Raje Kapil R, Hughes Gabriel P, Gondhalekar Ameya D, Ginzel Matthew D, Scharf Michael E
Department of Entomology, Purdue University, West Lafayette, IN.
J Econ Entomol. 2015 Aug;108(4):1479-85. doi: 10.1093/jee/tov109. Epub 2015 May 18.
Turmeric is an important spice crop with documented human health benefits associated with chemicals called curcuminoids. In this study, the termite Reticulitermes flavipes (Kollar) was exposed to different solvent extracts of turmeric to investigate potential termiticidal properties. Treating termites with hexane extracts of purified lab-grade curcuminoids had no effect on termites. However, in continuous exposure assays, the LC(50) for hexane extracts of crude turmeric powder was 9.6 mg, or 1.0 mg starting material per square centimeter of filter paper substrate. These active components were soluble in a range of polar and apolar solvents, but only hexane could selectively fractionate active components away from the inactive curcuminoids. The active constituents of turmeric separated by thin layer chromatography (TLC) fluoresced in short-wave UV light but were not visible in long-wave UV light. By re-extracting TLC-separated bands in hexane and performing bioassays and gas chromatography-mass spectrometry, we demonstrated that termiticidal components of turmeric are extractable as a blend containing mainly ar-turmerone, turmerone, and curlone. This determination is consistent with findings of preceding work by other researchers that investigated insecticidal properties of turmeric in other pest insects.
姜黄是一种重要的香料作物，其含有的姜黄素类化合物对人体健康有益。在本研究中，将黄胸散白蚁（Reticulitermes flavipes (Kollar)）暴露于姜黄的不同溶剂提取物中，以研究其潜在的杀白蚁特性。用纯化的实验室级姜黄素类化合物的己烷提取物处理白蚁对白蚁没有影响。然而，在连续暴露试验中，粗姜黄粉己烷提取物的半数致死浓度（LC(50)）为9.6毫克，即每平方厘米滤纸基质1.0毫克起始材料。这些活性成分可溶于一系列极性和非极性溶剂中，但只有己烷能将活性成分与无活性的姜黄素类化合物选择性地分离。通过薄层色谱法（TLC）分离的姜黄活性成分在短波紫外光下发出荧光，但在长波紫外光下不可见。通过用己烷重新提取TLC分离的条带并进行生物测定和气相色谱-质谱分析，我们证明姜黄的杀白蚁成分可以作为一种主要含有芳姜黄酮、姜黄酮和莪术酮的混合物提取出来。这一测定结果与其他研究人员之前对姜黄在其他害虫中的杀虫特性的研究结果一致。
