Curcumanes A and B, Two Bicyclic Sesquiterpenoids with Significant Vasorelaxant Activity from Curcuma longa.

Two novel sesquiterpenoids, curcumanes A (1) and B (2), possessing unprecedented skeletons with a dicyclo[3.2.1]octane and a dicyclo[3.3.1]nonane moiety, respectively, were isolated from Curcuma longa. Both of them had remarkable vasorelaxant activity on rat aorta via blocking extracellular Ca2+ influx through VDCCs and ROCCs. The activity of 1 was endothelium-independent, while that of 2 was endothelium-dependent. Compound 2 also prolonged APTT and TT to inhibit blood coagulation.