Termiticidal Activities of Chamaecyparis obtusa Endl. Heartwood

편백재의 흰개미 살충활성에 관한 연구

Termiticidal activities of Chamaecyparis obtusa were quantitatively evaluated, and the activity differences between supporting materials such as woodmeal and filter paper or between species were defined based on the termiticidal activity value(TAV). It was found that TAV was high in the following order ; C. obtusa>Litsea coreana>C. obtusa var. formosensis>Ternstroemia gymnanthera. In particular, termiticidal activity of C. obtusa heartwood was stronger by 5 to 9 times than that of other three species. Median survival dosage(MSD) of C. obtusa was 108.8 mg. In case of woodmeal or filter paper tests with C. obtusa, termiticidal activities were inversely proportional to logarithms values of an added sample weight and median survival time(MST). The difference of termiticidal activities between woodmeal and filter paper in the methanol extracts was small, but that in the neutral fraction was enormous as 3.21 times. However, termiticidal activity of neutral fraction was corresponded to 17 to 53% of original woodmeal, and 47 to 83% of termiticidal activity was considered as a loss in test process.

주요 목재해충인 흰개미에 대하여 천연산 편백이 가지는 살충활성의 크기를 정량적으로 취급하고, 수종간 및 서로 다른 함침재료 간에 발생되는 활성의 차이를 termiticidal activity value(TAV, 살충활성치)로 정의하여 해석했다. 그 결과, 흰개미에 대한 TAV는 편백>육박나무>대만편백>후피향나무의 순이었으며, 특히 편백의 활성은 다른 3 수종보다 $5{\sim}9$배 강력했다. 또 편백의 median survival dosage(MSD, 반수치사량)는 108.8 mg이었다. 편백에 의한 목분시험과 여과지 함침시험 어느 경우에도 흰개미 살충활성은 첨가 시료중량의 대수치와 그 median survival time(MST, 반수치사일수)의 대수치와의 사이에 반비례 관계가 성립했다. 또한 목분과 여과지에 대한 함침재료간 활성차는 메탄올추출물에서 작은 반면 중성부에서 3.21배로 매우 컸다. 그러나 중성부의 살충력은 원목분의 $17{\sim}53%$로서 실험 조작과정에서 $47{\sim}83%$의 활성손실이 확인되었다.