Table 6.
Green tea catechin metabolites in skin biopsies presupplementation and postsupplementation, with or without UVR exposure.
| Compound | Amount/biopsy weight |
|||
|---|---|---|---|---|
| Pre, No UVR | Pre, UVR | Post, No UVR | Post, UVR | |
| Conjugated form | Peak area ratio/mg | Peak area ratio/mg | Peak area ratio/mg | Peak area ratio/mg |
| O-Me-EC-O-sulfate | ND | ND | 20 (1) | ND |
| Gallic acid-O-glucuronide | ND | ND | 8 (1) | 9 (1) |
| O-Me-gallic acid-O-sulfate | ND | ND | ND | 6 (1) |
| O-Me-gallic acid-O-glucuronide | ND | ND | ND | 14 (1) |
| M6/M6′-O-sulfate | ND | ND | 9±5 (2) | 8±2 (3) |
| Free form | pmol/mg | pmol/mg | pmol/mg | pmol/mg |
| Quercetin | ND | ND | 120 (1) | ND |
| M6 | 240 (1) | 370 (1) | 230 (1) | 80 (1) |
Data are the average peak area ratio relative to internal standard (EG; 2 μg/ml) ×10−7, standardized to the initial weight of the biopsy. Samples were analyzed presupplementation and postsupplementation and with or without UVR irradiation. Samples were analyzed in technical duplicate; mean±SE; data in brackets are the number of subjects in which the metabolite was identified. EC, epicatechin; EG, ethyl gallate; Me, methyl; ND, not detected.