Cyclic diarylheptanoids from Myrica javanica : isolation, transformation, and bioactivity evaluation.

Three cyclic diarylheptanoids, myricanol ( 1 ), myricanone ( 2 ), and porson ( 3 ), were isolated from Myrica javanica (Myricaceae). As a major component, myricanol ( 1 ) was obtained from dry powdered bark and twigs (up to 1.6%). Transformation of myricanol ( 1 ) afforded 5-prenylmyricanol ( 4 ) and 5-benzylmyricanol ( 5 ) in 84.5% and 65% yields, respectively. The bioactivities of the isolated cyclic diarylheptanoids and their derivatives were investigated to determine their cytotoxicity and DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activities. The cytotoxicity assay against murine leukaemia P-388 cells demonstrated that compounds 4 and 5 showed an almost two-fold increase in the activity of their parent molecule ( 1 ), with an IC 50 value of 12 µM. Furthermore, the free radical scavenging assay showed that myricanol ( 1 ) had the highest radical scavenging activity, revealing the importance of the free phenolic group (IC 50 39.3 µM).