The Calyculaglycosides: Dilophol-Type Diterpene Glycosides Exhibiting Antiinflammatory Activity from the Caribbean Gorgonian Eunicea sp.(1)(,)(2).
ABSTRACT Three new diterpenoid hexose-glycosides, calyculaglycosides A-C (1-3) were isolated from the Caribbean gorgonian Eunicea sp. Calyculaglycosides A-C are rare diterpene glycosides possessing dilophol (4) aglycones related in biosynthetic origin to the elemene-type glycoside class of potent antiinflammatory agents known as fuscosides. The structures of the new compounds, which were assigned on the basis of spectral studies, were further corroborated by molecular modeling studies. Calyculaglycoside B (2) is an effective topical antiinflammatory agent stronger in potency than the industrial standard indomethacin. Calyculaglycoside B inhibits the synthesis of both prostaglandin PGE(2) and leukotriene LTB(4), suggesting it is a nonselective inhibitor of the 5-lipoxygenase and cyclooxygenase pathways. At concentrations of 10(-4)-10(-5)M, calyculaglycoside B produced LC(50)-level differential responses against a majority of the NCI ovarian cancer lines and several of the renal, prostate, and colon tumor lines.