Laboratório de Ecologia Comportamental, Centro de Estudos em Recursos Naturais, Universidade Estadual de Mato Grosso do Sul, Dourados, Mato Grosso do Sul, Brazil.
Programa de Pós-graduação em Recursos Naturais, Centro de Estudos em Recursos Naturais, Universidade Estadual de Mato Grosso do Sul, Dourados, Mato Grosso do Sul, Brazil.
Environ Entomol. 2021 Jun 18;50(3):580-588. doi: 10.1093/ee/nvab010.
Cuticular hydrocarbons perform multiple functions in insects such as protecting against desiccation and pathogenic infection, and signaling interactions. Evaluation of cuticular hydrocarbon (CHC) profiles of insects is commonly performed by extraction using a nonpolar solvent such as hexane. Specimens intended for CHC analysis are ideally handled by avoiding contact with solvents such as ethanol. However, insects are frequently stored in ethanol after collection, especially if intended for molecular analysis. To determine if it is possible that chemical compounds in the cuticles of specimens can withstand previous exposure to ethanol, we evaluated the efficiency of CHC extraction from specimens preserved in 95% ethanol. We extracted cuticular compounds from specimens of the social wasp Polybia paulista (Ihering) with no contact with ethanol solvents and compared them with those from specimens stored in 95% ethanol. We analyzed chemical composition from wasps and the 95% ethanol in which they had been stored by a gas chromatograph coupled to a mass spectrometer. In total, 56 compounds were detected: 50 that were classified as hydrocarbons which were mostly branched alkanes, followed by linear alkanes and alkenes. Three compounds were identified as fatty acids, and three compounds were unidentifiable. The ethanol-preserved specimens showed similar chemical profiles to those of specimens that had no contact with ethanol. Thus, we suggest that it is possible to study the chemical profiles of ethanol-preserved specimens.
表皮碳氢化合物在昆虫中具有多种功能，如防止脱水和病原感染，以及信号交互作用。昆虫表皮碳氢化合物 (CHC) 谱的评估通常通过使用非极性溶剂（如己烷）进行提取来进行。用于 CHC 分析的标本理想情况下应避免与溶剂（如乙醇）接触。然而，昆虫在收集后经常储存在乙醇中，特别是如果用于分子分析。为了确定标本表皮中的化学物质是否能够承受先前暴露于乙醇，我们评估了从保存在 95%乙醇中的标本中提取 CHC 的效率。我们用没有接触乙醇溶剂的方法从社会性黄蜂 Polybia paulista (Ihering) 的标本中提取了表皮化合物，并将其与储存在 95%乙醇中的标本进行了比较。我们通过气相色谱仪-质谱联用仪分析了黄蜂和它们储存的 95%乙醇的化学成分。总共检测到 56 种化合物：50 种被分类为碳氢化合物，主要是支链烷烃，其次是直链烷烃和烯烃。三种化合物被鉴定为脂肪酸，三种化合物无法识别。保存在乙醇中的标本与没有接触乙醇的标本具有相似的化学特征。因此，我们建议可以研究乙醇保存标本的化学特征。
