Abstract

The chemical constituents of hydrodistilled essential oils from the leaves of Litsea umbellata (Lour.) Merr. and Litsea iteodaphne (Ness) Hook. f. growing wild in central Vietnam and mosquito larvicidal activity of these oils against laboratory-reared larvae of Culex quinquefasciatus and Aedes albopictus were in- vestigated. The major constituents mostly terpenes (percentage abundance, respectively) of the oils were β- pinene (18.8 % and 6.6 %), β-caryophyllene (16.2 % and 21.4 %), α-pinene (10.4 % and 8.7 %) and germacrene D (9.1 % and 15.5 %). The oil of L. umbellata displayed larvicidal activity against Cx. quinquefasciatus with LC₅₀ of 36.19 μg/mL at both 24 h and 48 h, while LC₅₀ of 40.09 μg/mL and 27.33 μg/mL at 24 h and 48 h respecti- vely, were exhibited towards Ae. albopictus. Also, an LC₉₀ value of 54.17 μg/mL was obtained against Cx. quinquefasciatus at both 24 h and 48 h, while values of 68.79 and 60.49 μg/mL respectively, were recorded against Ae. albopictus at 24 h and 48 h. Moreover, the oil of L. iteodaphne exhibited activity against Cx. quinquefasciatus with LC₅₀ of 37.20 μg/mL (24 h) and 20.21 μg/mL (48 h) while LC₉₀ values were 39.27 μg/mL (24 h) and 23.78 μg/mL (48 h). Furthermore, L. iteodaphne oil displayed larvicidal activity against Ae. Albopictus with LC₅₀ values of 40.04 μg/mL (24 h) and 16.63 μg/mL (48 h) as well as LC₉₀ values of 42.40 μg/mL (24 h) and 23.64 μg/mL (48 h). This is the first report on the chemical composition and larvicidal activity of L. umbellata and L. iteodaphne essential oils.

摘要

来自Litsea umbellata（Lour。）Merr。的叶子的水蒸馏精油的化学成分。和Litsea iteodaphne（Ness）Hook。F。在越南中部的野生环境中进行了调查，调查了这些油类对库克昆士库克斯蚊和白纹伊蚊的实验室饲养幼虫的灭蚊活性。油中的主要萜类成分（分别为百分比丰度）是β-pin烯（18.8％和6.6％），β-石竹烯（16.2％和21.4％），α-pine烯（10.4％和8.7％）和germ胶D （9.1％和15.5％）。L. umbellata的油对Cx表现出杀幼虫活性。LC _50的昆西筋膜在24 h和48 h时，Ae的LC ₅₀分别为40.09μg/ mL和27.33μg/ mL，分别为36.19μg/ mL和27.33μg/ mL 。白化病。此外，相对于Cx，LC ₉₀值为54.17μg/ mL 。分别在24 h和48 h记录了quinquefasciatus的抗Ae值，分别为68.79和60.49μg/ mL 。在24 h和48 h的白化病。此外，iteodaphne的油对Cx表现出活性。LC ₅₀值为37.20μg/ mL（24 h）和20.21μg/ mL（48 h）的西洋参，LC ₉₀ 值为39.27μg/ mL（24 h）和23.78μg/ mL（48 h）。此外，iteodaphne油显示出对Ae的杀幼虫活性。纹伊蚊与LC _50个40.04微克/毫升（24小时）和16.63微克/毫升（48小时）的值，以及LC _90个42.40微克/毫升（24小时）和23.64微克/毫升（48小时）的值。这是关于伞形L. umbellata和L. iteodaphne精油的化学成分和杀幼虫活性的首次报道。