Demetalation Kinetics of Chlorophyll Derivatives Possessing Different Substituents at the 7‐Position Under Acidic Conditions
Demetalation Kinetics of Chlorophyll Derivatives Possessing Different Substituents at the 7‐Position Under Acidic Conditions
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酸性条件下7位不同取代基叶绿素衍生物的脱金属动力学
DOI：
10.1111/j.1751-1097.2010.00874.x
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发表时间：
2011
影响因子：
3.3
通讯作者：
Y. Saga
中科院分区：
文献类型：
--
作者：
Y. Hirai;S. Kashimura;Y. Saga
叶绿素（Chl）B中7位甲酰基通过羟甲基转化为甲基在Chl B降解中具有重要的生物学意义。为了阐明7位取代基对叶绿素B降解早期脱金属性质的影响，我们报道了具有7位羟甲基的叶绿素锌衍生物在酸性条件下的脱金属动力学，该衍生物是叶绿素B降解早期中间体分子的良好模型化合物，并将其性质与分别作为叶绿素a和B模型化合物的具有甲基和甲酰基的叶绿素锌衍生物的性质进行了比较。7-羟甲基锌二氢卟酚的脱金属速率常数远大于7-甲酰基锌二氢卟酚，但略小于7-甲基锌二氢卟酚。7-甲酰基二氢锌的脱金属反应活化能比其他衍生物大。7-去甲酰基-7-羟甲基Chl B b的脱金属速率常数也大于Chl B b的脱金属速率常数，与Chl a的脱金属速率常数相近。这表明，与7-甲酰基相比，二氢卟酚大环中的7-羟甲基对脱金属的影响较小。
Conversion of the formyl group at the 7‐position in chlorophyll (Chl) b to the methyl group via the hydroxymethyl group is biologically important in Chl b degradation. To clarify the effects of the 7‐substituents on demetalation properties of chlorophyllous pigments in the early process of Chl b degradation, we report demetalation kinetics of the zinc Chl derivative possessing a 7‐hydroxymethyl group, which is a good model compound of the intermediate molecule in the early process of Chl b degradation, under acidic conditions, and compare its properties with those of zinc Chl derivatives possessing a methyl and a formyl group, which are model compounds of Chls a and b, respectively. Demetalation rate constants of 7‐hydroxymethyl zinc chlorin were much larger than those of 7‐formyl zinc chlorin, but were slightly smaller than those of 7‐methyl zinc chlorin. The activation energy for demetalation reaction of 7‐formyl zinc chlorin was larger than those of other derivatives. Demetalation rate constants of 7‐deformyl‐7‐hydroxymethyl Chl b were also larger than those of Chl b, and were similar to those of Chl a. These indicate that the 7‐hydroxymethyl group in the chlorin macrocycle has a smaller effect on demetalation compared with the 7‐formyl group.
绿硫光合细菌纯化的光捕获细菌叶绿素异构体脱金属的物理化学研究
DOI：
--
发表时间：
2009
期刊：
Photochem. Photobiol. (印刷中)
影响因子：
--
作者：
尾高雅文;堀祥太;荒川孝俊;中山 洋;堂前 直;三野広幸;片山葉子;養王田正文;Y. Hirai
通讯作者：
Y. Hirai
影响因子：
5.2
作者：
Kunieda, T;Amano, T;Shioi, Y
通讯作者：
Shioi, Y
影响因子：
7.2
作者：
Sato, Yutaka;Morita, Ryouhei;Kusaba, Makoto
通讯作者：
Kusaba, Makoto