Termiticidal substances from the heartwood of Cryptomeria japonica D. Don

The termite resistance of Cryptomeria japonica D. Don was examined by termi te tests. In termite tests on small wood blocks and wood meal, the heartwoo d of C. japonica exhibits the highest termiticidal activity. Termiticidal s ubstances were found to be present in the ethanol extractives from the hear twood of C. japonica. The ether soluble portion of ethanol extractives was separated into acidic, phenolic and neutral fractions. The neutral fraction exhibits the highest termiticidal activity. The neutral fraction was separ ated by column chromatography on silica gel and high performance liquid chr omatography (HPLC). The termiticidal substances present in the neutral frac tion were identified as beta-eudesmol, sandaracopimarinol and 16-phylloclad anol. 16-Phyllocladanol exhibits the highest termiticidal activity among the subs tances extracted from the heartwood of C. japonica.