Honulactones: new bishomoscalarane sesterterpenes from the Indonesian sponge Strepsichordaia aliena.

From the dichloromethane/2-propanol (1:1) extract of the Indonesian marine sponge Strepsichordaia aliena, twelve new 20, 24-bishomoscalarane sesterterpenes, honulactones A-L (1-12) were isolated. Molecular structures were secured by spectroscopic methods, accurate mass measurements, and X-ray analysis. Honulactones A (1), B (2), C (3), and D (4) exhibit cytotoxycity against P-388, A-549, HT-29, and MEL-28 (IC(50) 1 microg/mL).