Angucycline antibiotics and its derivatives from marine-derived actinomycete Streptomyces sp. A6H

Abstract

Vineomycin A₁ (1) and B₂ (2) were isolated from the culture broth of marine actinomycete Streptomyces sp. A6H. Five hydrolysis products were obtained by rational hydrolysis and methanolysis of the fermentation extract. Their structures were characterised as aquayamycin (3), vineomycinone B₂ (4), 9-C-_D-olivosyltetrangulol (5), 7-O-methylgaltamycinone (6) and vineomycinone B₂ methyl ester (7). In addition to these compounds, two ester derivatives, vineolactone A (8) and vineomycinone B₂ benzyl ester (9) of compound 4 were generated semisynthetically. Compound 6 is a new analogue of galtamycinone, while compounds 8 and 9 are new members of vineomycins. Cytotoxic activities and antimicrobial activities were determined for all compounds. The results indicate that only compound 1 showed significant activities with IC₅₀ value of 0.34 μM against H1975 and MIC value of 4 μg/mL against Staphylococcus aureus.

Keywords:

• Streptomyces sp. A6H
• angucycline
• hydrolysis
• semisynthesis

Acknowledgements

We thank Mrs Yu Liu at College of Life Science of Zhejiang University for performing NMR spectrometry.

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

This work was supported by Zhejiang University Cross Researching Fund under [grant number JCZZ-2013021] and Public Welfare Technology Applied Research Planning Project of Zhejiang Province [grant number 2014C33173].