Coordenação de Pesquisas em Produtos Naturais, Instituto Nacional de Pesquisas da Amazônia, CP 478, 69011-970 Manaus-AM, Brazil.
Molecules. 2010 Aug 19;15(8):5734-41. doi: 10.3390/molecules15085734.
The essential oils of four Guarea species collected at Manaus (Amazonas, Brazil) were obtained by hydrodistillation and analyzed by GC-MS. Except for one diterpene detected, the compounds identified in the essential oils were hydrocarbons and oxygenated sesquiterpenes. The major sesquiterpenes were alpha-santalene (26.26%) and alpha-copaene (14.61%) from G. convergens branches; caryophyllene epoxide (40.91%) and humulene epoxide II (14.43%) from G. humaitensis branches; cis-caryophyllene (33.37%) and alpha-trans-bergamotene (11.88%) from G. scabra leaves; caryophyllene epoxide (36.54%) in leaves and spathulenol (14.34%) in branches from G. silvatica. The diterpene kaurene (15.61%) was found in G. silvatica leaves. Larvicidal activity assay of essential oils against third-instar Aedes aegypti larvae revealed that at higher concentrations (500 and 250 microg/mL), all the essential oils caused 100% mortality after 24 h of exposure. The most active essential oils were those of G. humaitensis branches (LC(50) 48.6 microg/mL), G. scabra leaves (LC(50) 98.6 microg/mL) and G. silvatica (LC(50) 117.9 microg/mL). The differences in the toxicity of essential oils of Guarea species on A. aegypti are due to qualitative and quantitative variations of the components, therefore the larvicidal effect may be due to higher amount of the sesquiterpenes with caryophyllane skeleton.
四种在马瑙斯（巴西亚马逊州）采集的 Guarea 物种的精油通过水蒸馏法获得，并通过 GC-MS 进行分析。除了检测到一种二萜外，精油中鉴定出的化合物为烃类和含氧倍半萜。主要的倍半萜为 alpha-檀香烯（26.26%）和 alpha-古巴烯（14.61%），来自 G. convergens 的枝条；G. humaitensis 的枝条中含有环氧石竹烯（40.91%）和葎草烯环氧 II（14.43%）；G. scabra 的叶子中含有顺式石竹烯（33.37%）和 alpha-反式佛手柑烯（11.88%）；G. silvatica 的叶子中含有环氧石竹烯（36.54%），而枝条中含有 spathulenol（14.34%）。在 G. silvatica 的叶子中发现了二萜贝壳杉烯（15.61%）。对 3 龄埃及伊蚊幼虫的精油进行的杀幼虫活性测定表明，在较高浓度（500 和 250 μg/mL）下，所有精油在暴露 24 小时后均导致 100%的死亡率。最有效的精油是 G. humaitensis 的枝条（LC50 为 48.6 μg/mL）、G. scabra 的叶子（LC50 为 98.6 μg/mL）和 G. silvatica（LC50 为 117.9 μg/mL）。Guarea 物种的精油对 A. aegypti 的毒性差异是由于成分的定性和定量变化所致，因此杀幼虫效果可能是由于含有较高量的 Caryophyllane 骨架的倍半萜。
