Synthesis of Isotopically Labelled Thiol Violatiles and Cysteine Conjugates for Quantification of Sauvignon Blanc Wine

Abstract

The thiols 4-mercapto-4-methylpentan-2-ol (4MMPOH), 3-mercaptohexan-1-ol (3MH), and 3-mercaptohexyl acetate (3MHA), which contribute to the aroma profile of Sauvignon Blanc, as well as other varieties of wine, have been synthesized with deuterium labels. The cysteinylated precursors of the thiols, 4-(4-methylpentan-2-one)-l-cysteine (4MMP-cys) and 4-(4-methylpentan-2-ol)-l-cysteine (4MMPOH-cys), found in grape must were also synthesized with deuterium labels. These deuterated compounds provide useful internal standards for the quantification of these thiols in wine using LCMS.