Diterpenoids from the roots of Croton dichogamus Pax

Abstract

Four previously undescribed diterpenoids including two crotofolanes, crotodichogamoin A and B, and two halimanes, crothalimene A and B, a new sesquiterpenoid, and fifteen previously reported compounds, including the crotofolane, crotohaumanoxide, the casbane, depressin, a further seven furanohalimane diterpenoids, three patchoulane and two further cadinane sesquiterpenoids and aleuritolic acid were isolated from the root of Croton dichogamus. Crotodichogamoin B is an important biosynthetic intermediate of the crotofolane class and this is the first report of patchoulene sesquiterpenoids from the genus. Compounds were tested at one concentration, 1 × 10−5 M, in the NCI59 cell one-dose screen but did not show significant activity snd were also evaluated for their cytotoxicity against Caco-2 cell lines using the neutral red assay. 10-epi-Maninsigin D reduced Caco-2 cell viability at 10, 30 and 100 μM, with values of decreased viability of 28%, 48% and 43% respectively. None of the other tested compounds showed significant activity.