Cembrane diterpenes from the southern African soft coral Cladiella kashmani

Two known cembrane diterpenes, flaccidoxide (1) and(1Z,3E,7E,11S,12S,14S)-1 1,12-epoxy cembra-1,3,7-trien-14-ol (2), and the new cembrane diterpene fla ccidoxide-13-acetate (3) were isolated from specimens of Cladiella kashmani collected off Ponto do Oura, Mozambique. The modified Mosher's method esta blished the previously unassigned absolute configuration of 1 as (1Z,3E,7E, 11S,12S,13S,14R)-14-acetoxy-11,12-epoxy cembra-1,3,7-trien-13-ol. Acetylati on of 1 yielded 3 and thus confirmed the structure of 3 as (1Z,3E,7E,11S,12 R,13S,14R)-13,14-diacetoxy-11,12-epoxy cembra-1,3,7-triene. All three diter penes were toxic to the brine shrimp Artemia salina.