Terpenes from bogwood of Cryptomeria japonica D. Don and characterization of its ash

The essential oils from a bogwood trunk of sugi (Cryptomeria japonica D. Don) from Sanbe-cho, Shimane, Japan, preserved for c. 3500–3800 years in volcanic ash (S-bogwood), were analyzed using gas chromatography-mass spectrometry (GC/MS). Eight sesquiterpenes and four diterpenes were identified. The main components were simonellite (19.2%), cis-calamenene (11.6%), and α-phyllocladane (8.8%). These results were compared with previous results for oils from a fresh stump of C. japonica, from Muikaichi-cho, Shimane, Japan (fresh wood) and for oils from a stump of another sugi bogwood preserved for c. 3000 years in sediment of a muddy field in Abu-cho, Yamaguchi, Japan (Y-bogwood). Simonellite, α-phyllocladane, selinane (4.3%), and eudalene (2.7%) were identified for the first time in bogwood trunk oil. Ash generated by oxidation of each of the two bogwood samples and fresh wood sample at 700 °C was analyzed using scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDXA). The major elements were S and Ca in S-bogwood ash, Fe and Ca in Y-bogwood ash, and K and Ca in the fresh wood ash, respectively. Sulfur in the S-bogwood ash is thought to have come from volcanic ash. The results suggest that S-bogwood was influenced directly by volcanic ash and the degree of terpenoid alteration was more drastic than that of Y-bogwood.