Donovan Jennifer L, Crespy Vanessa, Oliveira Manuel, Cooper Karen A, Gibson Bryan B, Williamson Gary
Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA.
Free Radic Res. 2006 Oct;40(10):1029-34. doi: 10.1080/10715760600868545.
Catechin is a flavonoid present in fruits, wine and cocoa products. Most foods contain the (+)-enantiomer of catechin but chocolate mainly contains ( - )-catechin, in addition to its major flavanol, ( - )-epicatechin. Previous studies have shown poor bioavailability of catechin when consumed in chocolate. We compared the absorption of ( - ) and (+)-catechin after in situ perfusion of 10, 30 or 50 micromol/l of each catechin enantiomer in the jejunum and ileum in the rat. We also assayed 23 samples of chocolate for (+) and ( - )-catechin. Samples were analyzed using HPLC with a Cyclobond I-2000 RSP chiral column. At all concentrations studied, the intestinal absorption of ( - )-catechin was lower than the intestinal absorption of (+)-catechin (p < 0.01). Plasma concentrations of ( - )-catechin were significantly reduced compared to (+)-catechin (p < 0.05). The mean concentration of ( - )-catechin in chocolate was 218 +/- 126 mg/kg compared to 25 +/- 15 mg/kg (+)-catechin. Our findings provide an explanation for the poor bioavailability of catechin when consumed in chocolate or other cocoa containing products.
儿茶素是一种存在于水果、葡萄酒和可可制品中的类黄酮。大多数食物中含有的是儿茶素的（+）对映体，但巧克力中除了主要的黄烷醇（-）-表儿茶素外，主要含有的是（-）-儿茶素。先前的研究表明，食用巧克力中的儿茶素时其生物利用度较低。我们比较了在大鼠空肠和回肠原位灌注10、30或50微摩尔/升的每种儿茶素对映体后（-）-儿茶素和（+）-儿茶素的吸收情况。我们还检测了23份巧克力样品中的（+）-儿茶素和（-）-儿茶素。样品使用配备Cyclobond I - 2000 RSP手性柱的高效液相色谱法进行分析。在所研究的所有浓度下，（-）-儿茶素的肠道吸收均低于（+）-儿茶素的肠道吸收（p < 0.01）。与（+）-儿茶素相比，（-）-儿茶素的血浆浓度显著降低（p < 0.05）。巧克力中（-）-儿茶素的平均浓度为218±126毫克/千克，而（+）-儿茶素为25±15毫克/千克。我们的研究结果解释了食用巧克力或其他含可可制品时儿茶素生物利用度较低的原因。
