Linoleic acid and stearic acid are biosynthetic precursors of (7Z,10Z)-7,10-hexadecadienal, the major component of the sex pheromone of Chilecomadia valdiviana (Lepidoptera: Cossidae)

The main pheromone compound of Chilecomadia valdiviana (Lepidoptera: Cossidae) has been recently identified as (7Z,10Z)-7,10-hexadecadienal. The biosynthesis of this pheromone compound showing attributes of both Type I and Type II lepidopteran pheromones was studied by the topical application of isotope-labeled fatty acids to the pheromone gland and subsequent analysis of the gland contents (pheromone compounds and fatty acyl compounds) by gas chromatography-mass spectrometry. The deuterium label of D11-linoleic acid was incorporated into the pheromone compound and its putative acyl precursor (7Z,10Z)-7,10-hexadecadienoate, demonstrating that the pheromone compound is biosynthesized from linoleic acid by chain-shortening and further functional group transformation. Furthermore, the deuterium label of D3-stearic acid was also incorporated into the pheromone compound, which indicates that the pheromone can be synthesized de novo by C. valdiviana, as is the case for Type I lepidopteran pheromone compounds.近日，智利柯斯蛾（Chilecomadia valdiviana，鳞翅目：木蠹蛾科）的主要信息素化合物被鉴定为(7Z,10Z)-7,10-十六碳二烯醛。针对该兼具I型与II型鳞翅目信息素特征的信息素化合物的生物合成过程，研究人员通过将同位素标记脂肪酸施用于其信息素腺体表面，并随后采用气相色谱-质谱联用法对腺体内容物（信息素化合物与脂酰化合物）进行分析展开研究。实验结果显示，D11-亚油酸的氘标记基团可被整合至该信息素化合物及其推定酰基前体(7Z,10Z)-7,10-十六碳二烯酸中，证明该信息素化合物由亚油酸经碳链缩短与后续官能团转化实现生物合成。此外，D3-硬脂酸的氘标记基团同样可被整合至该信息素化合物中，这表明智利柯斯蛾可如I型鳞翅目信息素化合物那样，从头合成该信息素。