Table 3 Metabolites identified in human intervention studies on tea
From: Biomarkers of intake for coffee, tea, and sweetened beverages
| Type of beverage | No. subjects | Sample type | Analytical method | Enzymatic hydrolysis | Discriminating metabolites/candidate biomarkers | Reference |
|---|---|---|---|---|---|---|
| Green tea, black tea | 18 | Urine | LC-ECD | Yes | Epicatechin, epigallocatechin | [49] |
| Green tea, black tea | 20 | Urine | GC-MS | Yes | 4-O-Methylgallic acid | [128] |
| Black tea | 10 | Plasma, urine | HPLC | ? | 4-O-Methylgallic acid, gallic acid | [55] |
| Green tea, black tea (extracts) | 17 | Urine | LC-MS | No | Hippuric acid | [129] |
| Green tea, black tea (decaffeinated) | 133 | Urine | LC-ECD | Yes | (−)-Epigallocatechin | [60] |
| Green tea, black tea | 30 | Plasma | LC-ECD | Yes | (−)-Epicatechin, (−)-epicatechin-3-gallate, (−)-epigallocatechin, (−)-epigallocatechin-3-gallate | [61] |
| Green tea | 10 | Plasma, urine | LC-MS | No | (−)-Epicatechin-3’-O-glucuronide, (epi)catechin-O-sulfates, 3’-O-methyl-(epi)catechin-O-sulfates, 4’-O-methyl-(epi)catechin-O-sulfate, (epi)gallocatechin-O-glucuronide, 4’-O-methyl-(epi)gallocatechin-O-sulfates (urine and plasma); (−)-epicatechin-3-O-gallate, 4’-O-methyl-(epi)gallocatechin-O-glucuronide, (−)-epigallocatechin-3-O-gallate (plasma only); (epi)gallocatechin-O-sulfates (urine only) | [42] |
| Green tea | 20 | Urine | LC-MS | No | (Epi)catechin glucuronide, (epi)catechin sulfate, (epi)catechin sulfoglucuronide, methyl(epi)catechin sulfate, (epi)gallocatechin glucuronide,(epi)gallocatechin sulfate, methyl(epi)gallocatechin glucuronide, methyl(epi)gallocatechin sulfate, methyl(epi)gallocatechin sulfoglucuronide, 5-(hydroxyphenyl)-γ-valerolactone glucuronide, 5-(hydroxyphenyl)-γ-valerolactone glucuronide sulfate, 5-(3′,5′-dihydroxyphenyl)-γ-valerolactone glucuronide,5-(3′,5′-dihydroxyphenyl)-γ-valerolactone glucuronide disulfate, 5-(4′,5′-dihydroxyphenyl)-γ-valerolactone glucuronide, 5-(4′,5′-dihydroxyphenyl)-γ-valerolactone glucuronide disulfate, 5-(4′,5′-dihydroxyphenyl)-γ-valerolactone glucuronide sulfoglucuronide, methyl-5-(4′,5′-dihydroxyphenyl)-γ-valerolactone glucuronide, 5-(3′,4′,5′-trihydroxyphenyl)-γ-valerolactone glucuronide, 5-(3′,4′,5′-trihydroxyphenyl)-γ-valerolactone glucuronide sulfate, methyl-5-(3′,4′,5′-trihydroxyphenyl)-γ-valerolactone glucuronide, methyl-5-(3′,4′,5′-trihydroxyphenyl)-γ-valerolactone sulfate | [43] |
| Black tea | 4 | Urine | LC-MS | No | (Epi)catechin sulfate, O-methylcatechin sulfate, O-methyl(epi)catechin sulfates, O-methyl(epi)gallocatechin sulfates, di-O-methyl(epi)gallocatechin sulfates, dihydronaringenin sulfates, 3’-O-methyl-5-(3′,4′-dihydroxyphenyl)-γ-valerolactone 4’-O-glucuronide, 4’-O-methyl-5-(3′,4′-dihydroxyphenyl)-γ-valerolactone 3’-O-glucuronide, 5-(3′,4′,5′-trihydroxyphenyl)-γ-valerolactone 3’-O-glucuronide, 4’-O-glucuronide, 3’-O-sulfate, 4’-O-sulfate and sulfoglucuronide, O-methyl-5-(3′,4′,5′-trihydroxyphenyl)-γ-valerolactone 3′- or 4’-O-glucuronides, 3′ or 5’-O-glucuronide and O-sulfate, 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone 3’-O-glucuronide, 4’-O-glucuronide and sulfates, 5-(3′,5′-dihydroxyphenyl)-γ-valerolactone 3’-O-glucuronide and 3’-O-sulfate, O-methyl-5-(3′,5′-dihydroxyphenyl)-γ-valerolactone glucuronides and sulfates, 5-(3′-hydroxyphenyl)-γ-valerolactone 3’-O-glucuronide, 4’-O-glucuronide, 5-(hydroxyphenyl)-γ-valerolactone sulfate, O-methyl-4-hydroxy-5-(3′,4′,5′-trihydroxyphenyl)valeric acid glucuronides, 4-hydroxy-5-(3′,4′-dihydroxyphenyl)valeric acid glucuronides, O-methyl-4-hydroxy-5-(3′,4′-dihydroxyphenyl)valeric acid glucuronides, 4-hydroxy-5-(3′,5′-dihydroxyphenyl)valeric acid glucuronide, O-methyl-4-hydroxy-5-(3′,5′-dihydroxyphenyl)valeric acid glucuronides, 4-hydroxy-5-(3′-hydroxyphenyl)valeric acid 3’-O-sulfate and 4’-O-sulfate, O-methyl-4-hydroxy-5-(dihydroxyphenyl)valeric acid sulfates, 4-hydroxy-5-(dihydroxyphenyl)valeric acid sulfates, O-methyl-4-hydroxy-5-(hydroxyphenyl)valeric acid sulfate, 4-hydroxy-5-(phenyl)valeric acid glucuronides and sulfates, hippuric acid, indole-3-acetic-acid glucuronide, indole-3-carboxylic acid glucuronide, p-cresol sulfate and glucuronide, pyrogallol 2-O-glucuronide, 1-O-sulfate and 2-O-sulfate, urolithin A-3-O-glucuronide, 8-O-glucuronide and sulfoglucuronide, urolithin B-O-glucuronide, vanilloylglycine, vanillic acid-4-O-glucuronide and 4-O-sulfate, phenylacetylglycine | [130] |
| Green tea (extract) | 14 | Urine | LC-MS | Yes | Catechin,, epicatechin, 3’-O-methylepicatechin, 4’-O-methylepicatechin, epicatechin-3-O-gallate, gallocatechin, gallocatechin gallate, epigallocatechin, 3’-O-methylepigallocatechin, 4’-O-methylepigallocatechin, epigallocatechin-3-O-gallate, 5-(3′,4′,5′-trihydroxyphenyl)-γ-valerolactone, 5-(3′,4′-dihydroxyphenyl)valerolactone, 5-(3′,5′-dihydroxyphenyl)valerolactone, gallic acid, 3-O-methyl gallic acid, 3-hydroxybenzoic acid, syringic acid, benzoic acid, hippuric acid | [131] |
| Black tea (extract) | 12 | Plasma | LC-MS | No | (Epi)catechin sulfate, O-methyl(epi)catechin sulfates, di-O-methyl(epi)catechin sulfate, O-methyl(epi)gallocatechin sulfate, (epi)catechin gallate sulfate and sulfoglucuronide, O-methyl(epi)catechin gallate sulfate and sulfoglucuronide, (epi)gallocatechin gallate, (epi)gallocatechin gallate sulfate, O-methyl(epi)gallocatechin gallate sulfate, δ-(3′,4′-dihydroxyphenyl)-γ-valerolactone) 3′-O-glucuronide, 4′-O-glucuronide, 3′-O-sulfate and sulfoglucuronide, 5-(3′-hydroxyphenyl)-γ-valerolactone 3′-O-glucuronide and 3′-O-sulfate, 5-(4′-hydroxyphenyl)-γ-valerolactone 4′-O-glucuronide, 5-(3′,4′,5′-trihydroxyphenyl)-γ-valerolactone 3′-O-glucuronide, 4′-O-glucuronide, 3′-O-sulfate and sulfoglucuronide, O-methyl-5-(3′,4′,5′-trihydroxyphenyl)-γ-valerolactone 3′/4′-O-glucuronide, 3′/5′-O-glucuronide and O-sulfates, 5-(3′,5′-dihydroxyphenyl)-γ-valerolactone 3′-O-glucuronide and 3′-O-sulfate, O-methyl-5-(3′,5′-dihydroxyphenyl)-γ-valerolactone 3′-O-glucuronide and 3′-O-sulfate, 4-hydroxy-5-(dihydroxyphenyl)valeric acid sulfates, O-methyl-4-hydroxy-5-(hydroxyphenyl)valeric acid sulfates, 4-hydroxy-5-(3′,4′-dihydroxyphenyl)valeric acid glucuronides, 4-hydroxy-5-(3′,5′-dihydroxyphenyl)valeric acid glucuronide, O-methyl-4-hydroxy-5-(3′,5′-dihydroxyphenyl)valeric acid glucuronide, O-methyl-4-hydroxy-5-(3′,4′,5′-trihydroxyphenyl)valeric acid glucuronide, kaempferol glucuronide, O-methylgallic acid sulfates, pyrogallol 2-O-glucuronide and 2-O-sulfate, O-methylcatechol sulfates, resorcinol glucuronide and sulfate, hippuric acid | [54] |
| Black tea (extract) | 19 | Plasma | LC-MS | Yes | (−)-Catechin, (−)-epicatechin, (−)-(epi)catechin gallate, (−)-epigallocatechin, (−)-epigallocatechin gallate, isorhamnetin, 3/4-O-methylgallic acid, 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone, 5-(3′-methoxy-4′-hydroxyphenyl)-γ-valerolactone | [56] |
| Black tea (extract) | 12 | Plasma | GC-MS | Yes | 4-O-Methylgallic acid, gallic acid, hippuric acid, pyrogallol | [57] |
| Green tea, black tea | 93 | Urine | LC-ECD | Yes | (−)-Epicatechin, (−)-epigallocatechin, 4’-O-methylepigallocatechin | [62] |