Antitermitic activity of extracts from Chamaecyparis obtusa branch heartwood

• Published in: European journal of wood and wood products Vol. 72; no. 5; pp. 651 - 657
• Main Authors: Morikawa, Takuya, Ashitani, Tatsuya, Kofujita, Hisayoshi, Takahashi, Koetsu
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.09.2014; Springer Berlin Heidelberg; Springer Nature B.V
• Subjects: Acetic acid; antifeedants; antifeeding activity; Biomedical and Life Sciences; branches; branching; Cadinol; Ceramics; Chamaecyparis obtusa; Composites; Ethyl acetate; Glass; heartwood; Isoptera; Life Sciences; lignans; Machines; Manufacturing; methanol; n-Hexane; Natural Materials; Original; Processes; Reticulitermes speratus; Sesquiterpenoids; Wood Science & Technology; Sesquiterpene; Termiticidal Activity; Antifeedant Activity; Sesquiterpene Compound; Harmful Organism
• ISSN: 0018-3768; 1436-736X
• DOI: 10.1007/s00107-014-0830-8

The antitermitic activity of extracts from the branch heartwood of Chamaecyparis obtusa (hinoki) against Japanese termites (Reticulitermes speratus) was compared with that of the trunk. Samples of branch and trunk heartwood were extracted with n-hexane, ethyl acetate, and methanol successively. n-Hexane extracts of branch and trunk heartwood were strongly antitermitic, and branch heartwood contained greater quantities of active n-hexane extracts than trunk heartwood. Germacra-1-(10), 5-dien-4β-ol, t-cadinol, α-cadinol, hinokiresinol, and hinokinin were separated from the branch extracts and the termiticidal and antifeedant activity of these compounds was tested by no-choice and dual-choice test methods. The sesquiterpenoids, germacra-1-(10), 5-dien-4β-ol, t-cadinol and α-cadinol were strongly termiticidal. The norlignan hinokiresinol and lignan hinokinin had weak termiticidal, and strong antifeedant and repellent activity. High concentrations of germacra-1-(10), 5-dien-4β-ol and hinokiresinol were present in branch heartwood. These compounds protect hinoki branches from termites and other harmful organisms. Hinoki branch heartwood, which is usually unused, is a potential source of active antitermitic compounds.