Laboratório de Química e Função de Proteínas e Peptídeos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, CEP 28013-602, Campos dos Goytacazes, RJ, Brazil.
Laboratório de Ciências Químicas, Centro de Ciência e Tecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Avenida Alberto Lamego, 2000, CEP 28013-602, Campos dos Goytacazes, RJ, Brazil.
Pestic Biochem Physiol. 2022 Aug;186:105167. doi: 10.1016/j.pestbp.2022.105167. Epub 2022 Jul 4.
Non-domesticated species may represent a treasure chest of defensive molecules which must be investigated and rescued. Clitoria fairchildiana R. Howard is a non-domesticated Fabacea, native from the Amazonian Forest whose seeds are exquisitely refractory to insect predation. Secondary metabolites from these seeds were fractionated by different organic solvents and the CHCl fraction (CFD - Clitoria fairchildiana dichloromethane fraction), as the most toxic to 3rd instar Aedes aegypti larvae (LC 180 PPM), was subjected to silica gel chromatography, eluted with a gradient of CHCl: MeOH and sub fractioned in nine fractions (CFD1 - CFD9). All obtained fractions were tested in their toxicity to the insect larvae. Two rotenoids, a 11α-O-β-D-glucopyranosylrotenoid and a 6-deoxyclitoriacetal 11-O-n-glucopyranoside, were identified in the mixture of CFD 7.4 and CFD 7.5, and they were toxic (LC 120 PPM) to 3rd instar Ae. aegypti larvae, leading to exoskeleton changes, cuticular detachment and perforations in larval thorax and abdomen. These C. fairchildiana rotenoids interfered with the acidification process of cell vesicles in larvae midgut and caused inhibition of 55% of V-ATPases activity of larvae treated with 80 PPM of the compounds, when compared to control larvae. The rotenoids also led to a significant increase in the production of reactive oxygen species (ROS) in treated larvae, especially in the hindgut region of larvae intestines, indicating a triggering of an oxidative stress process to these insects.
非驯化物种可能代表着防御分子的宝库，必须对其进行调查和抢救。野百合（Clitoria fairchildiana R. Howard）是一种非驯化的豆科植物，原产于亚马逊森林，其种子对昆虫捕食具有极高的抗性。从这些种子中分离出的次生代谢产物，用不同的有机溶剂进行了分级，其中 CHCl 级分（CFD-野百合二氯甲烷级分）对第 3 龄埃及伊蚊幼虫（LC 180 ppm）的毒性最强，随后用硅胶柱层析进行分离，用 CHCl:MeOH 梯度洗脱，并分成 9 个馏分（CFD1-CFD9）。对所有获得的馏分进行了对昆虫幼虫的毒性测试。在 CFD7.4 和 CFD7.5 的混合物中鉴定出两种鱼藤酮类化合物，一种是 11α-O-β-D-吡喃葡萄糖基鱼藤酮和一种是 6-去氧氯藤甲素 11-O-n-吡喃葡萄糖苷，它们对第 3 龄埃及伊蚊幼虫有毒（LC 120 ppm），导致幼虫外骨骼改变、表皮脱落和幼虫胸部和腹部穿孔。这些野百合鱼藤酮类化合物干扰了幼虫中肠细胞小泡的酸化过程，并导致处理幼虫的 V-ATPases 活性抑制了 80 ppm 化合物的 55%，与对照幼虫相比。鱼藤酮类化合物还导致处理幼虫中活性氧物质（ROS）的产生显著增加，特别是在幼虫肠道的后肠区域，表明这些昆虫发生了氧化应激过程。
