Antignawing factor derived from Cinnamomum cassia bark against mice

The antignawing activity of cinnamomi cortex (the dried bark of Cinnamomum cassia) derived materials against laboratory-reared mice was evaluated usin g a wire-dipping method. The biologically active component of C. cassia bar k was characterized by spectral analysis as cinnamaldehyde. The antignawing activity of the compound was compared with that of four commercially avail able compounds: cinnamyl alcohol, trans-cinnamic acid, eugenol, and salicyl aldehyde. Cinnamaldehyde and cinnamyl alcohol exhibited potent repellent ac tivity, whereas little or no activity was produced from salicylaldehyde. Mo derate activity was observed in trans-cinnamic acid and eugenol. Cinnamalde hyde and cinnamyl alcohol exhibited potent and moderate repellent activity at 5 and 2.5% solutions, respectively, of these compounds in ethanol. Littl e or no activity was observed in 1% solution. As a naturally occurring repe llent, cinnamaldehyde and cinnamyl alcohol could be useful as a new prevent ive agent against various kinds of damage caused by rodents.