Department of Analytical Chemistry, Faculty of Chemical Engineering and Technology, Cracow University of Technology, ul. Warszawska 24, 31-155 Cracow, Poland.
Chemistry Research, VDF FutureCeuticals, Inc., Momence, IL 60954, USA.
Molecules. 2020 Jan 16;25(2):378. doi: 10.3390/molecules25020378.
Hypochlorous acid (HOCl) produced by neutrophils is a part of the natural innate immune response system in the human body, but excessive levels of HOCl can ultimately be detrimental to health. Recent reports suggest that betacyanin plant pigments can act as potent scavengers of inflammatory factors and are notably effective against HOCl. In this contribution, chlorination mechanism and position of the electrophilic substitution in betacyanins was studied by high-resolution mass spectrometry and further structural analyses by NMR techniques, which completed the identification of the chlorinated betacyanins. For the study on the influence of the position of decarboxylation on the chlorination mechanism, a comparison of the chlorination position between betanin as well as 17-, and 2,17-decarboxylated betanins was performed. The structural study confirmed that the chlorination position in betanin occurs within the dihydropyridinic moiety at carbon C-18. Therefore, out of the aqueous free chlorine equilibrium species: HOCl, OCl, Cl, and ClO, the most potent chlorinating agents are HOCl and ClO postulated previously and the attack of the Cl ion on the carbon C-18 with a cyclic intermediate version is considered.
次氯酸（HOCl）是人体天然先天免疫反应系统的一部分，由中性粒细胞产生，但 HOCl 的过量水平最终可能对健康有害。最近的报告表明，甜菜红素植物色素可以作为炎症因子的有效清除剂，并且对 HOCl 特别有效。在这项研究中，通过高分辨率质谱和 NMR 技术进一步的结构分析研究了甜菜红素的氯化机制和亲电取代的位置，从而完成了氯化甜菜红素的鉴定。为了研究脱羧位置对氯化机制的影响，对甜菜红以及 17-和 2,17-脱羧甜菜红的氯化位置进行了比较。结构研究证实，甜菜红的氯化位置发生在二氢吡啶部分的碳 C-18 上。因此，在水相游离氯平衡物种：HOCl、OCl、Cl 和 ClO 中，之前推测最有效的氯化剂是 HOCl 和 ClO，并且认为 Cl 离子攻击具有环状中间物的碳 C-18。
