Plant Quality and Food Security, Leibniz Institute of Vegetable and Ornamental Crops, Theodor-Echtermeyer-Weg 1, 14979 Grossbeeren, Germany.
Department of Food Chemistry and Analysis, Institute of Food Technology and Food Chemistry, Technische Universität Berlin, TIB 4/3-1, Gustav-Meyer-Allee 25, 13355 Berlin, Germany.
Food Chem. 2018 Apr 15;245:564-569. doi: 10.1016/j.foodchem.2017.10.124. Epub 2017 Nov 5.
The epithionitriles, 1-cyano-2,3-epithiopropane, in particular, and 1-cyano-3,4-epithiobutane, are important, but yet underestimated glucosinolate hydrolysis products that are released instead of the cancer preventative isothiocyanates in Brassica vegetables, such as cabbage, broccoli, or pak choi. Here, we characterized the reactivity of 1-cyano-2,3-epithiopropane under aqueous heat treatment conditions and compared our findings to those of the related epithionitriles 1-cyano-3,4-epithiobutane and 1-cyano-4,5-epithiopentane. In contrast to the other epithionitriles, 1-cyano-2,3-epithiopropane is highly reactive. As a result, 2-aminothiophene and dimeric 1,4-dithiane-2,5-diacetonitrile were identified as main products and a reaction mechanism is proposed. Formation of 2-aminothiophene was also observed in cooked white cabbage samples. Moreover, three novel compounds were identified as derivatives of the related epithionitriles. The results imply that apart from isothiocyanates, process-derived compounds should be considered in regards to cancer preventative Brassica vegetable related bioactivity.
硫代乙腈类化合物，特别是 1-氰基-2,3-亚乙基硫代丙烷，以及 1-氰基-3,4-亚乙基硫代丁烷，是重要的但却被低估的硫代葡萄糖苷水解产物，它们在 Brassica 类蔬菜（如白菜、西兰花或白菜）中会取代具有防癌作用的异硫氰酸盐释放出来。在这里，我们对 1-氰基-2,3-亚乙基硫代丙烷在水热处理条件下的反应性进行了表征，并将我们的研究结果与相关的硫代乙腈 1-氰基-3,4-亚乙基硫代丁烷和 1-氰基-4,5-亚乙基硫代戊烷进行了比较。与其他硫代乙腈类化合物不同，1-氰基-2,3-亚乙基硫代丙烷具有很高的反应活性。因此，鉴定出主要产物为 2-氨基噻吩和二聚 1,4-二硫杂环戊烷-2,5-二乙腈，并提出了一种反应机制。在煮熟的白菜样品中也观察到了 2-氨基噻吩的形成。此外，还鉴定出三种新化合物是相关硫代乙腈类化合物的衍生物。这些结果表明，除了异硫氰酸盐之外，在考虑具有防癌作用的 Brassica 类蔬菜相关生物活性时，还应该考虑加工过程中形成的化合物。
