Programa de Pós-Graduação em Química, Universidade Federal do Ceará, 60451-970 Fortaleza-Ceará, Brazil.
Parasitol Res. 2013 Jul;112(7):2753-7. doi: 10.1007/s00436-013-3407-2. Epub 2013 Apr 20.
The aim of the present study was to evaluate the activity of pacharin isolated from the ethanol extract from roots of Bauhinia acuruana on third-instar larvae of Aedes aegypti Linn. (Diptera: Culicidae). The crude ethanol extract showed larvicidal activity at the concentration of 500 μg/mL. Given this larvicidal activity, this extract was submitted to chromatographic fractionation on a silica gel column eluted with n-hexane, dichloromethane, ethyl ether, ethyl acetate, and methanol in order to isolate the active compound(s). Pacharin, obtained in pure form from fraction eluted with ethyl ether, was evaluated for their larvicidal effects against A. aegypti. In these bioassays, the larvae were exposed at concentrations of 500, 250, 100, 50, and 25 μg/mL of the crude ethanol extract or pacharin. After 24 h, the number of dead larvae was counted and the LC₅₀ values for larval mortality were calculated. Pacharin showed LC50 value of 78.9 ± 1.8 μg/mL. The structure of isolated compound was identified on the basis of their spectral data (IR, 1D- and 2D-NMR) and by comparison with literature spectral data. The results indicate pacharin as a potential natural larvicide.
本研究旨在评估从翅荚决明根的乙醇提取物中分离得到的荩草素对埃及伊蚊（双翅目：蚊科）三龄幼虫的活性。粗乙醇提取物在 500μg/mL 的浓度下表现出杀幼虫活性。鉴于这种杀幼虫活性，将该提取物进行硅胶柱层析分离，用正己烷、二氯甲烷、乙醚、乙酸乙酯和甲醇洗脱，以分离活性化合物。荩草素从用乙醚洗脱的部分中以纯形式获得，并对其对埃及伊蚊的杀幼虫效果进行了评估。在这些生物测定中，将幼虫暴露于 500、250、100、50 和 25μg/mL 的粗乙醇提取物或荩草素浓度下 24 小时后，计算死亡幼虫的数量，并计算幼虫死亡率的 LC₅₀值。荩草素表现出 78.9±1.8μg/mL 的 LC50 值。根据其光谱数据（IR、1D 和 2D-NMR）和与文献光谱数据的比较，确定了分离化合物的结构。结果表明荩草素是一种有潜力的天然杀虫剂。
