Altersolanol-related compounds from the culture liquid of Alternaria solani

Two new crystalline pigments, 5-methylsulphonylmethylenealtersolanol A and 5-methylaltersolanol A, together with tetrahydroaltersolanol B, were isolated from the culture liquid of a strain of Alternaria solani, a pathogen of tomato Lycopersicon esculentum. Their structures have been established from spectroscopic studies, and the structures of 5-methylsulphonylmethylenealtersolanol A and 5-methylaltersolanol A were shown to be 6-methoxy-5-methylsulphonylmethylene-3 beta-methyl-1 beta,2 alpha,3 alpha,4 beta,8-pentahydroxy-1,2,3,4-tetrahydroanthraquinone and 6-methoxy-3 beta,5-dimethyl-1 beta,2 alpha,3 alpha,4 beta,8-pentahydroxy-1,2,3,4-tetrahydroanthraquinone, respectively.