or the amide group of the compound as described herein covalently attached to the substrate to form the coating.

[00141] According to an embodiment, the present disclosure relates to a coating obtained by hydrolysis of the ester or the amide group of the compound as described herein covalently attached to the substrate to form the coating, wherein the coating shows zwitterionic surfaces.

[00142] According to an embodiment, the present disclosure relates to a coating obtained by hydrolysis of the ester or the amide group of the compound as described herein covalently attached to the substrate to form the coating, wherein the coating retards adherence of microbes, particularly bacteria.

EXAMPLES

[00143] The following examples provide the details about the synthesis, activities and applications of the compounds of the present disclosure. It should be understood the following is representative only, and that the disclosure is not limited by the details set forth in these examples.

[00144] The disclosure will now be illustrated with working examples, which is intended to illustrate the working of disclosure and not intended to take restrictively to imply any limitations on the scope of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice of the disclosed methods and compositions, the exemplary methods, devices and materials are described herein. It is to be understood that this disclosure is not limited to particular methods, and experimental conditions described, as such methods and conditions may apply.

Materials and methods:

[00145] Reagent grade dichloromethane (DCM), dimethylformamide (DMF), chloroform (CHCb), methanol (MeOH) were obtained from Spectrochem (India). HPLC-grade ethanol (C₂H₅OH) and isopropanol (IPA) were also obtained from Spectrochem (India). The solvents were dried prior to use wherever necessary. 4- hydroxybenzophenone, 1,6-dibromohexane, bromoacetyl bromide, N, N'- dimethylamine, decylamine and propidium iodide were procured from Sigma-Aldrich. Potassium carbonate and decanol were purchased from SD Fine Chemical Ltd (India). These chemicals were directly used for the reaction. Analytical thin-layer chromatography (TLC) was done on silica gel 60 F₂₅₄ precoated E. Merck TLC plates and iodine were used for visualization purposes. Nuclear magnetic resonance (NMR) spectra were recorded in deuterated solvents employing Bruker AMX-400 spectrometer. Unbleached cotton and polyurethane, polypropylene, polyvinyl chloride sheets of thickness 0.3 mm were bought from a local vendor. A customized UV-curing chamber was used for coating. Tecan Infinite M200 PRO Microplate Reader was used for the measurement of optical density (O.D.). Methicillin -resistant Staphylococcus aureus MRSA (ATCC33591) and C. albicans (ATCC10231) S. aureus MTCC737 and E. coli MTCC443, MRSA R3545, MRSA R3889, MRSA R3890, VRE903, C. albicans AB226 and C. albicans AB399 were used in the study. Nutrient agar was used as a solid media for both Gram-negative and Gram-positive bacteria whereas YPD agar was used for fungi related experiments wherever necessary. 96 well plates, 6 well plates and 12 well plates were obtained from Vasa Scientific (Bangalore, India).

Example 1

[00146] Quaternary small molecules (QSMs) of Formula 1 where n = 6, X= -O-l- NH-, R = decyl aliphatic chain were synthesized in three to four steps. Final compounds were obtained with Br- as counterions. The final compounds can be synthesized with other counterions such as Cl-, or l-.

Example 1.1: Synthesis of (4-((6-bromohexyl)oxy)phenyl)(phenyl)methanone (Compound 1).

[00147] 4-Hydroxy benzophenone (5 g), 1,6-dibromohexane (4.3 mL), potassium carbonate (5.23 g) and dry DMF were stirred at room temperature under argon atmosphere for 18 hrs. The reaction mixture was poured into ice-water mixture (300 mL) and extracted with CHCI₃. The organic layer was collected followed by removal of the solvent under reduced pressure. The crude product was purified on a silica gel column by using 20:1 hexane: ethyl acetate mixture. Solid white product (Compound 1) was obtained with 71% yield upon evaporation of the solvent under reduced pressure. Yield, 71%; ¹H NMR (CDC1₃400MHZ) δ/ppm: 1.52-1.56 (t, -CftCH₂CH₂Br, 4H), 1.80-1.94 (m, -OCH₂CH₂CH₂CH₂-, 4H), 3.41-3.45 (t, -CH₂CH₂Br, 2H), 4.03-4.06 (t, -OCH₂CH₂-, 2H), 6.93-6.95 (d, Ar -H, 2H), 7.45-7.48 (m, Ar -H, 2H), 7.54-7.58 (m, Ar -H, 2H), 7.74- 7.75 (d, Ar -H, 1H), 7.76-7.82 (t, Ar -H, 2H).

Example 1.2: Synthesis of (4-((6-(dimethylamino)hexyl)oxy)phenyl)(phenyl) methanone (Compound 2)

[00148] Compound 1 (3 g) was dissolved in 40 mL of dry chloroform in a screw- top pressure tube. The collection of dry NHMe2 gas to the solution was done at 0 °C until roughly doubling the volume of the solution (~80 mL). Then the reaction mixture was stirred for 36 hrs at 85 °C. After 36 hrs, the pressure tube was cooled followed by transfer of the reaction mixture to a round bottom flask and the unreacted gas was carefully removed by slow heating. The final volume of the reaction mixture was made to 150 mL by the addition of chloroform and then washed with 2 M KOH solution. The organic layer was passed through anhydrous Na₂SO₄ and was dried to give brownish-yellow liquid product with 85% isolated yield. Yield, 85%; 1H-NMR (CDCl₃,400MHz) δ/ppm: 1.35-1.41 (m, -CH₂CH₂N(CH₃)₂, 2H), 1.46-1.54 (m, -CH₂CH₂ CH₂CH₂N-, 4H), 1.79- 1.86 (m, -OCH₂CH₂CH₂-, 2H), 2.22 (s, -CH₂N(CH 2), 2.25-2.29 (t, -CH₂CH₂N-, 2H), 4.02-4.05 (t, -OCH₂CH₂-, 2H), 6.93-6.95 (d, Ar -H, 2H), 7.44-7.48 (m, Ar -H, 2H), 7.54- 7.58 (m, Ar -H, 2H), 7.74-7.76 (d, Ar -H, 1H), 7.80-7.82 (d, Ar -H, 2H).

Example 1.3: Synthesis of decyl 2-bromoacetate (Compound 3).

[00149] Synthesis was performed following our previous report with slight modification. In dichloromethane (55 mL), decanol (10 g) was dissolved. Potassium carbonate, K₂CO₃ (13.1 g) was then dissolved in 60 mL of distilled water followed by addition of the solution to the organic solution. The resultant two-phase solution was then cooled to 5 °C. A solution of bromo acetyl bromide (19.1 g) in dichloromethane (55 mL) was carefully added dropwise to the cooled solution while maintaining the temperature at 5 °C for about 30 min. Then the reaction mixture was stirred at room temperature for 4 hrs. Separation of the aqueous solution was done and then washed with dichloromethane (2 x 25 mL). The organic solution was then washed with water (2 x 50 mL) and passed over the anhydrous Na₂SO₄. Then it was concentrated to yield a white solid quantitatively. Yield, 100%; ¹H NMR (CDC1₃, 400 MHz): δ/ppm 0.86-0.89 (t, terminal -CH₃, 3H), 1.29-1.36 (m, -CH₂(CH₂)₇CH₃, 14H), 1.62-1.69 (m, - CH₂(CH₂)₇CH₃, 2H), 3.82 (s, -COCH₂Br, 2H), 4.15-4.18 (t, -COOC H₂-, 2H).

Example 1.4: Synthesis of 2-bromo-N-decylacetamide (Compound 41.

[00150] Briefly, decyl amine (10 g) was dissolved in 55 mL dichlorome thane. Potassium carbonate (13.2 g) was dissolved in 60 mL of distilled water followed by addition to the organic solution. The resulting two-phase solution was then cooled to 5 °C. A solution of bromoacetyl bromide (19.25 g) in dichloromethane (55 mL) was carefully added dropwise to the cooled solution while maintaining the temperature at 5 °C for about 30 min. Then the reaction mixture was stirred at room temperature for 12 hrs. The aqueous solution was separated and washed with dichloromethane (2 x 25 mL). The organic solution was washed with water (2 x 50 mL) and passed over the anhydrous Na₂S0₄ and concentrated to yield a white solid quantitatively. Yield, 100%; 1H-NMR (CDC1₃, 400 MHz): δ/ppm 0.88-0.92 (t, terminal -CH₃, 3H), 1.28-1.32 (d, - CH₂(CH₂)7CH₃, 14H), 1.52-1.56 (m, -CH₂(CH₂)₇CH₃, 2H), 3.28-3.33 (q, -COOC H₂-, 2H), 3.91 (s, -COCH₂Br, 2H), 6.49 (br. s, amide -NHCO-, 1H).

Example 1.5:

Synthesis of Quaternary Small Molecule 1 (OSM 1; Quaternary Benzophenone -based Ester (QBEst)].

[00151] The compound 2 (1 g) and the compound 3 (1.28 g) was taken in a screw top pressure tube in dry CHC1₃ and stirred at 55 °C for 36 hrs. The reaction mixture volume was reduced in rotary evaporator and precipitation was done by anhydrous diethyl ether. The brownish yellow product was obtained with 70% yield. Yield, 70%;¹H NMR (CDC1_,3 400MHz) δ/ppm: 0.84-0.88 (t, -CH₂CH₂C H₃, 3H), 1.24-1.46 (t, - CH₂(CH₂) ₇CH₃, 14H), 1.48-1.52 (t, -COOCH₂C H₂, 2H), 1.58-1.63 (t, -

N⁺(CH₃)₂CH₂CH₂CH₂, 4H), 1.84-1.89 (m, -OCH₂CH₂CH₂-, 4H), 3.37 (s, -CH₂N⁺(CH₃)₂, 6H), 3.62-3.66 (t, -N⁺(CH₃)₂C H₂-, 2H), 3.84-3.88 (t, -COOC H₂, 2H), 4.02-4.05 (t, - OCH₂CH₂-, 2H), 4.64 (s, -N⁺(CH₃)₂CH₂CO, 2H), 6.92-6.94 (d, Ar -H, 2H), 7.44-7.48 (m, Ar -H, 2H), 7.51-7.58 (m, Ar -H, 2H), 7.74-7.75 (d, Ar -H, 1H), 7.80-7.82 (d, Ar -H, 2H). Example 1.6: Synthesis of Quaternary Small Molecule 2 (OSM 2; Quaternary Benzophenone -based Amide (QBAm)). [00152] The compound 2 ( 1 g) and the compounds 4 ( 1.25 g) were taken in a screw top pressure tube in dry CHC1₃ and stirred at 65 °C for 36 hrs. The reaction mixture volume was reduced in rotary evaporator and precipitation was done by anhydrous diethyl ether. Brownish solid product was obtained with 82% yield. Yield, 82%; ¹ H- NMR (CDC1₃, 400MHz) δ/ppm: 0.84-0.88 (t, -CH₂CH₂C H₃, 3H), 1.24-1.46 (t, - CH₂(CH₂)7CH₃, 14H), 1.48-1.52 (t, -CONHCH₂CH₂, 2H), 1.58-1.63 (t, -

N+(CH₃)2CH₂CH₂CH₂, 4H), 1.84-1.89 (m, -OCH₂CH₂CH₂-, 4H), 3.23-3.28 (t, - CONHC H₂, 2H), 3.37 (s, -CH₂N⁺(CH₃) 2, 6H), 3.62-3.66 (t, -N⁺(CH₃)₂C H₂-, 2H), 4.02- 4.05 (t, -OCH₂CH₂-, 2H), 4.64 (s, -N⁺(CH₃)₂CH₂CO, 2H), 6.92-6.94 (d, Ar -H, 2H), 7.44- 7.48 (m, Ar -H, 2H), 7.54-7.58 (m, Ar -H, 2H), 7.73-7.75 (d, Ar -H, 1H), 7.80-7.82 (d, Ar-

H, 2H).

Scheme 1: Synthesis of compounds QSM 1 and QSM 2

Example 2:

In-vitro antibacterial efficacy:

[00153] QSM 1 and QSM 2 were assayed for their antibacterial activity. Stock solutions were made by diluting the compounds using autoclaved millipore water. Bacteria were streaked on nutrient broth agar plates from the frozen stock (stored at -80 °C). These plates were then kept for incubation for 24 hrs at 37 °C for bacterial growth. Consequently, a single bacterial colony was taken in 3 mL of nutrient broth and incubated for 6 hrs (midlog phase) to obtain about 10⁸ to 10⁹ CFU/mL cells. The 6 hrs grown culture was then diluted to ~ 10⁵ CFU/mL in Mueller Hinton broth which was then used for assay. In a 96-well plate, compounds QSM 1 and QSM 2 were serially diluted in 2-fold from the starting concentration of 256 μg/mL using sterile millipore water. Afterwards, 180 μL of ~10⁵ CFU/mL bacterial solution was added in each wells containing 20 μL aqueous solution of the compounds. These plates were then kept for incubation for 18 hrs at 37 °C under shaking condition. The O.D. was then recorded at 600 nm by using TECAN (Infinite series, M200 PRO) plate reader. The antibacterial activity (MIC) was evaluated based on visual turbidity. Both QSM 1 and QSM 2 showed excellent activity against the Gram positive pathogens with MIC values ranging between 0.5-1 μg/mL. Both the compounds inactivated notorious MRS A cells including its clinical isolates even at 0.5- 1 μg/mL (Table 1).

[00154] Both the compounds showed excellent activity against drug resistant pathogen VRE with MIC of 1 μg/mL. Significantly, methicillin, a last resort antibiotic against Gram-positive pathogens, was found to be inactive against the MRSA strains with MIC value of 32 μg/mL. On the other hand, vancomycin showed efficient killing of MRSA with MIC of 0.5-1 μg/mL but was completely inactive against VRE with exceedingly high MIC value greater than 256 μg/mL. As MRSA is one of the threatening pathogens majorly responsible for the contamination of surfaces, this observation unveiled the applicability of these compounds to tackle surface-associated infections. The compounds were also found to be active against E. coli with MIC 4-8 μg/mL.

Table 1: Antibacterial activity of QSM 1 and QSM 2

Example 3

Determination of Bactericidal time-kill kinetics: [00155] Mid-log phase (~10⁸ CFU/mL) of MRSA ATCC33591 culture was suspended to ~10⁵ CFU/mL in MHB. This bacterial suspension was then treated with 2 μg/mL (4xMIC), 4μg/mL (8xMIC) of QSM 1 or 4 μg/mL (4xMIC), 8 μg/mL (8xMIC) of QSM 2 followed by incubation at 37 °C. As a negative control, same volume of saline was used instead of any antibacterial compounds. 20 μL of aliquots were then 10-fold serially diluted in saline at various time points such as 0, 30, 60, 120, 240 and 360 min. From these dilutions, 20 μL were spot plated on nutrient agar plate and incubated for 24 hrs in 37 °C for counting viable cells. The detection limit for this experiment is 50 CFU/mL.

[00156] It was found that the compounds exhibit a significant reduction in bacterial count as soon as the compounds are added to the bacterial suspension. Within 30 min, both the compounds killed MRSA cells completely at 4xMIC and 8xMIC proving their rapid bactericidal nature affecting ~6 log reduction in bacterial count compared to the control (Figure 1).

Example 4

Solubility of the compounds:

[00157] A small amount (10 mg) of QSM 1 and QSM 2 was added to 1 mL of various organic solvents (chloroform, dichloromethane, methanol, ethanol, DMF, DMSO) and water followed by vortexing for 5 min and solubility was observed visually. Also, to determine the limit of solubility, 100 mg of the compounds were dissolved in 1 mL of the above-mentioned solvents and in case of insolubility, further two-fold serial dilution was done. Both QSM 1 and QSM 2 were found to be soluble in chloroform, dichloromethane, ethanol, methanol, dimethyl sulphoxide, N, A-di methyl formamide even at 100 mg/mL. In water, both compounds were dissolved at a concentration of 25 mg/mL (Table 2), which can be ascribed to the presence of a long hydrophobic aliphatic chain in the molecules. The diverse solubility of QSM 1 and QSM 2 reveals their potential for use on different surfaces depending on their compatibility towards different solvents. Table 2: Solubility of QSM 1 and QSM 2 in different solvents

Example 5 Development of coating:

[00158] Polyurethane, polyvinyl chloride and polypropylene sheets were cut into

5 x 5 cm² pieces followed by rigorous washing with water and isopropanol. QSM 1 and QSM 2 were dissolved in ethanol to obtain a solution with a concentration of 10 mg/mL. 400 μL of ethanolic solution of the compounds were drop-casted with subsequent spreading on polymer sheets followed by air drying for 5 min. Then the sheets were exposed to UV irradiation at -365 nm in a custom-made UV curing chamber for 10 min. After UV exposure, the surfaces were rigorously washed with millipore water and acetone respectively to remove unadhered compounds. Finally, the coated surfaces were dried in a vacuum oven at 40 °C.

[00159] To coat cotton, the cotton surfaces were further cut into l x l cm² pieces followed by washing in water and isopropanol and acetone. Then the pieces were dipped in the 10 mg/mL aqueous solutions of QSM 1 or QSM 2. -20 pieces could be dipped in 1 mL with 10 pieces dipped at a time. Then the sheets were exposed to UV irradiation at -365 nm in a custom-made UV curing chamber for 10 min. After UV exposure, the surfaces were rigorously washed with millipore water and acetone respectively to remove unadhered compounds. Finally, the coated surfaces were dried in a vacuum oven at 40 °C.

[00160] These coatings were characterized by different spectroscopic and microscopic techniques including AFM, SEM and XPS.

Characterization of the Coated Surfaces.

Fourier Transform Infrared Spectroscopy (FTIR): Spectra of the QSM 1 and QSM 2 coated polypropylene (PPE) surfaces were recorded on a Bruker IFS 66v/S spectrometer using in ATR mode.

X-ray photoelectron spectroscopy (XPS): X-ray photoelectron spectroscopy was performed with PPE surfaces coated with QSM 2 was used on X-ray photoelectron spectrometer with an A1 K alpha source (1486.6 eV) at an operating voltage of 15 kV and at 10^-10 mbar pressure.

Field emission scanning electron microscopy (FESEM): Cotton and PU surfaces coated with QSM 1 or QSM 2 were used for FESEM studies. The samples were sputtered with gold prior to imaging. Energy dispersion X-ray ( EDX ): Energy dispersive X-ray analysis was performed cotton and PU surfaces coated QSM 1 or QSM 2 using Zeiss Gemini 500 FESEM comprising an EDX unit. The samples were sputtered with gold prior to imaging.

[00161] Atomic force microscopy (AFM): AFM measurement of the QSM 1 coated PU surfaces was performed on a Bruker Innova AFM operating in tapping mode using silicon cantilever tips with frequency between 300 and 400 kHz and a spring constant of 40-80 Nm^-1.

[00162] Immobilization of QSM 1 (QBEst) and QSM 2 (QBAm) on Different Surfaces and Characterization of Coating. Both QSM 1 and QSM 2 contain the benzophenone moiety in their molecular designs which can undergo h-p* transition upon mild UV-exposure thereby generating a biradical triplet excited state that can abstract a hydrogen atom from a neighboring aliphatic C-H group to form a new C-C bond. Different medically relevant surfaces containing myriads of C-H bond, e.g., cotton, polyurethane (PU), polyvinylchloride (PVC) and polypropylene (PPE) were chosen for immobilization of the compounds. Owing to the diverse solubility of QSM 1 and QSM 2, 10 mg/mL aqueous and ethanol solutions of both compounds were employed. For polymeric surfaces such as PU, PVC and PPE, 400 μL of 10 mg/mL ethanol solution of the compound was drop casted uniformly on 5 x 5 cm² substrates. After briefly drying the surfaces in air, they were irradiated by UV light (-365 nm) for 10 min (Figure 2A). For immobilization on cotton, the substrates were dipped into 10 mg/mL aqueous solution of the compounds followed by exposure to UV irradiation. The immobilization was confirmed from the FT-IR spectrum of PPE surfaces coated with QSM 1 and QSM 2 Amide coated surfaces showed amide I peak corresponding to C=0 stretching vibration at 1673 cm^-1 and amide II at 1553 cm^-1 which resulted from the N-H bending vibration (Figure 2B). On the other hand, PPE surface coated with QSM 1 showed a sharp peak corresponding to C=0 stretching at 1749 cm^-1. However, no peak was observed in the range of 1500-1800 cm^-1 for uncoated surface. To examine the formation of a coating, X-ray photoelectron spectroscopy was performed with QSM 2 coated PPE surfaces showing the presence of N Is peak (Figure 2C). To understand the morphology of the surface and the distribution of the compounds on the surface, SEM and energy dispersive X-ray spectroscopy were also done followed by colour mapping for the elements nitrogen (N) and bromine (Br) (Figure 3A and 3B). The fibrous network-like structure of the cotton was unhampered as evident from the SEM images. The elemental mapping of the surfaces further established the uniform distribution of nitrogen and bromine proving the uniform coating of cotton. Atomic Force Microscopic studies further validated the uniform nature of the coating with low surface roughness with RMS roughness 24 nm (Figure 3C and 3D)

Example 6

Antibacterial activity of the coated substrates:

[00163] Against Planktonic Cell. Different drug-resistant laboratory strains and clinically isolated strains of MRSA (MRSA ATCC33591, MRSA R3545, MRSA R3889 and MRSA R3890) were grown for 6 hrs in nutrient media at 37 °C under constant shaking. Then the bacteria were diluted to prepare ~10⁶ CFU/mL suspension in saline. 20 μL of this suspension was dropped on 1 x 1 cm² surfaces coated with QSM 1 or QSM 2. Non-coated surfaces were used as control in the experiment. After 2 hrs of incubation at 37 °C, the surfaces were dragged along the diameter and placed on nutrient agar plates. Then these plates were incubated at 37 °C for 18 hrs followed by imaging of the plates. Every sample was investigated in triplicate.

[00164] Against Stationary Cell. A mid-log phase MRSA ATCC33591 culture was diluted 1000 times in nutrient broth and kept for incubation at 37 °C for 16 hrs under shaking condition leading to stationary phase cells. Consequently, the bacterial suspension was centrifuged (9000 rpm, 2 min) and resuspended in saline. This suspension was further diluted in saline to obtain a concentration of ~10⁵ CFU/mL which was used for the experiment. The further protocol is similar to the previously mentioned protocol of antibacterial assay against planktonic cells (Figure 4 i).

[00165] No bacterial growth was observed for QSM 1 and QSM 2 coated surfaces. On the other hand, thick bacterial lawns were observed in the case of uncoated surfaces proving the excellent antibacterial efficacy of the coating. Remarkably, coated surfaces inactivated stationary phase cells of MRSA (Figure 4 i and 4 ii).

[00166] Antibacterial Activity of the Coated Surfaces through Visual Turbidity. MRSA ATCC33591 was grown for 6 hrs in suitable nutrient media at 37 °C under constant shaking. Then the bacteria was diluted to prepare ~10⁶ CFU/mL suspension in saline. 20 μL of this suspension was dropped on 1 x 1 cm² surfaces coated with QSM 1 or QSM 2. Non-coated surfaces were used as a control in the experiment. After 2 hrs of incubation at 37 °C, each of the surfaces was dropped into the freshly prepared nutrient broth (5 mL) individually and incubated for 18 hrs. Post-incubation, the tubes were visually investigated for the occurrence of any turbidity and their photographic images were captured.

Example 7

Bactericidal kinetics of cottons coated with QSM 1 or QSM 2:

[00167] Cotton surfaces coated with QSM 1 or QSM 2 were used for this experiment. Briefly, 20 μL of ~10⁶ CFU/mL suspension of MRS A ATCC33591 was dropped on 1 x 1 cm² cotton surfaces and incubated at 37 °C for 2 hrs. At time points 0 min, 15 min, 30 min, 45 min and 60 min, the surfaces were dragged and placed on nutrient agar plates. These plates were incubated at 37 °C for 18 hrs followed by subjecting to photographic capture. Upon incubation with MRSA, cotton surfaces coated with QSM 1 showed an immediate reduction in bacterial growth as evident from the diminished bacterial count in 15 min. Within 30-45 min, QSM 1 and QSM 2 coated cottons showed complete killing of bacteria suggesting rapid bactericidal nature of the coatings (Figure 5i).

[00168] Bacterial colonization by nosocomial pathogens on material surfaces can cause serious and life-threatening infections. Textiles and various polymeric surfaces are most prone to be contaminated by common infection spreading mechanisms, such as coughing, sneezing, etc. Hence, these surfaces need to kill bacterial cells in a rapid manner. In order to evaluate the time required for complete eradication of bacteria, bactericidal kinetics was performed for cotton surfaces coated with QSM 1 or QSM 2 against MRSA ATCC33591 cells. Upon incubation with MRSA, cotton surfaces coated with QSM 1 showed an immediate reduction in bacterial growth as evident from the diminished bacterial count in 15 min. Within 30 min, QSM 1 coated cottons showed the complete killing of bacteria (Figure 5i). On the other hand, surfaces coated with QSM 2 showed significant inhibition within 30 min and complete killing in 1 hr. Both the coated surfaces showed a rapid killing of bacteria where QSM 1 coated surfaces killed bacteria completely within 30 min and QSM 2 coating exerted complete bactericidal activity within 1 hr. These results thus indicated that the coatings have remarkably high killing rates making them suitable for efficient antimicrobial applications.

Visualization of Bacterial Killing through Scanning Electron Microscopy:

[00169] In order to observe bacterial killing through scanning electron microscopy, a previously reported protocol was followed with slight modification. 96 well plates were coated with QSM 1 or QSM 2. 200 μL of ~10⁷ CFU/mL MRSA ATCC33591 suspension in saline was added to the wells and incubated at 37 °C for 2 hrs (Figure 6 A). Uncoated wells were negative controls. Post-incubation, the cells were transferred to a 1 mL centrifuge tube followed by centrifugation at 5000 rpm for 5 min. The bacterial pellet was then resuspended in 30% ethanol. It was subsequently dehydrated with 50%, 70%, 90% aqueous solution of ethanol. The final resuspension was done in 70% ethanol. 5 μL of this bacterial suspension in ethanol was drop casted onto a silicon wafer and dried. The samples were sputter coated with gold prior to imaging with Zeiss Gemini 500 FESEM.

[00170] In order to have better understanding of the mechanism of killing of QSM

1 or QSM 2 coated surfaces, bacterial morphology of MRSA ATCC33591 cells was visualized through scanning electron microscopy (SEM) after incubation with coated polystyrene surfaces. The images of the bacterial cells incubated in uncoated wells showed retention of well-defined morphology and shape (Figure 6 B). On the contrary, cells incubated with QSM 1 or QSM 2 coated wells showed morphological distortion (Figure 6C and 6D). The images showed cells with irregular shape which indicated a loss of structural integrity, affirming the membrane rupturing nature of QSM 1 or QSM 2 coating comprising of hydrophobic aliphatic chains and polycationic nature.

[00171] Non-leaching Activity. To investigate the covalent immobilization and rule out the possibility of leaching of compounds from the surface, nonleaching activity of the coated cotton surfaces were performed. 100 μL of ~10⁷CFU/mL of MRSA ATCC33591 was spread on nutrient agar plates. In each plate containing bacteria, coated cotton surfaces were placed cautiously. Similarly, cotton surfaces only soaked in QSM 1 or QSM 2 solution without any UV exposure were also placed. The plates were then incubated at 37 °C for 24 hrs. Then the plates were photographed and zone of inhibition, if any, was observed visually. [00172] Repeated Killing of Bacteria using Coated Surfaces. The procedure is similar to previously mentioned antibacterial assay of the coated surfaces. Cotton surfaces coated with QSM 1 or QSM 2 were used for this experiment. After incubation for 24 hrs, the plates were subjected to imaging. Then, the surfaces were withdrawn and washed rigorously using 0.2 mg/mL aqueous solution of cetyltrimethylammonium bromide. These washed surfaces were again used to check antibacterial activity against MRSA ATCC33591. This procedure was repeated for 4 times.

[00173] Bacterial Adhesion Assay. In order to investigate the reduced bacterial adherence, cotton surfaces coated with QSM 1 or QSM 2 were subjected to hydrolysis by (1:1) TFA: thO or IN HC1 respectively for 24 hrs. Then the surfaces were washed in phosphate buffered saline of pH = 7.4. The surfaces were subsequently washed thoroughly in acetone and dried. Then the surfaces were dipped in 1 mL of ~10⁵ CFU/mL of MRSA ATCC33591 in saline and left for incubation for 1 hr. The surfaces were withdrawn carefully from the suspension with the help of a twizzer and rinsed in saline followed by dragging and placing them on nutrient agar plates. The plates were then incubated at 37 °C for 24 hrs. After incubation, the plates were photographed to observe any bacterial growth. To demonstrate the hydrolysable nature of the compounds, QSM 1 and QSM 2 was dissolved in TFA:HiO (1:1) and IN HC1 respectively at a concentration of 5 mg/mL and kept at room temperature for 24 hrs. Then, HRMS was performed with the solution to examine the presence of hydrolyzed product.

Example 8

Antifungal activity of cottons coated with QSM 1 or QSM 2:

[00174] Fungal strains were streaked on YPD agar plates and were incubated at 28 °C for 24 hrs. A single fungal colony was inoculated in 3 mL YPD medium for 10 hrs at 37 °C to grow to mid-log phase to give ~10⁸ CFU/mL concentration of cells. This midlog phase culture was then diluted to ~10⁵ CFU/mL in saline. Further procedure was similar to the previously mentioned antibacterial assay in Example 5. Thick fungal lawn was grown for uncoated cotton surfaces whereas no fungal growth was observed for QSM 1 or QSM 2 coated cotton substrates (Figure 5ii). Similar result was observed for all the fungal strains tested.

Example 9 Antiviral activity of the coating:

[00175] 2 x 1 cm² PU sheets (coated and non-coated) were placed in a polystyrene petri dish. 2 strains A/NWS/33 and A/PR/8/34 were used with initial pfu of (4.43 ± 0.3) x 10⁴and (2.8 ± 1.6) x 10⁴ respectively. A 10 μL dropletPBS buffered solution of viruses was placed on a 2 x 1 cm² polyurethane substrate coated with QSM 1 or QSM 2 and was covered by an uncoated substrate of same dimension for spreading of the droplet. After room temperature incubation for 30 min, the substrates were washed with PBS thoroughly. The wash solution from the uncoated surfaces upon 100 fold dilution was then used to infect a monolayer of Madin-Darby canine kidney (MDCK) cells performing two fold serial dilutions. In case of coated surfaces, two fold serial dilution of the wash solution was done without prior dilution by 100 folds. With these serially diluted viral suspensions, plaque assay was performed (Figure 7 i).

[00176] Plaque Assay: In brief, 6 well plates seeded with 2 mL of MDCK cells was incubated at 37 °C in a humidified-air atmosphere (5% C0₂/95% air) for 24 hrs until the cells reached -95% confluency with -5 x 10⁶ cells per well. The media was then removed by aspiration and the cells were washed twice with PBS. Then the cells were infected by adding 200 pi of the virus solutions. The plates were then incubated at room temperature for 1 hr. To avoid drying of the plate, occasional rocking was done. After 1 hr, the solution was removed and the cells were overlaid with 2 mL of plaque medium with oxoid agar followed by incubation at 37 °C for 72 hrs. Both QSM 1 and QSM 2 coated surfaces showed significant killing of influenza virus (Figure 7 ii).

Example 10

Bacterial Adhesion Assay

[00177] In order to investigate the reduced bacterial adherence, cotton surfaces coated with QSM 1 or QSM 2 were subjected to hydrolysis by (1:1) TFA: FLO or IN HC1 respectively for 24 hrs. Then the surfaces were washed in phosphate buffered saline of pH = 7.4. The surfaces were subsequently washed thoroughly in acetone and dried. Then the surfaces were dipped in 1 mL of ~10⁵ CFU/mL of MRSA ATCC33591 in saline and left for incubation for 1 hr. The surfaces were withdrawn carefully from the suspension with the help of a twizzer and rinsed in saline followed by dragging and placing them on nutrient agar plates. The plates were then incubated at 37 °C for 24 hrs. After incubation, the plates were photographed to observe any bacterial growth (Figure 8 A). To demonstrate the hydrolysable nature of the compounds, QSM 1 or QSM 2 was dissolved in TFA:H₂O (1:1) and IN HC1 respectively at a concentration of 5 mg/mL and kept at room temperature for 24 hrs. Then, HRMS was performed with the solution to examine the presence of hydrolyzed product. There was significantly reduced bacterial adherence in case of the hydrolysed cotton substrates. Presence of the hydrolyzed zwitterionic product for both the compounds therefore validated our assumption of zwitterionation (Figure 8 B).

Example 11

Coating of surfaces of the substrates:

[00178] Solution of QSM 2 was prepared in ethanol at a concentration of 10 mg/mL. 1 mL solution was sprayed on 80 cm² surface (nylon, PMMA, polyethylene, rubber, paper, leather, head cap, surgical mask). The surfaces were then irradiated -365 nm. For nylon, PMMA, rubber, leather, head cap and surgical mask, irradiation time was 5 min. For paper and polyethylene, the irradiation time was 2 min. The surfaces were then washed with water twice and dried at 40°C for 6 h. The surfaces were then cut into pieces of dimension of 1 x 1 cm² and 2x 2 cm² and then used for further experiments.

Characterization of the coated surfaces:

[00179] Coated polyethylene and surgical mask were characterized through scanning electron microscopy and energy dispersion X-ray analysis. The SEM images did not show any possible damage to the coated surfaces during the process of coating. The energy dispersive X-ray analysis of the surfaces showed uniform distribution of nitrogen (N) and bromide (Br) for both polyethylene and surgical mask surfaces. Figure 9 shows the SEM images of the coated surgical mask and polyethylene surfaces.

Example 12

Antibacterial Activity of the coated surfaces:

[00180] Coated and uncoated surfaces (PMMA, nylon, polyethylene, rubber, head-cap, paper, leather and surgical mask) were checked for their activity against MRS A ATCC33591, MRSA R3545, MRSA R3889, MRSA R3890, VRSA 1, VRSA 4. 10 μL of -10⁶ CFU/mL bacterial suspension in saline was dropped on the surfaces and incubated for 2 h. Then they were dragged on nutrient agar plates followed by incubation for 18 h at 37 °C. The coated surfaces showed no presence of bacteria whereas the uncoated surfaces showed presence of thick bacterial lawn. Figure 10 depicts the antibacterial activity of QSM 2 coated nylon, PMMA, polyethylene, rubber, head-cap, paper, leather and surgical mask surfaces against drug-resistant strains of MRSA and VRSA. The arrows indicate the direction of dragging.

Example 13

Antifungal activity of the coated surfaces:

[00181] Coated and uncoated surfaces (polyethylene, rubber, PVC, paper, surgical mask and leather) were checked for their activity against C. albicans ATCC 10231. 10 μL of -106 CFU/mL fungal suspension in saline was dropped on the surfaces and incubated for 2 h. Then they were dragged on YPD agar plates followed by incubation for 18 h at 37 °C. The coated surfaces showed no presence of fungi whereas the uncoated surfaces showed fungal growth in the plates. Figure 11 depicts the antifungal activity of QSM 2 coated surfaces against C. albicans ATCC10231. The arrows indicate the direction of dragging.

Example 14

Antiviral activity of the coated surfaces:

[00182] Coated and uncoated polyethylene and surgical mask surfaces were checked for anti-influenza activity against A/NWS/33. Briefly, 10 μL of 4.4 x 10⁶ PFU/mL viral suspension in saline was dropped and spread on coated and uncoated (polyethylene and surgical mask) surfaces. The surfaces were then incubated at 37 °C for 30 min. Then they were washed with 990 μL of saline. In case of coated surfaces, the wash solution was serially two fold-diluted for 5 times. The wash solution and the 5 dilutions were used for plaque assay. In case of uncoated surfaces, the wash solution was 100 fold diluted. The diluted solution was then further diluted by 20 folds followed by 4 times serial two fold-dilutions. The 100-fold diluted wash solution and the following 5 dilutions were then used for plaque assay.

[00183] Plaque assay. In brief, 6 well plates seeded with 2 mL of MDCK cells was incubated at 37 °C in a humidified-air atmosphere (5% CO₂/95% air) for 24 h until the cells reached -95% confluency. The media was then removed, and the cells were washed twice with PBS. Then the cells were infected by adding 200 pi of the virus solutions. The plates were then incubated at room temperature for 1 h. To avoid drying of the plate, occasional rocking was done. After 1 h, the solution was removed, and the cells were overlaid with 2 mL of plaque medium with oxoid agar followed by incubation at 37 °C for 72 h. After 72 h, the plaques were counted. The plates were imaged by discarding the agar and treatment with crystal violet. Uncoated mask showed presence of (3.5 ± 0.5) x 10⁴ plaques. On the other hand, uncoated polyethylene showed presence of (2 ± 1.03) x 10⁴ plaques. However, no plaque was seen for both the coated surfaces proving complete killing of viruses with >4 log reduction (>99.99%). Figure 12 depicts the anti-influenza (antiviral) activity of QSM 2- coated and uncoated surgical mask and polyethylene surfaces against human influenza virus A/NWS/33(H1N1). For uncoated surfaces, plaque assay was performed with the 100-fold diluted washings from uncoated surgical mask or polyethylene surface (well 1) and its 20- fold dilution (well 2) followed by 2-fold serial dilutions (well 3-6). For coated surfaces, the wash solution (well 1) and 2-fold serial dilutions were used (well 2-6).

Advantages

[00184] The above-mentioned implementation examples as described on this subject matter and its equivalent thereof have many advantages, including those which are described.

[00185] The compounds of the present disclosure can be covalently coated on various surfaces and can rapidly kill bacteria, fungi and influenza virus upon contact. The present disclosure further discloses a one-step curable coating based on organo- and water solution of small molecules. The coating was found to inactivate pathogens upon repeated challenges with bacteria. Also, upon hydrolysis, the coating switched to a bacteria-repellant nature which showed reduced adherence towards bacterial cells. Thus, the covalently immobilizable, switchable antimicrobial coating developed herein holds great potential to be developed for a number of biomedical applications and implant related infections. The antimicrobial coating comprising the compounds of the present disclosure or their zwitterionic forms exhibits significant antimicrobial activity against microbes such as bacteria, fungi or viruses. The antimicrobial coating of the present disclosure is extendable to various substrates selected from nylon, PMMA, polyethylene, rubber, natural fibers, synthetic fibers, plastics, polymers, metals, glass, or ceramics, and varied category of articles such as paper, leather, head cap, surgical mask, biomedical device, implant, surgical instrument, fabric, tubing, gauze, air filter, protective mask, face shield, gloves, hand railing, tabletop, doorhandle, door, window, wall, glass, or bathroom fittings. The present disclosure also provides a simple method of applying the antimicrobial coating on the surface of substrate.

[00186] Although the subject matter has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. As such, the spirit and scope of the disclosure should not be limited to the description of the embodiments contained herein.

Claims

I/We claim:

1. A compound of Formula I

Y is hydrogen or

; n is 2 to 12;

X is independently selected from -O- or -NH-;

2. The compound as claimed in claim 1, wherein Y is hydrogen; n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; X is independently selected from -O- or -NH-; R is independently selected from a group consisting of C₃-C₂₀ alkyl, C₃-C₂₀ alkenyl, and C₃-C₂₀ alkynyl; wherein C₃-C₂₀ alkyl, C₃-C₂₀ alkenyl, or C₃-C₂₀ alkynyl are independently unsubstituted or substituted; and Z- is a negatively charged counter anion selected from Br^~, Cl-, or G.

3. The compound as claimed in claim 1, wherein Y is

; n is 2,

3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; X is independently selected from -O- or -NH; R is independently selected from a group consisting of C₃-C₂₀ alkyl, C₃-C₂₀ alkenyl, and C₃-C₂₀ alkynyl; wherein C₃-C₂₀ alkyl, C₃-C₂₀ alkenyl, or C₃-C₂₀ alkynyl are independently unsubstituted or substituted; and Z- is a negatively charged counter anion selected from Br-, Cl-, or G .

4. The compound as claimed in claim 1, wherein Y is hydrogen; n is 2 to 12;

X is independently selected from -O- or -NH-;

R is substituted or unsubstituted C10 aliphatic radical; and Z- is Br-.

5. A compound of Formula II

X is independently selected from -O- or -NH-; R is substituted or unsubstituted C₃-C₂₀ aliphatic radical; and

Z- is a negatively charged counter anion selected from Br-, Cl-, or G.

6. A compound of Formula III

Formula III or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivatives thereof, wherein n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; X is independently selected from -O- or -NH-;

R is independently substituted or unsubstituted C₃-C₂₀ aliphatic radical;

Z- is a negatively charged counter anion selected from Br^~, Cl-, or G .

7. A process of preparing the compound as claimed in claims 1 to 6, the process comprising: reacting compound of Formula IV and Formula V to obtain a compound of Formula I.

8. The process as claimed in claim 7, wherein reacting compound of Formula IV and Formula V is carried out in the presence of solvent at a temperature in the range of 40 to 80°C for a time period in the range of 20 to 50 hours.

9. The process as claimed in claim 7, wherein the solvent is chloroform, or dichloromethane .

10. A compound as claimed in any one of the claims 1 to 6 or its stereoisomers, polymorphs, solvates, hydrates intermediates, and pharmaceutically active derivatives thereof for use in the treatment of microbial infection or in killing or inhibiting the growth of a microorganism selected from the group consisting of bacteria, virus, and fungi.

11. A pharmaceutical composition comprising the compound as claimed in any one of the claims 1 to 6 or its stereoisomers, polymorphs, solvates, hydrates, intermediatesand pharmaceutically active derivative thereof, together with a pharmaceutically acceptable carrier.

12. A pharmaceutical composition comprising the compound as claimed in any one of the claims 1 to 6 or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivative thereof, together with a pharmaceutically acceptable carrier, and in combination with at least one antibiotic.

13. Use of the compound as claimed in any one of the claims 1 to 6 or its stereoisomers, polymorphs, solvates, hydrates, intermediates, and pharmaceutically active derivative thereof, in killing or inhibiting the growth of a microorganism selected from the group consisting of bacteria, virus, and fungi.

14. A method for treatment of microbial infection in a subject comprising: administering to the subject an effective amount of the compound as claimed in any one of the claims 1 to 6 or its stereoisomers, polymorphs, solvates, hydrates, and pharmaceutically active derivative thereof.

15. The method as claimed in claim 14, wherein the microbial infection is caused by bacteria, virus, or fungi.

16. A zwitterionic compound obtained by the hydrolysis of the compound as claimed in any one of the claims 1-6.

17. The zwitterionic compound as claimed in claim 16, for use in preventing a microbial infection; and wherein the microbial infection is caused by a bacteria, virus, or fungi.

18. An antimicrobial coating composition comprising the compound as claimed in any one of the claims 1 to 6, or a zwitterionic compound as claimed in any one of the claims 16 to 17 thereof with a carrier.

19. The antimicrobial coating composition as claimed in claim 18, wherein the antimicrobial coating composition is applied on a surface of a substrate by dipping, drop-casting, spraying, or brushing; and the antimicrobial coating composition associates with the substrate via covalent interactions.

20. The antimicrobial coating composition as claimed in any one of the claims 18 to 20, wherein the substrate is selected from the group consisting of natural fibers, synthetic fibers, plastics, polymers, metals, glass, ceramics, and combinations thereof; and the substrate is selected from biomedical device, implant, surgical instrument, fabric, tubing, gauze, air filter, protective mask, face shield, gloves, hand railing, tabletop, door handle, door, window, wall, glass, or bathroom fitting.

21. An antimicrobial composition coated substrate comprising the antimicrobial coating composition as claimed in claim 18.

22. The antimicrobial composition coated substrate of claim 21, wherein the antimicrobial composition coated substrate has antibacterial, antifungal, or antiviral properties.

23. A method of killing microbes comprising providing the antimicrobial coating composition as claimed in claim 21.

24. The method as claimed in claim 23, wherein the microbe is selected from bacterium, fungus or virus.

25. The method as claimed in claim 24, wherein the microbe is an enveloped or non- enveloped virus.

26. The method as claimed in claim 25, wherein the enveloped virus is influenza vims, Covid-19, SARS, or MARS.

27. A method of forming an antimicrobial composition coated substrate as claimed in claim 21, the method comprising:

(a) preparing an antimicrobial coating composition comprising the compound as claimed in claims 1 to 6 or a zwitterionic composition as claimed in claim 16 thereof;

(b) applying the antimicrobial coating composition to a surface of a substrate; and

(c) curing the substrate by UV irradiation to obtain an antimicrobial composition coated substrate.

28. The method as claimed in claim 27, wherein the antimicrobial coating composition is applied by dipping, drop-casting, spraying, or brushing.

29. The method as claimed in claim 27, further comprising a step of treating the antimicrobial composition coated substrate after step (c) to hydrolyze the antimicrobial coating composition comprising the compound as claimed in claims 1 to 6.

30. The method as claimed in claim 27, wherein the antimicrobial composition coated substrate shows zwitterionic surfaces.

31. The method as claimed in claim 27, wherein the antimicrobial composition coated substrate retards adherence of microbes selected from bacteria, fungus or vims.