Antitermite Activity of β-Caryophyllene Epoxide and Episulfide

Caryophyllene-6,7-epoxide and caryophyllene-6,7-episulfide can be easily synthesized from beta-caryophyllene by autoxidation or episulfidation. The bioactivities of beta-caryophyllene and its derivatives were investigated against the subterranean termite Reticulitermes speratus Kolbe. The antifeedant, feeding, and termiticidal activities of each compound were tested using no-choice, dual-choice, and non-contact methods. Antitermitic activities were not shown by beta-caryophyllene, but were observed for the oxide and sulfide derivatives. Caryophyllene-6,7-episulfide showed especially high antifeedant and termiticidal activities. Thus, naturally abundant, non-bioactive beta-caryophyllene can be easily converted into an antitermite reagent via a non-biological process.