Jin Jong-Sik, Nishihata Tomohiro, Kakiuchi Nobuko, Hattori Masao
Institute of Natural Medicine, University of Toyama, Toyama, Japan.
Biol Pharm Bull. 2008 Aug;31(8):1621-5. doi: 10.1248/bpb.31.1621.
Puerarin and daidzein are the major naturally occurring isoflavones in leguminous plants. These two compounds are metabolized to equol by human intestinal flora. Here we isolated two intestinal bacteria capable of metabolizing puerarin and daidzein, respectively, from human feces. One of them, strain PUE, converted puerarin to daidzein by cleaving a C-glucosyl bond, whereas the other, strain DZE, converted daidzein to equol by reducing a double bond in ring C followed by elimination of an oxo group. Based on the 16S ribosomal RNA gene sequence, strain DZE showed 85% similarity with Eggerthella lenta. Equol produced by strain DZE was identified as (3S)-equol through several analytical methods. Moreover, we obtained (3S)-equol from puerarin by co-incubation with strain PUE and DZE. In addition, 5-hydroxyequol was obtained from genistein by incubation with strain DZE.
葛根素和大豆苷元是豆科植物中主要的天然异黄酮。这两种化合物可被人体肠道菌群代谢为雌马酚。在此，我们从人类粪便中分离出了两种分别能够代谢葛根素和大豆苷元的肠道细菌。其中一种，菌株PUE，通过裂解C-葡萄糖苷键将葛根素转化为大豆苷元，而另一种，菌株DZE，则通过还原C环中的双键并消除一个氧代基团将大豆苷元转化为雌马酚。基于16S核糖体RNA基因序列，菌株DZE与迟缓埃格特菌的相似度为85%。通过多种分析方法鉴定出菌株DZE产生的雌马酚为(3S)-雌马酚。此外，通过与菌株PUE和DZE共同孵育，我们从葛根素中获得了(3S)-雌马酚。另外，通过与菌株DZE孵育从染料木黄酮中获得了5-羟基雌马酚。
