Bioactive Neolignans and Lignans from the Bark of Machilus robusta

Sixteen new neolignans and lignans (1-16), together with 12 known analogues, have been isolated from an ethanol extract of the bark of Machilus robusta. Compounds 1 and 2 showed activity against HIV-I replication in vitro, with IC(50) values of 2.52 and 2.01 mu M, respectively. At 10 mu M, 6, 8, and 9 reduced DL-galactosamine-induced hepatocyte (WB-F344 cells) damage, and 9 could additionally attenuate rotenone-induced PC12 cell damage. The known compounds (-)-pinoresinol (17) and (+)-lyoniresinol (18) were active against serum deprivation induced PC12 cell damage.