García-Villalba Rocío, Beltrán David, Frutos María D, Selma María V, Espín Juan C, Tomás-Barberán Francisco A
Laboratory of Food & Health, Research Group on Quality, Safety, and Bioactivity of Plant Foods, Department of Food Science and Technology, CEBAS-CSIC, P.O. Box 164, 30100 Campus de Espinardo, Murcia, Spain.
Food Funct. 2020 Aug 1;11(8):7012-7022. doi: 10.1039/d0fo01649g. Epub 2020 Jul 27.
Gordonibacter urolithinfaciens and Ellagibacter isourolithinifaciens are two human gut bacterial species that convert ellagic acid into urolithins. Urolithins are bioactive postbiotics produced by dehydroxylation reactions catalyzed by different catechol-dehydroxylases. The metabolic ability of these anaerobic bacteria on other dietary-phenolic compounds is unknown. In the present study, we evaluated the metabolism of flavonoids (quercetin, hesperetin, hesperidin, nobiletin, catechin, isoxanthohumol), isoflavonoids (daidzein), coumarins (esculetin, umbelliferone, scoparone), phenylpropanoids [caffeic acid; 3-(3',4'-dihydroxyphenyl)propanoic acid (dihydrocaffeic acid); rosmarinic acid, and chlorogenic acid], benzoic acid derivatives (gallic acid, ellagic acid), lignans (secoisolariciresinol diglucoside), stilbenes (resveratrol), and secoiridoids (oleuropein) by G. urolithinfaciens DSM 27213 and E. isourolithinifaciens DSM 104140. Both strains metabolized ellagic acid leading to the characteristic urolithins. They also metabolized caffeic, dihydrocaffeic, rosmarinic, and chlorogenic acids. The rest of the phenolic compounds were not transformed. Catechol dehydroxylation and double bond reduction were prominent transformations observed during the incubations. The enzymatic activities seem to have a narrow substrate scope as many catechol- (quercetin, catechin, esculetin, gallic acid) and double bond-containing (resveratrol, esculetin, scoparone, umbelliferone) phenolics were not metabolized. The catechol-dehydroxylase activity was more efficient in E. isourolithinifaciens, while the reductase activity was more relevant in G. urolithinfaciens.
尿石素生成戈登氏菌和异尿石素生成埃拉格氏菌是两种可将鞣花酸转化为尿石素的人体肠道细菌。尿石素是由不同儿茶酚脱羟基酶催化的脱羟基反应产生的具有生物活性的后生元。这些厌氧菌对其他膳食酚类化合物的代谢能力尚不清楚。在本研究中，我们评估了尿石素生成戈登氏菌DSM 27213和异尿石素生成埃拉格氏菌DSM 104140对黄酮类化合物（槲皮素、橙皮素、橙皮苷、川陈皮素、儿茶素、异黄腐酚）、异黄酮类化合物（大豆苷元）、香豆素类化合物（七叶亭、伞形花内酯、滨蒿内酯）、苯丙烷类化合物[咖啡酸；3-(3',4'-二羟基苯基)丙酸（二氢咖啡酸）；迷迭香酸和绿原酸]、苯甲酸衍生物（没食子酸、鞣花酸）、木脂素类化合物（开环异落叶松脂素二葡萄糖苷）、芪类化合物（白藜芦醇）和裂环环烯醚萜类化合物（橄榄苦苷）的代谢情况。两种菌株都能代谢鞣花酸，生成特征性的尿石素。它们还能代谢咖啡酸、二氢咖啡酸、迷迭香酸和绿原酸。其余的酚类化合物未被转化。在培养过程中观察到儿茶酚脱羟基和双键还原是主要的转化反应。酶活性的底物范围似乎较窄，因为许多含儿茶酚的（槲皮素、儿茶素、七叶亭、没食子酸）和含双键的（白藜芦醇、七叶亭、滨蒿内酯、伞形花内酯）酚类化合物未被代谢。异尿石素生成埃拉格氏菌中的儿茶酚脱羟基酶活性更高，而尿石素生成戈登氏菌中的还原酶活性更显著。
