title: Synthesis of the individual diastereomers of the cysteine conjugate of 3-mercaptohexanol (3-MH).
abstract: The individual diastereoisomers of the cysteine conjugate of 3-mercaptohexanol (4) were synthesized with high isomeric purity (>98%). On treatment with Apotryptophanase enzyme, the 3R diastereoisomer of 4 gave an 82% yield of the R enantiomer of 1, with no trace of the 3S enantiomer present. Conversely, the 3S diastereoisomer of 4 gave the 3S enantiomer of 1 (43%) accompanied by a trace of the 3R form (S/R = 98.5:1.5), reflecting the diastereomeric purity of the cysteine conjugate. The same stereochemical outcome was observed when the individual diastereoisomers of 4 were added to fermentations with the Saccharomyces cerevisiae AWRI 1655 yeast strain, which gave 1 in 1% yield. A d(10)-analogue of 1 was synthesized and used as an internal standard to determine, by gas chromatography-mass spectrometry (GC-MS), the amounts of 1 formed in these transformations.
authors.affiliation: The Australian Wine Research Institute, P.O. Box 197, Glen Osmond, South Australia 5064, Australia.
authors.forename: Kevin H
authors.initials: KH
authors.lastname: Pardon
authors.forename: Sean D
authors.initials: SD
authors.lastname: Graney
authors.forename: Dimitra L
authors.initials: DL
authors.lastname: Capone
authors.forename: Jan H
authors.initials: JH
authors.lastname: Swiegers
authors.forename: Mark A
authors.initials: MA
authors.lastname: Sefton
authors.forename: Gordon M
authors.initials: GM
authors.lastname: Elsey
mesh_terms: D003545:Cysteine / Q000737:chemistry* / Q000378:metabolism; D005285:Fermentation; D008401:Gas Chromatography-Mass Spectrometry; D000441:Hexanols / Q000138:chemical synthesis* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D009812:Odorants / Q000032:analysis; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D013237:Stereoisomerism; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis* / Q000378:metabolism
chemical_list: D000441:Hexanols; D013438:Sulfhydryl Compounds; D003545:Cysteine; C477019:3-mercaptohexanol