RESUMO

A recent investigation of the constituents of Eunicea sp. from Colombia and Puerto Rico has provided two novel cembrane glycosides, calyculaglycosides D (6) and E (7), and a new cembranoid diterpene in free form, (+)-nephthenol (4). Metabolites 6 and 7 possess a glycosyl-fused cembrane skeleton with a 1S configuration. Biogenetic considerations have led to a revision of the previously assigned dilophol skeleton of calyculaglycosides A-C, which was confirmed by extensive 2D NMR investigation and a chemical degradation study. Consequently, the true structures for calyculaglycosides A-C are 8-10, respectively, not 1-3. This is the first report of the occurrence of marine diterpene glycosides having a cembrane aglycon.

Assuntos

Cnidários/química , Diterpenos/isolamento & purificação , Glicosídeos/isolamento & purificação , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Colômbia , Diterpenos/química , Diterpenos/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Glicosídeos/química , Glicosídeos/farmacologia , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Porto Rico , Espectrofotometria Infravermelho , Estereoisomerismo