Constituents of Werneria ciliolata and their in vitro anti-HIV activity.

The aerial part of Werneria ciliolata afforded a series of new diterpenes: two ent-kaurane derivatives, a norkaurane, an ent-manoyloxide derivative, a dimeric diterpene, as well as a rare diterpene. Their structures were elucidated by spectroscopic methods, including the concerted application of 1D NMR techniques (DEPT and NOEDS) and 2D NMR techniques (1H-1H COSY and HETCOR). In addition, four known kauranes, four coumarins and 6-hydroxytremetone were isolated. All isolated compounds from W. ciliolata and W. dactylophylla were tested in vitro for anti-viral activity against HIV-1, but only 6-hydroxytremetone showed a significant anti-HIV-1 activity.