Division of Environmental and Evolutionary Biology, Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow, UK.
Mol Nutr Food Res. 2010 Mar;54(3):323-34. doi: 10.1002/mnfr.200900194.
Green tea containing 634 micromol of flavan-3-ols was ingested by human subjects with an ileostomy. Ileal fluid, plasma, and urine collected 0-24 h after ingestion were analysed by HPLC-MS. The ileal fluid contained 70% of the ingested flavan-3-ols in the form of parent compounds (33%) and 23 metabolites (37%). The main metabolites effluxed back into the lumen of the small intestine were O-linked sulphates and methyl-sulphates of (epi)catechin and (epi)gallocatechin. Thus, in subjects with a functioning colon substantial quantities of flavan-3-ols would pass from the small to the large intestine. Plasma contained 16 metabolites, principally methylated, sulphated, and glucuronidated conjugates of (epi)catechin and (epi)gallocatechin, exhibiting 101-256 nM peak plasma concentration and the time to reach peak plasma concentration ranging from 0.8 to 2.2 h. Plasma pharmacokinetic profiles were similar to those obtained with healthy subjects, indicating that flavan-3-ol absorption occurs in the small intestine. Ileostomists had earlier plasma time to reach peak plasma concentration values than subjects with an intact colon, indicating the absence of an ileal brake. Urine contained 18 metabolites of (epi)catechin and (epi)gallocatechin in amounts corresponding to 6.8+/-0.6% of total flavan-3-ol intake. However, excretion of (epi)catechin metabolites was equivalent to 27% of the ingested (-)-epicatechin and (+)-catechin.
志愿者饮用含有 634 微摩尔黄烷-3-醇的绿茶后，通过回肠造口收集 0-24 小时的回肠液、血浆和尿液，并用 HPLC-MS 进行分析。回肠液中以母体化合物（33%）和 23 种代谢产物（37%）的形式含有 70%的摄入黄烷-3-醇。从回肠腔重新分泌到小肠腔的主要代谢产物是表儿茶素和表没食子儿茶素的 O-连接硫酸盐和甲基硫酸盐。因此，在结肠功能正常的受试者中，大量的黄烷-3-醇将从小肠转移到大肠。血浆中含有 16 种代谢物，主要是表儿茶素和表没食子儿茶素的甲基化、硫酸化和葡萄糖醛酸化缀合物，其峰值血浆浓度为 101-256 nM，达到峰值血浆浓度的时间范围为 0.8-2.2 h。血浆药代动力学特征与健康受试者相似，表明黄烷-3-醇的吸收发生在小肠。回肠造口术患者的血浆达到峰值浓度的时间早于结肠完整的患者，表明不存在回肠制动。尿液中含有（epi）儿茶素和（epi）没食子儿茶素的 18 种代谢产物，其含量相当于摄入黄烷-3-醇总量的 6.8+/-0.6%。然而，（epi）儿茶素代谢产物的排泄量相当于摄入（-）-表儿茶素和（+）-儿茶素的 27%。
