Resveratrol is absorbed in the small intestine as resveratrol glucuronide

We have studied the absorption and metabolism of resveratrol in the jejunum in an isolated rat small intestine model. Only small amounts of resveratro l were absorbed across the enterocytes of the jejunum and ileum unmetabolis ed. The major compound detected on the serosal side was the glucuronide con jugate of resveratrol (96.5% +/- 4.6 of the amount absorbed) indicating the susceptibility of resveratrol to glucuronidation during transfer across th e rat jejunum. The presence of the glucuronide was confirmed using HPLC-PDA and nanoES-MS/MS techniques. These findings suggest that resveratrol is mo st likely to be in the form of a glucuronide conjugate after crossing the s mall intestine and entering the blood circulation. This will have important implications for the biological functions of resveratrol in vivo. (C) 2000 Academic Press.