Department of Chemistry, Faculty of Science and Engineering, Kinki University, Higashi-Osaka, Osaka 577-8502, Japan.
Chem Biodivers. 2012 Sep;9(9):1659-83. doi: 10.1002/cbdv.201100435.
Natural chlorophylls (Chls) and bacteriochlorophyll (BChls), which are major pigments in photosynthesis, possess a central Mg (or Zn) in their cyclic tetrapyrrole macrocycles. Removal of the central metal atom from chlorophyllous pigments, called pheophytinization, is a biologically important reaction in that it allows production of the primary electron acceptors in photosystem II(-type) reaction centers and is one of the crucial steps in the Chl degradation pathway. Pheophytinization in processed and postharvest foods derived from vegetables and fruits has attracted considerable attention in agricultural and food chemistry from the viewpoints of maintenance of their color level and evaluation by consumers. In this review, we focus on in vivo demetalation reactions and demetalated products of chlorophyllous pigments. In addition, we summarize kinetic studies on in vitro demetalation of natural (B)Chl molecules and their synthetic analogs under acidic conditions.
天然叶绿素（Chls）和细菌叶绿素（BChls）是光合作用中的主要色素，它们的环状四吡咯大环中含有中心 Mg（或 Zn）原子。从叶绿素类色素中去除中心金属原子，称为脱镁作用，是一种在生物学上很重要的反应，因为它允许在光系统 II(-型)反应中心中产生最初的电子受体，并且是叶绿素降解途径中的关键步骤之一。在农业和食品化学领域，从蔬菜和水果中获得的加工和收获后食品中的脱镁作用，从维持其颜色水平和消费者评估的角度引起了相当大的关注。在这篇综述中，我们重点介绍叶绿素类色素的体内脱金属反应和脱金属产物。此外，我们还总结了在酸性条件下天然（B）Chl 分子及其合成类似物的体外脱金属动力学研究。
