Boshramycinones A-C: New anthracyclinones produced by a marine-derived Streptomyces sp.: isolation, structure elucidation and biological activities

Abstract

Boshramycinones A-C (1–3), three new anthracyclinones, were isolated from the culture broth of the marine-derived Streptomyces sp. Mei 16-1,2 together with 2-acetyl-1,8-dihydroxy-3-methyl-anthraquinone (4) and bafilomycins B1, B2, and C1-amide. The isolated compounds were identified by NMR spectroscopy and mass spectrometry, the absolute configuration of 3 was determined by comparison of experimental and ab initio-calculated chiroptical data. The antimicrobial activity of the bacterial extract and the isolated compounds were assayed using a set of microorganisms, and cytotoxic activities were determined against 36 human cancer cell lines.

Graphical Abstract

Keywords:

• Boshramycinones A-C
• anthracyclinones
• marine Streptomyces sp.
• biological activity

Acknowledgements

We thank R. Machinek for the NMR spectra, Dr. H. Frauendorf for the mass spectra, and F. Lissy and A. Kohl for technical assistance.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financed by a grant from the Bundesministerium für Bildung und Forschung (BMBF, grant 03F04153A).