New Pyran-2-ones from Alkalophilic Actinomycete, Nocardiopsis alkaliphila sp Nov YIM-80379

Two new pyran-2-ones, nocardiopyrones A and B (1 and 2, resp.), along with four known compounds, pyridinols 35, and 1-acetyl--carboline (6) were isolated from the alkalophilic actinomycete Nocardiopsis alkaliphila sp. nov. YIM-80379. Their structures were established on the basis of spectroscopic analysis, CD spectra, and the quantum-chemical ECD calculation. Pyridinols 35 were isolated from a natural source for the first time. Compounds 1 and 2 showed weak antibacterial activities against Pseudomonas aeruginosa, Enterobacter aerogenes, and Escherichia coli with MIC values of 2048M. Compound 2 showed weak antimicrobial activities against Candida albicans and Staphylococcus aureus with MIC values of 24 and 48M, respectively.