Botryane Metabolites from the Fungus Geniculosporium sp. Isolated from the Marine Red Alga Polysiphonia

Eleven new botryane metabolites (1−11) were isolated together with four known cytochalasins (12−15) from the mitosporic fungus Geniculosporium sp., which is associated with the red alga Polysiphonia sp. The structures of 1−11 differ from known botryanes in substitution pattern, degree of saturation, and altered sites of oxidation, alkylation, unsaturation, etc. They were determined by spectroscopic methods (mainly extensive 1D and 2D NMR experiments and mass spectral measurements) and X-ray single-crystal analysis. The herbicidal, antifungal, and antibacterial activities of these new natural products were evaluated.