Cadinane sesquiterpenes from Curcuma phaeocaulis with their inhibitory activities on nitric oxide production in RAW 264.7 cells.

Four new cadinane-type sesquiterpenes named phacadinanes A–D ( 1 – 4 ) were isolated from the rhizomes of Curcuma phaeocaulis . Their structures were elucidated by 1D and 2D NMR, as well as accurate mass measurements. Compound 4 was the first example of a rare 4,5- seco -cadinane sesquiterpene isolated from the Zingiberaceae family. Furthermore, inhibitory effects of the isolated compounds on nitric oxide production in LPS-activated macrophages were evaluated. Compounds 1 and 2 showed strong inhibitory activities on NO production with IC 50 values of 3.88 ± 0.58 and 2.25 ± 0.71 μM, respectively. A possible biogenetic pathway for 4,5- seco -cadinane sesquiterpene ( 4 ) was postulated. [ABSTRACT FROM AUTHOR]