在氢过氧化物裂解酶链裂解反应中烯醇中间体的检测。

Detection of an enol intermediate in the hydroperoxide lyase chain cleavage reaction.

作者信息

Grechkin Alexander N, Mukhtarova Lucia S, Hamberg Mats

机构信息

Kazan Institute of Biochemistry and Biophysics, Russian Academy of Sciences, Kazan, Russia.

出版信息

FEBS Lett. 2003 Aug 14;549(1-3):31-4. doi: 10.1016/s0014-5793(03)00758-0.

DOI:10.1016/s0014-5793(03)00758-0

PMID:12914919

Abstract

Guava (Psidium guajava) hydroperoxide lyase (HPL) preparations were incubated with 1-(14)C-13-hydroperoxy-9,11,15-octadecatrienoic acid for 1 min at 0 degrees C, followed by rapid extraction/trimethylsilylation. Analysis of the trimethylsilylated products by gas chromatography-mass spectrometry and radio-high-performance liquid chromatography revealed a single predominant (14)C-labelled compound, identified by its (1)H-nuclear magnetic resonance, ultraviolet and mass spectra as the trimethylsilyl ether/ester of (9Z,11E)-12-hydroxy-9,11-dodecadienoic acid. Longer time incubations afford smaller yield of this enol due to its partial tautomerization into (9Z)-12-oxo-9-dodecenoic acid. The data obtained demonstrate that formation of (9Z)-12-oxo-9-dodecenoic acid in the HPL reaction is preceded by unstable enol oxylipin, and further suggest that hemiacetals are the true products of HPL catalysis.

摘要

将番石榴（番石榴属）的氢过氧化物裂解酶（HPL）制剂与1-(14)C-13-氢过氧基-9,11,15-十八碳三烯酸在0℃下孵育1分钟，然后进行快速提取/三甲基硅烷化。通过气相色谱-质谱联用和放射性高效液相色谱对三甲基硅烷化产物进行分析，结果显示有一种主要的(14)C标记化合物，通过其(1)H-核磁共振、紫外光谱和质谱鉴定为(9Z,11E)-12-羟基-9,11-十二碳二烯酸的三甲基硅醚/酯。较长时间的孵育会使这种烯醇的产率降低，因为它会部分互变异构为(9Z)-12-氧代-9-十二碳烯酸。所获得的数据表明，在HPL反应中(9Z)-12-氧代-9-十二碳烯酸的形成之前存在不稳定的烯醇式氧化脂质，并且进一步表明半缩醛是HPL催化的真正产物。