New Cladiellane Diterpenes from the Soft Coral Cladiella australis of the Andaman and Nicobar Islands

Abstract

Five new cladiellane diterpenes, (1R*,2R*,3R*,6S*,7S*,9R*,10R*,14R*)-3- acetoxy-6-(3-methylbutanoyloxy)cladiell-11(17)-en-7-ol [2], (1R*,2R*,3R*,6S*,7S*,9R*, 10R*,14R*)-3-butanoyloxycladiell-11(17)-en-6,7-diol [3], (1R*,2R*,3R*,6S*,9R*,10R*,14R*)-3-acetoxycladiell-7(16),11(1 7)-dien-6-ol [4], 3-acetoxycladiell-11(17)-en-6-one [5], and its stereoisomer [6], have been isolated from the soft coral Cladiella australis collected on the coasts of the Andaman and Nicobar Islands of the Indian Ocean. In addition, sclerophytins C [7] and E [8], reported earlier from Sclerophytum capitalis, were also isolated. The structures of these metabolites were elucidated by interpretation of spectral data.