Transformation of lactone to lactam in sarcophine and antimalarial activity of the resulting N-substituted azasarcophines

Sarcophine (1) is a furanocembranoid diterpene first reported from the Red Sea soft coral Sarcophyton glaucum with remarkable yields of up to 3% dry weight. Semisynthetic transformation of the lactone to lactam in sarcophine by reaction with benzyl and ethylamine afforded six new N-substituted azasarcophines (2-7), in addition to an asymmetric novel dimer 8. The in vitro activity of azasarcophines against Palsmodium falciparium (D6 clone) and P. falciparium (W2 clone) are also discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.