New lignans from the heartwood of Cunninghamia lanceolata.

Two new lignans, including the aryltetralin-type lignan, lanceoline (1), and the diaryl butyrolactone-type lignan, 5-methoxytrachelogenin (2), together with 5-methoxywikstromol (3), were isolated from the low-polar layer of a heartwood extract of Cunninghamia lanceolata as their acetylated derivatives 1a, 2a and 3a, respectively, and were identified by spectroscopic analyses. The (13)C-NMR data for 3a are reported for the first time in this paper.