Instrumental Analysis of Terminal-Conjugated Dienes for Reexamination of the Sex Pheromone Secreted by a Nettle Moth,<i>Parasa lepida lepida</i>
作者:MD. Azharul ISLAM、Rei YAMAKAWA、Nguyen Duc DO、Naoko NUMAKURA、Toshiro SUZUKI、Tetsu ANDO
DOI:10.1271/bbb.90047
日期:2009.5.23
Conjugated dienyl compounds make one of the main groups of lepidopteran sex pheromones, and GC has been frequently used to determine the configurations of the double bonds. However, the separation of two geometric isomers of a terminal-conjugated diene, such as 7,9-decadien-1-ol secreted by a nettle moth Parasa lepida lepida (Limacodidae), is assumed to be difficult. In order to clarify the chromatographic separation of the terminal dienes, 7,9-decadienyl and 9,11-dodecadienyl compounds (alcohols, acetates, and aldehydes) were analyzed by GC and HPLC. On a capillary GC column, the (E)-isomers flowed out slightly faster than the corresponding (Z)-isomers, but their peaks almost overlapped. On the other hand, HPLC equipped with an ODS column completely separated the two geometric isomers examined and the (Z)-isomers eluted from the column faster than the (E)-isomers without dependence on a functional group. In addition to undergoing direct HPLC analysis without derivatization, the dienyl alcohols were converted into 3,5-dinitrobenzoates and analyzed by LC-ESI-MS operated under the same reversed-phase condition. The two separated geometric isomers were sensitively monitored by negative ions at m⁄z 211, M, M+1, M+17, and M+31, which were characteristically derived from the benzoates. Based on these results, a pheromone extract of P. l. lepida was examined, and it was confirmed that the female moths exclusively produced the (Z)-isomer of the 7,9-diene. Furthermore, a GC-EAD analysis and a field evaluation with both geometrical isomers indicated that the mating communication of P. l. lepida is predominantly mediated with the (Z)-isomer.
共轭二烯基化合物是鳞翅目性信息素的主要基团之一,GC 经常用于确定双键的构型。然而,末端共轭二烯的两个几何异构体的分离,例如由荨麻蛾 Parasa lepida lepida (Limacodidae) 分泌的 7,9-decadien-1-ol,被认为是困难的。为了阐明末端二烯的色谱分离,通过 GC 和 HPLC 分析了 7,9-癸二烯基和 9,11-十二二烯基化合物(醇、乙酸酯和醛)。在毛细管气相色谱柱上,(E)-异构体的流出速度略快于相应的(Z)-异构体,但它们的峰几乎重叠。另一方面,配备ODS柱的HPLC完全分离了所检查的两种几何异构体,并且(Z)-异构体从柱中洗脱得比(E)-异构体更快,而不依赖于官能团。除了不进行衍生化直接进行 HPLC 分析外,还将二烯醇转化为 3,5-二硝基苯甲酸酯,并通过在相同反相条件下操作的 LC-ESI-MS 进行分析。通过 m/z 211、M、M+1、M+17 和 M+31 处的负离子灵敏地监测这两种分离的几何异构体,这些异构体通常源自苯甲酸盐。基于这些结果,P. l. 的信息素提取物。对lepida进行了检查,证实雌性蛾只产生7,9-二烯的(Z)-异构体。此外,GC-EAD 分析和对两种几何异构体的现场评估表明,P. l. 的交配通讯。 lepida 主要由 (Z)-异构体介导。