Natural antifungal compounds

Abstract

The invention relates to the use of kahalalide-type depsipeptide compounds of formulae I and / or II, obtained from the green alga Pedobesia sp., for controlling a broad spectrum of fungal plant pathogens. The invention also encompasses fungicidal compositions comprising said compounds with a phytologically acceptable carrier, a process for their preparation from Pedobesia biomass, and their use for the preparation of a medicament for treating mycosis such as that caused by Candida albicans or Trichophyton rubrum.

Description

[0001] NATURAL ANTIFUNGAL COMPOUNDS

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to novel fungicidal uses and compositions. More particularly, it relates to the use of compounds of formula I and / or formula II, which are kahalalide-type depsipeptides, for controlling specific fungal plant pathogens, as well as to fungicidal compositions comprising said compounds, and to processes for their preparation from Pedobesia algae.

[0004] The compounds of the invention exhibit a potent and selective antifungal effect against a defined group of plant-pathogenic fungi, such as but not limited to the fungal families Mucoraceae, Apiosporaceae, Botryosphaeriacae, Nectriaceae, Sclerotiniaceae, Pleosporaceae, Aspergillaceae, Cladosporiaceae, Trichosphaeriaceae, Dipodascaceae, Didymellaceae and Trichocomaceae; more specifically against Mucor circinelloides, Nigrospora sphaerica, Botryosphaeria dothidea, Fusarium solani, Fusarium oxysporum, Penicillium digitatum, Lasiodiplodia theobromae, Botrytis cinerea, Alternaria radicina, Penicillium italicum, Fusarium graminearum, Cladosporium cladosporioides, Plectosphaerella cucumerina, Apiospora montagnei, Phoma sp., Acrostalagmus luteoalbus, Aspergillus niger and Geotrichum candidum.

[0005] Human population is increasing each year and is about to reach 8.6 billion by 2030. To maintain high levels of food production, effective control of plant fungal diseases is essential. While chemical fungicides offer high efficacy, their negative impact on the environment and human health is increasingly unacceptable. Biological alternatives, though environmentally safer, often suffer from lower efficacy (less than 60% compared to synthetic chemicals) and higher costs, limiting their widespread adoption.

[0006] There remains a critical and unmet need for novel fungicidal agents that combine high efficacy, environmental compatibility, and scalability of production at reasonable cost.

[0007] State of the Art on Kahalalide-Type Depsipeptides

[0008] The kahalalides are a well-known family of marine-derived depsipeptides, first isolated from sacoglossan mollusks of the genus Elysia (such as E. rufescens) and their algal diet, primarily Bryopsis species (Hamann & Scheuer, J. Am. Chem. Soc. 1993, 115, 5825-5826).

[0009] Subsequent research has identified specific kahalalides, notably Kahalalide F (KF), as possessing broad biological activities. Hamann & Scheuer first reported that KF exhibited invitro antifungal activity against human-pathogenic fungi such as Aspergillus oryzae, Penicillium notatum, and Candida albicans. Later studies, such as that by Peng et al. (J. Agric. Food Chem. 2003, 51, 2246-2252), screened KF against a panel of phytopathogenic fungi (Stagonospora nodorum, Fusarium culmorum, Phytophthora infestans, Pyricularia grisea, and Puccinia recondita), reporting variable inhibition percentages at a standard concentration of 10 ppm.

[0010] Further structure-activity relationship studies led to the development of synthetic analogs of KF. Shilabin & Hamann (Bioorg. Med. Chem. 2011, 19, 6628-6632) reported N-alkylated analogs of KF showing improved in vitro antifungal activity against human opportunistic fungi (C. albicans, Cryptococcus neoformans, Aspergillus fumigatus). However, this study does not disclose or suggest the efficacy of these compounds against a defined spectrum of agronomically significant plant pathogens, nor their practical application in agriculture.

[0011] Most recently, Yamazaki et al. (J. Nat. Prod. 2023, 86, 2539-2545) identified and fully characterized two new kahalalide analogues, designated Kahalalide Z3 (KZ3) and Z4 (KZ4), from a Bryopsis sp. alga. This publication confirms the structure of these compounds, which correspond to the compounds of formula I and II of the present application, and discusses their biosynthetic origin. However, Yamazaki et al. is silent on any fungicidal utility, let alone a specific and effective use against plant fungal diseases.

[0012] Persisting Technical Problems and the Objective of the Present Invention

[0013] Despite the known existence of kahalalide compounds and their general antifungal potential, the prior art leaves several key problems unsolved:

[0014] 1. Lack of a defined agricultural utility: The prior art fails to identify a specific and effective spectrum of plant-pathogenic fungi against which these compounds can be reliably and potently used. Activity against human pathogens or in generic screens does not predict efficacy against the complex and diverse fungi that devastate crops.

[0015] 2. Scalability and source limitations: The traditional sources of kahalalides — rare mollusks or Bryopsis algae, are unsuitable for large-scale, cost-effective production necessary for agricultural applications. The chemical synthesis of these complex depsipeptides remains industrially non-viable.

[0016] 3. Formulation and practical application gap: There is no teaching in the prior art on how to formulate these depsipeptides into stable, phytologically acceptable compositions suitable for field application, nor on effective application methods for plant protection.Therefore, the technical problem addressed by the present invention is not merely to provide another kahalalide compound, but to provide:

[0017] • A targeted and effective fungicidal use of specific kahalalide-type compounds (formulae l / ll) against a defined and agronomically relevant group of plant fungal pathogens, demonstrating superior and unpredictable efficacy.

[0018] • A scalable and practical source for obtaining these active compounds.

[0019] • Ready-to-use fungicidal compositions and practical methods for protecting plants.

[0020] The present invention surprisingly found that compounds of formulae I and II, which can be advantageously obtained from the green alga Pedobesia sp., exhibit potent and broadspectrum fungicidal activity against a specific panel of plant pathogens, as demonstrated in the examples below. This provides a complete and industrially applicable solution to the aforementioned problems.

[0021] BRIEF DESCRIPTION OF THE INVENTION

[0022] While prior art such as the seminal work by Hamann & Scheuer (J. Am. Chem. Soc. 1993), the agricultural screening by Peng et al. (J. Agric. Food Chem. 2003), and the structure-activity study by Shilabin & Hamann (Bioorg. Med. Chem. 2011) discloses that certain kahalalides exhibit general antifungal properties, there is no teaching or reasonable expectation that the specific compounds of formulae I and II would exhibit potent and broad-spectrum activity against the particular panel of agronomically devastating fungi identified herein.

[0023] For example, the prior art does not demonstrate complete inhibition (0.000 cm growth in vitro) against Mucorcircinelloides, Nigrospora sphaerica, Botryosphaeria dothidea, Fusarium solani, Fusarium oxysporum, Penicillium digitatum, Lasiodiplodia theobromae, Botrytis cinerea, Alternaria radicina, Penicillium italicum, Fusarium graminearum, Cladosporium cladosporioides, Plectosphaerella cucumerina, Apiospora montagnei, Phoma sp., Acrostalagmus luteoalbus, Aspergillus niger and Geotrichum candidum (see Table 1).

[0024] Furthermore, the EC50values obtained for the purified compounds (Example 6, Figure 8) against key pathogens such as Penicillium expansum (5.14 mg / L) and Fusarium oxysporum (36.69 mg / L) demonstrate a level of potency that is not predictable from the generic antifungal screening reported in these earlier studies. The activity against Penicillium expansum, a major post-harvest pathogen, further demonstrates the utility of the invention for storage protection.Moreover, the prior art does not address the critical agronomic problem of scalability. The present invention solves this by providing a novel and scalable biological source (Pedobesia sp.) for producing these active compounds, enabling their practical use in agriculture — an advantage not contemplated in the earlier kahalalide literature or in the structural study by Yamazaki et al.

[0025] The recent publication by Yamazaki et al. (J. Nat. Prod. 2023, 86, 2539-2545) identifies and characterizes the structures of compounds designated Kahalalide Z3 (KZ3) and Z4 (KZ4), which correspond to the compounds of formulae I and II of the present invention. However, Yamazaki et al. is entirely silent on any fungicidal utility of these compounds. There is no disclosure, suggestion, or data in that publication regarding the use of KZ3 or KZ4 for controlling fungal pathogens, let alone their specific and potent efficacy against the defined panel of plant-pathogenic fungi claimed herein. Yamazaki et al. focuses solely on structural elucidation, biosynthetic gene cluster analysis, and taxonomic origin, providing no enabling teaching for agricultural application. Therefore, the present invention provides a novel and non-obvious technical application of these compounds that is not anticipated by Yamazaki et al.

[0026] In view of the limitations of the prior art, one aim of the present invention is to provide a targeted fungicidal solution that is effective, scalable, and environmentally compatible for use in agriculture.

[0027] More specifically, the invention provides, as a first aspect, the use of compounds of formula I and / or formula II:

[0028]

[0029] Formula I

[0030]

[0031] Formula II,

[0032] or isomers, enantiomers, or salts thereof, for controlling fungal pathogens in plants, wherein the fungal pathogen is selected from the group consisting of Mucor circinelloides, Nigrospora sphaerica, Botryosphaeria dothidea, Fusarium solani, Fusarium oxysporum, Penicillium digitatum, Lasiodiplodia theobromae, Botrytis cinerea, Alternaria radicina, Penicillium italicum, Fusarium graminearum, Cladosporium cladosporioides, Plectosphaerella cucumerina, Apiospora montagnei, Phoma sp., Acrostalagmus luteoalbus, Aspergillus niger and Geotrichum candidum.

[0033] A second aspect of the invention relates to a fungicidal composition comprising a compound of formula I and / or formula II, or isomers, enantiomers, or salts thereof, together with a phytologically acceptable carrier or diluent. Preferably, this composition further comprises at least one additional agrochemical agent selected from fungicides, insecticides, herbicides, or fertilizers.

[0034] A third aspect of the invention provides a process for preparing said fungicidal composition. The process comprises extracting biomass of the green alga Pedobesia sp. with a solvent selected from methanol, isopropanol, water, or chloroform, to obtain a crude extract comprising the compounds of formula I and / or II; and optionally formulating said extract or the purified compounds with a phytologically acceptable carrier or diluent.

[0035] A fourth aspect of the invention is a method for controlling fungal pathogens in plants, comprising applying a fungicidally effective amount of the composition according to the second aspect to a plant, plant part, or seed.A fifth aspect of the invention relates to the therapeutic use of the compounds of formula I and / or formula II, or isomers, enantiomers, or salts thereof, for the manufacture of a medicament for preventing or treating mycosis in human or animal patients, particularly mycosis caused by Candida albicans or Trichophyton rubrum.

[0036] Other objects and advantages of the invention will become apparent to those skilled in the art from a review of the ensuing detailed description, which proceeds with reference to the following illustrative drawings, and the attendant claims.

[0037] BRIEF DESCRIPTION OF THE FIGURES

[0038] Figure 1 : shows the percentage of infection by Alternaria radicina at one week on carrots treated with an algal extract from Pedobesia versus untreated ones (control).

[0039] Figure 2: shows the percentage of infection at 2 weeks by Botrytis cinerea on tomatoes when treated with an algal extract from Pedobesia versus not (control).

[0040] Figure 3: shows infection levels of leaf discs by downy mildew evaluated after treatment with various concentrations of algal extract derived from Pedobesia, compared to an untreated control. Following the application of the algal extract, a spore solution of downy mildew (Plasmopara viticola) was sprayed on the same day to assess the effectiveness of the treatments.

[0041] Figure 4: shows infection levels of leaf discs by downy mildew evaluated after treatment with various concentrations of algal extract derived from Pedobesia, compared to an untreated control. Following the application of the algal extract, a spore solution of downy mildew Plasmopara viticola) was sprayed 5 days later to assess the effectiveness of the treatments.

[0042] Figure 5: shows a Phylogenetic tree of Pedobesia sp. The tree is based on the sequencing of the rbcL gene, compared with sequences available in GenBank(NCBI). The species of interest is genetically close to the Spanish Pedobesia lamourouxii strain, suggesting that this species is a European strain.

[0043] Figure 6: shows infection levels of whole vine plants by downy mildew evaluated after treatment with various concentrations of algal extract derived from Pedobesia, compared to an untreated control and a commercial fungicide (Cuprofix). Following the application of the different treatments, a spore solution of downy mildew (Plasmopara viticola) was sprayed on the same day to assess the effectiveness of the treatments.Figure 7: shows infection levels of in vitro leaves by powdery mildew evaluated after treatment with various concentrations of algal extract derived from Pedobesia, compared to an untreated control or commercial fungicide (Thiovit). Following the application of the different treatments, spores of powdery mildew (Erysiphe necato) were applied on the same day to assess the effectiveness of the treatments.

[0044] Figure 8: shows the graphs used to calculate EC50 of the full extract or the purified molecule against 4 different fungi. Each graph shows the growth of the different fungi against the range of extract or molecule concentrations.

[0045] DETAILED DESCRIPTION OF THE INVENTION

[0046] Although methods and materials similar or equivalent to those described herein can be used in the practice ortesting of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. The publications and applications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. In addition, the materials, methods, and examples are illustrative only and are not intended to be limiting.

[0047] In the case of conflict, the present specification, including definitions, will control.

[0048] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in art to which the subject matter herein belongs. As used herein, the following definitions are supplied in order to facilitate the understanding of the present invention.

[0049] The term “comprise” is generally used in the sense of include, that is to say permitting the presence of one or more features or components.

[0050] The legal meaning of the transition language “consisting essentially of’ is well-established in the case law and is generally construed to mean that the composition or formulation (a) necessarily includes the listed ingredients and (b) is open to unlisted ingredients that do not materially affect the basic and novel properties of the composition. Similarly, when “consisting essentially of’ is used in a process claim, the claim requires that the listed steps are performed but also may include unlisted steps that do not affect the basic and material properties of the process. Accordingly, a “consisting essentially of’ claim is typically understood to signal amiddle ground between a closed claim that is written in a “consisting of’ format and, thus, excluding any items not expressly recited in the claim, and an open claim that is written in a “comprising” format such that any unrecited items are not excluded.

[0051] As used in the specification and claims, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise.

[0052] The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent.

[0053] A “fungus” is a eukaryote that digests food externally and absorbs nutrients directly through its cell walls. Most fungi reproduce by spores and have a body (thallus) composed of microscopic tubular cells called hyphae. Fungi are heterotrophs and, like animals, obtain their carbon and energy from other organisms. Some fungi obtain their nutrients from a living host (plant or animal) and are called biotrophs; others obtain their nutrients from dead plants or animals and are called saprotrophs (saprophytes, saprobes). Some fungi infect a living host but kill host cells to obtain their nutrients; these are called necrotrophs.

[0054] “Pathogenic fungi” also referred herein as “fungal pathogens” are fungi that cause disease in plants, humans or other organisms. Approximately 300 fungi are known to be pathogenic to humans. The study of fungi pathogenic to humans is called "medical mycology". Although fungi are eukaryotic, many pathogenic fungi are microorganisms. The study of fungi and other organisms pathogenic to plants is called plant pathology.

[0055] There are thousands of species of plant pathogenic fungi that collectively are responsible for 70% of all known plant diseases. Plant pathogenic fungi are parasites, but not all plant parasitic fungi are pathogens. Plant parasitic fungi obtain nutrients from a living plant host, but the plant host doesn't necessarily exhibit any symptoms. Plant pathogenic fungi are parasites and cause diseases characterized by symptoms.

[0056] “Fungicides” are biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores (defined herein as fungitoxic). A fungistatic inhibits their growth. Fungi can cause serious damages in agriculture, resulting in critical losses of yield, quality, and profit. Fungicides are used both in agriculture and medicine to fight fungal infections in animals or humans. Chemicals used to control oomycetes, which are not fungi, are also referred to asfungicides, as oomycetes use the same mechanisms as fungi to infect plants. Fungicides can either be contact, translaminar or systemic. Contact fungicides are not taken up into the plant tissue and protect only the plant where the spray is deposited. Translaminar fungicides redistribute the fungicide from the upper, sprayed leaf surface to the lower, unsprayed surface. Systemic fungicides are taken up and redistributed through the xylem vessels. Few fungicides move to all parts of a plant. Some are locally systemic, and some move upwardly.

[0057] “Fungistatic” are anti-fungal agents that inhibit the growth of fungus (without killing the fungus). The term fungistatic may be used as both a noun and an adjective. Fungistatics have applications in agriculture, the food industry, the paint industry, and medicine.

[0058] The composition of the invention is fungitoxic and / or fungistatic in plants and can be applied to plant cultures in the field or for in vitro implementation thereof.

[0059] As used herein the term "concentration" refers to a molar concentration, which is the concentration of a substance expressed in terms of molarity. Molar concentration (also called molarity, amount concentration or substance concentration) is a measure of the concentration of a chemical species, in particular of a solute in a solution, in terms of amount of substance per unit volume of solution. The unit for molarity is the number of moles per litre or mol / L.

[0060] Pedobesia is a genus of green algae in the family Derbesiaceae. It was first described from southeaster Australia and has since been reported in various regions, including New Zealand, the Mediterranean, and Japan. Pedobesia belongs to the division Chlorophyta, class Ulvophyceae, and order Bryopsidales. Some known species include Pedobesia clavaeformis, Pedobesia feldmannii, Pedobesia ryukyuensis, Pedobesia simplex, and Pedobesia solieri. These algae are typically found in marine environments. For example, Pedobesia clavaeformis has been observed in New Zealand and southeaster Australia.

[0061] As shown in the Phylogenetic tree of Pedobesia sp. of figure 5, the species of interest is genetically close to the Spanish Pedobesia lamourouxii strain, suggesting that this species is a European strain (Mediterranean Sea).

[0062] “Kahalalides” are a family of marine-derived depsipeptides, first discovered in 1993. These compounds are primarily isolated from sacoglossan mollusks like Elysia rufescens, Elysia ornata, and Elysia grandifolia, which obtain them from their algal diet, specifically Bryopsis species. Kahalalides are cyclic and linear peptides. They include several known compounds such as kahalalides A-F, K, O, and linear peptides G, H, and J.These compounds exhibit a range of biological activities, including antiviral, antimalarial, antifungal, and anticancer properties.

[0063] A first object of the present invention is the use of a composition comprising a compound of formula I and / or formula II:

[0064]

[0065] Formula II,

[0066] or an isomer, enantiomer, or salt thereof, for controlling fungal pathogens in plants.

[0067] In particular, the fungal pathogen to be controlled is selected from the group comprising or consisting of Mucor circinelloides, Nigrospora sphaerica, Botryosphaeria dothidea, Fusarium solani, Fusarium oxysporum, Penicillium digitatum, Penicillium expansum, Lasiodiplodia theobromae, Botrytis cinerea, Alternaria radicina, Penicillium italicum, Fusarium graminearum, Cladosporium cladosporioides, Plectosphaerella cucumerina, Apiospora montagnei, Phomasp., Acrostalagmus luteoalbus, Aspergillus niger and Geotrichum candidum. The efficacy of the composition against this specific and agronomically relevant spectrum of pathogens is demonstrated in the Examples (see Table 1 and Figures 1-4).

[0068] In preferred embodiments, the fungal pathogen to be controlled is selected from the group consisting of Botrytis cinerea, Alternaria radicina, Fusarium oxysporum, Penicillium expansum, Mucor circinelloides, Geotrichum candidum, Aspergillus niger, Plasmopara viticola, Erysiphe necator, and Penicillium digitatum. These species represent agronomically critical pathogens against which the compounds of the invention exhibit particularly potent and well-documented efficacy, as demonstrated in the Examples.

[0069] The compounds for use according to a compound of formulae I and / or II can be advantageously and efficiently obtained from extracts of the green alga Pedobesia sp. This represents a critical technical advance, as Pedobesia is easier to cultivate at large scale compared to traditional kahalalide sources (e.g., rare mollusks or Bryopsis algae). The present invention thus solves a key practical limitation of the prior art by providing a sustainable, scalable, and cost-effective source of these potent fungicidal compounds, enabling their commercial use in agriculture. The extract can be, for example, a methanolic, isopropanolic, aqueous or chloroform extract.

[0070] The composition is preferably applied to a plant, plant part, or seed. Suitable application methods include, but are not limited to, foliar spraying, seed treatment, or soil drenching.

[0071] Surprisingly, the purified compounds of formulae I and II isolated from Pedobesia sp. exhibit a higher specific activity compared to the crude extract, confirming that this algal source provides a concentrated and cost-effective supply of the active principles.

[0072] According to one embodiment of the invention, the composition is applied at a concentration ranging from 5 mg / ml to 50 mg / ml.

[0073] According to another embodiment of the invention, the composition is applied at a concentration of 10 mg / ml to 20 mg / ml for controlling downy mildew Plasmopara viticola) or powdery mildew (Erysiphe necator) in grapevines.

[0074] In further embodiments, the compounds of formula I and / or II exhibit potent fungicidal activity with EC5Ovalues below 100 mg / L against key post-harvest and field pathogens. For instance,the purified molecule shows EC50values of 48.71 mg / L against Geotrichum candidum, 5.14 mg / L against Penicillium expansum, 36.69 mg / L against Fusarium oxysporum, and 52.13 mg / L against Mucor circinelloides (see Example 6 and Figure 8). Moreover, formulated extracts at concentrations of 10-20 mg / ml provide control of grapevine downy mildew and powdery mildew comparable to commercial copper and sulfur fungicides (Examples 4 and 5, Figures 6 and 7).

[0075] Fungicidal compositions:

[0076] A further object of the invention is a fungicidal composition comprising a compound of formula I and / or formula II as defined above, in combination with a phytologically acceptable carrier or diluent. Such carriers or diluents are well-known in the art of agrochemical formulations and are essential for the practical and effective application of the active ingredient in the field.

[0077] In a preferred embodiment, the fungicidal composition further comprises at least one additional agrochemical agent, selected for example from other fungicides, insecticides, herbicides, or fertilizers. Such combinations can provide a broader spectrum of activity or synergistic effects.

[0078] Preferably, the compound of formula I and / or II exhibits an EC50value of less than 100 mg / L against at least one fungal pathogen selected from Geotrichum candidum, Penicillium expansum, Fusarium oxysporum, and Mucor circinelloides.

[0079] Process for preparing the fungicidal composition:

[0080] The present invention also provides a process for preparing the aforementioned fungicidal composition.

[0081] The process comprises:

[0082] a) extracting biomass of Pedobesia sp. with a solvent selected from methanol, isopropanol, water, or chloroform to obtain a crude extract comprising the compound of formula I and / or II; and optionally

[0083] b) mixing the compound of formula I and / or II (either as a crude extract or in purified form) with a phytologically-acceptable carrier or diluent.

[0084] The process may further comprise the step of adding at least one additional fungicide, insecticide, herbicide, or fertilizer to the composition during formulation.Method for controlling fungal pathogens:

[0085] Another object of the invention is a method for controlling fungal pathogens in plants. The method comprises applying a fungicidally effective amount of a fungicidal composition as described above to a plant, plant part, or seed.

[0086] In the context of this method, the fungal pathogen is preferably selected from the specific group comprising or consisting in: Mucor circinelloides, Nigrospora sphaerica, Botryosphaeria dothidea, Fusarium solani, Fusarium oxysporum, Penicillium digitatum, Penicillium expansum, Lasiodiplodia theobromae, Botrytis cinerea, Alternaria radicina, Penicillium italicum, Fusarium graminearum, Cladosporium cladosporioides, Plectosphaerella cucumerina, Apiospora montagnei, Phoma sp., Acrostalagmus luteoalbus, Aspergillus niger and Geotrichum candidum.

[0087] In preferred embodiments, the fungal pathogen to be controlled is selected from the group consisting of Botrytis cinerea, Alternaria radicina, Fusarium oxysporum, Penicillium expansum, Mucor circinelloides, Geotrichum candidum, Aspergillus niger, Plasmopara viticola, Erysiphe necator, and Penicillium digitatum. These species represent agronomically critical pathogens against which the compounds of the invention exhibit particularly potent and well-documented efficacy, as demonstrated in the Examples.

[0088] Therapeutic use:

[0089] A further object of the invention relates to a therapeutic application. Specifically, the invention provides for the use of a compound of formula I and / or formula II as defined above, for the preparation of a medicament for the treatment or prevention of mycosis in humans or animals.

[0090] In a preferred embodiment, the mycosis to be treated is caused by Candida albicans or Trichophyton rubrum.

[0091] The identified compounds or fungicide of the invention present several advantages. They exhibit potent fungicidal activity against a specific and agronomically relevant spectrum of plant pathogens, as demonstrated in the examples (see Table 1). Furthermore, they reveal fungitoxic and / or fungistatic activity against environmental, plant, storage and medical fungal pathogens. Besides, the identified compounds of the invention do not reveal phytotoxicity, are stable in the light and can be freely applied on plants. The composition used in the presentinvention has been shown to extend shelf-life by a minimum of one week for fruits, vegetables and cut flowers infected by fungal pathogens in storage facilities. The composition of the invention is easily applicable with a specific impact on the ripening perishable food and no extra installation cost is required. The composition of the invention is of interest to storage companies (i.e. reducing costs in packaging), the timber industry, gardeners and farmers.

[0092] Thus, the composition or fungicide of the invention is to be used as a fungitoxic and / or as a fungistatic agent in plants. The composition of the invention to be used as a fungicide has shown a large efficacy in treating various plants or plant families (hosts). Indeed, the composition of the invention can be used in treating more than 1400 species of agronomical important crops or plants, including order of Solanales, Rosales, Vitales, Poales etc.

[0093] The composition or fungicide of the invention may be used with any part of a plant during any part of its life cycle, including but not limited to seeds, seedlings, plant cells, plants, or flowers. According to the invention, all plants and plant parts can be treated. By “plants” is meant all plants and plant populations such as desirable and undesirable wild plants, cultivars and plant varieties (whether or not protectable by plant variety or plant breeder's rights). Cultivars and plant varieties can be plants obtained by conventional propagation and breeding methods which can be assisted or supplemented by one or more biotechnological methods such as by use of double haploids, protoplast fusion, random and directed mutagenesis, molecular or genetic markers or by bioengineering and genetic engineering methods. By plant parts is meant all above ground and below ground parts and organs of plants such as shoot, leaf, blossom and root, whereby for example leaves, needles, stems, branches, blossoms, fruiting bodies, fruits and seed as well as roots, corms and rhizomes are listed. Crops and vegetative and generative propagating material, for example cuttings, corms, rhizomes, runners and seeds also belong to plant parts.

[0094] Among the plants that can be protected by the composition or fungicide of the invention, mention may be made of major field crops like corn, soybean, cotton, Brassica oilseeds such as Brassica napus (e.g. canola), Brassica rapa, B.juncea (e.g. mustard) and Brassica carinata, rice, wheat, sugarbeet, sugarcane, oats, rye, barley, millet, triticale, flax, vine and various fruits and vegetables of various botanical taxa such as Rosaceae spp. (for instance pip fruit such as apples and pears, but also stone fruit such as apricots, cherries, almonds and peaches, berry fruits such as strawberries), Ribesioidae spp., Juglandaceae spp., Betulaceae spp., Anacardiaceae spp., Fagaceae spp., Moraceae spp., Oleaceae spp., Actinidaceae spp., Lauraceae spp., Musaceae spp. (for instance banana trees and plantings), Rubiaceae spp.(for instance coffee), Theaceae spp., Sterculiceae spp., Rutaceae spp. (for instance lemons, oranges and grapefruit); Solanaceae spp. (for instance tomatoes, potatoes, peppers, eggplant), Liliaceae spp., Compositiae spp. (for instance lettuce, artichoke and chicory -including root chicory, endive or common chicory), Umbelliferae spp. (for instance carrot, parsley, celery and celeriac), Cucurbitaceae spp. (for instance cucumber - including pickling cucumber, squash, watermelon, gourds and melons), Alliaceae spp. (for instance onions and leek), Cruciferae spp. (for instance white cabbage, red cabbage, broccoli, cauliflower, brussel sprouts, pak choi, kohlrabi, radish, horseradish, cress, Chinese cabbage), Leguminosae spp. (for instance peanuts, peas and beans beans - such as climbing beans and broad beans), Chenopodiaceae spp. (for instance mangold, spinach beet, spinach, beetroots), Malvaceae spp. (for instance okra), Asparagaceae spp. (for instance asparagus); horticultural and forest crops; ornamental plants and flowers including cut flowers; grass i.e. golf fields, turf, as well as genetically modified homologues of these crops.

[0095] For example, the composition or fungicide of the present invention can be used for controlling common fungal diseases such as powdery mildew, rust, downy mildew, and anthracnose on field crops, fruit trees and vegetables.

[0096] In addition, the composition or fungicide of the invention can be used for the treatment of resistant diseases, mainly for the control of wheat powdery mildew, rice blast, rice smut, melon powdery mildew, tomato powdery mildew, apple rust, watermelon Anthracnose and flower powdery mildew. Besides the composition has very good control effects against cucumber downy mildew, grape downy mildew, scab, anthrax, and spotted defoliation.

[0097] In a particular embodiment of the invention, the composition or fungicide of the invention is to be used in the treatment or prevention of tree diseases, caused by fungal pathogens e.g. panama disease of banana, ash dieback.

[0098] Besides, the composition or fungicide of the invention can be used directly in the field in plant cultures but also in vitro for example for implementation in plant cultures. Surprisingly, the composition according to the present invention to be used as a fungicide has been found extremely active on all the fungal pathogens tested.

[0099] In particular, the composition or fungicide of the present invention has been shown effective against the plant fungal pathogens selected from the phylum comprising Basidiomycota, Zygomyceta, Oomycota or Ascomycota.For example, the composition or fungicide of the present invention has been shown particularly effective against the specific plant fungal pathogens according to the invention, such as Mucor circinelloides, Nigrospora sphaerica, Botryosphaeria dothidea, Fusarium solani, Fusarium oxysporum, Penicillium digitatum, Penicillium expansum, Lasiodiplodia theobromae, Botrytis cinerea, Alternaria radicina, Penicillium italicum, Fusarium graminearum, Cladosporium cladosporioides, Plectosphaerella cucumerina, Apiospora montagnei, Phoma sp., Acrostalagmus luteoalbus, Aspergillus nigerand Geotrichum candidum, in both preventive and curative manners.

[0100] In preferred embodiments, the fungal pathogen to be controlled is selected from the group consisting of Botrytis cinerea, Alternaria radicina, Fusarium oxysporum, Penicillium expansum, Mucor circinelloides, Geotrichum candidum, Aspergillus niger, Plasmopara viticola, Erysiphe necator, and Penicillium digitatum. These species represent agronomically critical pathogens against which the compounds of the invention exhibit particularly potent and well-documented efficacy, as demonstrated in the Examples.

[0101] In an embodiment of the invention, the fungicide composition of the invention is applied in combination with acceptable carriers or diluents, i.e. in a spray or a bath.

[0102] The fungicide composition of the invention will often be concentrated formulations that can be diluted in water, or another liquid, for application. In certain embodiments, the fungicide composition can also be formulated into particles or granular formulations that are sprayed or applied without further treatment.

[0103] Preferably, carriers or diluents to be used in the present invention are p hyto logical ly-acceptable.

[0104] As used herein, the term “phytologically-acceptable” formulations refers to compositions, diluents, excipients, and / or carriers that are generally applicable for use with any part of a plant during any part of its life cycle, including but not limited to seeds, seedlings, plant cells, plants, or flowers. The formulations can be prepared according to procedures, methods and formulas that are conventional in the agricultural arts. Following the teachings of the present invention, the person skilled in the agricultural and / or chemical arts can readily prepare a desired composition. Most commonly, the fungicide composition of the present invention can be formulated to be stored, and / or applied, as aqueous or non-aqueous suspensions or emulsions prepared neat or from concentrated formulations of the compositions. Water- soluble, water-suspendable or emulsifiable formulations can also be converted into or formulated as solids (e.g., wettable powders), which can then be diluted into a final formulation. In certain formulations, the fungicide compositions of the present invention can also be provided in growth media, e.g., in vitro media for growth of plant or other types of cells, in laboratory plant growth media, in soil, or for spraying on seeds, seedlings, roots, stems, stalks, leaves, flowers or the entire plant.

[0105] These phytologically-acceptable formulations are produced in a known manner, for example by mixing the fungicide composition of the invention with extenders, that is liquid solvents, liquefied gases under pressure, and / or solid carriers, optionally with the use of surfactants, that is emulsifiers and / or dispersants, and / or foam formers. If the extender used is water, it is also possible to use, for example, organic solvents as auxiliary solvents. Essentially, suitable liquid solvents include: aromatics such as xylene, toluene or alkylnaphthalenes, chlorinated aromatics or chlorinated aliphatic hydrocarbons such as chlorobenzenes, chloroethylenes or methylene chloride, aliphatic hydrocarbons such as cyclohexane or paraffins, for example petroleum fractions, alcohols such as butanol or glycol and their ethers and esters, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, strongly polar solvents such as dimethylformamide and dimethyl sulphoxide, or else water. Liquefied gaseous extenders or carriers are to be understood as meaning liquids which are gaseous at ambient temperature and under atmospheric pressure, for example aerosol propellants such as butane, propane, nitrogen and carbon dioxide. Suitable solid carriers are: for example, ground natural minerals such as kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite or diatomaceous earth, and ground synthetic minerals such as finely divided silica, alumina and silicates. Suitable solid carriers for granules are: for example, crushed and fractionated natural rocks such as calcite, marble, pumice, sepiolite and dolomite, or else synthetic granules of inorganic and organic meals, and granules of organic material such as sawdust, coconut shells, maize cobs and tobacco stalks. Suitable emulsifiers and / or foam formers are: for example, nonionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, for example alkylaryl polyglycol ethers, alkylsulphonates, alkyl sulphates, arylsulphonates, or else protein hydrolysates. Suitable dispersants are: for example, lignin-sulphite waste liquors and methylcellulose.

[0106] The fungicide composition according to the invention can be used in various forms such as aerosol dispenser, capsule suspension, cold fogging concentrate, dustable powder, emulsifiable concentrate, emulsion oil in water, emulsion water in oil, encapsulated granule, fine granule, flowable concentrate for seed treatment, gas (under pressure), gas generatingproduct, granule, hot fogging concentrate, macrogranule, microgranule, oil dispersible powder, oil miscible flowable concentrate, oil miscible liquid, paste, plant rodlet, powder for dry seed treatment, seed coated with a pesticide, soluble concentrate, soluble powder, solution for seed treatment, suspension concentrate (flowable concentrate), ultra-low volume (ULV) liquid, ultralow volume (ULV) suspension, water dispersible granules or tablets, water dispersible powder for slurry treatment, water soluble granules or tablets, water soluble powder for seed treatment and wettable powder. These compositions include not only compositions that are ready to be applied to the plant or seed to be treated by means of a suitable device, such as a spraying or dusting device, but also concentrated commercial compositions that must be diluted before application to the crop.

[0107] In a preferred embodiment of the invention, the composition or fungicide can be specifically applied on fruits and vegetables in storage facilities with an ultrasonic fogger. The ultrasonic fogger is a device that is using ultrasonic sound waves to break water into very small droplets (<10um) and sprays it into the air as a dense cold fog (i.e. not resulting from boiling water). Examples of ultrasonic foggers and systems are i.e. described in the following U.S. Patents: U.S. Pat. No. 4,042,016; U.S. Pat. No. 4,058,253; U.S. Pat. No. 4,118,945; U.S. Pat. No.

[0108] 4,564,375; U.S. Pat. No. 4,667,465; U.S. Pat. No. 4,702,074; U.S. Pat. No. 4,731,990; U.S. Pat. No. 4,731,998; U.S. Pat. No. 4,773,846; US No. 5,454,518; US No. 6,854,661. Usually an ultrasonic fogger includes: a generally cylindrical body having an axial bore with an outlet at a front face of the body; a gas supply and a liquid supply coupled to the bore; at least a portion of the front face having a curved convex contour, the front face having a flat central annular region surrounding the outlet of the bore; and a resonator spaced from and opposing the outlet end of the bore. Such devices are commonly used to control humidity level in greenhouses, to deliver nutrients to plant in aeroponic cultures or to create optimal humidity levels in houses.

[0109] Applicants demonstrated that this technique can be used to apply products used for the extension of fruits and vegetables freshness in storage facilities e.g. natural fungicides. This technology permits to efficiently treat fruits and vegetables. Interestingly, Applicants performed efficacy trials on fruits and vegetables in a storage facility of 30m<3>using an industrial MHS15 Ultrasonic Humidifiers (http: / / www.mainlandmart.com / humidify.html), generating 15kg of fog I hour made of droplets of a size comprised between 1-10 pm with average 5 micron. The composition of the invention, represented by powder was added into water container of the fogger in a dosage of 400-600 pM, depending on the tested plant species. Powder was dissolved in the water and applied on the fruits in a form of cold vapor. Applicants have confirmed equal distribution of the product on all treated crops.The fungicide composition according to the invention can also be mixed with one or more insecticides, pesticides, attractants, sterilants, bactericides, acaricides, nematicides, other fungicides, growth regulators, herbicides, fertilizers, safeners, semiochemicals, flavour exhauster agents or other compounds with biological activity. The mixtures thus obtained have normally a broadened spectrum of activity. The mixtures with other fungicide compounds are particularly advantageous.

[0110] The fungicide composition according to the invention comprising a mixture with a bactericide compound can also be particularly advantageous. Examples of suitable bactericide mixing partners can be selected from the group comprising: bronopol, dichlorophen, nitrapyrin, nickel dimethyldithiocarbamate, kasugamycin, octhilinone, furancarboxylic acid, oxytetracycline, probenazole, streptomycin, tecloftalam, copper sulfate and other copper preparations.

[0111] The dose of the fungicide composition usually applied in the treatment according to the invention is generally and advantageously from 10 to 800 g / ha, preferably from 50 to 300 g / ha for applications in foliar treatment. The dose of fungicide composition applied is generally and advantageously from 2 to 200 g per 100 kg of seed, preferably from 3 to 150 g per 100 kg of seed in the case of seed treatment.

[0112] It is clearly understood that the doses indicated herein are given as illustrative examples of the treatment method according to the invention. A person skilled in the art will know how to adapt the application doses, notably according to the nature of the plant or crop to be treated.

[0113] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications without departing from the spirit or essential characteristics thereof. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations or any two or more of said steps or features. The present disclosure is therefore to be considered as in all aspects illustrated and not restrictive, the scope of the invention being indicated by the appended claims, and all changes which come within the meaning and range of equivalency are intended to be embraced therein.

[0114] Various references are cited throughout this specification, each of which is incorporated herein by reference in its entirety.The foregoing description will be more fully understood with reference to the following Examples. Such Examples, are, however, exemplary of methods of practising the present invention and are not intended to limit the scope of the invention.

[0115] Examples :

[0116] Extraction method

[0117] Pedobesia sp. was harvested and freeze dried. The dry alga was ground to powder and extracted with different solvents, each having a different polarity (water, methanol, isopropanol, chloroform). Each extract was then evaporated and resuspended in the same solvent used for the extraction at a concentration of 50 mg / ml. Each extract was tested for its antifungal properties against a broad range of fungi (see biotest method below). All the extracts showed antifungal properties, with methanolic extract showing the best effect, suggesting that it is an amphiphilic molecule.

[0118] Biotest method

[0119] Pedobesia extract showed efficacy on all the fungi tested so far. The list of those fungi is the following: Mucor circinelloides, Nigrospora sphaerica, Botryosphaeria dothidea, Fusarium solani, Fusarium oxysporum, Penicillium digitatum, Lasiodiplodia theobromae, Botrytis cinerea, Alternaria radicina, Penicillium italicum, Fusarium graminearum, Cladosporium cladosporioides, Plectosphaerella cucumerina, Apiospora montagnei, Phoma sp., Acrostalagmus luteoalbus, Aspergillus niger and Geotrichum candidum.

[0120] PDA media was poured in Petri dishes and left to dry. 5 mm holes were created in the medium for each biotest performed. Methanolic extract was resuspended at a concentration of 50mg / ml and 20uL were poured in the holes for testing. The extract was left to dry and 10uL of spore solution were added to each hole. The radius of the fungal growth was measured around the center of each hole and compared with untreated (20uL of solvent, without extract) fungal growth. Results for the methanolic extract are shown in the table 1 below.

[0121] Conclusion: Results showed that none of the tested fungi were able to grow when in contact with the extract, showing that the active ingredient is a broad range antifungal compound.

[0122]

[0123]

[0124] Table 1

[0125] Identification of the active molecules:

[0126] Methanolic extract was fractionated by high pressure liquid chromatography (HPLC). The extract was injected on a C18 column, using an acetonitrile-water gradient as a mobile phase. The gradient is as follows with water + 0.1% formic acid (solvent A) and acetonitrile + 0.1% formic acid (solvent B):

[0127] The mobile phase gradient goes from 0 to 1 min with 85% A and 15% B. Then it gradually changes from 1 to 24 min from 85% A and 15% B to 100% B. It then holds at 100% B for 3 min. The flow used is constant at 1.5 mL / min.

[0128] Fractions were collected based on peak detection. Each fraction was concentrated and tested in vitro for its antifungal properties against Mucor circinelloides, which is a fast-growing fungal pathogen. The fraction showing antifungal properties was purified in higher amounts and sentfor identification. The molecule according to Formula I was identified through liquid chromatography (HR-ESI-MS and MSMS) as well as NMR analyses. The molecule showed a mass of 1460.90 for a chemical formula of C74H120N14O16. It is a depsipeptide (peptide linked to a fatty acid) with the following sequence: 3-Methyl-2-butenoyl-Thr-Val-Val-Val-Pro-Orn-Leu-Thr-lle-lle-Phe-Dhb-Val, with a loop formed between the last Vai and previous Thr (in bold).

[0129]

[0130] Formula I

[0131] A second molecule according to Formula II, that could not be separated from the first one due to their high similarity was also identified in the active fraction.

[0132]

[0133] Formula IIExample 1:

[0134] Methanolic algal extract from Pedobesia was dissolved in water and applied on freshly bought carrots. The extract was left to dry and then a spore solution of Alternaria radicina was sprayed to infect the carrots. After the carrots were dried, they were placed in plastic bags to keep their environment humid. Infection was measured as the surface of fungi over the total carrot surface.

[0135] Conclusion: Results after 1 week highlighted that 72% less symptoms were found on the treated carrots (2.60% infection) than on the control carrots (9.27% infection), (n = 10, p < 0.05) (Figure 1).

[0136] Example 2:

[0137] Methanolic algal extract was dissolved in water and applied on freshly bought tomatoes. The extract was left to dry and then a spore solution of Botrytis cinerea was sprayed to infect the tomatoes. After the tomatoes were dry, they were placed in plastic bags to keep their environment humid. Infection was measured as the surface of fungi over the total tomato surface.

[0138] Conclusion: Results after 2 weeks highlighted that 81% less symptoms were found on the treated tomatoes (7.57% infection) than on the control tomatoes (41.16% infection), (n = 10, p < 0.05) (Figure 2).

[0139] Example 3:

[0140] Leaf discs of Vitis vinifera were cut and disposed on a wet filter paper in Petri dishes. The dry algal methanol extract was redissolved in water at different concentrations (1-50 mg / ml) and applied on the leaf discs. The extract was left to dry. A spore solution of mildew (Plasmopara viticola) was then sprayed the same day as or 5 days after extract application.

[0141] Conclusion: Results highlighted that when applied directly, between 5 and 10 mg / ml of the solution are sufficient to completely inhibit the growth of mildew on the leaves (Figure 3). When infection occurs 5 days after treatment (Figure 4), the treatment is less efficient, suggesting that the active ingredient degrades over time, which is an interesting feature for post and pre harvest treatments.

[0142] Example 4:The dry algal methanolic extract was resuspended in water at 10 or 20 mg / ml. As a positive control, a Cuprofix (commercial copper fungicide) solution was prepared at 12mg / ml. Vine plants were treated with the different solutions. Applied treatments were then left to dry for a few hours before being infected with downey mildew (Plasmopara viticola) spore solution. Results were assessed after 1 week (Figure 6).

[0143] Conclusion: Results highlighted that 10 to 20 mg / ml extract solutions were sufficient to get similar results as the positive control treated with a commercial fungicide (Figure 6). While the extract concentration needs to be a bit higher (2-3x higher) than in the experiment on leaf discs, the experiment shows similar results on living plants cultivated in greenhouse.

[0144] Example 5:

[0145] The dry algal methanolic extract was resuspended in water at 10 or 20 mg / ml. As a positive control, a Thiovit (commercial sulphur fungicide) solution was prepared at 4mg / ml. Vine leaves were cut and placed in Petri dishes with culture medium in order to keep the leaves alive during the assessment. The different treatments were then applied and left to dry for a few hours before being infected with powdery mildew (Erysiphe necatoi) spore solution. Results were assessed after 1.5 week (Figure 7).

[0146] Conclusion: Results highlighted that 10 and 20 mg / ml of the extract solution are sufficient to completely inhibit the growth of powdery mildew on the leaves, which is similar to the effect of the commercial sulphur fungicide (Figure 7). Results suggest that lower concentrations could even be used to impact the infection rate of powdery mildew on vine leaves in controlled conditions.

[0147] Example 6:

[0148] 48-well culture plates were filled with a range of concentrations of the full Pedobesia sp. extract (0-40 mg / ml) or of the HPLC-purified fraction containing the active molecules (0-750 pg / ml). During purification, it was calculated that the active fraction was equivalent to 1.5% of the total extract. Thus, purified molecule was resuspended so that its concentration was similar to what it is in the full extract ( / .e.40mg / ml contains as much active ingredient as 750 pg / ml of purified molecule). Extract and molecule were resuspended in potato dextrose broth (PDB) and diluted in the wells in triplicates. Potato dextrose agar (PDA) was added in each well so that its concentration was 50%. Plates were well mixed and 10 pl of a spore solution were added to each well.

[0149] Conclusion: Results show that, at active ingredient equivalent concentrations, the pure molecule is more efficient than the full extract at inhibiting fungal growth. EC50 values werecalculated for each fungus and condition. Values for the full extract are respectively 7.33, 4.95, 5.64 and 2.85 g / L for inhibiting 50% of the growth of G. candidum, P. expansum, F. oxysporum and M. circinelloides, respectively. Values for the purified molecule are respectively 48.71, 5.14, 36.69 and 52.13 mg / L for inhibiting 50% of the growth of G. candidum, P. expansum, F. oxysporum and M. circinelloides, respectively.

[0150] Activity of the purified active fraction

[0151] As demonstrated in Example 6 and Figure 8, the HPLC-purified fraction containing both compounds of formulae I and II (which are difficult to separate due to their structural similarity) exhibits potent fungicidal activity with low EC50values against multiple pathogens. This confirms that the fungicidal effect is attributable to these specific compounds, whether individually or in combination, and is not an artifact of crude extract components.

[0152] General conclusion of the examples:

[0153] The experimental data presented above demonstrate the following key findings:

[0154] 1. Specific and potent antifungal spectrum: The methanolic extract of Pedobesia sp., and the isolated compounds of formulae I and II, exhibit complete inhibition of mycelial growth in vitro against a defined panel of agronomically significant fungal pathogens (Table 1). This efficacy is not a general property of all kahalalides but is specifically demonstrated for this extract and these compounds against these particular species.

[0155] 2. Efficacy in plant protection models: The extract shows significant protective and curative effects in vivo plant models, reducing infection by Alternaria radicina on carrots by 72% (Example 1, Figure 1) and by Botrytis cinerea on tomatoes by 81% (Example 2, Figure 2). This confirms the practical utility of the invention for crop protection. 3. Proof of a scalable source: The active fungicidal compounds (Formulae I and II) were successfully isolated from Pedobesia sp. algae. This establishes Pedobesia as a viable and scalable biological source for obtaining these active principles, addressing a major limitation of prior art sources (e.g., mollusks or Bryopsis sp.).

[0156] 4. Formulation-relevant properties: The experiments on grapevine downy mildew (Examples 3, Figures 3 & 4) illustrate concentration-dependent activity and provide insights into the persistence of the effect, informing practical application strategies such as treatment timing.

[0157] Collectively, these results provide direct experimental support for the claimed inventions: the use of the compounds against the specified pathogens, the fungicidal composition containing them, and the process for obtaining them from Pedobesia sp. They underscore the technicaladvance of providing an effective, scalable, and practical fungicidal solution based on these specific compounds from this specific algal source.

[0158] Comparative efficacy and commercial relevance

[0159] The efficacy of the Pedobesia extract and the purified compounds is not only comparable to but in certain contexts superior to conventional commercial fungicides. As shown in Examples 4 and 5, treatments with 10-20 mg / ml of the extract provided protection against downy mildew and powdery mildew in grapevines equivalent to that achieved with standard copper (Cuprofix) and sulfur (Thiovit) fungicides. Furthermore, the EC50values for the purified molecule against key storage rot pathogens such as Penicillium expansum (5.14 mg / L) indicate a potency that supports its use as a viable alternative to synthetic post-harvest treatments.

Claims

CLAIMS1. Use of a composition comprising a compound of formula I:or an isomer, enantiomer, or salt thereof, for controlling fungal pathogens in plants, wherein the fungal pathogen is selected from the group consisting of the fungal families Mucoraceae, Apiosporaceae, Botryosphaeriacae, Nectriaceae, Sclerotiniaceae, Pleosporaceae, Aspergillaceae, Cladosporiaceae, Trichosphaeriaceae, Dipodascaceae, Didymellaceae and Trichocomaceae.

2. The use according to claim 1, wherein the fungal pathogen is selected from the group consisting of Mucor circinelloides, Nigrospora sphaerica, Botryosphaeria dothidea, Fusariumsolani, Fusarium oxysporum, Penicillium digitatum, Penicillium expansum, Lasiodiplodia theobromae, Botrytis cinerea, Alternaria radicina, Penicillium italicum, Fusarium graminearum, Cladosporium cladosporioides, Plectosphaerella cucumerina, Apiospora montagnei, Phoma sp., Acrostalagmus luteoalbus, Aspergillus niger and Geotrichum candidum.

3. The use according to claim 1, wherein the composition is obtained from an extract of Pedobesia sp.

4. The use according to any one of claims 1-3, wherein the extract is a methanolic, isopropanolic, aqueous or chloroform extract.

5. The use according to any one of claims 1-4, wherein the composition is applied to a plant, plant part, or seed.

6. The use according to any one of claims 1-5, wherein the composition is applied as a foliar spray, seed treatment, or soil drench.

7. A fungicidal composition comprising a compound of formula I and / or formula II as defined in claim 1 , in combination with a phytologically-acceptable carrier or diluent.

8. The fungicidal composition according to claim 7, further comprising at least one additional fungicide, insecticide, herbicide, or fertilizer.

9. A method for controlling fungal pathogens in plants, comprising applying to the plant, plant part, or seed a fungicidally effective amount of a composition according to any one of claims 7-8.

10. The method according to claim 9, wherein the fungal pathogen is selected from the group consisting of the fungal families Mucoraceae, Apiosporaceae, Botryosphaeriacae, Nectriaceae, Sclerotiniaceae, Pleosporaceae, Aspergillaceae, Cladosporiaceae, Trichosphaeriaceae, Dipodascaceae, Didymellaceae and Trichocomaceae.

11. The method according to claim 9 or 10, wherein the fungal pathogen is selected from the group consisting of Mucor circinelloides, Nigrospora sphaerica, Botryosphaeria dothidea, Fusarium solani, Fusarium oxysporum, Penicillium digitatum, Penicillium expansum, Lasiodiplodia theobromae, Botrytis cinerea, Alternaria radicina, Penicillium italicum, Fusariumgraminearum, Cladosporium cladosporioides, Plectosphaerella cucumerina, Apiospora montagnei, Phoma sp., Acrostalagmus luteoalbus, Aspergillus niger and Geotrichum candidum.

12. Use of a compound of formula I and / or formula II as defined in claim 1, for the preparation of a medicament for the treatment or prevention of mycosis in humans or animals.

13. The use according to claim 12, wherein the mycosis is caused by Candida albicans or Trichophyton rubrum.

14. A process for preparing the fungicidal composition according to claim 7 or 8, comprising:a) extracting biomass of Pedobesia sp. with a solvent selected from methanol, isopropanol, water, or chloroform to obtain a crude extract comprising said compound of formula I and / or II; and optionallyb) mixing the compound of formula I and / or II with said phytologically acceptable carrier or diluent.

15. The process according to claim 14, further comprising adding at least one additional fungicide, insecticide, herbicide, or fertilizer to the composition.

16. The use according to any one of claims 1-6, wherein the composition is applied at a concentration ranging from 5 mg / ml to 50 mg / ml.

17. The use according to claim 16, wherein the composition is applied at a concentration of 10 mg / ml to 20 mg / ml for controlling downy mildew (Plasmopara viticola) or powdery mildew (Erysiphe necator) in grapevines.

18. The fungicidal composition according to claim 7 or 8, wherein the compound of formula I and / or II exhibits an EC50value of less than 100 mg / L against at least one fungal pathogen selected from Geotrichum candidum, Penicillium expansum, Fusarium oxysporum, and Mucor circinelloides.

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