New Anthraquinones from a Marine Streptomyces sp. – Isolation, Structure Determination and Biological Activities

Two new anthraquinones were isolated from the marine Streptomyces sp. B8000, in addition to the known metabolites 3,8-dihydroxy-1-propylanthraquinone-2-carboxylic acid (1a), indole-3- carboxylic acid, 2-desoxythymidin, indole-3-acetic acid methyl ester, N-acetyltyramine, and nicotinic acid. The structures of the new compounds were established as 8-hydroxy-3-methoxy-1- propylanthraquinone (2a) and 3,8-dihydroxy-1-propylanthraquinone (2c) on the basis of extensive spectroscopic analyses. Some derivatives were prepared and their biological activities were studied.