title: Quantitation of Thioprolines in Grape Wine by Isotope Dilution-Liquid Chromatography-Tandem Mass Spectrometry.
abstract: Cysteine reacts with reactive carbonyls to form thioprolines, which have been demonstrated to possess various pharmaceutical properties. Therefore, thioproline formation is considered as a major detoxification pathway for carcinogenic reactive carbonyls. In this study, we report the initial identification of thiazolidine-4-carboxylic acid (1) and 2-methylthiazolidine-4-carboxylic acid (2), two very common thioprolines, formed by reacting formaldehyde and acetaldehyde with cysteine in grape wine samples. We have developed an isotope dilution-liquid chromatography-tandem mass spectrometry method featuring high sensitivity (limit of detection of ≤1.5 ng/mL) and selectivity to quantitate compounds 1 and 2. The method after validated to be highly accurate (recovery of ≥92%) and precise [intraday relative standard deviation (RSD) of ≤4.1% and interday RSD of ≤9.7%] was applied to determine the varying compound 1 and 2 contents in grape wine samples. Results revealed the grape type and storage duration-dependent formation of thioprolines in grape wines. Overall, the results are expected to facilitate compound-dependent investigations of the health benefits of grape wine, and our findings could be adopted to predict the age of grape wine.
authors.affiliation: Environmental Science Programs, and ‡Department of Chemistry, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong Special Administrative Region of the People's Republic of China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Liu
authors.affiliation: Environmental Science Programs, and ‡Department of Chemistry, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong Special Administrative Region of the People's Republic of China.
authors.forename: Xiangpeng
authors.initials: X
authors.lastname: Meng
authors.affiliation: Environmental Science Programs, and ‡Department of Chemistry, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong Special Administrative Region of the People's Republic of China.
authors.forename: Wan
authors.initials: W
authors.lastname: Chan
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007201:Indicator Dilution Techniques; D053719:Tandem Mass Spectrometry / Q000379:methods*; D053778:Thiazolidines / Q000032:analysis*; D027843:Vitis / Q000737:chemistry*; D014920:Wine / Q000032:analysis*
chemical_list: D053778:Thiazolidines; C003438:thiazolidine-4-carboxylic acid
keywords: 2-methylthiazolidine-4-carboxylic acid; HPLC−MS/MS; grape wine; thiazolidine-4-carboxylic acid; thioprolines