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1.
Fungal Biol ; 126(3): 250-266, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35183341

RESUMO

Many species in the Fusarium fujikuroi Species Complex (FFSC) have an affinity for grass species, with whom they live in an endophytic association or cause disease. We recovered isolates of Fusarium from agriculturally important grasses in Africa and Brazil, and characterized them with morphological markers, mating type, and Amplified Fragment Length Polymorphisms (AFLPs). We also conducted multi-locus phylogenetic analyses based on partial DNA sequences of translation elongation factor-1α (TEF1), ß-tubulin (TUB), and the second largest subunit of RNA polymerase (RPB2) gene regions. Sexual cross fertility was used to test the biological species concept and the sexual stage of F. madaense is described. A novel species within the FFSC, Fusarium mirum, that is different from the other known species in the complex, was formally described. Fusarium mirum, F. madaense, and Fusarium andiyazi are a tightly intertwined species trio that are morphologically identical, but phylogenetically distinguishable, and amongst whom interspecific genetic exchange may still occur. These three species are so close that they cannot be reliably distinguished if only sequences of the TEF1 gene are used. In pathogenicity tests, all tested isolates of F. madaense from sugarcane, sorghum, maize, millet and Brachiaria could induce stalk rot in sorghum, maize and millet, and pokkah boeng in sugarcane. This study increases our understanding of the diversity of species within the FFSC that cause disease in tropical grasses or act as endophytes, and their geographic distributions. The genetically close relationship between F. mirum, F. madaense, and F. andiyazi provides an opportunity to study and identify factors underlying their limited inter-specific cross-fertility and sympatric speciation.


Assuntos
Fusarium , Fusarium/genética , Filogenia , Poaceae , Zea mays
2.
Int J Food Microbiol ; 330: 108667, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-32531666

RESUMO

Fusarium fujikuroi species complex (FFSC) species are commonly encountered infecting rice, but knowledge of the diversity and toxigenic potential of the species is lacking in Brazil, the largest rice-producing country outside Asia. One hundred FFSC isolates obtained from national rice were identified using morphology and phylogeny of TEF, CAL and TUB genes. Eight previously known and one novel Fusarium species were identified. Three species accounted for around 60% of the strains: F. fujikuroi (n = 23), F. proliferatum (n = 22) and F. verticillioides (n = 16). The less frequent species were F. volatile (n = 8), F. anthophilum (n = 6), F. pseudocircinatum (n = 4), F. sterilihyphosum (n = 2) and F. begoniae (n = 1). The novel Fusarium species was represented by 18 isolates. All species produced at least one of the analyzed mycotoxins [beauvericin (BEA), fumonisins (FBs), moniliformin (MON) and enniatins (ENNs)]. BEA was produced by all species but F. verticillioides. The FBs (mainly FB1) were produced mostly by F. fujikuroi, F. proliferatum and F. verticillioides. F. begoniae and F. verticillioides did not produce ENNs and F. sterilihyphosum and F. begoniae did not produce MON, while the other species produced MON and ENNs. Our results add new knowledge of the diversity, geographical distribution and host range of FFSC species.


Assuntos
Fusarium/química , Fusarium/classificação , Oryza/microbiologia , Biodiversidade , Brasil , Fusarium/genética , Fusarium/isolamento & purificação , Especificidade de Hospedeiro , Micotoxinas/análise , Filogenia , Venenos/análise
3.
Int J Food Microbiol ; 306: 108267, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31330453

RESUMO

Fusarium incarnatum-equiseti species complex (FIESC) is commonly detected in Brazilian rice, but knowledge of the species limits and their toxigenic potential is lacking. Seventy strains morphologically identified as FIESC-like, isolated from the major rice-growing regions of Brazil, were subjected to sequencing of EF-1α gene. Among them, 18 strains were selected and analyzed for their RPB2 gene sequences. Nine phylogenetic species were identified, among which eight matched the previously reported FIESC 4 (F. lacertarum), 6, 16, 17 (F. pernambucanum), 20 (F. caatingaense), 24, 26 and 29. One new phylogenetic species was identified, and named FIESC 38. Five strains formed new singleton lineages. The most dominant species were FIESC 26 (22/70 strains) and FIESC 38 (21/70), the newly identified species. The incarnatum morphotype was dominant (10 phylogenetic species) over the equiseti (4 species). Among 46 strains selected to represent all species, only 16 strains produced detectable levels of mycotoxins in vitro. FIESC 26 produced ZEA and FIESC 38 produced both ZEA and DON. ZEA was produced by nine isolates of three other species, among which few isolates produced trichothecenes: DON (5/46), NIV (3/46), 4-ANIV (2/46), 15-ADON (1/46) and 3-ADON (1/46). The T-2 and HT-2 mycotoxins were not detected. Our results contribute novel information on species limits and mycotoxin production within cereal-infecting FIESC in the southern hemisphere and provide baseline data for further exploring morphological differences among the species.


Assuntos
Fusarium/classificação , Fusarium/patogenicidade , Micotoxinas/metabolismo , Oryza/microbiologia , Tricotecenos/metabolismo , Brasil , Grão Comestível/microbiologia , Fusarium/genética , Fusarium/isolamento & purificação , Micotoxinas/genética , Fator 1 de Elongação de Peptídeos/genética , Filogenia , RNA Polimerase II/genética , Tricotecenos/genética
4.
Bioorg Chem ; 78: 436-443, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29702360

RESUMO

The plant diastereoisomeric diterpenes ent-pimara-8(14)-15-dien-19-oic acid, obtained from Viguiera arenaria, and isopimara-8(14)-15-dien-18-oic acid, isolated from Cupressus lusitanica, were distinctly functionalized by the enzymes produced in whole cell cultures of the fungus Preussia minima, isolated from surface sterilized stems of C. lusitanica. The ent-pimaradienoic acid was transformed into the known 7ß-hydroxy-ent-pimara-8(14)-15-dien-19-oic acid, and into the novel diterpenes 7-oxo-8 ß-hydroxy-ent-pimara-8(14)-15-dien-19-oic and 7-oxo-9ß-hydroxy-ent-pimara-8(14)-15-dien-19-oic acids. Isopimara-8(14)-15-dien-18-oic acid was converted into novel diterpenes 11α-hydroxyisopimara-8(14)-15-dien-18-oic acid, 7ß,11α-dihydroxyisopimara-8(14)-15-dien-18-oic acid, and 1ß,11α-dihydroxyisopimara-8(14)-15-dien-18-oic acid, along with the known 7ß-hydroxyisopimara-8(14)-15-dien-18-oic acid. All compounds were isolated and fully characterized by 1D and 2D NMR, especially 13C NMR. The diterpene bioproduct 7-oxo-9ß-hydroxy-ent-pimara-8(14)-15-dien-19-oic acid is an isomer of sphaeropsidin C, a phytotoxin that affects cypress trees produced by Shaeropsis sapinea, one of the main phytopathogen of Cupressus. The differential metabolism of the diterpene isomers used as substrates for biotransformation was interpreted with the help of computational molecular docking calculations, considering as target enzymes those of cytochrome P450 group.


Assuntos
Ascomicetos/química , Cupressus/microbiologia , Diterpenos/química , Biotransformação , Cupressus/química , Diterpenos/isolamento & purificação , Diterpenos/metabolismo , Conformação Molecular , Simulação de Acoplamento Molecular , Estereoisomerismo
5.
J Nat Prod ; 80(5): 1674-1678, 2017 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-28425292

RESUMO

Three new isoaigialones, A, B, and C (1-3), along with aigialone (4), were isolated from the crude EtOAc extract of a Phaeoacremonium sp., an endophytic fungus obtained from the leaves of Senna spectabilis. The structures of these compounds were elucidated based on the analysis of spectroscopic data. Compounds 2 and 4 were active against the phytopathogenic fungi Cladosporium cladosporioides and C. sphaerospermum. This is the first report of metabolites produced by an Phaeoacremonium sp., associated with S. spectabilis.


Assuntos
Acetais/isolamento & purificação , Acetais/farmacologia , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Ascomicetos/química , Cladosporium/química , Cetonas/isolamento & purificação , Cetonas/farmacologia , Lactonas/isolamento & purificação , Folhas de Planta/química , Senna/química , Acetais/química , Antifúngicos/química , Cetonas/química , Lactonas/química , Lactonas/metabolismo , Lactonas/farmacologia , Estrutura Molecular
6.
Nat Prod Res ; 31(22): 2599-2603, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28135874

RESUMO

A fungal strain of Aspergillus niger was recovered from sediments collected in the Northeast coast of Brazil (Pecém's offshore port terminal). Cultivation in different growth media yielded a new ester furan derivative, 1, along with malformin A1, malformin C, cyclo (trans-4-hydroxy-L-Pro-L-Leu), cyclo (trans-4-hydroxy-L-Pro-L-Phe), cyclo (L-Pro-L-Leu), cyclo (L-Pro-L-Phe), pseurotin D, pseurotin A, chlovalicin, cyclo (L-Pro-L-Tyr) and cyclo (L-Pro-L-Val). Compound 1 was cytotoxic against HCT-116 cell line, showing IC50 = 2.9 µg/mL (CI 95% from 1.8 to 4.7 µg/mL).


Assuntos
Antineoplásicos/farmacologia , Aspergillus niger/química , Antineoplásicos/química , Brasil , Cicloexanonas/isolamento & purificação , Cicloexanonas/farmacologia , Dipeptídeos/isolamento & purificação , Dipeptídeos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Compostos de Epóxi/isolamento & purificação , Compostos de Epóxi/farmacologia , Furanos/química , Sedimentos Geológicos/microbiologia , Células HCT116 , Humanos , Concentração Inibidora 50 , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Peptídeos Cíclicos/química , Peptídeos Cíclicos/isolamento & purificação , Peptídeos Cíclicos/farmacologia , Pirrolidinonas/isolamento & purificação , Pirrolidinonas/farmacologia
7.
Fungal Biol ; 120(1): 51-60, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26693684

RESUMO

Isolates of Fusarium obtained from soybean plants showing symptoms of root rot collected in subtropical southern and tropical central Brazil were characterized based on phylogenetic analyses, sexual crossing, morphology, and pathogenicity tests. A novel species within the Fusarium solani species complex (FSSC) causing soybean root rot is formally described herein as Fusarium paranaense. This species can be distinguished from the other soybean root rot pathogens in the FSSC, which are commonly associated with soybean sudden death syndrome (SDS) based on analyses of the combined DNA sequences of translation elongation factor 1-α and the second largest subunit of RNA polymerase II and on interspecies mating compatibility. Bayesian and maximum parsimony phylogenetic analyses showed that isolates of F. paranaense formed a distinct group in clade 3 of the FSSC in contrast to the pathogens currently known to cause SDS, which are in clade 2. Female fertile tester strains were developed that can be used for the identification of this new species in the FSSC based on sexual crosses. All isolates were heterothallic and belonged to a distinct mating population. Fusarium tucumaniae, a known SDS pathogen, was found in the subtropical southern region of the country.


Assuntos
Fusarium/isolamento & purificação , Glycine max/microbiologia , Doenças das Plantas/microbiologia , Brasil , Proteínas Fúngicas/genética , Fusarium/classificação , Fusarium/genética , Fusarium/crescimento & desenvolvimento , Genótipo , Dados de Sequência Molecular , Filogenia , Raízes de Plantas/microbiologia , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/isolamento & purificação
8.
Molecules ; 20(9): 17627-44, 2015 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-26404231

RESUMO

UHPLC-DAD-HRMS based dereplication guided the detection of new halogenated alkaloids co-produced by Talaromyces wortmannii. From the fungal growth in large scale, the epimers 2,8-dichlororugulovasines A and B were purified and further identified by means of a HPLC-SPE/NMR hyphenated system. Brominated rugulovasines were also detected when the microbial incubation medium was supplemented with bromine sources. Studies from 1D/2D NMR and HRMS spectroscopy data allowed the structural elucidation of the dichlorinated compounds, while tandem MS/HRMS data analysis supported the rationalization of brominated congeners. Preliminary genetic studies revealed evidence that FADH2 dependent halogenase can be involved in the biosynthesis of the produced halocompounds.


Assuntos
Indóis/isolamento & purificação , Talaromyces/química , Talaromyces/crescimento & desenvolvimento , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Alcaloides de Claviceps/biossíntese , Flavina-Adenina Dinucleotídeo/análogos & derivados , Flavina-Adenina Dinucleotídeo/metabolismo , Proteínas Fúngicas/metabolismo , Halogenação , Indóis/química , Estrutura Molecular , Talaromyces/enzimologia
9.
Chem Biodivers ; 12(3): 432-42, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25766916

RESUMO

The cytotoxic activities of extracts (50 µg/ml) from 48 fungal strains, recovered from sediments of Pecém's offshore port terminal (Northeast coast of Brazil), against HCT-116 colon cancer cell lines were investigated. The most promising extract was obtained from strain BRF082, identified as Dichotomomyces cejpii by phylogenetic analyses of partial RPB2 gene sequence. Thus, it was selected for bioassay-guided isolation of the cytotoxic compounds. Large-scale fermentation of BRF082 in potato dextrose broth, followed by chromatographic purification of the bioactive fractions from the liquid medium, yielded gliotoxin (4) and its derivatives acetylgliotoxin G (3), bis(dethio)bis(methylsulfanyl)gliotoxin (1), acetylgliotoxin (5), 6-acetylbis(dethio)bis(methylsulfanyl)gliotoxin (2), besides the quinazolinone alkaloid fiscalin B. All isolated compounds were tested for their cytotoxicities against the tumor cell lines HCT-116, revealing 4 and 3 as the most cytotoxic ones (IC50 0.41 and 1.06 µg/ml, resp.).


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Fungos/química , Sedimentos Geológicos/microbiologia , Antineoplásicos/isolamento & purificação , Produtos Biológicos/isolamento & purificação , Brasil , Neoplasias do Colo/tratamento farmacológico , Fungos/genética , Gliotoxina/análogos & derivados , Gliotoxina/química , Gliotoxina/isolamento & purificação , Gliotoxina/farmacologia , Células HCT116 , Humanos , Indóis/química , Indóis/isolamento & purificação , Indóis/farmacologia , Filogenia , Quinazolinas/química , Quinazolinas/isolamento & purificação , Quinazolinas/farmacologia
10.
Nat Prod Res ; 29(16): 1545-50, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25532964

RESUMO

A fungal strain of Aspergillus sp. (BRF 030) was isolated from the sediments collected in the northeast coast of Brazil, and the cytotoxic activity of its secondary metabolites was investigated against HCT-116 tumour cell line. The cytotoxicity-guided fractionation of the extracts from this fungus cultured in potato-dextrose-sea water for 14 days at room temperature yielded the hetero-spirocyclic γ-lactams pseurotin A (1), pseurotin D (2) and pseurotin FD-838 (7), the alkaloids fumitremorgin C (5), 12,13-dihydroxy fumitremorgin C (6), methylsulochrin (4) and bis(dethio)bis(methylthio)gliotoxin (3). Among them, fumitremorgin C (5) and 12,13-dihydroxy fumitremorgin C (6) were the most active. The cytotoxic activities of the extracts from Aspergillus sp. grown from 7 to 28 days were investigated, and they were associated with the kinetic production of the compounds. The most active extracts (14 and 21 days) were those with the highest relative concentrations of the compounds fumitremorgin C (5) and 12,13-dihydroxy fumitremorgin C (6).


Assuntos
Antineoplásicos/química , Aspergillus/química , Antineoplásicos/isolamento & purificação , Aspergillus/isolamento & purificação , Brasil , Linhagem Celular Tumoral/efeitos dos fármacos , Sedimentos Geológicos/microbiologia , Humanos , Indóis/química , Indóis/isolamento & purificação , Estrutura Molecular , Água do Mar/microbiologia
11.
Fungal Biol ; 118(12): 1004-12, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25457948

RESUMO

We assessed the species diversity among 45 strains of Clonostachys from different substrates and localities in Brazil using molecular phylogenetics, and compared the results with the phenotypic classification of strains obtained from matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Phylogenetic analyses were based on beta tubulin (Tub), ITS-LSU rDNA, and a combined Tub-ITS DNA dataset. MALDI-TOF MS analyses were performed using intact conidia and conidiophores of strains cultivated on oatmeal agar and 4% malt extract agar. Six known species were identified: Clonostachys byssicola, Clonostachys candelabrum, Clonostachys pseudochroleuca, Clonostachys rhizophaga, Clonostachys rogersoniana, and Clonostachys rosea. Two clades and two singleton lineages did not correspond to known species represented in the reference DNA dataset and were identified as Clonostachys sp. 1-4. Multivariate cluster analyses of MALDI-TOF MS data classified the strains into eight clusters and three singletons, corresponding to the ten identified species plus one additional cluster containing two strains of C. rogersoniana that split from the other co-specific strains. The consistent results of MALDI-TOF MS supported the identification of strains assigned to C. byssicola and C. pseudochroleuca, which did not form well supported clades in all phylogenetic analyses, but formed distinct clusters in the MALDI-TOF dendrograms.


Assuntos
Biodiversidade , Hypocreales/classificação , Filogenia , Brasil , DNA Fúngico/genética , DNA Ribossômico/genética , Hypocreales/genética , Análise de Sequência de DNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Esporos Fúngicos/crescimento & desenvolvimento
12.
Molecules ; 19(11): 19243-52, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-25421415

RESUMO

In this study, eight endophytic fungi were isolated from the leaves, stems and roots of Michelia champaca. The isolates were screened and evaluated for their antifungal, anticancer and acetylcholinesterase (AChE) inhibitory activities. All of the extracts exhibited potent activity against two evaluated phytopathogenic fungi. Chemical investigation of EtOAc extracts of the endophytic fungus Colletotrichum gloeosporioides resulted in the isolation of one new compound, 2-phenylethyl 1H-indol-3-yl-acetate (1), and seven known compounds: uracil (2), cyclo-(S*-Pro-S*-Tyr) (3), cyclo-(S*-Pro-S*-Val) (4), 2(2-aminophenyl)acetic acid (5), 2(4-hydroxyphenyl)acetic acid (6), 4-hydroxy- benzamide (7) and 2(2-hydroxyphenyl)acetic acid (8). All of the compound structures were elucidated using 1D and 2D NMR and MS analyses. The antifungal and AChE inhibitory activities of compounds 1-8 were evaluated in vitro. Compound 1 exhibited promising activity against Cladosporium cladosporioides and C. sphaerospermum that was comparable to that of the positive control nystatin.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Colletotrichum/química , Fungos/efeitos dos fármacos , Magnoliaceae/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Cladosporium/efeitos dos fármacos , Testes de Sensibilidade Microbiana/métodos , Folhas de Planta/química , Raízes de Plantas/química , Caules de Planta/química
13.
Nat Prod Commun ; 9(9): 1279-82, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25918791

RESUMO

A quantitative profile of cytochalasin D production by Xylaria arbuscula was followed by growing the fungus in rice, Czapek, Czapek enriched with yeast extract, wheat, and corn. This cytochalasin producer, X. arbuscula, was collected as an endophytic fungus from healthy tissues of Cupressus lusitanica (Cupressaceae). A new HPLC method was developed using a synthetic N-acetyl-L-phenylalanine ethyl ester as internal standard, which showed a good correlation coefficient (r2 = 0.9995). The results varied from 6.40 to 39.55 mg per 100 g of culture medium, with wheat being the best medium for cytochalasin D production. The level of any free amino acids in the medium, not necessarily phenylalanine, appeared to be an important factor to enhance cytochalasin D biosynthesis.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Citocalasina D/metabolismo , Xylariales/química , Xylariales/metabolismo , Meios de Cultura/metabolismo , Xylariales/crescimento & desenvolvimento
14.
Phytopathology ; 103(5): 400-8, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23379853

RESUMO

In this letter, we advocate recognizing the genus Fusarium as the sole name for a group that includes virtually all Fusarium species of importance in plant pathology, mycotoxicology, medicine, and basic research. This phylogenetically guided circumscription will free scientists from any obligation to use other genus names, including teleomorphs, for species nested within this clade, and preserve the application of the name Fusarium in the way it has been used for almost a century. Due to recent changes in the International Code of Nomenclature for algae, fungi, and plants, this is an urgent matter that requires community attention. The alternative is to break the longstanding concept of Fusarium into nine or more genera, and remove important taxa such as those in the F. solani species complex from the genus, a move we believe is unnecessary. Here we present taxonomic and nomenclatural proposals that will preserve established research connections and facilitate communication within and between research communities, and at the same time support strong scientific principles and good taxonomic practice.


Assuntos
Fusarium/classificação , Plantas/microbiologia , Fusarium/genética , Filogenia , Doenças das Plantas/microbiologia
15.
Nat Prod Res ; 27(18): 1705-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23439233

RESUMO

Propolis is a natural product widely known for its medicinal properties. In this work, fungi present on propolis samples were isolated, identified and tested for the production of antimicrobial metabolites. Twenty-two fungal isolates were obtained, some of which were identified as Alternaria alternata, Aspergillus flavus, Bipolaris hawaiiensis, Fusarium merismoides, Lasiodiplodia theobromae, Penicillium citrinum, Penicillium crustosum, Penicillium janthinellum, Penicillium purpurogenum, Pestalotiopsis palustris, Tetracoccosporium paxianum and Trichoderma koningii. These fungi were grown in liquid media to obtain crude extracts that were evaluated for their antibiotic activity against pathogenic bacteria, yeast and Cladosporium cladosporioides and A. flavus. The most active extract was obtained from L. theobromae (minimum inhibitory concentration = 64 µg/mL against Listeria monocitogenes). Some extracts showed to be more active than the positive control in the inhibition of Staphylococcus aureus and L. monocitogenes. Therefore, propolis is a promising source of fungi, which produces active agents against relevant food poisoning bacteria and crop-associated fungi.


Assuntos
Antibacterianos/química , Anti-Infecciosos/química , Fungos/química , Própole/química , Alternaria/química , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Ascomicetos/química , Cladosporium/efeitos dos fármacos , Fusarium/química , Penicillium/química , Staphylococcus aureus , Trichoderma/química
16.
Mycologia ; 104(6): 1408-19, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22675046

RESUMO

Fusarium tupiense, the main causal agent of mango malformation in Brazil, is described through a combination of morphological, biological and molecular markers. This new species belongs to the Gibberella fujikuroi species complex (GFSC) and has an anamorph morphologically similar to Fusarium mangiferae and F. sterilihyphosum. F. tupiense can be differentiated from other species in the G. fujikuroi species complex on the basis of sexual crosses, amplified fragment length polymorphism (AFLP) markers and partial sequences of the tef1 and tub2 genes. Female fertility for field isolates of F. tupiense appears to be low. PCR with primers specific for the mating type (MAT) alleles and sexual crosses identified this species as heterothallic with two idiomorphs. Female-fertile tester strains were developed for the identification of field strains of this species through sexual crosses.


Assuntos
Fusarium/classificação , Gibberella/classificação , Mangifera/microbiologia , Filogenia , Doenças das Plantas/microbiologia , Alelos , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Brasil , Cruzamentos Genéticos , DNA Fúngico/genética , Fusarium/citologia , Fusarium/genética , Fusarium/isolamento & purificação , Genes Fúngicos Tipo Acasalamento/genética , Gibberella/citologia , Gibberella/genética , Gibberella/isolamento & purificação , Inflorescência/microbiologia , Brotos de Planta/microbiologia , Esporos Fúngicos/classificação , Esporos Fúngicos/citologia , Esporos Fúngicos/genética , Esporos Fúngicos/isolamento & purificação
17.
Fungal Biol ; 116(2): 249-60, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22289771

RESUMO

Phomopsis and related taxa comprise important endophytic and plant pathogenic species, and are known for the production of a diverse array of secondary metabolites. Species concepts within this group based on morphological characters and assumed host specificity do not reflect phylogenetic affinities. Additional phenotypic characters, such as profiles of secondary metabolites, are needed for practical species recognition. We investigated 36 strains of Phomopsis spp. and Cytospora-like fungi, obtained as endophytes of different host plants in Brazil, using metabolite profiling based on HPLC-UV/liquid chromatography -mass spectrometry (LC-MS) combined with cluster analysis of the results. Strains were also subjected to phylogenetic analyses based on internal transcribed spacer (ITS) rDNA. Six chemotypes were identified. Chemotypes 1-5 contained Phomopsis strains, while Cytospora-like strains formed the chemotype 6. Strains of chemotype 1 typically produced alternariols, altenusin, altenuene, cytosporones, and dothiorelones. Alternariol and seven unknown compounds were consistently produced by strains of chemotype 2. Members of chemotypes 3-5 produced poor metabolite profiles containing few chemical markers. Cytospora-like endophytes (chemotype 6) produced a characteristic set of metabolites including cytosporones and dothiorelones. Bayesian and Maximum Parsimony (MP) trees classified strains of each chemotype into single phylogenetic lineages or closely related groups. Strains of chemotypes 1 and 2 formed a monophyletic group along with Diaporthe neotheicola. The remaining Phomopsis strains formed monophyletic (chemotype 4) or polyphyletic (chemotypes 3 and 5) lineages inside a large and well supported clade. Cytospora-like strains formed a monophyletic lineage located at an intermediary position between Diaporthe/Phomopsis and Valsa/Cytospora clades. The combined results show that the production of secondary metabolites by Phomopsis and related Diaporthales may be species-specific, giving support to the use of metabolite profiling and chemical classification for phenotypic recognition and delimitation of species.


Assuntos
Ascomicetos/química , Ascomicetos/genética , Endófitos/química , Endófitos/genética , Metaboloma , Plantas/microbiologia , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Brasil , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Endófitos/classificação , Endófitos/isolamento & purificação , Genótipo , Espectrometria de Massas , Dados de Sequência Molecular , Fenótipo , Filogenia , Análise de Sequência de DNA , Espectrofotometria
18.
J Nat Prod ; 73(8): 1431-3, 2010 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-20617817

RESUMO

A new product of biotransformation of ent-16-oxo-17-norkauran-19-oic acid (1) by Fusarium proliferatum was isolated and identified as a 2beta-hydroxy derivative (2). The structure of 2 was elucidated on the basis of spectroscopic data interpretation and single-crystal X-ray diffraction analysis. The allelopathic activity of compound 2 was evaluated on the growth of radicals and shoots of Lactuca sativa (lettuce). This is the first time that fungal hydroxylation at position C-2 has been reported on an ent-kaurane diterpene skeleton.


Assuntos
Diterpenos do Tipo Caurano/química , Fusarium/metabolismo , Lactuca/efeitos dos fármacos , Biotransformação , Brasil , Cristalografia por Raios X , Hidroxilação , Lactuca/crescimento & desenvolvimento , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Wedelia/química
19.
Braz. j. pharm. sci ; 45(4): 677-685, Oct.-Dec. 2009. tab, ilus
Artigo em Inglês | LILACS | ID: lil-543663

RESUMO

A total of 22 endophytic fungi isolated from coffee (Coffea arabica L.) were cultivated in vitro and their crude extracts tested. The screening was carried out using the agar diffusion method against Staphylococcus aureus, Escherichia coli and Candida albicans. The most effective isolate was Alternaria alternata, and subsequently, its extract was assayed. The total phenolic content was 3.44 μg GAE/mg of the crude extract. For the antibacterial and antifungal activity assays, minimum inhibitory concentrations (MIC) and minimum bactericidal and fungicidal concentrations (MBC and MFC) were determined. The ranges of MIC values were 50-100 μg/mL for S. aureus and 400-800 μg/mL for E. coli. The extract did not show activity in the tested concentrations for C. albicans. The fungal crude extract was assayed for antioxidant activities. Its ability to scavenge DPPH radicals and antioxidant activity by β-carotene/linoleic acid system oxidation was not significant. In addition, antitumor activity was studied using the MTT assay. At a dilution of 400 μg/mL, the extract displayed a cytotoxic activity of approximately 50 percent towards HeLa cells in vitro. The results indicate that endophytic fungi could be a promising source of bioactive compounds and warrant further study.


Total de 22 fungos endofíticos isolados de café (Coffea arabica L.) foi cultivado in vitro e seus extratos testados. A triagem foi conduzida pelo método de difusão em agar contra bactérias Gram-positiva, Gram-negativa e uma levedura. O isolado mais efetivo foi Alternaria alternata e, subsequentemente, seu extrato foi analisado. O conteúdo de fenólicos totais do extrato bruto foi de 3,44 μg EAG/mg de extrato. Para os testes de atividade antimicrobiana, a concentração inibitória mínima (CIM) e concentração bactericida e fungicida mínima (CBM e CFM) contra Staphylococcus aureus, Escherichia coli e Candida albicans foram determinadas. Resultados da CIM variaram entre 50-100 μg/mL para S. aureus e 400-800 μg/mL para E. coli. O extrato bruto não apresentou atividade nas concentrações testadas para C. albicans. Foram analisadas as atividades antioxidantes do extrato bruto. Sua habilidade para seqüestrar radicais DPPH e a atividade antioxidante pela oxidação do sistema β-caroteno/ácido linoléico não foram significativas. Além disso, a atividade antitumoral foi estudada pelo teste do MTT. À diluição de 400 μg/mL, o extrato apresentou atividade de aproximadamente 50 por cento sobre as células HeLa in vitro. Os resultados indicam que fungos endófitos poderiam ser uma fonte promissora de compostos bioativos necessitando de estudos futuros.


Assuntos
Alternaria/crescimento & desenvolvimento , Alternaria/química , Coffea Cruda/análise , Fermentação , Antioxidantes/metabolismo , Compostos Químicos/análise , Sinergismo Farmacológico
20.
Electron. j. biotechnol ; 12(4): 8-9, Oct. 2009. ilus, tab
Artigo em Inglês | LILACS | ID: lil-558551

RESUMO

The morphological features of a Penicillium, isolated from Brazilian cerrado soil, were characterized and showed to be distinctly different from all well-defined Penicillium species. Chemical and biological investigation on the ethyl acetate extract of this Penicillium isolate resulted in the isolation of three new naphthalenoids: a major metabolite, methyl 6-acetyl-4-methoxy-5,7,8-trihydroxynaphthalene-2-carboxylate and two minor ones, methyl 6-acetyl-4-methoxy-7,8-dihydroxynaphthalene-2-carboxylate and methyl 6-acetyl-4-methoxy-5,8-dihydroxynaphthalene-2-carboxylate. Their structures were determined based on their mono and bidimensional nuclear magnetic resonance data. Acetyl, allyl and methoxyl derivatives of the major metabolite were prepared in order to establish structure-activity relation. Antimicrobial activity of the major natural product and its semi-synthetic derivatives was screened by macro dilution methodology and the corresponding minimum inhibitory concentrations were determined. Natural secondary metabolite methyl 6-acetyl-4-methoxy-5,7,8-trihydroxynaphthalene-2-carboxylate, isolated in a very high yield (0.3175 mg.L-1) showed to be the most active compound, possessing expressive activity against Candida albicans (minimum inhibitory concentration (MIC) 32 ug/mL), Listeria monocitogenes and Bacillus cereus (MIC 64 µg/mL for both).


Assuntos
Animais , Fungos/isolamento & purificação , Penicillium/isolamento & purificação , Penicillium/classificação , Penicillium/metabolismo , Brasil , Espectroscopia de Ressonância Magnética/métodos , Metilação , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão/métodos
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