Antignawing factor of crude oil derived fromThujopsis dolabrata S. et Z. var.hondai sawdust against mice.

The antignawing activity of the steam distillate ofThujopsis dolabrata S. et. Z. var.hondai sawdust against mice was evaluated using a wire-dipping method. This method is suitable for measuring repellent activities of chemicals and plant-derived materials. The steam distillate of theThujopsis sawdust was shown to have potent antignawing activity. Three terpenoid compounds with antignawing activity were isolated from the steam distillate of theThujopsis sawdust: thujopsene, carvacrol, andβ-thujaplicine. Carvacrol exhibited the most potent repellent activity. As a naturally occurring repellent, carvacrol could be useful as new preventive agent against various kinds of damage caused by rodents.