Biselyngbyolide A, a Novel Cytotoxic Macrolide from the Marine Cyanobacterium Lyngbya sp.

A novel cytotoxic macrolide biselyngbyolide A (1) was isolated from the marine cyanobacterium Lyngbya sp., collected on Tokunoshima Island, Japan. This macrolide was revealed to be structurally related to biselyngbyaside (2). The gross structure of 1 was elucidated based on the extensive application of 2D NMR techniques. The stereostructure was deduced based on analyses of the NOESY spectrum and CD data. Biselyngbyolide A (1) exhibited strong apoptosis-inducing activity against HeLa S-3 cells and HL60 cells.