Biomolecules and Genetics Division, School of Biosciences and Technology, VIT University, Vellore 632 014, Tamil Nadu, India.
Parasitol Res. 2013 Feb;112(2):719-29. doi: 10.1007/s00436-012-3192-3. Epub 2012 Nov 22.
Ticks and mosquitoes are ectoparasitic arthropods that can transmit a variety of diseases to humans and animals during blood feeding and causing serious infectious disorders. The purpose of the present study was to assess the acaricidal and insecticidal property of ethyl acetate extract and its compounds isolated from marine actinobacteria, Streptomyces VITSTK7 sp. against the larvae of cattle ticks, Haemaphysalis bispinosa and Rhipicephalus (Boophilus) microplus (Acari: Ixodidae); fourth-instar larvae of malaria vector, Anopheles subpictus; and filarial vector, Culex quinquefasciatus (Diptera: Culicidae). The ethyl acetate extract was loaded on silica gel column and separated with chloroform, methanol, and acetone as the solvents system. The separation of fractions was visualized by the thin layer chromatography (TLC) plate, further confirmed by high-performance liquid chromatography, and followed by gas liquid chromatography. Three major fractions were analyzed in mass spectroscopy (MS) and matched with existing compounds in the data base. Based on the fragment pattern, it led to the major compounds which were predicted as cyclopentanepropanoic acid, 3,5-bis(acetyloxy)-2-[3-(methoxyimino)octyl], methyl ester (13.3 %) 1; 5-azidomethyl-3-(2-ethoxy carbonyl-ethyl)-4-ethoxycarbonylmethyl-1H-pyrrole-2-carboxylic acid, ethyl ester (18.2 %) 2; and akuammilan-16-carboxylic acid, 17-(acetyloxy)-10-methoxy, methyl ester (16R) (53.3 %) 3. The maximum efficacy was observed in compounds 1, 2, and 3, and the ethyl acetate extract of Streptomyces VITSTK7 sp. against the larvae of H. bispinosa (LC(50) = 1,573.36, 1,333.09, 1,073.29, and 409.71 ppm; r(2) = 0.0.990, 0.934, 0.935, and 0.908), R. microplus (LC(50) = 1,877.86, 815.83, 1,631.14, and 441.54 ppm; r(2) = 0.981, 0.926, 0.0970, and 0.915), A. subpictus (LC(50) = 273.89, 687.69, 464.75, and 223.83 ppm; r(2) = 0.758, 0.924, 0.841, and 0.902), and C. quinquefasciatus (LC(50) = 430.06, 881.59, 777.0, and 195.70 ppm; r(2) = 0.839, 0.859, 0.870, and 0.882), respectively. Results of the present study provide evidence that the maximum parasitic activity of ethyl acetate extract and a synergistic effect of combinations of different compounds have been suggested. The control (distilled water) showed nil mortality in the concurrent assay. In the present study, a novel, targeted, simple, and eco-friendly approach has been suggested to control blood-feeding parasites.
蜱和蚊子是吸血的外寄生虫节肢动物，在吸血过程中可以将多种疾病传播给人类和动物，引起严重的传染病。本研究的目的是评估海洋放线菌链霉菌 VITSTK7 sp. 的乙酸乙酯提取物及其化合物对牛蜱幼虫、长角血蜱和微小牛蜱（蜱科：硬蜱科）、疟蚊幼虫、按蚊亚种和丝虫媒介库蚊、致倦库蚊（双翅目：库蚊科）的杀蜱和杀虫特性。乙酸乙酯提取物加载到硅胶柱上，用氯仿、甲醇和丙酮作为溶剂系统进行分离。通过薄层色谱（TLC）板可视化分离的馏分，通过高效液相色谱进一步确认，然后通过气相色谱进行分析。对三个主要馏分进行质谱（MS）分析，并与数据库中的现有化合物匹配。根据碎片模式，主要化合物被预测为环戊烷丙酸，3,5-双（乙酰氧基）-2-[3-（甲氧基亚氨基）辛基]甲酯（13.3%）1；5-叠氮甲基-3-（2-乙氧羰基-乙基）-4-乙氧羰基甲基-1H-吡咯-2-羧酸乙酯（18.2%）2；和阿库米兰-16-羧酸，17-（乙酰氧基）-10-甲氧基，甲酯（16R）（53.3%）3。化合物 1、2 和 3 的最大功效，以及链霉菌 VITSTK7 sp. 的乙酸乙酯提取物对长角血蜱幼虫（LC50 = 1,573.36、1,333.09、1,073.29 和 409.71 ppm；r（2）= 0.0.990、0.934、0.935 和 0.908）、微小牛蜱幼虫（LC50 = 1,877.86、815.83、1,631.14 和 441.54 ppm；r（2）= 0.981、0.926、0.0970 和 0.915）、按蚊亚种幼虫（LC50 = 273.89、687.69、464.75 和 223.83 ppm；r（2）= 0.758、0.924、0.841 和 0.902）和致倦库蚊幼虫（LC50 = 430.06、881.59、777.0 和 195.70 ppm；r（2）= 0.839、0.859、0.870 和 0.882），分别。本研究结果表明，乙酸乙酯提取物的最大寄生活性和不同化合物组合的协同作用已被证实。对照（蒸馏水）在同时进行的测定中未显示出任何死亡率。在本研究中，提出了一种新的、有针对性的、简单的和环保的方法来控制吸血寄生虫。
