Cytotoxic butanolides and secobutanolides from the stem wood of Formosan Lindera communis.

Bioassay-guided fractionation of the chloroform-soluble fraction from the stem wood of Formosan Lindera communis led to the isolation of two new cytotoxic butanolides, lincomolide C (1), lincomolide D (2), as well as two new secobutanolides, secolincomolide A (3), secolincomolide B (4), together with four known compounds, including one butanolide, isoobtusilactone A (5), and one secobutanolide, secoisolancifolide (6), one sesquiterpene, epi-cubenol (7), one steroid: beta-sitosterol (8). Compound 4 existed in enol [(2E)-2-[(1R)-1-hydroxy-2-oxo-propyl]-6,9-dimethyl-8-hydroxy-hexadec-2,7-dienoic acid methyl ester] (4a) and keto [(2E)-2-[(1R)-1-hydroxy-2-oxo-propyl]-6,9-dimethyl-8-oxo-hexadec-2-enoic acid methyl ester] (4b) tautomers. Compound 2 showed significant cytotoxicity against P-388 and HT-29 cancer cell lines. Also, 2 exhibited marginal activity against A549, 5 against P-388, and 1 against P-388, A549 and HT-29 cancer cell lines. Their structures were determined by spectroscopic analyses.