Holophyllin A, a rearranged abietane-type diterpenoid from the trunk of Abies holophylla

Abstract Holophyllin A ( 1 ), a novel rearranged abietane-type diterpenoid was isolated, together with a new diterpene glycoside, holophyllin B ( 2 ), from the trunk of Abies holophylla . The structures of 1 and 2 were established by extensive spectroscopic analyses and their absolute configurations were determined by ECD calculation. All the isolates were tested for their inhibitory effects on NO production in LPS-activated murine microglial cells.