Hur H, Rafii F
Division of Microbiology, National Center for Toxicological Research, US FDA, Jefferson, AR 72079, USA.
FEMS Microbiol Lett. 2000 Nov 1;192(1):21-5. doi: 10.1111/j.1574-6968.2000.tb09353.x.
Eubacterium limosum (ATCC 8486), a strict anaerobe from the human intestinal tract that is capable of O-demethylation of several compounds, was tested for the ability to metabolize three methoxylated isoflavonoids, biochanin A, formononetin, and glycitein. High-performance liquid chromatography elution profiles of metabolites produced from biochanin A, formononetin, and glycitein showed peaks that had identical retention times to authentic genistein, daidzein, and 6,7,4'-trihydroxyisoflavone, respectively. The metabolites were identified, using an on line liquid chromatography-electrospray mass spectrometer. E. limosum produced 61.4 microM of genistein and 13.2 microM of daidzein from 100 microM of biochanin A and formononetin, after 26 days incubation. O-demethylase activity is cell-associated and was not detected in the extracellular fraction of bacterial culture. This is the first study in which conversion of biochanin A, and formononetin to more potent phytoestrogens by a bacterium has been shown.
黏液真杆菌（ATCC 8486）是一种来自人类肠道的严格厌氧菌，能够对多种化合物进行O-去甲基化，该菌被测试了代谢三种甲氧基化异黄酮（染料木黄酮、芒柄花素和大豆黄素）的能力。由染料木黄酮、芒柄花素和大豆黄素产生的代谢产物的高效液相色谱洗脱图谱显示，其峰的保留时间分别与 authentic 染料木素、大豆苷元和6,7,4'-三羟基异黄酮相同。使用在线液相色谱-电喷雾质谱仪对代谢产物进行了鉴定。在26天的培养后，黏液真杆菌从100微摩尔的染料木黄酮和芒柄花素中产生了61.4微摩尔的染料木素和13.2微摩尔的大豆苷元。O-去甲基酶活性与细胞相关，在细菌培养的细胞外部分未检测到。这是首次表明细菌将染料木黄酮和芒柄花素转化为更强效植物雌激素的研究。
