RESUMO
An endophytic Cryptosporiopsis sp. was isolated from Clidemia hirta and analyzed for its secondary metabolites that lead to the isolation of three bioactive molecules. The compounds were purified from the culture broth of the fungus and their structures were determined by spectroscopic methods as (R)-5-hydroxy-2-methylchroman-4-one (1), 1-(2,6-dihydroxyphenyl)pentan-1-one (2) and (Z)-1-(2-(2-butyryl-3-hydroxyphenoxy)-6-hydroxyphenyl)-3-hydroxybut-2-en-1-one (3). Compound 1 exhibited significant cytotoxic activity against the human leukemia cell line, HL-60 with an IC50 of 4 µg/ml. This compound induced G2 arrest of the HL-60 cell cycle significantly. In addition, out of these compounds, 2 and 3 were active against several bacterial pathogens. Compound 2 was active against Bacillus cereus, Escherichia coli and Staphylococcus aureus with IC50 values varying from 18 to 30 µg/ml, and compound 3 displayed activity against Pseudomonas fluorescens with an IC50 value of 6 µg/ml. Compounds 2 and 3 are novel whereas compound 1 was reported earlier but the stereochemistry of its C-2 methyl is established for the first time.
Assuntos
Ascomicetos/química , Bactérias/efeitos dos fármacos , Butirofenonas/farmacologia , Cromonas/uso terapêutico , Leucemia/tratamento farmacológico , Melastomataceae/microbiologia , Pentanonas/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Bacillus/efeitos dos fármacos , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Butirofenonas/química , Butirofenonas/isolamento & purificação , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Cromonas/química , Cromonas/isolamento & purificação , Cromonas/farmacologia , Endófitos/química , Escherichia coli/efeitos dos fármacos , Células HL-60 , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Pentanonas/química , Pentanonas/isolamento & purificação , Pseudomonas fluorescens/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacosRESUMO
Oncideres humeralis Thomson (Cerambycidae) was observed girdling the main trunk of plants of the Melastomataceae family in south-eastern Brazil. The main objectives of this work were to identify which host plants O. humeralis selects in the field and which are the characteristics of the preferred plants. O. humeralis specifically used Melastomataceae as host plants, attacking only four of the 11 species present in the study area. From the four attacked species, Miconia sellowiana Naudin and M. jucunda Triana were the preferred owes; they are the most abundant and the largest species, respectively. When the plants were taller, O. humeralis girdled the trunk at higher positions, indicating that females select plants with optimum trunk diameter and adjust the point to girdle according to the host height. Females also selected plants with greater numbers of secondary branches. These results indicate that O. humeralis is specific to certain species of Melastomataceae, and that host plants are selected on the basis of their abundance, size or number of secondary branches.
Oncideres humeralis Thomson (Cerambycidae) foi observado serrando o tronco principal de plantas da família Melastomataceae no sudeste do Brasil. Os principais objetivos deste trabalho identificar quais plantas hospedeiras O. humeralis seleciona no campo e quais as características das plantas preferidas. O. humeralis usou somente Melastomataceae como plantas hospedeiras, atacando quatro das 11 espécies presentes na área de estudo. Das quatro espécies atacadas, Miconia sellowiana Naudin e M. jucunda Triana, a espécie mais abundante e a maior, respectivamente, foram as preferidas. Quando as plantas eram altas, O. humeralis serrou o tronco em posições mais elevadas, indicando que as fêmeas selecionam plantas com diâmetro ótimo de tronco e ajustam o ponto para serrar em função da altura da hospedeira. As fêmeas também selecionaram plantas com maior número de ramos secundários. Estes resultados indicam que O. humeralis apresenta especificidade para determinadas espécies de Melastomataceae e que plantas hospedeiras são selecionadas pela sua abundância, tamanho ou número de ramos secundários.