Insect Antifeedants, Pterocarpans and Pterocarpol, in Heartwood of<i>Pterocarpus macrocarpus</i>Kruz.
作者:Masanori MORIMOTO、Hiromi FUKUMOTO、Masaru HIRATANI、Warinthorn CHAVASIRI、Koichiro KOMAI
DOI:10.1271/bbb.60017
日期:2006.8.23
The insect antifeedant activities of pterocarpans and a sesquiterpene alcohol from the dichloromethane extract of Pterocarpus macrocarpus Kruz. (Leguminosae) were evaluated against the common cutworm, Spodoptera litura F. (Noctuidae), and the subterranean termite, Reticulitermes speratus (Kolbe)(Rhinotermitidae). Three pterocarpans, (−)-homopterocarpin (1), (−)-pterocarpin (2), and (−)-hydroxyhomopterocarpin (3) and the sesquiterpene alcohol, (+)-pterocarpol (5), were isolated from the dichloromethane extract of the heartwood of P. macrocarpus under guidance by a biological assay. Among these natural products, the most active insect antifeedant against both S. litura and R. speratus was 1. On the other hand, sesquiterpene alcohol 5 showed less insect antifeedant activity than the other pterocarpans against both insect species. While its methylated derivative, (−)-methoxyhomopterocarpin (4), showed high biological activity, 3 showed less insect antifeedant activity in this study. Interestingly, racemic 1 did not show insect antifeedant activity against S. litura. However, all of the test pterocarpans and isoflavones showed antifeedant activity against the test termites. Additionally, since these compounds were major constituents of P. macrocarpus, these antifeedant phenolics may act as chemical defense factors in this tree. In Thailand, lumber made from this tree is used to make furniture and in building construction due to its resistance to termite attack.
对来自大果紫檀(Pterocarpus macrocarpus Kruz.)二氯甲烷提取物的紫檀苷和倍半萜醇(豆科)的昆虫拒食活性进行了评估,以对抗普通切根虫斜纹夜蛾(Spodoptera litura F.)(夜蛾科)和地下白蚁(Reticulitermes speratus (Kolbe))(鼻白蚁科)。在生物测定指导下,从大果紫檀心材的二氯甲烷提取物中分离出三种紫檀苷(-)-紫檀苷(1)、(-)-紫檀苷(2)和(-)-羟基紫檀苷(3)以及倍半萜醇(+)-紫檀醇(5)。在这些天然产物中,对斜纹夜蛾和R. speratus最有效的昆虫拒食剂是1。另一方面,倍半萜醇5对这两种昆虫的昆虫拒食活性低于其他紫檀苷。虽然其甲基化衍生物(-)-甲氧基紫檀苷(4)显示出高生物活性,但在这项研究中,3的昆虫拒食活性较低。有趣的是,外消旋1对斜纹夜蛾没有表现出昆虫拒食活性。然而,所有