The Mosquito Larvicidal Activity of Lignans from Branches of Cinnamomum camphora chvar. Borneol

The chemical investigation of branches of Cinnamomum camphora chvar. Borneol guided by mosquito larvicidal activity led to the isolation of fourteen known lignans (1–14). Their structures were elucidated unambiguously based on comprehensive spectroscopic analysis and comparison with the literature data. This is the first report of these compounds being isolated from branches of Cinnamomum camphora chvar. Borneol. Compounds 3–5 and 8–14 were isolated from this plant for the first time. All compounds isolated were subjected to anti-inflammatory, mosquito larvicidal activity and cytotoxic activity evaluation. Compounds (1–14) showed significant mosquito larvicidal activity against Culex pipiens quinquefasciatus with lethal mortality in 50% (LC(50)), with values ranging from 0.009 to 0.24 μg/mL. Among them, furofuran lignans(1–8) exhibited potent mosquito larvicidal activity against Cx. p. quinquefasciatus, with LC(50) values of 0.009–0.021 μg/mL. From the perspective of a structure–activity relationship, compounds with a dioxolane group showed high mosquito larvicidal activity and have potential to be developed into a mosquitocide.