BIOSYNTHESIS OF VINEOMYCINS A₁ AND B₂

Abstract

Biosynthetic studies of the antibacterial and antitumor antibiotics vineomycins A₁ (1) and B₂ (2), produced by Streptomyces matensis subsp. vineus, were carried out by labeling experiments with [1-¹³C]- and [1, 2-¹³C₂]sodium acetate followed by ¹³C NMR spectroscopy. The results show that the benz[a]anthraquinone chromophore of 1 is derived from a decacetate metabolite with decarboxylation at the carboxyl end and that 2 is formed via C-C bond cleavage of 1. Isolation of rabelomycin from the fermentation broth of the same strain suggests a close biosynthetic relationship among the simple benz[a]anthraquinone antibiotics such as rabelomycin, tetrangomycin, aquayamycin, a C-glycosylated benz[a]anthraquinone, and vineomycins. These biosynthetic data prompted us to reconsider the previously published structure of the antibiotic SS-228Y, which has now been revised.