Chemical and cytotoxic constituents from the stem of Machilus zuihoensis

Five new compounds, including a novel lactone, machilactone (=rel-(2R,3aR,6E,6aS)-2-heptadecyl-3a-methyl-6-octadecylidene-6,6a-dihydrofuro[2,3-d][1,3]dioxol-5(3aH)-one; 1), a new sesquiterpene, 3,4-dihydroxy-beta-bisabolol (=rel-(1R,2S,4R)-1-[(1R)-1,5-dimethylhex-4-enyl]-1-methylcyclohexane-1,2,4-triol; 2), a new secobutyrolactone, methyl (2E)-2-(1-hydroxy-2-oxopropyl)eicos-2-enoate (3), two new butyrolactones, machicolide A (4) and machicolide B (5) (=3E,4R,5R)- and (3Z,4R,5R)-4,5-dihydro-4-hydroxy-5-methoxy-5-methyl-3-octadecylidenefuran-2(3H) -one, resp.) as a mixture, together with known caryophyllene oxide (=4,12,12-trimethyl-9-methylene-5-oxatricyclo[8.2.0.0(4,6)]dodecane), hexacosane, tetracosanoic acid, isomahubanolide-23 (=(3E,4R)-4,5-dihydro-4-hydroxy-5-methylidene-3-octadecylidenefuran-2(3H)-one), and beta-bisabolol (=(1S)-1-[(1S)-1,5-dimethylhex-4-enyl]-4-methylcyclohex-3-en-1-ol) were isolated from the stem wood of Machilus zuihoensis. The structures of these compounds were established by spectroscopic studies. The eicos-2-enoate (3) and P-bisabolol exhibited marginal cytotoxicity against NUGC and HONE-1 cancer cell lines in vitro.