Rechner Andreas R, Smith Martin A, Kuhnle Gunter, Gibson Glenn R, Debnam Edward S, Srai S Kaila S, Moore Kevin P, Rice-Evans Catherine A
Antioxidant Research Group, Wolfson Centre for Age-Related Diseases, School of Biomedical Sciences, King's College London, SE1 9RT, London, UK.
Free Radic Biol Med. 2004 Jan 15;36(2):212-25. doi: 10.1016/j.freeradbiomed.2003.09.022.
The metabolism of chlorogenic acid, naringin, and rutin, representative members of three common families of dietary polyphenols, the hydroxycinnamates, the flavanones, and the flavonols, respectively, was studied in an in vitro mixed culture model of the human colonic microflora. Time- and concentration-dependent degradation of all three compounds was observed, which was associated with the following metabolic events after cleavage of the ester or glycosidic bond: reduction of the aliphatic double bond of the resulting hydroxycinnamate caffeic acid residue; dehydroxylation and ring fission of the heterocyclic C-ring of the resulting deglycosylated flavanone, naringenin, and of the deglycosylated flavonol, quercetin (which differed depending on the substitution). The metabolic events, their sequences, and major phenolic end products, as identified by GC-MS or LC-MS/MS, were elucidated from the structural characteristics of the investigated compounds. The major phenolic end products identified were 3-(3-hydroxyphenyl)-propionic acid for chlorogenic acid, 3-(4-hydroxyphenyl)-propionic acid and 3-phenylpropionic acid for naringin, and 3-hydroxyphenylacetic acid and 3-(3-hydroxyphenyl)-propionic acid for rutin. The degree of degradation of the compounds studied was significantly influenced by the substrate concentration as well as individual variations in the composition of the fecal flora. The results support extensive metabolism of dietary polyphenols in the colon, depending on substrate concentration and residence time, with resultant formation of simple phenolics, which can be considered biomarkers of colonic metabolism if subsequently absorbed. It is also apparent that a relatively small number of phenolic degradation products are formed in the colon from the diverse group of natural polyphenols.
在人结肠微生物群的体外混合培养模型中，研究了三种常见膳食多酚家族（分别为羟基肉桂酸酯类、黄烷酮类和黄酮醇类）的代表性成员绿原酸、柚皮苷和芦丁的代谢情况。观察到所有这三种化合物均有时间和浓度依赖性降解，这与酯键或糖苷键断裂后的以下代谢事件相关：所得羟基肉桂酸咖啡酸残基的脂肪族双键还原；所得去糖基化黄烷酮柚皮素和去糖基化黄酮醇槲皮素（其因取代情况而异）的杂环C环脱羟基和环裂变。通过气相色谱 - 质谱联用仪（GC-MS）或液相色谱 - 串联质谱仪（LC-MS/MS）鉴定出的代谢事件、其顺序以及主要酚类终产物，是根据所研究化合物的结构特征阐明的。鉴定出的主要酚类终产物，绿原酸为3-(3-羟基苯基)丙酸，柚皮苷为3-(4-羟基苯基)丙酸和3-苯基丙酸，芦丁为3-羟基苯乙酸和3-(3-羟基苯基)丙酸。所研究化合物的降解程度受底物浓度以及粪便菌群组成的个体差异显著影响。结果支持膳食多酚在结肠中的广泛代谢，这取决于底物浓度和停留时间，会生成简单酚类物质，如果随后被吸收，这些物质可被视为结肠代谢的生物标志物。同样明显的是，从多种天然多酚类物质中，在结肠中形成的酚类降解产物数量相对较少。
