RESUMO
Fungal infections of cultivated food crops result in extensive losses of crops at the global level, while resistance to antifungal agents continues to grow. Supercritical fluid extraction using CO2 (SFE-CO2) has gained attention as an environmentally well-accepted extraction method, as CO2 is a non-toxic, inert and available solvent, and the extracts obtained are, chemically, of greater or different complexities compared to those of conventional extracts. The SFE-CO2 extracts of Achillea millefolium, Calendula officinalis, Chamomilla recutita, Helichrysum arenarium, Humulus lupulus, Taraxacum officinale, Juniperus communis, Hypericum perforatum, Nepeta cataria, Crataegus sp. and Sambucus nigra were studied in terms of their compositions and antifungal activities against the wheat- and buckwheat-borne fungi Alternaria alternata, Epicoccum nigrum, Botrytis cinerea, Fusarium oxysporum and Fusarium poae. The C. recutita and H. arenarium extracts were the most efficacious, and these inhibited the growth of most of the fungi by 80% to 100%. Among the fungal species, B. cinerea was the most susceptible to the treatments with the SFE-CO2 extracts, while Fusarium spp. were the least. This study shows that some of these SFE-CO2 extracts have promising potential for use as antifungal agents for selected crop-borne fungi.
Assuntos
Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Doenças das Plantas/prevenção & controle , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Botrytis/efeitos dos fármacos , Dióxido de Carbono/química , Cromatografia com Fluido Supercrítico/métodos , Produtos Agrícolas/microbiologia , Fagopyrum/microbiologia , Fungos/efeitos dos fármacos , Fungicidas Industriais/isolamento & purificação , Doenças das Plantas/microbiologia , Extratos Vegetais/isolamento & purificação , Triticum/microbiologiaRESUMO
The investigation of the metabolites from endophyte Irpex lacteus cultured in host "tian ma" (Gastrodia elata) revealed five new tremulane sesquiterpenes (1-5), and a new tetrahydrofuran derivative (6). Compound 1 was the first tremulane glucoside, and 6 possessed a rare tetrahydropyran-tetrahydrofuran scaffold. Main metabolite (2,3-dihydroxydodacane-4,7-dione, 14) from I. lacteus showed significant selectivity for antifungal activity against phytopathogen and endophytes associated with G. elata rather than against Armillaria sp. providing nutrition for the host G. elata. 14 accounted for 27.4% of isolated compounds from G. elata medium, and 69.3% by co-culturing with Armillaria sp. So the I. lacteus tended to promote the growth of Armillaria sp. in co-culture by producing 2,3-dihydroxydodacane-4,7-dione (14) to selective inhibit the phytopathogen and endophyte existed in host G. elata for the benefit of G. elata-Armillaria symbiosis. And the results were in accord with the real environment of G. elata depending on the nutrition of Armillaria. Some metabolites had anti-fungal activities against phytopathogens of G. elata with MICs ≤8 µg/mL.
Assuntos
Fungicidas Industriais/farmacologia , Gastrodia/microbiologia , Polyporales/química , Sesquiterpenos/farmacologia , Armillaria/crescimento & desenvolvimento , China , Endófitos/química , Fungicidas Industriais/isolamento & purificação , Estrutura Molecular , Sementes/microbiologia , Sesquiterpenos/isolamento & purificaçãoRESUMO
Two new bioactive trisubstituted furanones, named pinofuranoxins A and B (1 and 2), were isolated from Diplodia sapinea, a worldwide conifer pathogen causing severe disease. Pinofuranoxins A and B were characterized essentially by NMR and HRESIMS spectra, and their relative and absolute configurations were assigned by NOESY experiments and computational analyses of electronic circular dichroism spectra. They induced necrotic lesions on Hedera helix L., Phaseolus vulgaris L., and Quercus ilex L. Compound 1 completely inhibited the growth of Athelia rolfsii and Phytophthora cambivora, while 2 showed antioomycetes activity against P. cambivora. In the Artemia salina assay both toxins showed activity inducing larval mortality.
Assuntos
Ascomicetos/química , Furanos/farmacologia , Doenças das Plantas/microbiologia , Animais , Artemia/efeitos dos fármacos , Basidiomycota/efeitos dos fármacos , Fungicidas Industriais/isolamento & purificação , Fungicidas Industriais/farmacologia , Furanos/isolamento & purificação , Hedera/efeitos dos fármacos , Estrutura Molecular , Phaseolus/efeitos dos fármacos , Phytophthora/efeitos dos fármacos , Quercus/efeitos dos fármacos , TunísiaRESUMO
The genus Poiretia belongs to the Fabaceae (Leguminosae) family and it encompasses twelve species of flowering plants. The chemistry of this genus is scarcely investigated, although some studies have demonstrated the potential of Poiretia species to produce important bioactive compounds. Herein, we describe the phytochemical investigation of P. bahiana C. Mueller leaves. A new isoflavone glucoside named as 2',4',5'-trimethoxyisoflavone-7-O-ß-D-glucopyranoside (1), along with six known isoflavones (2-7), two rotenones (8-9), cyclitol 3-O-methyl-chiro-inositol (10), the amino acid proline (11), a mixture of sitosterol (12) and stigmasterol (13), and a mixture of the triterpenes lupeol (14) and ß-amirine (15) were obtained from P. bahiana leaves. The structures were established by extensive analysis of their spectroscopic data, which included 1H NMR, 13C NMR, DEPT, and 2D-NMR (13C1H HETCOR and 13C1H COLOC). Two isoflavones (3 and 5) and two rotenones (8-9) exhibited antifungal activity against the plant pathogenic fungus Cladosporium sphaerospermum. Furthermore, the biogenetic implications of the oxygenation pattern of the B-ring of the isoflavones, and the chemophenetics and fragmentation pattern of the isoflavones and rotenones are discussed.
Assuntos
Fabaceae/química , Fungicidas Industriais/farmacologia , Glucosídeos/farmacologia , Isoflavonas/farmacologia , Brasil , Cladosporium/efeitos dos fármacos , Fungicidas Industriais/isolamento & purificação , Glucosídeos/isolamento & purificação , Isoflavonas/isolamento & purificação , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Folhas de Planta/químicaRESUMO
Four new meroterpenes named as guignardones U-X (1-4), along with eleven known meroterpenes (5-15) and three known dioxolanone derivatives (16-18), were obtained from the endophytic fungus Phyllosticta sp. WGHL2. The structural elucidation was conducted by HRESIMS, NMR, single crystal X-ray diffraction, along with ECD calculations and comparison. In antifungal tests, compound 16 possessed broad-spectrum antifungal activities against Rhizoctonia solani, Fusarium graminearum and Botrytis cinerea with inhibition ratio of 48.43%, 40.98%, and 49.53% at 50 µg/mL, respectively. Moreover, compound 16 showed moderate protective effect against B. cinerea in vivo at 200 µg/mL and exhibited effective inhibition on the spore germination of B. cinerea.
Assuntos
Ascomicetos/química , Botrytis/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Fusarium/efeitos dos fármacos , Rhizoctonia/efeitos dos fármacos , China , Endófitos/química , Fungicidas Industriais/isolamento & purificação , Testes de Sensibilidade Microbiana , Estrutura Molecular , Oleaceae/microbiologiaRESUMO
Five new tremulane sesquiterpenoids were isolated from co-culture of endophyte Irpex lacteus, phytopathogen Nigrospora oryzae, and entomopathogen Beauveria bassiana. All compounds showed obvious antifeedant activities against silkworm with inhibition percentages of 73-99%, at concentrations of 50 µg/cm2. Compound 11 indicated notable antifeedant activity with inhibition percentage of 93% at concentration of 6.25 µg/cm2 among them. Compounds 2, 3, 4, 8, 9, 15 and 16 indicated anti-fungal activities against I. lacteus with MIC values ≤8 µg/mL, compounds 11, 12, 16-18 showed significant anti-fungal activity against N. oryzae with MICs ≤ 4 µg/mL, and compounds 2, 5, 12 and 18 indicated significant anti-fungal activity against B. bassiana with MICs ≤ 8 µg/mL. In addition, the I. lacteus should unite B. bassiana to inhibit the production of phytotoxins from N. oryzae in the ternary culture.
Assuntos
Ascomicetos/química , Beauveria/química , Bombyx/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Polyporales/química , Sesquiterpenos/farmacologia , Animais , Ascomicetos/efeitos dos fármacos , China , Técnicas de Cocultura , Dendrobium/microbiologia , Endófitos/química , Fermentação , Fungicidas Industriais/isolamento & purificação , Testes de Sensibilidade Microbiana , Estrutura Molecular , Polyporales/efeitos dos fármacos , Sementes/microbiologia , Sesquiterpenos/isolamento & purificaçãoRESUMO
In recent years, the antimicrobial activity of peptides isolated from a wide variety of organs from plant species has been reported. However, a few studies have investigated the potential of antimicrobial peptides (AMPs) found in fruits, especially Capsicum chinense (pepper). The present study aimed to purify and characterize peptides from Capsicum chinense fruits and evaluate their inhibitory activities against different phytopathogenic fungi and also analyze the possible mechanisms of action involved in microbial inhibition. After fruit protein extraction and high-performance liquid chromatography (HPLC), different fractions were obtained, named F1 to F10. Peptides in the F4 and F5 fractions were sequenced and revealed similarity with the plant antimicrobial peptides like non-specific lipid transfer proteins and defensin-like peptide. The F4 and F5 fractions presented strong antimicrobial activity against the fungus Fusarium solani and Fusarium oxysporum, causing toxic effects on these fungi, leading to membrane permeabilization, endogenous reactive oxygen species increase, activation of metacaspase and loss of mitochondrial function.
Assuntos
Capsicum , Frutas , Fungicidas Industriais/farmacologia , Fusarium/efeitos dos fármacos , Extratos Vegetais/farmacologia , Proteínas Citotóxicas Formadoras de Poros/farmacologia , Capsicum/química , Frutas/química , Fungicidas Industriais/isolamento & purificação , Fusarium/crescimento & desenvolvimento , Fusarium/metabolismo , Viabilidade Microbiana/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Proteínas Citotóxicas Formadoras de Poros/isolamento & purificaçãoRESUMO
A simple and sensitive enantiomeric analytical method was established for the determination of two new isopropanol-triazole fungicides mefentrifluconazole and ipfentrifluconazole in plant-origin foods using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The best enantioseparation of the four target stereoisomers was achieved on a Chiral MX(2)-RH column within 7 min by reversed-phase liquid chromatography, which is a significant improvement in the resolution of different chiral compounds under one set of conditions. A simple and effective pretreatment procedure was developed for the extraction and purification of the two target chiral fungicides using reversed-dispersive solid-phase extraction (r-DSPE) with multiwalled carbon nanotubes (MWCNTs). The influence of the type and amount of MWCNTs on the purification efficiencies and recoveries was evaluated. The mean recoveries for all four stereoisomers were in the range of 76.9-91.2%, with relative standard deviation (RSD) values below 7.2%. The limit of quantification (LOQ) of all stereoisomers of mefentrifluconazole and ipfentrifluconazole was 5 µg/kg for all tested matrixes. The results of the method validation and real samples analysis confirm that the established method is efficient and reliable for the enantiomeric determination of mefentrifluconazole and ipfentrifluconazole in plant-origin food samples.
Assuntos
2-Propanol/química , Fungicidas Industriais/química , Extratos Vegetais/química , Triazóis/química , 2-Propanol/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Fungicidas Industriais/isolamento & purificação , Nanotubos de Carbono/química , Extratos Vegetais/isolamento & purificação , Plantas/química , Extração em Fase Sólida , Estereoisomerismo , Espectrometria de Massas em Tandem , Triazóis/isolamento & purificaçãoRESUMO
Diterpenoids are the main secondary metabolites of plants and with a range of biological activities. In the present study, 7 compounds were isolated from the hulls of rice (Oryza sativa L.). Among them, 3 diterpenoids are new namely, 3,20-epoxy-3α-hydroxy- 8,11,13-abietatrie-7-one (1), 4,6-epoxy-3ß-hydroxy-9ß-pimara-7,15-diene (2) and 2-((E)-3- (4-hydroxy-3-methoxyphenyl) allylidene) momilactone A (3). While, 4 terpenoids are known, namely momilactone A (4), momilactone B (5), ent-7-oxo-kaur-15-en-18-oic acid (6) and orizaterpenoid (7). The structures of these diterpenoids were elucidated using 1D and 2D NMR in combination with ESI-MS and HR-EI-MS. Furthermore, all isolated compounds displayed antifungal activities against four crop pathogenic fungi Magnaporthe grisea, Rhizoctonia solani, Blumeria graminearum and Fusarium oxysporum, and phytotoxicity against paddy weed Echinochloa crusgalli. The results suggested that rice could produce plenty of secondary metabolites to defense against weeds and pathogens.
Assuntos
Diterpenos/farmacologia , Fungicidas Industriais/farmacologia , Herbicidas/farmacologia , Oryza/química , Sementes/química , Diterpenos/isolamento & purificação , Echinochloa/efeitos dos fármacos , Fungicidas Industriais/isolamento & purificação , Herbicidas/isolamento & purificação , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologiaRESUMO
Naturally occurring thiophenes possess excellent nematicidal and fungicidal activities. However, thiophenes often have limited application in soil due to their light-dependent toxicity given the living and reproductive condition of soil-borne pathogens. In this study, six new (1-6) and six known thiophenes (7-12) were isolated from Echinops grijsii. Compounds 1-2, 4-5, 8-9, 11 , and 12 showed stronger nematicidal activity against Meloidogyne incognita than commercial nematicide abamectin. 4-10 were demonstrated as nonphototoxic thiophenes. Among these, 4 and 8 were the most potent thiophenes (LC50 values 2.57 and 0.91 µg/mL in light, 1.80 and 0.86 µg/mL in dark, respectively) against M. incognita. SAR revealed that thiophene skeleton was essential for nematicidal activity, while disubstituted groups were helpful for nonphototoxicity. Although an increased number of acetylenes improved activity, it decreased nonphototoxicity. Acyl groups could suppress the effects of light on activity, with the level of inhibitory effects depending on its number and chain length, while chlorine played important roles in promoting activity. Additionally, compounds 1-2, 4-5, 7, 8, and 10 displayed antifungal activity against six soil-borne fungi in various degrees. The discovery of nonphototoxic thiophenes and elucidation of SAR provide important information for the exploitation and utilization of thiophenes in the integrative management regarding disease complexes caused by the combination of root-knot nematode and soil-borne fungi.
Assuntos
Antinematódeos/química , Echinops (Planta)/química , Fungicidas Industriais/química , Extratos Vegetais/química , Tiofenos/química , Animais , Antinematódeos/isolamento & purificação , Antinematódeos/farmacologia , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Fungicidas Industriais/isolamento & purificação , Fungicidas Industriais/farmacologia , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Raízes de Plantas/microbiologia , Raízes de Plantas/parasitologia , Microbiologia do Solo , Relação Estrutura-Atividade , Tiofenos/isolamento & purificação , Tiofenos/farmacologia , Tylenchoidea/efeitos dos fármacos , Tylenchoidea/crescimento & desenvolvimentoRESUMO
A 11 kDa antifungal protein FEAP was purified from buckwheat ( Fagopyrum esculentum) seed extract with a procedure involving (NH4)2SO4 precipitation and chromatography on SP-Sepharose, Affi-gel blue gel, Mono S, and Superdex peptide. Its N-terminal sequence was AQXGAQGGGAT, resembling those of buckwheat peptides Fα-AMP1 and Fα-AMP2. FEAP exhibited thermostability (20-100 °C) and acid resistance (pH 1-5). Its antifungal activity was retained in the presence of 10-150 mmol/L of K+, Mn2+, or Fe3+ ions, 10-50 mmol/L of Ca2+ or Mg2+ ions, and 50% methanol, 50% ethanol, 50% isopropanol, or 50% chloroform. Its half-maximal inhibitory concentrations toward spore germination and mycelial growth in Botrytis cinerea were 79.9 and 236.7 µg/mL, respectively. Its antifungal activity was superior to the fungicide cymoxanil mancozeb (248.1 µg/mL). FEAP prevented B. cinerea from infecting excised leaves, intact leaves, and isolated fruits of cherry tomato. Its mechanism involved induction of an increase in cell membrane permeability and a decrease in mitochondrial membrane potential.
Assuntos
Botrytis/fisiologia , Fagopyrum/química , Fungicidas Industriais/farmacologia , Doenças das Plantas/prevenção & controle , Proteínas de Plantas/farmacologia , Solanum lycopersicum/microbiologia , Motivos de Aminoácidos , Botrytis/efeitos dos fármacos , Frutas/microbiologia , Fungicidas Industriais/química , Fungicidas Industriais/isolamento & purificação , Doenças das Plantas/microbiologia , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificaçãoRESUMO
Two new coumarins (1 and 2), two new lignans (3 and 4), one new phloroglucinol derivative (5), together with eleven known compounds, were isolated from Artemisia annua. Their structures were identified by spectroscopic methods with 1 to be secured by X-ray diffraction. Antifungal activities of the isolates against Fusarium oxysporum, Fusarium solani, and Cylindrocarpon destrutans were evaluated. It was found that compound 1 could inhibit all the fungal strains with respective MIC values of 18.75, and 25.00⯵g/mL. In contrast, compounds 4, 5, 7, and 8 are active toward C. destrutans and 14 displays inhibitory property toward F. solani.
Assuntos
Artemisia annua/química , Cumarínicos/farmacologia , Fungicidas Industriais/farmacologia , Fusarium/efeitos dos fármacos , Lignanas/farmacologia , China , Cumarínicos/isolamento & purificação , Fungicidas Industriais/isolamento & purificação , Lignanas/isolamento & purificação , Testes de Sensibilidade Microbiana , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologiaRESUMO
The discovery of potent natural and ecofriendly pesticides is one of the focuses of the agrochemical industry, and plant species are a source of many potentially active compounds. We describe the bioassay-guided isolation of antifungal and phytotoxic compounds from the ethyl acetate extract of Ambrosia salsola twigs and leaves. With this methodology, we isolated and identified twelve compounds (four chalcones, six flavonols and two pseudoguaianolide sesquiterpene lactones). Three new chalcones were elucidated as (S)-ß-Hydroxy-2',3,4,6'-tetrahydroxy-5-methoxydihydrochalcone (salsolol A), (S)-ß-Hydroxy-2',4,4',6'-tetrahydroxy-3-methoxydihydrochalcone (salsolol B), and (R)-α, (R)-ß-Dihydroxy-2',3,4,4',6'- pentahydroxydihydrochalcone (salsolol C) together with nine known compounds: balanochalcone, six quercetin derivatives, confertin, and neoambrosin. Chemical structures were determined based on comprehensive direct analysis in real time-high resolution mass spectrometry (HR-DART-MS), as well as 1D and 2D NMR experiments: Cosy Double Quantum Filter (DQFCOSY), Heteronuclear Multiple Quantum Coherence (HMQC) and Heteronuclear Multiple Bond Coherence (HMBC), and the absolute configurations of the chalcones were confirmed by CD spectra analysis. Crystal structure of confertin was determined by X-ray diffraction. The phytotoxicity of purified compounds was evaluated, and neoambrosim was active against Agrostis stolonifera at 1 mM, while confertin was active against both, Lactuca sativa and A. stolonifera at 1 mM and 100 µM, respectively. Confertin and salsolol A and B had IC50 values of 261, 275, and 251 µM, respectively, against Lemna pausicotata (duckweed). The antifungal activity was also tested against Colletotrichum fragariae Brooks using a thin layer chromatography bioautography assay. Both confertin and neoambrosin were antifungal at 100 µM, with a higher confertin activity than that of neoambrosin at this concentration.
Assuntos
Ambrosia/química , Fungicidas Industriais/isolamento & purificação , Fungicidas Industriais/farmacologia , Herbicidas/isolamento & purificação , Herbicidas/farmacologia , Dicroísmo Circular , Colletotrichum/efeitos dos fármacos , Fungicidas Industriais/química , Herbicidas/química , Lactuca/efeitos dos fármacos , Estrutura Molecular , Extratos Vegetais/análise , Folhas de Planta/química , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Difração de Raios XRESUMO
Fusarium solani H915 (MCCC3A00957), a fungus originating from mangrove sediment, showed potent inhibitory activity against tea pathogenic fungus Pestalotiopsis theae. Successive chromatographic separation on an ethyl acetate (EtOAc) extract of F. solani H915 resulted in the isolation of five new alkenoic diacid derivatives: fusarilactones A-C (1-3), and fusaridioic acids B (4) and C (5), in addition to seven known compounds (6-12). The chemical structures of these metabolites were elucidated on the basis of UV, IR, HR-ESI-MS, and NMR spectroscopic data. The antifungal activity of the isolated compounds was evaluated. Compounds with a ß-lactone ring (1, 2, and 7) exhibited potent inhibitory activities, while none of the other compounds show activity. The ED50 values of the compounds 1, 2, and 7 were 38.14 ± 1.67, 42.26 ± 1.96, and 18.35 ± 1.27 µg/mL, respectively. In addition, inhibitory activity of these compounds against 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase gene expression was also detected using real-time RT-PCR. Results indicated that compounds 1, 2, and 7 may inhibit the growth of P. theae by interfering with the biosynthesis of ergosterol by down-regulating the expression of HMG-CoA synthase.
Assuntos
Camellia sinensis/microbiologia , Fungicidas Industriais/farmacologia , Fusarium/química , Lactonas/farmacologia , Doenças das Plantas/microbiologia , Água do Mar/microbiologia , Fungicidas Industriais/química , Fungicidas Industriais/isolamento & purificação , Fungicidas Industriais/metabolismo , Fusarium/genética , Fusarium/isolamento & purificação , Fusarium/metabolismo , Lactonas/química , Lactonas/isolamento & purificação , Lactonas/metabolismo , Estrutura Molecular , Xylariales/efeitos dos fármacos , Xylariales/genética , Xylariales/crescimento & desenvolvimentoRESUMO
The citrus black spot (CBS), caused by Phyllosticta citricarpa, is one of the most important citrus diseases in subtropical regions of Africa, Asia, Oceania, and the Americas, and fruits with CBS lesions are still subject to quarantine regulations in the European Union. Despite the high application of fungicides, the disease remains present in the citrus crops of Central and South America. In order to find alternatives to help control CBS and reduce the use of fungicides, we explored the antifungal potential of endophytic actinomycetes isolated from the Brazilian medicinal plant Vochysia divergens found in the Pantanal biome. Two different culture media and temperatures were selected to identify the most efficient conditions for the production of active secondary metabolites. The metabolites produced by strain Microbacterium sp. LGMB471 cultured in SG medium at 36 °C considerably inhibited the development of P. citricarpa. Three isoflavones and five diketopiperazines were identified, and the compounds 7-O-ß-D-glucosyl-genistein and 7-O-ß-D-glucosyl-daidzein showed high activity against P. citricarpa, with the MIC of 33 µg/mL and inhibited the production of asexual spores of P. citricarpa on leaves and citrus fruits. Compounds that inhibit conidia formation may be a promising alternative to reduce the use of fungicides in the control of CBS lesions, especially in regions where sexual reproduction does not occur, as in the USA. Our data suggest the use of Microbacterium sp. LGMB471 or its metabolites as an ecological alternative to be used in association with the fungicides for the control of CBS disease.
Assuntos
Actinomycetales/química , Ascomicetos/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Ásia , Brasil , Citrus/microbiologia , Meios de Cultura , Dicetopiperazinas/isolamento & purificação , Dicetopiperazinas/farmacologia , Fungicidas Industriais/isolamento & purificação , Isoflavonas/isolamento & purificação , Isoflavonas/farmacologia , Testes de Sensibilidade Microbiana , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Metabolismo Secundário , Esporos Fúngicos/efeitos dos fármacos , Estados UnidosRESUMO
In this work, screening of Lauraceae species for their antifungal activity against Collectotrichum tamarilloi was carried out and the ethanol extract derived from the bark of Endlicheria arenosa was found to be the best candidate. From the ethanolic extract of the bark of E. arenosa, the hexane and chloroform fractions were found to be active, from these five fatty acids were identified and two lactones were isolated. The most active fatty acid was the dodecanoic acid with a minimal inhibitory concentration (MIC) of 78.0 µM. The butyrolactone 3R,4R-licunolide A, it has not previously reported, and licunolide B show both the lowest MIC (55.3 µM). This is the first report of compounds of natural origin as growth inhibitors of C. tamarilloi.
Assuntos
Colletotrichum/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Lactonas/farmacologia , Lauraceae/química , Colômbia , Fungicidas Industriais/isolamento & purificação , Lactonas/isolamento & purificação , Testes de Sensibilidade Microbiana , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Casca de Planta/química , Extratos Vegetais/farmacologiaRESUMO
ABSTRACT Anthracnose is a crop disease usually caused by fungi in the genus Colletotrichum or Gloeosporium. These are considered one of the main pathogens, causing significant economic losses, such as in peppers and guarana. The current forms of control include the use of resistant cultivars, sanitary pruning and fungicides. However, even with the use of some methods of controlling these cultures, the crops are not free of anthracnose. Additionally, excessive application of fungicides increases the resistance of pathogens to agrochemicals and cause harm to human health and the environment. In order to find natural antifungal agents against guarana anthracnose, endophytic fungi were isolated from Amazon guarana. The compounds piliformic acid and cytochalasin D were isolated by chromatographic techniques from two Xylaria spp., guided by assays with Colletotrichum gloeosporioides. The isolated compounds were identified by spectrometric techniques, as NMR and mass spectrometry. This is the first report that piliformic acid and cytochalasin D have antifungal activity against C. gloeosporioides with MIC 2.92 and 2.46 µmol mL-1 respectively. Captan and difenoconazole were included as positive controls (MIC 16.63 and 0.02 µmol mL-1, respectively). Thus, Xylaria species presented a biotechnological potential and production of different active compounds which might be promising against anthracnose disease.
Assuntos
Doenças das Plantas/prevenção & controle , Xylariales/química , Paullinia/microbiologia , Endófitos/química , Fungicidas Industriais/farmacologia , Filogenia , Doenças das Plantas/microbiologia , Espectrometria de Massas , Xylariales/isolamento & purificação , Xylariales/genética , Xylariales/metabolismo , Estrutura Molecular , Colletotrichum/efeitos dos fármacos , Colletotrichum/fisiologia , Endófitos/isolamento & purificação , Endófitos/genética , Endófitos/metabolismo , Fungicidas Industriais/isolamento & purificação , Fungicidas Industriais/químicaRESUMO
Plants contain a number of bioactive compounds that exhibit antimicrobial activity, which can be recognized as an important source of agrochemicals for plant disease control. As part of our search for new antimicrobial agents from natural sources, we found that a crude methanol extract of Trevesia palmata exhibited a promising antifungal activity against phytopathogenic fungi, such as Magnaporthe oryzae and Botrytis cinerea. Furthermore, based on activity-guided fractionation, we isolated five antifungal compounds from the methanol extract of T. palmata: two new triterpene glycosides (TPGs), TPG1 (hederagenin-3-O-ß-D-glucopyranosyl-(1 â 3)-α-L-rhamnopyranosyl-(1 â 2)-α-L-rhamnopyranosyl-(1 â 2)-α-L-arabinopyranoside) and TPG5 (3-O-α-L-rhamnopyranosyl asiatic acid), along with three known TPGs (TPG2 [macranthoside A], TPG3 [α-hederin], and TPG4 [ilekudinoside D]). The chemical structures of the TPGs were determined by spectroscopic analyses and by comparison with literature data. An in vitro antifungal bioassay revealed that except for TPG4 (ilekudinoside D; IC50 >256 µg/ml), the other TPGs exhibited strong antifungal activities against the rice blast pathogen M. oryzae with IC50 values ranging from 2-5 µg/ml. In particular, when the plants were treated with compound TPG1 (500 µg/ml), disease control values against rice blast, tomato grey mold, tomato late blight, and wheat leaf rust were 84, 82, 88, and 70%, respectively, compared to the non-treatment control. Considering the in vitro and in vivo antifungal activities of the TPGs and the T. palmata methanol extracts, our results suggest that T. palmata can be a useful source to develop new natural fungicides.
Assuntos
Araliaceae/química , Fungicidas Industriais/isolamento & purificação , Doenças das Plantas/prevenção & controle , Triterpenos/isolamento & purificação , 1-Butanol , Acetatos , Avaliação Pré-Clínica de Medicamentos , Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Glicosídeos , Metanol , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/química , Extratos Vegetais/química , Solventes , Triterpenos/química , Triterpenos/farmacologiaRESUMO
Three new phenanthrenes (1-3), designated as 2-methoxy-1,6-dimethyl-5-vinyl-9, 10-dihydrophenanthren-7-ol, 1,6-dimethyl-4,5-dihydropyrene-2,7-diol and 1-(3,7- dihydroxy-2,8-dimethyl-9,10-dihydrophenanthren-1-yl)ethanone, were isolated from the aerial parts of Juncus effusus. Their structures were determined by extensive spectroscopic experiments (NMR and MS) and comparing with those related known compounds. The antifungal and antibacterial activities of 1-3 were evaluated. Compound 1 showed remarkable antifungal activities against six agricultural pathogenic fungi (Rhizoctonia solani, Verticillium dahliae Kleb, Sclerotinia sclerotiorum, Gibberella saubinetii, Bipolaris zeicola, and Phytophthora parasitica) with minimum inhibitory concentration (MIC) values ranging from 3.125 to 12.5⯵g/mL, and also displayed significant antibacterial activities against two human pathogenic bacteria (Bacterium paratyphosum B and Micrococcus lysodeikticus) with MIC values of 12.5 and 25⯵g/mL, respectively.
Assuntos
Antibacterianos/farmacologia , Fungicidas Industriais/farmacologia , Magnoliopsida/química , Fenantrenos/farmacologia , Antibacterianos/isolamento & purificação , China , Fungicidas Industriais/isolamento & purificação , Estrutura Molecular , Fenantrenos/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Componentes Aéreos da Planta/química , Plantas Medicinais/químicaRESUMO
Five new metabolites belonging to two backbones of pulvilloric acid-type azaphilone and tremulane sesquiterpene were obtained and their structures were determined by spectral analysis. Based on the biogenesis analysis, tremulane sesquiterpenes were obtained from Irpex lacteus by the stimulation of mixed-culture. The antifungal selectivities of metabolites produced by fungus against their co-culture fungus and common pathogens, exhibited competitive interaction of this mix-culture. The tremulane sesquiterpene conocenol B produced by I. lacteus through the induction of Nigrospora oryzae showed selectivity of anti-fungal activity against its co-culture fungus, N. oryzae, with MICs at 16 µg/mL and 128 µg/mL against I. lacteus. The fungus can metabolize these new compounds to inhibit the growth of co-culture fungus while not inhibiting its own growth. Compound 5 was active against acetylcholinesterase (AChE) with a ratio of 35% at the concentration of 50 µM.