Bisabocurcumin, a new skeleton curcuminoid from the rhizomes of Curcuma longa L.

A new skeleton bisabolane-type sesquiterpene curcuminoid, bisabocurcumin (1), along with 5 known compounds, curcumin (2), demethoxycurcumin (3), bidemethoxycurcumin (4), (1E,4E)-1,5-bis(4-hydroxy-3-methoxyphenyl)-penta-1,4-dien-3-one (5), and (1E,4E)-1-(4-hydroxy-3-methoxyphenyl)-5-(4-hydroxy phenyl-)-penta-1,4-dien-3-one (6) were isolated from the rhizomes of Curcuma longa L. Their structures were determined on the basis of spectroscopic analysis. Bisabocurcumin (1) is firstly obtained from nature with a new skeleton combined by a bisabolane-type sesquiterpene and a 1,7-diphenylheptanoid through a C–C bond.