Anthracycline Antibiotics isolated from a Marine-Derived Actinomycete Streptomyces cinereoruber 112CH-337

Abstract

The Streptomyces species are well known for their ability to produce secondary metabolites with various biological activities. This study focuses on the isolation of antimicrobial metabolites from a marine-derived strain of Streptomyces cinereoruber 112CH-337 isolated from a crown-of-thorns starfish, Acanthaster planci, collected from the Chuuk, Federated States of Micronesia. In the course of screening for new antimicrobial compounds, an extract of the strain 112CH-337 was found to exhibit potent antimicrobial activity. Bioassay-guided fractionation and purification of the culture extract of the strain 112CH-337 led to the isolation of two anthracycline derivatives known as α-citromycinone and β-rhodomycinone. These two anthracycline derivatives exhibited potent antimicrobial activities against both Gram-positive and negative bacteria. This is the first report on the isolation of α-citromycinone and β-rhodomycinone, anthracycline metabolites from a marine-derived S. cinereoruber 112CH-337.