Cystothiazoles C-F, new bithiazole-type antibiotics from the myxobacterium Cystobacter fuscus

Abstract Bithiazole-type antifungal products, cystothiazoles C-F ( 3–6 ), have been isolated from a culture broth of the myxobacterium Cystobacter fuscus as minor components. These are structurally related to cystothiazole A ( 1 ), which was isolated as a cytotoxic antibiotic from the same microorganism in our previous work. The structures of these compounds were elucidated by spectroscopic analyses. These new compounds inhibit the phytopathogenic fungus, Phytophthora capsici , but are less active than 1 .