The Peruvian stick insect Oreophoetes peruana is the only known animal source for unsubstituted quinoline in nature. When disturbed, these insects discharge a defensive secretion containing quinoline. Analysis of samples obtained from l-[2′,4′,5′,6,′7′-²H₅]tryptophan-fed stick insects demonstrated that the insects convert it to [5,6,7,8-²H₄]quinoline by removing the 2′-CH moiety in the indole ring of tryptophan. Analogous experiments using l-[1′-¹⁵N]tryptophan and l-[1′-¹⁵N,¹⁵NH₂]tryptophan showed that the indole-N atom is retained while the α-amino group is eliminated during the biosynthesis. Mass spectra recorded from quinoline derived from [2-¹³C₁]tryptophan-fed insects indicated that the α-carbon atom of tryptophan is incorporated as the C-2 atom of the quinoline ring.

中文翻译：

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竹节虫生物合成喹啉

秘鲁竹节虫Oreophoetes peruana是自然界中唯一已知的未取代喹啉的动物来源。当受到干扰时，这些昆虫会释放出含有喹啉的防御性分泌物。对从l -[2',4',5',6,'7'- ² H ₅ ] 色氨酸喂养的竹节虫获得的样品的分析表明，昆虫将其转化为 [5,6,7,8- ² H ₄ ]喹啉通过去除色氨酸吲哚环中的 2'-CH 部分。使用l -[1'- ¹⁵ N] 色氨酸和l -[1'- ¹⁵ N, ¹⁵ NH _{2 的}类似实验]色氨酸表明吲哚-N原子被保留，而α-氨基在生物合成过程中被消除。从[2- ¹³ C ₁ ]色氨酸喂养的昆虫衍生的喹啉记录的质谱表明色氨酸的α-碳原子作为喹啉环的C-2原子被并入。