Department of Food Chemistry and Analysis, Institute of Food Technology and Food Chemistry, Technische Universität Berlin, TIB 4/3-1, Gustav-Meyer-Allee 25, D-13355 Berlin, Germany.
J Agric Food Chem. 2012 Aug 8;60(31):7735-45. doi: 10.1021/jf301718g. Epub 2012 Jul 26.
Glucosinolates, present in Brassica vegetables, are thought to contribute to human health prevention because of their enzymatically induced breakdown products, primarily isothiocyanates (ITCs). ITCs are reactive substances that readily react with nucleophilic (food) compounds. The reactivity of allyl-ITC and 4-(methylsulfinyl)butyl-ITC (sulforaphane) toward thiol and amino groups of cysteine and lysine derivatives was studied in buffered model systems as well as broccoli sprouts. The thiol group is the preferred reaction site, and it was demonstrated that even endogenously released sulforaphane is able to react very fast with cysteine in broccoli sprouts. Amino groups reacted slower and only under basic conditions. However, great differences in the reactivity between the different amino compounds were revealed. The aliphatic allylamine reacted very fast with allyl-ITC, forming N,N'-diallylthiourea, a compound identified as a main thermal degradation product of allyl-ITC.
硫代葡萄糖苷存在于十字花科蔬菜中，由于其酶促分解产物，主要是异硫氰酸酯（ITCs），被认为对人类健康有预防作用。ITCs 是反应性物质，容易与亲核（食物）化合物发生反应。在缓冲模型系统和西兰花芽中研究了丙烯基-ITC 和 4-（甲基亚磺酰基）丁基-ITC（萝卜硫素）与半胱氨酸和赖氨酸衍生物的巯基和氨基的反应性。巯基是首选的反应位点，并且证明即使是内源性释放的萝卜硫素也能够非常快速地与西兰花芽中的半胱氨酸反应。氨基的反应较慢，仅在碱性条件下进行。然而，不同氨基酸化合物之间的反应性存在很大差异。脂肪族烯丙胺与丙烯基-ITC 反应非常迅速，形成 N,N'-二烯丙基硫脲，这是一种被鉴定为丙烯基-ITC 主要热降解产物的化合物。
