Plant Quality and Food Security, Leibniz Institute of Vegetable and Ornamental Crops (IGZ) e.V., Theodor-Echtermeyer-Weg 1, 14979 Großbeeren, Germany.
Institute of Food Technology and Food Chemistry, Technische Universität Berlin, Gustav-Meyer-Allee 25, 13355 Berlin, Germany.
Food Res Int. 2022 Jul;157:111237. doi: 10.1016/j.foodres.2022.111237. Epub 2022 Apr 9.
Glucosinolates are plant secondary metabolites occurring in Brassicaceae plants. Upon tissue disruption, these compounds can be enzymatically hydrolyzed into isothiocyanates, which are very reactive and can react with nucleophiles during thermal processes such as boiling. Here, a novel type of glucosinolate degradation product was identified resulting from the reaction of thioglucose with the isothiocyanates sulforaphane or allyl isothiocyanate during aqueous heating. The two heterocyclic compounds 4-hydroxy-3-(4-(methylsulfinyl)butyl)thiazolidine-2-thione and 3-allyl-4-hydroxythiazolidine-2-thione were isolated and their structure elucidated by NMR spectroscopy and high-resolution mass spectrometry. Based on a set of chemical experiments, a reaction mechanism was proposed. Finally, the formation of the two 3-alk(en)yl-4-hydroxythiazolidine-2-thiones was quantified in boiled cabbage samples using a standard addition method in which 92 pmol/g and 19 pmol/g fresh weight of the sulforaphane and allyl isothiocyanate derivatives were found, respectively.
硫代葡萄糖苷是存在于十字花科植物中的植物次生代谢物。在组织破坏时，这些化合物可以被酶水解成异硫氰酸酯，它们非常活泼，可以在热过程（如煮沸）中与亲核试剂反应。在这里，鉴定出一种新型的硫代葡萄糖苷降解产物，它是在水热处理过程中，硫葡萄糖与萝卜硫素或丙烯基异硫氰酸酯反应生成的。两种杂环化合物 4-羟基-3-(4-(甲亚磺酰基)丁基)噻唑烷-2-硫酮和 3-丙烯基-4-羟基噻唑烷-2-硫酮通过核磁共振波谱和高分辨率质谱法进行了分离和结构阐明。基于一系列化学实验，提出了反应机制。最后，采用标准添加法对煮沸的甘蓝样品中两种 3-烯丙基-4-羟基噻唑烷-2-硫酮的形成进行了定量分析，发现其萝卜硫素和丙烯基异硫氰酸酯衍生物的含量分别为 92 pmol/g 和 19 pmol/g 鲜重。
