RESUMO
A new phthalide derivative, xylarphthalide A (1), along with two known compounds (-)-5-carboxylmellein (2) and (-)-5-methylmellein (3), were isolated from the endophytic fungus Xylaria sp. GDG-102 cultured from the Chinese medicinal plant Sophora tonkinensis. Their structures were identified by MS and NMR experiments, and the absolute configuration of 1 was further confirmed by single-crystal X-ray diffraction analysis. Compound 1-3 showed antibacterial activities against Bacillus megaterium, Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Shigella dysenteriae with MIC values of 12.5-25 µg/mL.
Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Benzofuranos/química , Benzofuranos/farmacologia , Xylariales/química , Bacillus subtilis/efeitos dos fármacos , Cristalografia por Raios X , Endófitos/química , Escherichia coli/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Plantas Medicinais/microbiologia , Sophora/microbiologia , Staphylococcus aureus/efeitos dos fármacosRESUMO
Two new cyclopentapeptides, xylapeptide A (1) with an uncommon L-pipecolinic acid moiety, and xylapeptide B (2) having a common L-proline residue were identified from an associated fungus Xylaria sp. isolated from the Chinese medicinal plant Sophora tonkinensis. Their planar structures were elucidated by a comprehensive analysis of NMR and MS spectroscopic spectra. The absolute configurations were determined by Marfey's method and single-crystal X-ray diffraction (Cu Kα) analysis. Xylapeptide A (1) is the first example of cyclopentapeptide with L-Pip of terrestrial origin and showed strong antibacterial activity against Bacillus subtilis and B. cereus with MIC value of 12.5 µg/mL.