RESUMO
A new antimycin group antibiotic, antimycin A9, was isolated from a cultured broth of Streptomyces sp. K01-0031 together with antimycins A3a, A3b, A4, and A7, and flazin methyl ester. Antimycin A9 is the first antimycin having an aromatic 8-acyl residue. It showed potent nematocidal and insecticidal activities against Caenorhabditis elegans and Artemia salina, respectively. It inhibited bovine heart NADH oxidase at nanomolar level like other known antimycins.
Assuntos
Antibacterianos/isolamento & purificação , Antimicina A/análogos & derivados , Antimicina A/isolamento & purificação , Antinematódeos/isolamento & purificação , Animais , Antibacterianos/farmacologia , Antimicina A/farmacologia , Antinematódeos/farmacologia , Artemia/efeitos dos fármacos , Caenorhabditis elegans/efeitos dos fármacos , Bovinos , Testes de Sensibilidade Microbiana , Complexos Multienzimáticos/antagonistas & inibidores , NADH NADPH Oxirredutases/antagonistas & inibidores , Streptomyces , Relação Estrutura-AtividadeRESUMO
New antibiotics, miyakamides A1, A2, B1, and B2, were isolated from the cultured broth of Aspergillus flavus Link var. columnaris FKI-0739 together with known compounds, parasiticolide A, hydroxyaspergillic acid, and kojic acid. The structure of miyakamide A1 is N-acetyl-L-phenylalanyl-N-methyl-L-phenylalanyl-(alphaZ)-alpha,beta-didehydrotryptamine, and miyakamide A2 is E isomer of A1 at didehydrotryptamine. The structure of miyakamide B1 is N-acetyl-L-tyrosyl-N-methyl-L-phenylalanyl-(alphaZ)-alpha,beta-didehydrotryptamine, and B2 is E isomer of B1. Both miyakamides A1 and B1 existed as equilibrium isomers in solvents, and this isomerism was associated with cis-trans rotation of the amide bond between two amino acids. Conformational isomerism between two amino acids of miyakamides A2 and B2 is cis-form. Miyakamides showed growth inhibitory activity against brine shrimp, Artemia salina.
