Department of Bioscience, Faculty of Applied Bioscience, Tokyo University of Agriculture, Tokyo, 156-8502, Japan.
J Chem Ecol. 2010 Sep;36(9):955-65. doi: 10.1007/s10886-010-9841-z. Epub 2010 Aug 10.
Callosobruchus analis (Coleoptera: Chrysomelidae: Bruchinae), found throughout tropical Asia and Africa, is a pest of stored legumes. Previous work has shown that females of this species produce a contact sex pheromone that elicits copulatory behavior in males. Comparisons of copulatory activity between any two of four congeneric species suggest that the contact sex pheromones are species specific. In laboratory bioassays, male C. analis exhibited copulatory behavior to a female dummy to which a crude extract of virgin females was applied. The extract had been collected by a filter paper method and was purified by acid-base partition and chromatographic techniques. Gas chromatography-mass spectrometry (GC-MS) analyses of active fractions revealed that the active compounds were 2,6-dimethyloctane-1,8-dioic acid (1) and callosobruchusic acid, (E)-3,7-dimethyl-2-octene-1,8-dioic acid (2), previously identified as contact sex pheromones of Callosobruchus maculatus (F.) and C. chinensis (L.), respectively. The stereoisomeric and chemical compositions were determined by the 2D-HPLC-Ohrui-Akasaka method as (2S,6R)-1:(S)-2=1.8:1, which meant that both compounds in C. analis were stereochemically pure, unlike the case of C. maculatus and C. chinensis. An examination of the influence of synthetic pheromone compounds on male copulatory activity revealed that (2S,6R)-1 is the main component, and that (S)-2 has an additive effect. In the examination of the stereochemistry-activity relationship, no copulatory behavior was elicited by (2R,6S)-1, and, furthermore, the enantiomer significantly masked the pheromonal activity of (2S,6R)-1. Glass rod dummy assays also suggested the presence of synergists. These results could elucidate the specificity of mate recognition in C. analis.
艳色皱胫步甲（鞘翅目：叶甲科：斑胫步甲亚科）分布于整个热带亚洲和非洲，是一种储存豆类的害虫。以前的研究表明，该物种的雌性会产生一种接触性性信息素，雄性对其产生交配行为。四种同属物种之间交配活动的比较表明，接触性性信息素具有物种特异性。在实验室生物测定中，雄性艳色皱胫步甲对涂有处女雌性粗提取物的雌性假虫表现出交配行为。提取物是通过滤纸法收集的，并通过酸碱分配和色谱技术进行纯化。活性部分的气相色谱-质谱（GC-MS）分析表明，活性化合物为 2,6-二甲基辛烷-1,8-二酸（1）和艳色皱胫步甲酸，（E）-3,7-二甲基-2-辛烯-1,8-二酸（2），它们分别被鉴定为 Callosobruchus maculatus（F.）和 C. chinensis（L.）的接触性性信息素。通过二维 HPLC-Ohrui-Akasaka 方法确定立体异构体和化学组成分别为（2S,6R）-1：（S）-2=1.8:1，这意味着艳色皱胫步甲中的两种化合物都是立体化学纯的，而不是 C. maculatus 和 C. chinensis 的情况。合成信息素化合物对雄性交配活性影响的研究表明，（2S,6R）-1 是主要成分，（S）-2 具有加性效应。在立体化学-活性关系的研究中，（2R,6S）-1 没有引起交配行为，并且，该对映体显著掩盖了（2S,6R）-1 的信息素活性。玻璃棒假虫试验也表明存在协同剂。这些结果可以阐明艳色皱胫步甲中配偶识别的特异性。
