Abstract
Sugi contains characteristic phenolic compounds (C6-C5-C6) called norlignans in its heartwood. Some norlignans appears to be involved in color formation of the heartwood. The pathways of norlignan biosynthesis are unknown. Norlignans have been reported to generate in sapwood during withering of C. japonica logs. Assuming that this phenomenon would be helpful for studying the mechanisms of norlignan biosynthesis, we investigated the composition of norlignans generated in the withering sapwood of C. japonica, Wood discs were collected over 70 days from a log stored indoors. The level of a single norlignan species gradually increased in the inner sapwood and reached a maximum on the 41st day after cutting. The norlignan was identified by gas chromatography-mass spectrometry as agatharesinol, a typical heartwood norlignan of C. japonica. These results show that the production of norlignans in sapwood of cut logs provides a useful model system for studying the molecular mechanisms of norlignan biosynthesis.
