Takagaki Akiko, Nanjo Fumio
Food Research Laboratories, Mitsui Norin Co., Ltd.
Biol Pharm Bull. 2015;38(2):325-30. doi: 10.1248/bpb.b14-00646.
Four isoflavone-metabolizing bacteria were tested for their abilities to degrade (-)-epigallocatechin (EGC) and its isomer (-)-gallocatechin (GC). Biotransformation of both EGC and GC was observed with Adlercreutzia equolifaciens JCM 14793, Asaccharobacter celatus JCM 14811, and Slackia equolifaciens JCM 16059, but not Slackia isoflavoniconvertens JCM 16137. With respect to the degradation of EGC, strain JCM 14793 only catalyzed 4'-dehydroxylation to produce 4'-dehydroxylated EGC (7). Strain JCM 14811 mainly produced 7, along with a slight formation of the C ring-cleaving product 1-(3,4,5-trihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol (1). Strain JCM 16059 catalyzed only C ring cleavage to form 1. Interestingly, the presence of hydrogen promoted the bioconversion of EGC by these bacteria. In addition, strain JCM 14811 revealed the ability to catalyze 4'-dehydroxylation of 1 to yield 1-(3,5-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol (2) in the presence of hydrogen. In the case of GC, strain JCM 14793 mainly produced C ring-cleaving product (1) with only a very small amount of 4'-dehydroxylated GC (8), while Strain JCM 14811 only catalyzed 4'-dehydroxylation to form 8. Strain JCM 16059 formed 1. The bioconversion of GC by the three strains was stimulated by hydrogen. Strain JCM 14793 showed the ability to convert 1 into 2 in the presence of hydrogen as did strain JCM 14811. Furthermore, strains JCM 14793 and JCM 14811 were found to have the ability to catalyze p-dehydroxylation of the pyrogallol moiety in the EGC metabolites 4-hydroxy-5-(3,4,5-trihydroxyphenyl)valeric acid (3) and 5-(3,4,5-trihydroxyphenyl)-γ-valerolactone (4), and this ability was enhanced by the presence of hydrogen.
测试了四种异黄酮代谢细菌降解（-）-表没食子儿茶素（EGC）及其异构体（-）-没食子儿茶素（GC）的能力。在马尿酸阿德勒克雷茨菌JCM 14793、塞拉无糖杆菌JCM 14811和马尿酸斯拉奇菌JCM 16059中观察到了EGC和GC的生物转化，但在异黄酮转化斯拉奇菌JCM 16137中未观察到。关于EGC的降解，菌株JCM 14793仅催化4'-去羟基化反应生成4'-去羟基化EGC（7）。菌株JCM 14811主要生成7，同时少量生成C环裂解产物1-（3,4,5-三羟基苯基）-3-（2,4,6-三羟基苯基）丙-2-醇（1）。菌株JCM 16059仅催化C环裂解生成1。有趣的是，氢气的存在促进了这些细菌对EGC的生物转化。此外，菌株JCM 14811显示在氢气存在下能够催化1的4'-去羟基化反应生成1-（3,5-二羟基苯基）-3-（2,4,6-三羟基苯基）丙-2-醇（2）。对于GC，菌株JCM 14793主要生成C环裂解产物（1），仅生成极少量的4'-去羟基化GC（8），而菌株JCM 14811仅催化4'-去羟基化反应生成8。菌株JCM 16059生成1。这三种菌株对GC的生物转化受到氢气的刺激。菌株JCM 14793与菌株JCM 14811一样，在氢气存在下能够将1转化为2。此外，发现菌株JCM 14793和JCM 14811能够催化EGC代谢产物4-羟基-5-（3,4,5-三羟基苯基）戊酸（3）和5-（3,4,5-三羟基苯基）-γ-戊内酯（4）中邻苯三酚部分的对去羟基化反应，并且氢气的存在增强了这种能力。
