Redox potential of chlorophyll d in vitro
Redox potential of chlorophyll d in vitro
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DOI：
10.1016/j.bbabio.2007.02.015
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发表时间：
2007-06-01
影响因子：
4.3
通讯作者：
Watanabe, Tadashi
中科院分区：
文献类型：
--
作者：
Kobayashi, Masami;Ohashi, Shunsuke;Watanabe, Tadashi
叶绿素（Chl）d是一种新的产氧原核生物Acaryochloris marina的主要叶绿素。本文首次报道了叶绿素d在体外的氧化还原电位。Chl d的氧化电位为+0.88 V vs. SHE;该值高于Chl a（+0.81 V），低于Chl B（+0.94 V）。氧化电位顺序为Chl 1）> Chl d > Chl a，这是由于取代基对大环共轭π电子体系的诱导作用所致。相应的脱镁叶绿素含量顺序为：Phe B（+1.25 V）> Phe d（+1.21 V）> Phe a（+1.21 V）。14 V），但这些值显着高于叶绿素，这是合理的，在电子密度降低的π系统的镁与更多的电负性氢的替代。因此，叶绿素a的氧化电位被认为是最低的ChIs和Phes。这些结果将有助于我们拓宽对A.码头(c)2007 Elsevier B.V保留所有权利。
Chlorophyll (Chl) d is a major chlorophyll in a novel oxygenic prokaryote Acaryochloris marina. Here we first report the redox potential of Chl d in vitro. The oxidation potential of Chl d was +0.88 V vs. SHE in acetonitrile; the value was higher than that of Chl a (+0.81 V) and lower than that of Chl b (+0.94 V). The oxidation potential order, Chl 1) > Chl d > Chl a, can be explained by inductive effect of substituent groups on the conjugated pi-electron system on the macrocycle. Corresponding pheophytins showed the same order; Phe b (+1.25 V) > Phe d (+1.21 V) > Phe a (+1. 14 V), but the values were significantly higher than those of Chls, which are rationalized in terms of an electron density decrease in the pi-system by the replacement of magnesium with more electronegative hydrogen. Consequently, oxidation potential of Chl a was found to be the lowest among ChIs and Phes. The results will help us to broaden our views on pbotosystems in A. marina. (c) 2007 Elsevier B.V All rights reserved.