Uses of dihydrochalcones, derivatives and analogs thereof against legionella SP.

Abstract

The present disclosure provides a use of a compound of Formula (I), wherein: - one of A and B is H and the other is (II); - G is R2 and E is H, -CH2-E' or (III), or G and E' are both single carbon atoms, said carbon atoms being directly linked together by a single bond, G being substituted by (IV) and E' being substituted by R6; - Re is H or OR1; - Rf is H or OR8, wherein R8 is H or C1-C12 alkyl; - each of R1, R2, R3, and R4 is independently H or C1-C12 alkyl; and - each of R5, R6, and R10 is independently H, OH, C1-C12 alkyl, or C1-C12 alkoxy, or a salt, ester, or solvate thereof, for preventing or reducing Legionella growth. Also provided is a kit comprising the compound.

Description

[0001] TITLE USES OF DIHYDROCHALCONES, DERIVATIVES AND ANALOGS THEREOF AGAINST LEGIONELLA SP. CROSS REFERENCE TO RELATED APPLICATIONS This application is a PCT application Serial No PCT / CA2025 filed on August 2025 and published in English under PCT Article 21(2), which itself claims benefit of U.S. provisional application Serial No.63 / 683,883, filed on August 16, 2024. All documents above are incorporated herein in their entirety by reference. FIELD OF THE DISCLOSURE The present disclosure relates to uses of dihydrochalcones, derivatives and analogs thereof and extract comprising same against Legionella sp. More specifically, the present disclosure is concerned with uses of dihydrochalcones, derivatives and analogs thereof and extract comprising same for preventing or reducing Legionella growth. BACKGROUND OF THE DISCLOSURE There is a demand from population, and scientists and industrials to diminish chemical pesticides and antibiotics and provide safe potential alternatives with fewer negative side effects (Ebadollahi et al., 2020). Legionella is a Gram-negative, rod-shaped, flagellated bacterium measuring 0.5 µm by 2 µm. Bacteria of this genus proliferate rapidly in water at temperatures between 25 and 45 degrees Celsius. Cooling systems such as water towers provide an ideal environment for the development of Legionella. In order to reduce the risk of Legionella contamination among workers, it is necessary to minimize bacterial concentration and prevent the formation of biofilms in water systems. Currently, chemical disinfectants such as chlorine and bromine are used to prevent Legionella growth. These treatments are effective at high concentrations that are harmful to human health and the environment, including aquatic fauna and flora. These treatments also lead to premature wear of cooling systems and results in significant maintenance costs. Premature wear also leads to difficult to treat biofilm formation within the system. Finally, the management of waste materials that result from the use of these toxic chemicals is onerous and time consuming. There is a need for alternatives to toxic chemical products that pose lower risks to human health and have reduced environmental toxicity. The present description refers to a number of documents, the content of which is herein incorporated by reference in their entirety. SUMMARY OF THE DISCLOSURE The present disclosure shows that dihydrochalcones, derivatives and analogs thereof and Populus balsamifera extracts comprising same are active against Legionella. It more particularly shows that these compounds or extracts, alone or in combination with plant extracts such as monarda extracts or components thereof such as thymol, carvacrol, or geraniol can be used in the prevention and reduction of Legionella growth in water circulation systems and can be used as safer and less toxic alternatives to chemicals such as chlorine. More specifically, in accordance with the present disclosure, there are provided the following items and items’: Item 1. Use of a compound of Formula (I) , wherein: - one ; - G is R2and E is H or , or G and E are both carbon atoms being directly linked together by a single bond, G being substituted by and E being substituted by R6; - each of R1, R2, R3, and R4is independently H or C1-C12alkyl; and - each of R5, R6, and R10is independently H, OH, C1-C12alkyl, or C1-C12alkoxy, or salt, ester, or solvate thereof, for preventing or reducing Legionella growth. Item' 1. (I), wherein: - one of A and B is H and the other is ; - G is R2and E is H, -CH2-E’ or , or G and E’ are both carbon said carbon atoms being directly linked together by a single bond, G being substituted by and E’ being substituted by R6; - Reis H or OR1;- Rfis H or OR8, wherein R8is H or C1-C12alkyl; - each of R1, R2, R3, and R4is independently H or C1-C12alkyl; and - each of R5, R6, and R10is independently H, OH, C1-C12alkyl, or C1-C12alkoxy, or a salt, ester, or solvate thereof, for preventing or reducing Legionella growth. Item' 2. (i) A is and B is H; (ii) one or more of R2, R3, and R4is independently H, or C1-C4alkyl; (iii) one or more of R5, R6and R10, preferably one or more of R5and R10, is independently H, OH, C1-C4alkyl or C1-C4alkoxy; or (iv) a combination of at least two of (i) to (iv). Item' 3. The use of item’ 1 or 2, wherein: (i) one or more of R2, R3, and R4is independently H, or C1-C3alkyl; (ii) one or more of R5, R6and R10,preferably one or more of R5and R10, is independently H, OH, C1-C3alkyl or C1-C3alkoxy; or (iii) a combination of (i) and (ii). Item' 4. The use of any one of item’s 1 to 3, wherein: (i) one or more of R2, R3, and R4is independently H, or CH3; (ii) one or more of R5, R6and R10,preferably one or more of R5and R10, is independently H, OH, CH3or - OCH3; or (iii) a combination of (i) and (ii). Item' 5. The use of any one of item’s 1 to 4, wherein G is R2. Item' 6. The use of any one of item’s 1 to 5, wherein: (i) E is H; (ii) R5independently H, OH, or -OCH3; (iii) R10is H; or (iv) a combination of at least two of (i) to (iii). Item' 7. (i) Reis H or OR1; (ii) R1is H, or C1-C4alkyl; (iii) R5is H, OH, or C1-C4alkoxy; (iv) R10is H; or (v) a combination of at least two of (i) to (iv). Item' 8. The use of item’ 7, wherein: (i) R8is H or C1-C3alkyl; (ii) R1is H or C1-C3alkyl; (iii) R5is H, OH, or C1-C3alkoxy; or (iv) a combination of at least two of (i) to (iii). Item' 9. The use of item’ 7 or 8, wherein: (i) R8is H or CH3, preferably CH3; (ii) R1 is H or CH3; (iii) R5is H, OH, or -OCH3; or (iv) a combination of at least two of (i) to (iii). Item' 10. The use of any one of item’s 1 to 9, wherein R5is H or OH. Item' 11. The use of item’ 1, wherein the is of Formula (II) wherein R7is H or ; wherein Rfis H or OR8, wherein R1is as defined in any one of item’s 1 and 7-9, each of R2, R3, and R4are independently as defined in any one of item’s 1-4, R5is as defined in any one of item’s 1 and 6-10, R8is as defined in any one of item’s 1 and 7 to 9, and R10is as defined in any one of item’s 1, 6 and 7, or a salt, ester, or solvate thereof. Item' 12. The use of item’ 1, wherein the compound is of Formula (III) or (IV) (IV), wherein Rfis H or OR8, wherein R1is as defined in any one of item’s 1 and 7-9, each of R2, R3, and R4are independently as defined in any one of item’s 1-4, R5is as defined in any one of item’s 1 and 6-10, R8is as defined in any one of item’s 1 and 7 to 9, and R10is as defined in any one of item’s 1, 6 and 7, or a salt, ester, or solvate thereof.

[0002] Item' , , , or a salt, ester, or solvate thereof. Item' 14. Use of a Populus balsamifera extract for preventing or reducing Legionella growth, comprising a compound defined in any one of item’s 1 to 13. Item' 15. The use of any one of item’s 1 to 14, wherein the Legionella is Legionella pneumophila. Item' 16. The use of any one of item’s 1 to 15, further comprising (i) a Monarda oil extract or fraction thereof comprising thymol, carvacrol, and / or geraniol; (ii) thymol, carvacrol, and / or geraniol; or (iii) a combination of (i) and (ii). Item' 17. The use of item’ 16, wherein the monarda is Monarda fistulosa. Item' 18. The use of item’ 16 or 17, wherein the use comprises the Monarda oil extract or fraction thereof or thymol. Item' 19. The use of any one of item’s 1 to 18, wherein the use is for preventing or reducing Legionella growth in water circulation system. Item' 20. The use of item’ 18, wherein the water circulation system is a cooling water tower. Item' 21. Compound of formula , or a salt, ester, or solvate thereof. Item' 22. Composition comprising the compound, salt, ester, or solvate thereof defined in claim 21, and at least one carrier. Item' 23. Kit or composition comprising (a) the compound as defined in any one of item’s 1 to 13 or 21, the extract defined in item’ 14 or the composition defined in item’ 22; and (b) (i) a Monarda oil extract or fraction thereof comprising thymol, carvacrol, and / or geraniol; (ii) thymol, carvacrol, and / or geraniol; (iii) ethanol; or (iv) a combination of at least two of (i) to (iii). Other objects, advantages and features of the present disclosure will become more apparent upon reading of the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the appended drawings: FIG.1: Antibacterial activity of balsacone C against L. pneumophila after 48h compared to chlorine (trichloroethylene). FIG.2: Antibacterial activity of balsacone C, thymol and chlorine (trichloroethylene) against L. pneumophila. FIG.3: Antibiofilm activity of 1, 2, 4, 8, and 16 µg / mL balsacone C against L. pneumophila after 48h. FIG.4: Antibiofilm activity of 0.5 µg / mL, 1 µg / mL, and 2 µg / mL balsacone C against L. pneumophila after 24 hours. FIG.5: Balsacone C stability over time against L. pneumophila at 250 M CFU / mL. FIG.6: Balsacone C stability depending on pH against L. pneumophila at 250 M CFU / mL. FIGs. 7A-B: Toxicity of balsacone C (FIG. 7A) compared to trichloroethylene (chlorine) (FIG. 7B) against L. pneumophila, Daphnia magna, Vibrio fischeri, and Raphidocelis subcapitata. FIG. 8: Cellular leakage of nucleic acid and protein from L. pneumophila after 3 h of exposure to balsacone C. Experiments were performed at a cell density of 4 × 107CFU / mL following exposure to 1 µg / mL, 2 µg / mL, 4 µg / mL, and 8 µg / mL balsacone C. Control represents the untreated cells. For all data n = 3. *Significantly different from control (P < 0.05). FIG.9: Antibacterial activity of combination of balsacone C (0.02, 0.03, 0.06, 0.13, 0.25, 0.50, 1, or 2 µg / mL) and thymol, as compared to that of balsacone C alone against L. pneumophila. FIG.10: Histogram of antibacterial activities of two chemotypes of M. fistulosa HE (% survival x concentration). FIGs. 11A-E: Toxicity of chlorine (FIG. 11A), dihydrochalcone C (FIG. 11B), thymol (FIG. 11C), thymol and dihydrochalcone C (FIG.11D) and carvacrol (FIG.11E) against D. magna. FIG.12: Effectiveness of the formulation (DHC-C + thymol) against L. pneumophila in a pilot water tower. DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS The present disclosure presents the use of compounds and / or plant extracts or fractions thereof comprising at least one of these compounds for inhibiting Legionella growth. Compounds In the event of any discrepancies between the compound names and the structures presented herein, the structures shall take precedence. In formulas of the present disclosure and in specifically disclosed compounds, certain hydrogen atoms are not explicitly shown for simplicity and clarity’s sake. Compounds of the present disclosure include dihydrochalcones and dihydrochalcone derivatives and analogs; thymol, thymol carvacrol geraniol The terms “dihydrochalcone compounds of the disclosure based on the skeleton of dihydrochalcones: . Dihydrochalcone and dihydrochalcone derivatives and analogs of the present disclosure are compounds of Formula (I), (II), (III), or (IV) presented herein, and salts, esters, solvates and isomers thereof. In specific embodiments, the compound of formula (I) is

[0003] (hereinafter called “Dihydrochalcone A” or “DHC-A”; or 4,2',6'-trihydroxy-4'-methoxy-dihydrochalcone), (hereinafter called “Dihydrochalcone C” or “DHC-C”; or 2',4',6'-trihydroxydihydrochalcone), Analog 1; 2',4',6'-trihydroxy-3'-(3'',4''-dimethoxycinnamyl)-dihydrochalcone. Compounds, or salts, esters, solvates, and isomers thereof as described herein may be used in the disinfection of objects and / or water treatment and / or therapeutic purposes as described herein. As used herein, the term "alkyl" refers to saturated hydrocarbons of formula –CnH2n+1. In embodiments, the alkyl is branched or linear has a number of carbon atoms between 1 and 12, more specifically between 1 and 6, even more specifically between 1 and 3. In embodiments, the alkyl is methyl or ethyl, preferably methyl. As used herein, the term “alkoxy” refers to -O-alkyl groups having a number of carbon atoms between 1 and 12, more specifically between 1 and 6, even more specifically between 1 and 4 or between 1 and 3. In embodiments, alkoxy is methoxy. In specific embodiments of the above, R1is H or -CH3; if present, R2is H or -CH3; R3is H; R4is H or CH3; R5is H, OH or O-CH3; if present R6is H or –OH, if present R8is CH3, R10is H or -CH3; if present Reis -OH or -OCH3; if present Rfis H or -OCH3. Isomers, tautomers, and polymorphs: As used herein, the term “isomers” refers to optical isomers (enantiomers), diastereoisomers, as well as the other known types of isomers. Some of the compounds of the disclosure have at least one asymmetric carbon atom and can therefore exist in the form of optically pure enantiomers (optical isomers), as racemates and as mixtures thereof. Some of the compounds have at least two asymmetric carbon atoms and can therefore exist in the form of pure diastereoisomers and as mixtures thereof. It is to be understood, that, unless otherwise specified, the present disclosure embraces the racemates, the enantiomers, and / or the diastereoisomers of the compounds of the disclosure, as well as mixtures thereof. In addition, the present disclosure embraces all geometric and positional isomers. For example, when a compound of the disclosure incorporates a double bond or a fused ring, both the cis- and trans-forms, as well as mixtures, are embraced within the scope of the disclosure. Within the present disclosure, it is to be understood that a compound of the disclosure may exhibit the phenomenon of tautomerism, and that the formula drawings within this specification can represent only one of the possible tautomeric forms. It is to be understood that the disclosure encompasses any tautomeric form and is not to be limited merely to any one tautomeric form utilized within the formula drawings. It is also to be understood that certain compounds of the disclosure may exhibit polymorphism, and that the present disclosure encompasses all such forms. Salts The present disclosure relates to the compounds of the disclosure as hereinbefore defined as well as to salts thereof. The term “salt(s)”, as employed herein, denotes basic salts formed with inorganic and / or organic bases. Salts for use in water-treatment compositions will be non-toxic for the environment (assays to determine this environment toxicity are described in Examples 7, 11, 16, and 21 for example), but other salts may be useful in the production of compounds of the disclosure. More specifically, these salts retain the biological effectiveness and properties of the anti-Legionella compounds of the disclosure and are formed from suitable non-toxic organic or inorganic acids or bases. For example, where the compounds of the disclosure are sufficiently acidic, the salts of the disclosure include base salts formed with an inorganic or organic base. Such salts include alkali metal salts such as sodium, lithium, and potassium salts; alkaline earth metal salts such as calcium and magnesium salts; metal salts such as aluminium salts, iron salts, zinc salts, copper salts, nickel salts, and cobalt salts; inorganic amine salts such as ammonium or substituted ammonium salts, such as e.g., trimethylammonium salts; and salts with organic bases (for example, organic amines) such as chloroprocaine salts, dibenzylamine salts, dicyclohexylamine salts, dicyclohexylamines, diethanolamine salts, ethylamine salts (including diethylamine salts and triethylamine salts), ethylenediamine salts, glucosamine salts, guanidine salts, methylamine salts (including dimethylamine salts and trimethylamine salts), morpholine salts, morpholine salts, N,N'-dibenzylethylenediamine salts, N-benzyl-phenethylamine salts, N-methylglucamine salts, phenylglycine alkyl ester salts, piperazine salts, piperidine salts, procaine salts, tert-butyl amines salts, tetramethylammonium salts, tert-octylamine salts, tris-(2-hydroxyethyl)amine salts, and tris(hydroxymethyl)aminomethane salts. Preferred salts include those formed with sodium, lithium, potassium, calcium, and magnesium. Such salts can be formed routinely by those skilled in the art using standard techniques. Indeed, the chemical modification of a compound into a salt is a technique well known to chemists. Salts of the compounds of the disclosure may be formed, for example, by reacting a compound of the disclosure with an amount of acid or base, such as an equivalent amount, in a medium such as one in which the salt precipitates or in an aqueous medium followed by lyophilization. Esters The present disclosure relates to the compounds of the disclosure as hereinbefore defined as well as to the esters thereof. The term “ester(s)”, as employed herein, refers to compounds of the disclosure or salts thereof in which hydroxy groups have been converted to the corresponding esters using, for example, inorganic or organic anhydrides, acids, or acid chlorides. Esters for use in water treatment compositions will be non-toxic for the environment (assays to determine this environment toxicity are described in Examples 7, 11, 16, and 21 for example), but other esters may be useful in the production of the compounds of the disclosure. Esters retain the biological effectiveness and properties of the anti-Legionella compounds of the disclosure and act as prodrugs which, when in use produce the parent alcohol compound. Esters of the present compounds include among others the following groups (1) carboxylic acid esters obtained by esterification of the hydroxy groups, in which the non-carbonyl moiety of the carboxylic acid portion of the ester grouping is selected from straight or branched chain alkyl (for example, ethyl, n-propyl, tert-butyl, n-butyl, methyl, propyl, isopropyl, butyl, isobutyl or pentyl), alkoxyalkyl (for example, methoxymethyl, acetoxymethyl, and 2,2- dimethylpropionyloxymethyl), aralkyl (for example, benzyl), aryloxyalkyl (for example, phenoxymethyl), aryl (for example, phenyl optionally substituted with, for example, halogen, C1-4 alkyl, or C1-4 alkoxy or amino); (2) sulfonate esters, such as alkyl- or aralkylsulfonyl (for example, methanesulfonyl); (3) amino acid esters (for example, L-valyl or L-isoleucyl); (4) phosphonate esters ; (5) mono-, di-, or triphosphate esters (including phosphoramidic cyclic esters). The phosphate esters may be further esterified by, for example, a C1-20 alcohol or reactive derivative thereof, or by a 2,3-di(C6-24)acyl glycerol. (6) carbamic acid ester (for exemple N-methylcarbamic ester); and (7) carbonic acid ester (for exemple methylcabonate) The compounds of this disclosure may be esterified by a variety of conventional procedures including reacting the appropriate anhydride, carboxylic acid, or acid chloride with the alcohol group of a compound of this disclosure. For example, an appropriate anhydride may be reacted with an alcohol in the presence of a base, such as 1,8- bis[dimethylamino]naphthalene or N,N-dimethylaminopyridine, to facilitate acylation. Also, an appropriate carboxylic acid can be reacted with the alcohol in the presence of a dehydrating agent such as dicyclohexylcarbodiimide, 1-[3- dimethylaminopropyl]-3-ethylcarbodiimide or other water-soluble dehydrating agents which are used to drive the reaction by the removal of water, and, optionally, an acylation catalyst. Esterification can also be achieved using the appropriate carboxylic acid. Reaction of an acid chloride with the alcohol can also be carried out. When a compound of the disclosure contains a number of free hydroxy groups, those groups not being converted into a prodrug functionality may be protected (for example, using a tert-butyl-dimethylsilyl group), and later deprotected. Also, enzymatic methods may be used to selectively phosphorylate or dephosphorylate alcohol functionalities. One skilled in the art would readily know how to successfully carry out these as well as other known methods of esterification of alcohols. Esters of the compounds of the disclosure may form salts. Where this is the case, this is achieved by conventional techniques as described above. Solvates The compounds of the disclosure may exist in unsolvated as well as solvated forms with solvents such as water, ethanol, and the like, and it is intended that the disclosure embrace both solvated and unsolvated forms. “Solvate” means a physical association of a compound of this disclosure with one or more solvent molecules. This physical association involves varying degrees of ionic and covalent bonding, including hydrogen bonding. In certain instances, the solvate will be capable of isolation, for example when one or more solvent molecules are incorporated in the crystal lattice of the crystalline solid. “Solvate” encompasses both solution-phase and isolatable solvates. Solvates for use in water-treatment compositions will be non-toxic for the environment (assays to determine this environment toxicity are described in Examples 7, 11, 16, and 21 for example), but other solvates may be useful in the production of the compounds of the disclosure. More specifically, these solvates retain the biological effectiveness and properties of the anti-Legionella compounds of the disclosure and are formed from suitable non-toxic solvents. Non-limiting examples of suitable solvates include ethanolates, methanolates, and the like, as well as hydrates, which are solvates wherein the solvent molecules are H2O. A typical, non-limiting, process for preparing a solvate involves dissolving the inventive compound in desired amounts of the desired solvent (organic or water or mixtures thereof) at a higher than ambient temperature and cooling the solution at a rate sufficient to form crystals which are then isolated by standard methods. Analytical techniques such as, for example IR spectroscopy, can be used to show the presence of the solvent (or water) in the crystals as a solvate (or hydrate). Formulation The compounds and / or extracts of the present disclosure may be formulated in a composition with one or more carriers. The term “carrier” refers to a solvent, diluent, adjuvant, excipient, or vehicle with which the compounds and / or extracts of the present disclosure may be used, applied (e.g., on a surface to disinfect) or administered (e.g., to treat a subject in need thereof, such as a subject suffering from a Legionella infection). The compounds and extracts of the present disclosure were formulated in an 95% ethanol solvent (e.g., 1 mg of compound or extract per mL of 95% ethanol). This formulation was used in assays in Examples 1-23 described herein. Other (e.g., non-toxic for water treatment uses) solvents able to solubilize the hydrophobic compounds and extracts of the disclosure e.g., other alcohols such as methanol, are also appropriate solvents. When the compounds and extracts of the present disclosure are used for pharmaceutical purposes, suitable pharmaceutical carriers known in the art and as described in e.g., “Remington’s Pharmaceutical Sciences” by E.W. Martin can be used. For example, compositions of the present disclosure may contain excipients / carriers such preserving agents, solubilizing agents, stabilizing agents, wetting agents, emulsifiers, sweeteners, colorants, odorants, salts for the variation of osmotic pressure, buffers, coating agents or antioxidants. For the preparation of tablets, coated tablets, dragees or hard gelatin capsules, the compounds of the present disclosure may be admixed with any known pharmaceutically inert, inorganic, or organic excipient and / or carrier. Examples of suitable excipients / carriers include lactose, maize starch or derivatives thereof, talc or stearic acid or salts thereof. Suitable excipients for use with soft gelatin capsules include for example vegetable oils, waxes, fats, semi- solid or liquid polyols, etc. For the preparation of solutions and syrups, excipients which may be used include for example water, polyols, saccharose, invert sugar, and glucose. Extracts The present disclosure also provides plant extracts or fractions thereof comprising one or more compounds of the present disclosure. In specific embodiments, the plant extracts or fractions thereof are Populus or Monarda extracts or fractions thereof. As used in claims, the term “extract” encompasses fractions as described herein. Monarda is a genus of flowering plants in the mint family, Lamiaceae, common in North America. English names variously applied to these species include bergamot, bee balm, horsemint, and oswego tea. Plant extracts or fractions in accordance with the present disclosure thereof can be essential oils or fractions thereof from stems and / or flowers of Monarda fistulosa or from another Monarda species. Examples of other Monarda species include Monarda didyma. Populus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to these species include poplar, aspen, and cottonwood. Plant extracts or fractions thereof can be from buds of Populus balsamifera (commonly called balsam poplar) or from another Populus species. Examples of other Populus species include those in the Tacamahaca section of this genus, such as Populus trichocarpa (also known as black cottonwood, western balsam poplar, or California poplar). The above extracts or fractions thereof comprise at least one (one or more: at least two, at least three, etc.) of the compounds of the disclosure as described herein. Extract preparation Grinding: In embodiment, the plant or plant part, e.g., Populus (e.g., P. balsamifera) buds or Monarda stems and flowers may first be coarsely grinded using an electrical blender or mortar and pestle. The buds may optionally be first soaked in liquid nitrogen to freeze resin. Other methods known in the art for grinding may be used. Nonpolar components / impurities. Additional extractions / suspensions may then be carried out to remove non-polar components / impurities of the first extract / residue. This additional extraction is performed with a second solvent (or mixture of solvents) on the first extract / residue obtained with the first solvent (or mixture of solvents). In an embodiment, the first extract / residue obtained with the first solvent (or mixture of solvents) is suspended in methanol and extracted with an alkane that is non-soluble in methanol (e.g., hexane, pentane, or petroleum ether). The non-polar components / impurities are thus solubilized with the alkane (e.g., hexane) phase which is then discarded. The methanol phase is then evaporated to generate a second extract / residue. Polar components / impurities. In an embodiment, the second residue / extract obtained with the second solvent (or mixture of solvents) is subjected to a third suspension / extraction to remove polar components / impurities of the second extract / residue. For instance, the second extract / residue can be suspended in diethyl ether (Et2O), butanol, or chlorinated solvents such as chloroform or chloromethane and extracted with water. In an embodiment, the residue is suspended in Et2O and extracted with water. The polar components / impurities are thus solubilized with the water phase which is then discarded. The diethyl ether phase is then evaporated to generate a third extract / residue. The extracts can be in a liquid or dried form. In embodiments, a preliminary extraction of Populus or Monarda (i.e. prior to the first extraction [e.g., ethanol extraction or hydro distillation]) can be performed on the matrix to remove undesirable compounds. For example, hexane or another solvent (e.g.¸ hexane, ether, pentane, or petroleum ether) could be used to remove non-polar compounds, such as waxy compounds. The first extraction can then be performed on the cleaned matrix. Specific illustrations of extracts and fractions of the present disclosure are described in Examples presented herein. Extracts and fractions are described herein may be used in the disinfection of objects and / or water as described herein. Populus extract preparation The grinded buds are first extracted using a first solvent. In an embodiment, the Populus extract or fraction thereof is an aqueous extract or fraction thereof. In another embodiment, it is an hydroalcoholic extract or fraction thereof. In a more specific embodiment, it is an ethanolic or methanolic extract or fraction thereof or an extract obtained from a C1-10 aliphatic alcohol or a fraction thereof. In another embodiment, the extract is an extract obtained using an organic solvent, examples of which include ketones (such as C1-10 ketones), hydrocarbons (such as hexane), organic acids, esters (such as ethyl acetate), ethers (such as diethyl ether), alkyl chlorides (such as methylene chloride), etc. A mixture of any two or more of the foregoing solvents may be used. The first solvent is evaporated to generate a first extract / residue. In more specific embodiments, the extract is an ethanolic extract of P. balsamifera buds (or a combination of several such extracts) in liquid form or dried form. In more specific embodiments, there is provided a methanolic extract of the above-cited dried ethanolic extract, said methanolic extract having optionally being extracted with hexane one or more times. This methanolic extract can be in liquid or dry form. In even more specific embodiments, there is provided a diethyl ether extract of the above dried methanolic extract, said diethyl ether extract having optionally been extracted with water one or more times. This diethyl ether extract can be in liquid or dry form. In embodiments, there are provided one or more fractions obtained by chromatographic separation of this dried diethyl ethyl extract. In an embodiment, the Monarda extract, or fraction thereof is an essential oil or fraction thereof and is obtained by hydrodistillation or supercritical CO2extraction. Components thereof such as thymol, carvacrol, or geraniol can be extracted by solvents such as petroleum ether or hexane. Disinfectants and water treatment compositions The present disclosure also relates to the use of the compounds of the disclosure and their salts, esters, solvates, and isomers thereof as well as the use of the extracts (including fractions thereof) of the disclosure in the preparation of a disinfectant or water treatment composition. In specific embodiments, the compounds and / or extracts are formulated in a non-toxic hydroalcoholic composition such as an ethanolic composition. The present disclosure also relates to water treatment compositions comprising the above-mentioned compounds of the disclosure and their salts, esters, and solvates thereof and / or the above extracts of the disclosure. As used herein, the terms “subject” refers to an animal such as, but not limited to a human, mammal such as cattle (e.g., bovine), mouse, rat or other animal (e.g., pets such as cats, dogs, horses, etc.; and fishes, swine, poultry, etc.). As used herein, the terms “subject in need thereof” refer to a subject who would benefit from receiving an effective amount of the compound, extract or composition of the present disclosure. In the context of treating a Legionella infection, it refers to a subject (e.g., a human) suffering from or at risk of suffering from a Legionella infection. The use of the terms "a" and "an" and "the" and similar referents in the context of describing the disclosure (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising", "having", "including", and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to") unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All subsets of values within the ranges are also incorporated into the specification as if they were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the disclosure and does not pose a limitation on the scope of the disclosure unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure. Herein, the term "about" has its ordinary meaning. In embodiments, it may mean plus or minus 10% of the numerical value qualified. Unless otherwise defined, 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. Other objects, advantages and features of the present disclosure will become more apparent upon reading of the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the accompanying drawings. The present disclosure is illustrated in further detail by the following non-limiting examples. EXAMPLE 1: Materials and Methods Plant material and chemicals Extraction and fractionation of P. balsamifera buds Fresh P. balsamifera buds (50 g) were extracted three consecutive times in 250 mL of ethanol during 1 h at reflux. After filtration, the solvent was rotary evaporated, and the residue was lyophilised to provide 22 g of crude extract.16 g of crude extract were then fractionated using a column of Diaion®HP20 resin eluting with a gradient from 60 to 95% of EtOH in H2O to provide eight fractions (A-H) including a dihydrochalcone-rich fraction (fraction A, 3.9 g) and a balsacone-rich fraction (fraction C, 1.1 g).3.0 g of the dihydrochalcone (DHC)-rich fraction A were dissolved in ethylacetate and washed with a saturated aqueous solution of NaHCO3. The organic phase was dried with Na2SO4, filteredand the solvent was rotary evaporated to provide 0.82 g of washed fraction A2. Enrichment of the washed dihydrochalcone-rich fraction A2 through the in situ hemisynthesis of balsacones General procedure. Fraction A2 and 4-hydroxycinnamyl alcohol were dissolved in ethyl acetate. Polystyrene-supported 4-toluenesulfonic acid (2 mmol / g) was added and the mixture was stirred 18 h at room temperature. After filtration, the solvent was rotary evaporated. The residue was suspended in water and lyophilised to provide the enriched fraction. Fraction P1, enriched with 5% w / w of 4-hydroxycinnamyl alcohol. Following the general procedure above, a mixture of fraction A2 (49.8 mg), 4-hydroxycinnamyl alcohol (2.5 mg) and supported 4-toluenesulfonic acid (16.6 mg) provided the enriched-fraction P1 as a yellow-orange solid (51.7 mg). Fraction P2, enriched with 10% w / w of 4-hydroxycinnamyl alcohol. Following the general procedure above, a mixture of fraction A2 (120.0 mg), 4-hydroxycinnamyl alcohol (12.0 mg) and supported 4-toluenesulfonic acid (79.9 mg) provided the enriched-fraction P2 as a yellow-orange solid (132.0 mg). Fraction P3, enriched with 15% w / w of 4-hydroxycinnamyl alcohol. Following the general procedure above, a mixture of fraction A2 (120.0 mg), 4-hydroxycinnamyl alcohol (18.1 mg) and supported 4-toluenesulfonic acid (120.0 mg) provided the enriched-fraction P3 as a yellow-orange solid (120.0 mg). Fraction P4, enriched with 20% w / w of 4-hydroxycinnamyl alcohol. Following the general procedure above, a mixture of fraction A2 (120.0 mg), 4-hydroxycinnamyl alcohol (24.1 mg) and supported 4-toluenesulfonic acid (160.0 mg) provided the enriched-fraction P4 as a yellow-orange solid (119.0 mg). Fraction P5, enriched with 30% w / w of 4-hydroxycinnamyl alcohol. Following the general procedure above, a mixture of fraction A2 (50.7 mg), 4-hydroxycinnamyl alcohol (15.2 mg) and supported 4-toluenesulfonic acid (101.0 mg) provided the enriched-fraction P5 as a yellow-orange solid (62.1 mg). Fraction P6, enriched with 35% w / w of 4-hydroxycinnamyl alcohol. Following the general procedure above, a mixture of fraction A2 (50.2 mg), 4-hydroxycinnamyl alcohol (17.6 mg) and supported 4-toluenesulfonic acid (117.0 mg) provided the enriched-fraction P6 as a yellow-orange solid (63.4 mg). Dihydrochalcones, derivatives and analogs thereof Dihydrochalcones A and C were isolated from P. balsamifera buds following the procedure detailed in Lavoie et al. (2013) and as summarized hereinabove. Balsacone Balsacones A, and C were isolated from P. balsamifera buds following the procedure detailed in Lavoie et al. (2013). Balsacones A, and C were also synthesised by reacting the corresponding dihydrochalcone with 4-hydroxycinnamyl alcohol as described in Alsarraf et al. (2020) and as summarized and adapted hereinbelow: wherein: R C CH3H H H OH H Friedel-Crafts Alkylation PTSA : Paratoluenesulfonic acid MeCN : acetonitrile Chlorine Trichloroethylene or hypochlorite was used as a comparative source of chlorine. Gas chromatography analysis All chromatographic analyses were run on an Agilent™ 6890N GC (Agilent Technologies, Santa Clara, CA, USA) equipped with a non-polar DB-5 column (Agilent Technologies, Santa Clara, CA, USA) and a polar SolGel-Wax™ column (30 m × 0.25 mm × 0.25 mm; Agilent Technologies, Santa Clara, CA, USA) as well as two flame ionisation detectors (FID; Agilent Technologies, Santa Clara, CA, USA). The oils were injected in an undiluted (0.1 µL injection volume, split 1:235) and undried state. The temperature program was 40°C for 2 min, 2°C·min−1up to 210°C, and then 210°C for 13 min. Samples were also injected on an Agilent™ 7890A GC (Agilent Technologies, Santa Clara, CA, USA) coupled to an Agilent™ 5975C InertXL EI / CI mass spectrometer (Agilent Technologies, Santa Clara, CA, USA), equipped with a DB-5MS column (Agilent Technologies, Santa Clara, CA, USA) using the same temperature program as above and a split of 1:1000. Compounds were identified from their retention indexes as calculated from even- numbered C8 to C36 alkane standards and / or from MS databases (NIST08), HPCH 2205, and custom libraries built from pure compounds (Laboratoire LASEVE, UQAC, Qc, Canada). Quantification was derived from the FID detector response on the DB-5 column without any correction factor. All standards were co-injected to validate the identification. Monarda fistulosa First chemotype was extracted from M. fistulosa grown in agricultural field in Saint-Fulgence, Québec, Canada and collected in August 2018 during flowering period for extraction (7 to 14 August 2018). Voucher specimen no. QFA0625782 was filed at the Louis-Marie herbarium of Université Laval, Québec City, Québec, Canada. Essential oil was obtained from freshly harvested aerial parts by steam distillation over a 3-h period. Second chemotype of essential oil from M. fistulosa was purchased from Aliksir (Grondines, Québec, Canada). The extracted essential oil was then stored in the dark at a temperature of 4°C. Thymol, carvacrol, geraniol Thymol, carvacrol and geraniol were purchased from Sigma-Aldrich (St. Louis, MO, USA). Evaluation of antibacterial activity The antibacterial activities of extracts and compounds were tested against at least one of gram-negative Legionella pneumophila (ATCC 33152), Legionella bozemanii (ATCC 33217), Legionella anisa (ATCC 35292),Legionella dumofii (ATCC 33279) and Staphylococcus aureus using the microdilution method of Banfi et al. (2003). Briefly, 50 µL of exponentially growing bacteria were plated in 96-well plates (Costar, Corning Inc.) in nutrient broth (Difco) for Staphylococcus aureus and in BYE medium for Legionella. Increasing concentrations of extracts and compounds (diluted in ethanol) were then added in triplicate. For the synergy assay, a single concentration of thymol was initially added to a 96-well plate, followed by the addition of increasing concentrations of the extract. The final concentration of ethanol in the culture medium was maintained at 0.1% (v / v) to avoid solvent toxicity. The negative control was a bacterial suspension without treatment, and the blank consisted of a culture medium only. The bacterial suspension plus solvent was tested to demonstrate the absence of solvent toxicity. Concentration of 2.5×106CFU / mL was used unless otherwise indicated. Microplates were incubated for 48 h at 37°C. A one hundred (100) µL of resazurin sodium salt solution having a concentration of 50 µg / mL (Sigma R-2127, St-Louis, MO, USA) was then added to each well. Fluorescence was read on an automated Fluoroskan™ Ascent FLTM plate reader (Labsystems, Milford, MA, USA). Results were expressed as the concentration at which 100% of bacterial growth is inhibited (MIC) or were expressed as the minimum concentration inhibiting ninety percent of bacterial growth (IC90). Antibiofilm activity Biofilms of Legionella were developed by the inventors, following methods adapted from the methods described in Nomura et al. (2013) and Selvarai et al. (2019). Initially, anti-biofilm activity was tested using a 96-well plate assay. L. pneumophila bacteria were cultured for 72 hours at a concentration of 109CFU / mL, wells were washed with PBS to retain only the bacteria present in the biofilm. Compounds were tested at various concentrations directly on the biofilms. After a 24-hour incubation at 37°C with the compounds, resazurin was added to measure bacterial viability using fluorescence readings. Stability Increasing concentrations of the mixture of balsacone C in 95% ethanol were directly diluted in water. The bacteria were incubated for different time periods (15 minutes to 7 days in Example 5; 3 hours in Example 6) and at different pH values (at pH 7 as recommended for L. pneumophila in Example 5; and at a pH from 6 to 10 in Example 6). The activity was assessed in Examples 5 and 6 using a bacterial concentration of L. pneumophila of 250 x 106CFU / mL, namely a concentration 100 times higher than that used previously for antibacterial activity tests, in order to detect a signal in the aqueous medium. Cytotoxicity Exponentially growing cells of human skin fibroblasts WS1 were plated in 96-well microplates, each containing 100 µLof culture medium, at a density of 5 × 103cells per well (Costar, Corning Inc., Lowell, MA, USA). The cells were allowedto adhere for 16 h before treatment. Cells were then treated with extracts or compounds in ethanol. The final concentration of ethanol in the culture medium was 0.5% (v / v) to avoid solvent toxicity. After 48 h, the cytotoxicity was assessed using the resazurin reduction test. Fluorescence was measured on an automated Fluoroskan™ Ascent FLTM plate reader (Labsystems, Milford, MA, USA) using an excitation wavelength of 530 nm and an emission wavelength of 590 nm. Cytotoxicity was expressed as the concentration that inhibited cell growth by 50% (IC50). Environmental toxicity Environmental toxicity of compounds was tested against luminescent bacteria Vibrio fischeri, algae Raphidocelis subcapitata, and small planktonic crustaceans Daphnia magna. For all organisms, maximum tolerated concentration (MTC) was determined, which represents at least survival of 80% after 48 h. Vibrio fischeri (now Aliivibrio fischeri) To determine the toxicity of compounds, the short-term bioluminescence inhibition assay using the marine luminescent bacterium V. fischeri was performed. The reagent (the freeze-dried bioluminescent bacterium V. fischeri) and the other required test solutions were purchased from ATCC (7744). The experiments were carried out in accordance with the test conditions and operating protocol of Microtox. Luminescence was measured with Cytation3™ (Cell Imaging Multi- Mode Reader). The toxic effect (MTC) values reflect the ratio of the decrease in bacterial light production to the remaining light. The V. fischeri bioluminescence inhibition was measured after 24 h. To evaluate the toxicity for individual chemicals, the test was performed in triplicate on control and nine concentrations of each toxicant, which were obtained by serial dilution from a stock solution. Raphidocelis subcapitata Cells of R. subcapitata were propagated photoautotrophically in a 250 mL Erlenmeyer flask containing 100 mL of liquid HB-4 medium and incubated in a rotator shaker (100 rpm) at 25°C with illumination by cool-white fluorescent lights with intensities of 450 E m−2s−1in continuous mode. For toxicity tests, 200 µL of the HB-4 medium containing 5×104algal cells / mL were inoculated into 96-well plate. A wide range of concentrations of the compounds were tested according to the results of previous tests conducted in the inventors’ laboratory. The cultures of R. subcapitata were then incubated for 72 h on an orbital shaker running at 100 rpm at 25 °C and under a continuous light intensity of 450 E m−2s−1. Cell counts were correlated with absorbance over time for 72 h on a Cytation3™ (Cell Imaging Multi-Mode Reader) at 680 nm. The toxicity tests for BC concentrations were conducted in triplicate. Control cultures containing no compounds were included in each toxicity test. Results were expressed in concentration that inhibits 20% of cell growth after 72h (MTC). Daphnia magna Daphnia magna crustacea were obtained from the UQAC Aquatic Laboratory which has been continuously maintained for over two years in the LASEVE laboratory. According to the OECD guideline 202, D. magna was cultured in containers as recommended in standard protocol (OECD, 2004). The culture medium was refreshed weekly. The test organisms were fed regularly with Raphidocelis subcapitata algae and maintained inside a temperature-controlled chamber (20^±^1°C) under a 16:8 light-dark cycle. For toxicity assay, five neonates were added to each container with different compound concentrations. Daphnia were observed after 48^h. Mortality was recorded as per OECD protocol 202 (OECD, 2004). Anti-amoebic activity Anti-amoebic activity was measured against Acanthamoeba castellanii and Hartmannella vermiformis. In order to determine the activity, the microdilution test in liquid medium was adapted from the method used by Anwar et al. with the amoeba A. castellanii. Briefly, exponentially growing amoebas were cultured in 96-well plates at a density of 5 x 105CFU / mL in RPMI-1640 medium. Increasing concentrations of BC, with or without thymol, were added (100 µL per well), and chlorhexidine was used as a positive control. The final concentration of solvent (ethanol) in the culture medium was maintained at 0.1% (v / v) to avoid toxicity. The microplates were then incubated at 30°C with high humidity. Absorbance was measured after 6 and 24 hours using a Varioskan™ 96-well plate reader (Thermo, Labsystems) at a wavelength of 600 nm. The results are expressed as the minimum inhibitory concentration for 50% (MIC50) and 100% (MIC) inhibition of amoeba growth compared to untreated microorganisms. The minimum bactericidal concentration (MBC) is also evaluated by subculturing wells without measured growth (≤ MIC) on solid agar and quantifying the number of colonies. Tubing weight loss Samples of copper-zinc alloy representative of RT system are used according to the following dimensions: 2 x 2 cm². The samples will be treated in different concentrations of formulation, immersed for 30 minutes in two oxidizing solutions (15% hydrochloric acid; chlorine) and then rinsed with distilled water. The different samples are then be cleaned with isopropanol and dried in a desiccator for 24 hours. The samples are weighed using a precision balance before and after treatment. The weight loss is calculated using the following formula: % inhibition = (initial weight – final weight) / initial weight x 100, and the corrosion rate according to the following formula: corrosion rate = (87.6 x weight loss) / (surface area x time x density). The measurements of the treated samples are compared to untreated samples. Electrochemical impedance spectroscopy Electrochemical impedance spectroscopy allows the measurement of the corrosion rate, with defects altering the appearance of impedance diagrams obtained. A standard three-electrode cell is used with an alternating current of 10 mA AC and a frequency range from 100 kHz to 0.05 mHz. To ensure result reproducibility, measurements are repeated three times for each treated and untreated sample. Scanning Electron Microscopy (SEM) The samples were prepared for scanning electron microscopy (SEM) following De Sousa et al. (2012) with some modifications. Briefly, untreated and treated samples having BC (4 µg / mL) were grown 3 h at 37°C. The samples were removed from the cultures, washed them with PBS and then the samples were fixed in phosphate buffers (pH 7.2) containing 2.5% glutaraldehyde for 2 h at room temperature. The fixed cells were collected via centrifugation at 2,000 × g and washed three times with phosphate buffers. The fixed bacteria were dehydrated with ethanol (30 to 95%). The dried specimens were mounted on aluminum stubs using a conductive carbon cement; the specimens were allowed to dry and were then coated with a carbon film. The samples were observed with an SEM at 20 kV and 20,000 X magnification. Cellular leakage of nucleic acid and protein from L. pneumophila Intracellular material released from the cells was quantified as described in Virto et al. (2005) with some modifications. Briefly, we added 4 × 107CFU / mL to tubes containing 10 ml BYE broth. Untreated and treated samples having BC (1-2-4 and 8 µg / mL) were grown 3 h at 37◦C and were then centrifuged at 2,000 × g for 10 min. We transferred the supernatant in a cuvette and measured the UV absorbance using a spectrophotometer (MultiskanTMGO Spectrophotometer – Thermo Fisher Scientific) – nucleic acids have an absorption peak at 260 nm, proteins at 280 nm. We compared our results with those of untreated control samples. Treatment of Legionella pneumophila in water cooling tower Day Before Experiment The day before the experiment, L. pneumophila was inoculated into sterile liquid BYE medium. The culture was then incubated at 37°C overnight to obtain cells in the exponential growth phase. Meanwhile, the pilot cooling tower was prepared. A preliminary disinfection was carried out by adding a sodium hypochlorite solution to reach a final concentration of 1 ppm in the system. The water in the tower was then heated to reach 60°C and maintained at this temperature for two (2) hours. The system was then left to cool until the following day. Experimental Procedure On the morning of the experiment, the cooling tower was rinsed twice with sterile autoclaved water. Once the tower was cleaned, 30 liters of sterile autoclaved water were introduced into the tower. The tower was then operated for 15 minutes. The initial contamination was then carried out by injecting L. pneumophila at a target concentration of 1×106CFU / L into the circuit. The water was circulated for 10 minutes to ensure homogeneous bacterial dispersion. A 150 mL sample (3 x 50 mL) was then collected via the sampling valve to quantify the initial bacterial load (Sample 1). The anti-Legionella treatment (volume of 10 mL of formulation containing 300 mg / mL of DHC-C and 300 mg / mL of thymol) was then injected through the same valve and left in contact with the system for 15 minutes after which a second 150 mL sample (3 x 50 mL) was collected (Sample 2). A third sample (3 x 50 mL) was collected after 1 hour (Sample 3). To conclude the experiment, a final disinfection treatment was carried out by adding sodium hypochlorite at a concentration of 10 ppm. This treatment was maintained for 48 hours to ensure complete disinfection of the system. Sample Processing The collected samples were centrifuged for 10 minutes at 5000 rpm. The supernatant was discarded, leaving 0.5 mL of liquid at the bottom of each tube. The bacterial pellets were thoroughly resuspended, and samples from the same sampling point were pooled (for a total of 1.5 mL). A 100 µL aliquot of the suspension was plated onto BCYE selective agar (n = 6), ensuring uniform bacterial spreading. An additional plate without cysteine supplementation was included to confirm colony identity, as Legionella spp. require cysteine-enriched media for growth. The plates were incubated at 37°C for 72 hours. After incubation, bacterial colonies were counted using the ImageJ™ image analysis software. Statistical analysis For all analyses, two-way ANOVAs were performed all followed by a post-test Holm-Sidak method using SigmaStat™ software (Systat Software Inc., California, USA). Differences were deemed as statistically significant when P < 0.05. EXAMPLE 2: Antibacterial activity of dihydrochalcone derivatives including balsacone C against L. pneumophila after 48 h The antibacterial activity of dihydrochalcone (DHC) derivatives including balsacone A, balsacone C, DHC-A, and DHC- C, was tested against L. pneumophila as described in Example 1. A concentration range from 0.156 µg / mL to 20 µg / mL was utilized to determine the minimum inhibitory concentration (MIC) with all compounds. High activity was found with balsacones A (BA) and C (BC) with respective MIC of 0.02 µg / mL and 0.6 µg / mL at L. pneumophila at bacterial concentration of 2.5 x 106CFU / mL. Dihydrochalcones were also shown to have anti- Legionella activity, with DHC-C and DHC-A with respective MIC of 1.04 µg / mL and 18 µg / mL. Subsequently, antibacterial activity of BC was determined against growing concentration of bacteria (1.25×105CFU / mL to 40×106CFU / mL). A concentration range from 0.156 µg / mL to 20 µg / mL was utilized to determine the minimum inhibitory concentration (MIC). Microplates were incubated for 48 h at 37°C.100 µL of resazurin sodium salt solution having a concentration of 50 µg / mL (Sigma R-2127, St-Louis, MO, USA) was then added to each well. Fluorescence was read on an automated Fluoroskan™ Ascent FLTM plate reader (Labsystems, Milford, MA, USA). Results are expressed as the concentration at which 100% of bacterial growth is inhibited (MIC). Results showing the antibacterial activity of balsacone C against different concentrations of L. pneumophila are presented in Table I below. Table I: Activity of balsacone C against different concentrations of L. pneumophila 40 x 1062.2 ± 0.1 EXAMPLE 3: Antibiotic activity of balsacone C, thymol, and chlorine against L. pneumophila The antibiotic activity of BC against L. pneumophila was first compared to that of trichloroethylene (chlorine), which is usually used to prevent or treat contamination in the water system by Legionella sp. Results comparing the antibacterial activity of BC and of trichloroethylene at concentrations of 0.3 µg / mL to 250 µg / mL in terms of L. pneumophila survival as described in Example 1 are presented in FIG.1. BC’s anti-Legionella’s activity was superior to that of trichloroethylene at each tested concentration. The antibiotic activity of each of BC, thymol, and trichloroethylene against L. pneumophila were then compared. A concentration range from 0.156 µg / mL to 20 µg / mL was utilized to determine the minimum inhibitory concentration (MIC) for BC, and 1.56 µg / mL to 200 µg / mL was utilized for thymol and trichloroethylene. Results obtained for each of BC and thymol and were compared with trichloroethylene and presented in FIG.2. BC and thymol were found to be highly active against L. pneumophila with respective MICs of < 1 µg / mL and 6 µg / mL, compared to trichloroethylene (MIC = 182 µg / mL). BC’s antibacterial activity was also tested against gram-positive bacteria and additional gram-negative bacteria. The bacterial concentration was 3.5×105CFU / mL and concentrations of BC ranging between 0.8 µg / mL and 100 µg / mL were used (Table II, below). Of note, BC was not active against most gram-negative strains tested. Table II: Antibiotic activity of balsacone C against different gram-positive and gram-negative bacteria Antibacterial activity of balsacone C Bacteria taxa Strain Gram MIC (mg / L) Staphylococcus aureus ATCC 25923 + 3.4 ± 0.7 Methicillin-resistant S. aureus 08-U-0222 + (MRSA) 3.5 ± 0.5 Enterococcus faecalis ERV + 10.9 ± 0.8 Listeria monocytogenes B8222880 + 20 ± 3 Staphylococcus epidermidis B9030482 + 27 ± 2 Streptococcus uberis CL + 10.1 ± 0.7 Burkholderia cepacia C6101997 - 32 ± 2 Enterobacter aerogenes C3032834 - >100 Enterobacter cloacae B9040334 - >100 Escherichia coli ATCC 25922 - >100 Klebsiella pneumonia B8302928 - >100 Salmonella typhimurium C6162763 - >100 Data are representative of three different experiments. Main ± standard deviation, n = 3. MIC is defined as the lowest concentration able to inhibit 100% of bacterial growth. EXAMPLE 4: Antibiofilm activity of balsacone C against L. pneumophila Balsacone C was first tested at concentrations of 1, 2, 4, 8, and 16 µg / mL directly on the biofilms as described in Example 1. Biofilm activity was tested using a 12-well plate assay. L. pneumophila was cultured for 72 hours at a concentration of 109CFU / mL, wells were washed with PBS to retain only the bacteria present in the biofilm. Compounds were tested at various concentrations directly on the biofilms. After a 24-hour incubation at 37°C with the compounds, resazurin was added to measure bacterial viability using fluorescence readings. Results are presented in FIG.3. The simultaneous addition of BC and L. pneumophila was also tested to determine the compound’s activity directly on biofilm formation (FIG.4). EXAMPLE 5: Balsacone C stability over time against L. pneumophila The stability of balsacone C antibacterial activity against L. pneumophila at 2.5 x 106CFU / ml was tested over periods of 15 minutes to 7 days, as described in Example 1. A concentration range from 0.156 µg / mL to 20 µg / mL was utilized to determine the minimum inhibitory concentration (MIC). Results are presented in FIG.5 and show that the incubation time of BC in the presence of L. pneumophila increases its antibacterial activity, with activity being rapidly achieved (15 minutes), but doubling after 3 hours of exposure. The results obtained also demonstrate that BC remains active after 7 days in water, although the minimum inhibitory concentration (MIC) is slightly higher, and it subsequently degrades into non-toxic compounds, suggesting that BC will not remain for a long time in the environment. It should be noted that stability tests in water require Legionella concentrations 250 times higher, which explains the higher MIC values compared to usual values. EXAMPLE 6: Balsacone C stability depending on pH against L. pneumophila The stability of balsacone C antibacterial activity against L. pneumophila at 2.5 x 106CFU / ml was also tested at various pHs, namely 6, 7, 8, 9, and 10 for an incubation time of three hours as described in Example 1. Results are presented in FIG.6 and show that increasing the pH from 7 to 10 enhances the antibacterial activity of BC against L. pneumophila. It should be noted that stability tests in water require Legionella concentrations 250 times higher, which explains the higher MIC values compared to usual values. EXAMPLE 7: Environmental toxicity of dihydrochalcones and derivatives The environmental toxicity of BC was tested against small planktonic crustaceans D. magna, luminescent bacteria V. fischeri, and algae Raphidocelis subcapitata and compared with those of trichloroethylene (chlorine) as described in Example 1. The environmental toxicity of DHC-C was tested against Daphnia magna as described in Example 1. A concentration range from 0.1 to 10 µg / mL of DHC-C was utilized to determine the minimum inhibitory concentration (MIC). For all tested organisms, MTC of BC (MTC between 1.7 and 5.7 µg / mL) was over the active antimicrobial concentration against L. pneumophila (MIC = 0.6 µg / mL), while that of trichloroethylene (chlorine) was not. Results are presented in FIGs.7A-B. These result shows that use of BC instead of chlorine or in addition to a lower concentration of chlorine can reduce the overall environmental impact of industrial activities. DHC-C’s MTC of 5 µg / mL was over the active antimicrobial concentration of DHC-C against L. pneumophila (MIC = 1.4 µg / mL) EXAMPLE 8: Mechanism of action of balsacone C on Legionella To confirm membrane damage with BC, L. pneumophila was observed with scanning electron microscopy (SEM) at 20000 X magnification, as described in Example 1. SEM images of samples having a 3-h exposure to BC atconcentration of 4 µg / mL (2 x MIC obtain with 40 x106CFU) were analyzed. Damage induced by antibacterial agentssuch as BC can provoke the release of intracellular components as proteins and nucleic acids. Treated cells showed important leakage on the cell membrane when nucleic acid and protein released from L. pneumophila was measured compared to control as shown in FIG.8. EXAMPLE 9: Antibacterial activity of balsacone C in water from cooling towers with a high concentration of Legionella. Cooling tower waters can contain contaminants that could influence antibacterial activity of compounds and extracts of the present disclosure. To determine whether balsacone C remained active against L. pneumophila in these conditions, cooling towers with a high concentration of Legionella (2.5 x 106CFU / mL) were treated with balsacone C in 95% ethanol. A concentration range of BC from 0.156 to 20 µg / mL was utilized to determine the minimum inhibitory concentration (MIC). Microdilution assay was performed as described in Evaluation of antibacterial activity in Example 1, however water from cooling system was used instead of BYE broth. Waters were collected directly from cooling towers from different origins (see Table III below). The pH of collected waters was found to be around 8 (see Table III below), a pH known to be optimal for Legionella growth. The results show that the formulation (BC diluted in ethanol 95%) remained highly active compared to the activity achieved in pH 8 water alone (negative control; MIC = 4.59 ± 0.10 µg / mL), showing that BC is effective in cooling towers water conditions comprising suspended matter and minerals. The very high concentration of Legionella used explains the higher MIC achieved. Table III. Antibacterial activity of BC against Legionella in water towers F 9.14 9.1±0.8 Fe Negative control 8 4.6±0.1 EXAMPLE 10: Antibacterial activity of combination of balsacone C and thymol against L. pneumophila Synergy tests were conducted between BC and thymol as described in Example 1. Results show that the combination of BC with thymol is synergistic. Specifically, the MIC obtained for BC used alone was 0.68 µg / mL, that for thymol used alone was 23.6 µg / mL whereas that for the combination of BC with thymol at a concentration of 3 µg / mL was 0.43 µg / mL (FIG.9). This represents a significant activity gain of 36% vs. BC alone. EXAMPLE 11: Anti-amoebic activity of combination of compounds alone or in combination with thymol The anti-amoebic activity of DHC-C, balsacone C, thymol and of a combination of DHC-C and thymol as compared to chlorine is determined as described in Example 1. Results are presented in Table IV below. Table IV. Anti-amoebic Activity µg EXAMPLE 12: Corrosion inhibiting effect of combination of balsacone C and thymol on pipes of the cooling system The anti-corrosion effect of compounds of the disclosure (e.g., DHC-C, balsacone C), alone or in combination with thymol, is assessed by measuring tubing weight loss, electrochemical impedance spectroscopy for measuring the corrosion rate, and SEM is determined as described in Example 1. EXAMPLE 13: Production and characterization of Monarda fistulosa essential oils M. fistulosa essential oils were produced as described in Example 1. The M. fistulosa essential oil obtained was yellow with a pleasant fresh carvacrol scent, showing little resemblance to oregano essential oil. The extraction yield obtained was between 0.44% and 0.51% (w / w) (see Table V below). The refractive index and the density measured using a pycnometer are also shown in Table V below. Table V. Density, refractive index and yield (%) of Monarda essential oils Second chemotype First chemotype Density (g / mL) 0.913* 0.900* Refractive index 1.4964* 1.5024* Yield (%) 0.44 0.51 *Data are mean of three different measures. Evaluation of EO composition from two M. fistulosa chemotypes The chemical composition of M. fistulosa essential oils was analysed by gas chromatography – flame ionisation detector (GC-FID) and gas chromatography – mass spectrometry (GC-MS), as detailed in Example 1. The analysis of the whole plant (stem and flower) essential oils of the Monarda chemical composition was conducted. Table VI presents at least 14 constituents (≥ 0.5%) of the essential oils. The first chemotype was mainly composed by phenolic compound carvacrol (56.11%), thymol (4.28%), and common monoterpenes γ-terpinene (15.17%) and p-cymene (5.39%). The second chemotype was mainly composed by geraniol (90.16%). Table VI. Composition of Monarda fistulosa EO Identified KIα-α-1- 6- α- p- γ- β- cis- β- Germacrene-D MS, RI 0.71 1.18 Total 96.92 97.161MS: Identification by GC-MS; RI: Validation by retention time in comparison with literature data EXAMPLE 14: Evaluation of anti-Legionella activity of chemotypes of M. fistulosa The antibacterial activity of concentrations of 3.9 to 250 µg / mL of two chemotypes of M. fistulosa, as described in Table VI above, was tested against L. pneumophila as described in Example 1. Both chemotypes were shown to display useful antibacterial activity. Results are presented in FIG.10. EXAMPLE 15: Evaluation of anti-Legionella activity of essential oils and compounds of M. fistulosa against various Legionella species The anti-Legionella properties of M. fistulosa essential oils and major constituents thereof, namely thymol, carvacrol, and geraniol, were also evaluated against four strains of Legionella species (L. pneumophila, L. bozemanii, L. dumofii, and L. anisa), as described in Example 1. All samples were active against all four strains with MIC90ranging from 7 to 81 µg / mL (Table VII, below). The activity appeared derived principally from main compounds thymol, carvacrol, and geraniol with MIC90ranging from 1.63 to 37 µg / mL. Table VII. Antibacterial activity of M. fistulosa chemotypes and their major constituents against L. pneumophila, L. bozemanii, L. d Com M. fi M. fi Thy Carv Gera Trichloroethylene 110 ± 38 96 ± 12 281 ± 23 248 ± 1 ND: Not determined The anti-Legionella properties of major constituents of Monarda, namely thymol, carvacrol, and geraniol, were then also evaluated against different concentrations of L pneumophila and are presented in Table VIII, below. Tabl tions (CFU / mL) µg µg µg 1.25 x 105< 2 3 ± 1 11 ± 2 EXAMPLE 16: Environmental toxicity of thymol, carvacrol, and geraniol The environmental toxicities of M. fistulosa essential oil, prepared as described in Example 1, and of their constituents, thymol, carvacrol, and geraniol, were tested against human cell WS1 fibroblasts, V. fischeri, R. subcapitata, and D. magna compared with those of trichloroethylene (chlorine). Results are presented in Table IX, below. Table IX. Maximal tolerated toxicity (MTC) of M. fistulosa essential oil and of selected compounds against human cell WS1 Com First Seco Thym Carv Gera Trichloroethylene 34 ± 2 0.11 ± 0.02 13.4 ± 22.3 6.1 ± 0.3 ND: Not determined These results show that all tested Monarda essential oil samples containing high phenolic constituents such as carvacrol, thymol, and geraniol may be used as a source of bioactive essential oil against Legionella. EXAMPLE 17: Formulation of dihydrochalcone and derivatives thereof for use in treatment of water distribution system 95% ethanol was shown to allow solubilization and good dispersion of in water. Both BC and DHC-C have very high solubility in ethanol, allowing preparation of concentrated stocks that can later be diluted in water systems. Ethanol is advantageously considered as a green solvent. EXAMPLE 18: Antibacterial activity of Populus balsamifera crude extract and fractions thereof The antibiotic activity of the crude extract, balsacones-rich fraction, and fractions P1-P6 obtained as described in Example 1 under the header Extraction and fractionation of P. balsamifera buds on L. pneumophila was tested and compared with those of chloramphenicol and gentamicin. Results are presented in Table X below. Table X: Antibiotic activity of Populus balsamifera crude extract and fractions thereof Sam Cru Bals Fra Fra Fra Fra Fra Fra Chl Gentamicin 1.9 ± 0.3 EXAMPLE 19: Structure and characterization of dihydrochalcone analog 2',4',6'-trihydroxy-3'-(3'',4''- dimethoxycinnamyl)-dihydrochalcone (Analog 1) Analog 1 was synthesized following the scheme presented below using 3,4-dimethoxycinnamyl alcohol and 2',4',6'- O PTSA OH CH O O3CN OH O OH O 1H NMR (500 MHz, (CD3)2CO): δ 7.31 – 7.23 (m, 4H), 7.18 – 7.12 (m, 1H) 6.97 (s, 1H), 6.83 (s, 2H), 6.34 (d, J = 15.8 Hz, 1H), 6.22 (dt, J = 6.5, 15.7 Hz, 1H), 6.12 (s, 1H), 3.79 (s, 3H), 3.76 (s, 3H), 3.45 – 3.38 (m, 4H), 2.98 (t, J = 7.8 Hz, 2H); 13C NMR (151 MHz, (CD3)2CO) δ 205.3, 163.1, 161.1, 150.4, 149.6, 143.0, 132.1, 130.1, 129.3, 129.2, 127.3, 126.6, 119.6, 112.7, 109.9, 106.3, 105.0, 95.1, 56.1, 56.0, 46.5, 31.5, 26.2. Analog 1. EXAMPLE 20: Antibacterial activity of dihydrochalcone analogs Analog 1 was tested against L. pneumophila and S. aureus as described in Example 1. Results are presented in Table XI below. Table XI: Antibacterial Activity of Analog 1 Pre Dihy alcoholaConcentration inhibiting 90% of bacterial proliferation after 24 hours EXAMPLE 21: Toxicity on Daphnia magna The environmental toxicity of the compounds was tested against Daphnia magna as described in Example 1. The tests were conducted in a volume of 1 L of water containing 20 Daphnia magna for 48 hours. Chlorine, dihydrochalcone C, thymol, a combination thymol and dihydrochalcone C, and carvacrol were tested at different concentrations to study the mortality threshold of the Daphnia. For chlorine, dilutions were made from a stock solution at 1000 mg / mL of chlorine in water.20 µL of this solution were added to a volume of 1 L. For dihydrochalcone C, dilutions presented in Table XII below were made from a stock solution at 1000 mg / mL of dihydrochalcone C in ethanol.20 µL of this solution were added to a volume of 1 L. For thymol, dilutions presented in the Table XII below were made from a stock solution at 500 mg / mL of thymol in ethanol.200 µL of this solution were added to a volume of 1 L. For the combination of thymol and dihydrochalcone C, the thymol dilutions used were those described immediately above and presented in the Table XII below. The dihydrochalcone C dilutions presented in the Table XII below were made from a stock solution at 1000 mg / mL of dihydrochalcone C in ethanol.200 µL of thymol solution and 200 µL of dihydrochalcone C solution were added to a volume of 1 L. For carvacrol, dilutions were made from a stock solution at 500 mg / mL of carvacrol in ethanol.40 µL of this carvacrol solution were added to a volume of 1 L. Table XII: Tested dilution concentrations 6.25%0.625 1.256.251.5625 1.25Results of toxicity of chlorine, dihydrochalcone C, thymol, a combination thymol and dihydrochalcone C, and carvacrol on Daphnia magna are presented in FIGs.11A-E, respectively. EXAMPLE 22: In vitro antibacterial activity of molecules in water from cooling towers with a high concentration of Legionella pneumophila The antibacterial activity of compounds of the present disclosure have been tested in vitro on water from cooling towers as described in Example 1. Results are presented in XIII below. Table Sam Chl Bals Dihy Thy DHC-C + thymol N.A. 1.1 ± 0.1 N.A. not available Chlorine had a 90% inhibitory activity in vitro on L. pneumophila at 69 µg / mL. In comparison, balsacone C and dihydrochalcone C were very active with an IC90of 0.68 and 1.35 µg / mL, respectively. EXAMPLE 23: Evaluation of the efficacy of combination (DHC-C+thymol) in a pilot-scale cooling tower model under controlled NC2 laboratory conditions The efficacy of a combination DHC-C and thymol was tested in a pilot-scale cooling tower model as described in Example 1. The results presented in FIG. 12 show that the formulation containing DHC-C and thymol allows for complete elimination of Legionella pneumophila present in the water tower (>50000 CFU / L) after 15 minutes and 60 minutes of treatments. To validate the safety of the diluent used (EtOH), an initial test was conducted with ethanol at 1 ppm. No significant variation in bacterial concentration was observed after 15 minutes (152200 CFU / L), confirming that ethanol does not affect bacterial viability at the concentration used. A chlorine shock treatment (10 ppm) was applied as positive control. This treatment resulted in a complete reduction of the bacterial population after 15 minutes (85600 CFU / L), a 100% decrease, demonstrating the maximum expected efficacy under the experimental conditions. The scope of the claims should not be limited by the embodiments set forth in the examples but should be given the broadest interpretation consistent with the description as a whole.

[0004] References Alsarraf, J., Bilodeau, J.-F., Legault, J., Simard, F., Pichette, A., Exploring the biomass-derived chemical space emerging from natural dihydrochalcones through the single-step hemisynthesis of antibacterial balsacones. ACS Sustain. Chem. Eng.2020, 8, 6194-6199. Anwar, A., Ting, E. L. S., Anwar, A., ul Ain, N., Faizi, S., Shah, M. R., Khan, N. A., Siddiqui, R., Antiamoebic activity of plant-based natural products and their conjugated silver nanoparticles against Acanthamoeba castellanii (ATCC 50492). AMB Express, 2020, 10, 24. Banfi, E., Scialino, G., and Monti-Bragadin, C., Development of a microdilution method to evaluate Mycobacterium tuberculosis drug susceptibility. J. Antimicrob. Chemother., 2003, 52, 796–800. Bartie, C., Venter, S. N., Nel, L. H., Identification methods for Legionella from environmental samples. Water Res., 2003, 37, 1362–1370. De Sousa, P. J., De Araujo Torres, R., De Azeredo, G. A., Figueiredo, R. C. B., Da Silva Vasconcelos, M. A., De Souza, E. L., Carvacrol and 1,8-cineole alone or in combination at sublethal concentrations induce changes in the cell morphology and membrane permeability of Pseudomonas fluorescens in a vegetable-based broth. Int. J. Food Microbiol., 2012, 158, 9–13. Ebadollahi, A., Ziaee, M., and Palla, F., Essential oils extracted from different species of the Lamiaceae plant family as prospective bioagents against several detrimental pests. Molecules, 2020, 25, 1–15. Edagawa, A., Kimura, A., Kawabuchi-Kurata, T., Adachi, S., Furuhata, K., Miyamoto, H., Investigation of legionella contamination in bath water samples by culture, amoebic co-culture, and real-time quantitative PCR methods. Int. J. Environ. Res. Public Health, 2015, 12, 13118–13130. Lavoie, S., Legault, J., Simard, F., Chiasson, É., Pichette, A., New antibacterial dihydrochalcone derivatives from buds of Populus balsamifera. Tetrahedron Lett.2013, 54, 1631-1633. Nomura, H., Isshiki, Y., Sakuda, K., Sakuma, K., and Kondo, S., Effects of oakmoss and its components on biofilm formation of Legionella pneumophila. Biol. Pharm. Bull., 2013, 36, 833–837. Selvaraj, A., Jayasree, T., Valliammai, A., and Pandian, S. K., Myrtenol attenuates MRSA biofilm and virulence by suppressing sarA expression dynamism. Front. Microbiol., 2019, 10, 1–15. Simard F, Legault J, Lavoie S et Pichette A. Balsacones D-I, dihydrocinnamoyl flavans from Populus balsamifera buds. Phytochem, 2014, 100 : 141-149. Simard F, Gauthier C, Legault J, Lavoie S, Mshvildadze V et Pichette A. Structure elucidation of anti-methicillin resistant Staphylococcus aureus (MRSA) flavonoids from balsam poplar buds. BMCL, 2016, 24, 4188-4198. Virto, R., P. Man, S. Condon, and J. Raso.2005. Membrane damage and microbial inactivation by chlorine in the absence and presence of a chlorine-demanding substrate. Applied and Environmental Microbiology 71:5022– 5028.

Claims

AMENDED CLAIMS received by the International Bureau on 19 January 2026 (19.01.2026)1. Use of a compound of Formula (I)wherein:- one of A and B is H and the other is- G is R2and E is H orE is -CH2-E’ and G and E’ are both single carbon atoms, said carbon atoms being directly linked together by a single bond, G being substituted byand E’ being substituted by R6;- Reis H or OR1 :- Rfis H or OR8, wherein R8is H or C1-C12alkyl;- each of R1, R2, R3, and R4is independently H or C1-C12alkyl; and- each of R5, R6, and R10is independently H, OH, C1-C12alkyl, or C1-C12alkoxy, or a salt, ester, or solvate thereof, for preventing or reducing Legionella growth.

2. The use of claim 1 , wherein:(i) A isand B is H;(ii) one or more of R2, R3, and R4is independently H, or C1-C4alkyl;(iii) one or more of R5, R6and R10, preferably one or more of R5and R10, is independently H, OH, C1-C4alkyl or C1-C4alkoxy; or(iv) a combination of at least two of (i) to (iv).

3. The use of claim 1 or 2, wherein:(i) one or more of R2, R3, and R4is independently H, or C1-C3alkyl;(ii) one or more of R5, R6and R10, preferably one or more of R5and R10, is independently H, OH, C1-C3alkyl or C1-C3alkoxy; or(iii) a combination of (i) and (ii).

4. The use of any one of claims 1 to 3, wherein:(i) one or more of R2, R3, and R4is independently H, or CH3;(ii) one or more of R5, R6and R10, preferably one or more of R5and R10, is independently H, OH, CH3or - OCH3; or(iii) a combination of (i) and (ii).

5. The use of any one of claims 1 to 4, wherein 0 is R2.

6. The use of any one of claims 1 to 5, wherein:(i) E is H;(ii) R5independently H, OH, or -OCH3;(iii) R10is H; or(iv) a combination of at least two of (i) to (iii).

7. The use of any one of claims 1 to 5, wherein:(i) E is, wherein Rfis H or OR8, wherein R8is H or C1-C4alkyl and wherein Reis H or OR1;(ii) R1is H, or C1-C4alkyl;(iii) R5is H, OH, or C1-C4alkoxy;(iv) R10 is H; or(v) a combination of at least two of (i) to (iv).

8. The use of claim 7, wherein:(i) R8is H or C1-C3alkyl;(ii) R1is H or C1-C3alkyl;(Hi) R5is H, OH, or C1-C3alkoxy; or(iv) a combination of at least two of (i) to (iii).

9. The use of claim 7 or 8, wherein:(i) R8is H or CH3, preferably CH3;(ii) R1is H or CH3;(iii) R5is H, OH, or -OCH3; or(iv) a combination of at least two of (i) to (iii).

10. The use of any one of claims 1 to 9, wherein R5is H or OH.

11. The use of claim 1, wherein the compound is of Formula (II)wherein R7is H orwherein Rfis H or OR8, wherein R1is as defined in anyone of claims 1 and 7-9, each of R2, R3, and R4are independently as defined in any one of claims 1-4, R5is as defined in any one of claims 1 and 6-10, R8is as defined in any one of claims 1 and 7 to 9, and R10is as defined in any one of claims 1 , 6 and 7, or a salt, ester, or solvate thereof.

12. The use of claim 1, wherein the compound is of Formula (III) or (IV)wherein Rfis H or OR8, wherein R1is as defined in anyone of claims 1 and 7-9, each of R2, R3, and R4are independently as defined in any one of claims 1-4, R5is as defined in any one of claims 1 and 6-10, R8is as defined in any one of claims 1 and 7 to 9, and R10is as defined in any one of claims 1 , 6 and 7, or a salt, ester, or solvate thereof.

13. The use of claim 1 , wherein the compound is, or a salt, ester, or solvate thereof.

14. Use of a Populus balsamifera extract for preventing or reducing Legionella growth, comprising a compound defined in any one of claims 1 to 13.

15. The use of any one of claims 1 to 14, wherein the Legionella is Legionella pneumophila.

16. The use of any one of claims 1 to 15, further comprising (i) a Monarda oil extract or fraction thereof comprising thymol, carvacrol, and / or geraniol; (ii) thymol, carvacrol, and / or geraniol; or (iii) a combination of (i) and (ii).

17. The use of claim 16, wherein the monarda is Monarda fistulosa.

18. The use of claim 16 or 17, wherein the use comprises the Monarda oil extract or fraction thereof or thymol.

19. The use of any one of claims 1 to 18, wherein the use is for preventing or reducing Legionella growth in water circulation system.

20. The use of claim 18, wherein the water circulation system is a cooling water tower.

21. Compound of formula , or asalt, ester, or solvate thereof.

22. Composition comprising the compound, salt, ester, or solvate thereof defined in claim 21 , and at least one carrier.

23. Kit or composition comprising (a) the compound as defined in any one of claims 1 to 13 or 21 , the extract defined in claim 14 orthe composition defined in claim 22; and (b) (i) a Monarda oil extract or fraction thereof comprising thymol, carvacrol, and / or geraniol; (ii) thymol, carvacrol, and / or geraniol; (iii) ethanol; or (iv) a combination of at least two of (i) to (iii).

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