title: Larvicidal activity of tectoquinone isolated from red heartwood-type Cryptomeria japonica against two mosquito species.
abstract: Mosquito larvicidal activities of methanolic extracts from different plant parts of red heartwood-type Cryptomeria japonica D. Don against the fourth-instar larvae of Aedes aegypti and Aedes albopictus were examined. Results of mosquito larvicidal tests demonstrated that the n-hexane fraction of C. japonica sapwood methanolic extract had an excellent inhibitory effect against the larvae of A. aegypti and A. albopictus and its LC50 values were 2.4 and 3.3 microg/ml, respectively, in 24h. Following the bioactivity-guided fractionation procedure, the active constituent isolated from C. japonica sapwood was characterized as tectoquinone by spectroscopic analyses. The LC50 values of tectoquinone against A. aegypti and A. albopictus in 24h were 3.3 and 5.4 microg/ml, respectively. In addition, comparisons of mosquito larvicidal activity of anthraquinone congeners demonstrated that anthraquinone skeleton with a methyl group at C-2 position, such as tectoquinone, exhibited the strongest mosquito larvicidal activity. Results of this study show that the methanolic extract of C. japonica sapwood may be considered as a potent source and tectoquinone as a new natural mosquito larvicidal agent.
authors.affiliation: The Experimental Forest, National Taiwan University, Nan-Tou 557, Taiwan.
authors.forename: Sen-Sung
authors.initials: SS
authors.lastname: Cheng
authors.forename: Chin-Gi
authors.initials: CG
authors.lastname: Huang
authors.forename: Wei-June
authors.initials: WJ
authors.lastname: Chen
authors.forename: Yueh-Hsiung
authors.initials: YH
authors.lastname: Kuo
authors.forename: Shang-Tzen
authors.initials: ST
authors.lastname: Chang
mesh_terms: D000330:Aedes / Q000187:drug effects*; D000818:Animals; D000880:Anthraquinones / Q000494:pharmacology; D032485:Cryptomeria / Q000737:chemistry* / Q000187:drug effects; D007814:Larva / Q000187:drug effects; D000432:Methanol; D009032:Mosquito Control; D010936:Plant Extracts / Q000494:pharmacology; D011809:Quinones / Q000302:isolation & purification* / Q000494:pharmacology*