title: Stereospecificity of an enzymatic monoene 1,4-dehydrogenation reaction: conversion of (Z)-11-tetradecenoic acid into (E,E)-10,12-tetradecadienoic acid.
abstract: In this article, we report the first stereochemical study of an enzymatic 1,4-dehydrogenation reaction, namely, the transformation of (Z)-11-tetradecenoic acid into (E,E)-10,12-tetradecadienoic acid, involved in the sex pheromone biosynthesis of the moth Spodoptera littoralis. The investigation was carried out using the labeled substrates (R)-[10-(2)H]- and (S)-[10-(2)H]-tridecanoic acids ((R)-2 and (S)-2, respectively) and (R)-[2,2,3,3,13-(2)H(5)]- and (S)-[2,2,3,3,13-(2)H(5)]-tetradecanoic acids ((R)-1 and (S)-1, respectively). Probes (R)-2 and (S)-2 were prepared as described in a previous article.(1) The synthesis of the pentadeuterated chiral substrates (R)-1 and (S)-1 was accomplished by kinetic resolution of the racemic 12-tridecyn-2-ol (6) with immobilized porcine pancreatic lipase. The enantiomerically pure alcohols (R)-6 and (S)-6 were transformed into the final acids (S)-1 and (R)-1, respectively, by a sequence of well-established reactions. The analyses of methanolyzed lipidic extracts from glands incubated separatedly with each individual probe showed that in the transformation of (Z)-11-tetradecenoic acid into (E,E)-10,12-tetradecadienoic acid, both pro-(R) hydrogen atoms at C-10 and C-13 are removed from the substrate. This is the first example reported of a desaturase with pro-(R)/pro-(R) stereospecificities that gives rise to (E)-double bonds. A mechanistic explanation for the stereochemical outcome of this reaction is advanced.
authors.affiliation: Department of Biological Organic Chemistry and Deparment of Peptide and Protein Chemistry, IIQAB-CSIC, Jordi Girona 18-26, 08034-Barcelona, Spain.
authors.forename: Sergio
authors.initials: S
authors.lastname: Rodríguez
authors.forename: Pere
authors.initials: P
authors.lastname: Clapés
authors.forename: Francisco
authors.initials: F
authors.lastname: Camps
authors.forename: Gemma
authors.initials: G
authors.lastname: Fabriàs
mesh_terms: D000818:Animals; D001234:Aspergillus niger / Q000201:enzymology; D001665:Binding Sites; D002175:Candida / Q000201:enzymology; D002384:Catalysis; D005229:Fatty Acids, Monounsaturated / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008049:Lipase / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009036:Moths / Q000378:metabolism*; D009227:Myristic Acids / Q000737:chemistry / Q000378:metabolism*; D011549:Pseudomonas / Q000201:enzymology; D020103:Rhizomucor / Q000201:enzymology; D012724:Sex Attractants / Q000096:biosynthesis*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013552:Swine
chemical_list: C447625:10,12-tetradecadienoic acid; C432948:11-tetradecenoic acid; D005229:Fatty Acids, Monounsaturated; D009227:Myristic Acids; D012724:Sex Attractants; D008049:Lipase