The synthesis of melithiazol B (4) has been accomplished in five steps and 19% overall yield starting from myxothiazol A (1). Key steps include the conversion of the amide into the methyl ester 4, oxygenation to hydroperoxides 7 and 9, and subsequent Hock cleavage to ketones 11 and 12, followed by a Wittig reaction to give 4 and 13. The biological activities of intermediates, melithiazol B and derivatives thereof are compared.

A group of new polyene metabolites was detected in several crude extracts of the myxobacterium Stigmatella aurantiaca. The main compound dawenol (1) was isolated from cultures of S. aurantiaca, strain DW4/3-1. Its n-eicosaheptaene structure was elucidated by spectroscopic methods.

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