Gallocatechin gallate

All chemicals were at least of analytical grade. Toluene, 1-propanol, formic acid, acetic acid, hydrochloric acid (37%) and 4-dimethylaminocinnamaldehyde (DMACA) were from Merck (Darmstadt, Germany). Ethanol, acetone, as well as HPLC grade acetonitrile and mEthanol were purchased from Sigma-Aldrich (St. Louis, MO, USA). LC-MS grade acetonitrile and mEthanol used for MS analyses were from Fluka (Buchs, Switzerland). MilliQ 18.2 MΩ water (Millipore, Bedford, MA, USA) was also used.
Standards of (−)-epicatechin gallate, (−)-epigallocatechin, (−)-epigallocatechin gallate, (−)-catechin gallate, (−)-gallocatechin, (−)-gallocatechin gallate, procyanidin B1, procyanidin B2, procyanidin B3 and procyanidin C1 were obtained from Extrasynthèse (Genay, France), while (−)-epicatechin was from Sigma-Aldrich and (+)-catechin from Carl Roth (Karlsruhe, Germany).

All chemicals were at least of analytical grade. Acetic acid, formic acid, hydrochloric acid (37%), toluene, 1-propanol, and 4-dimethylaminocinnamaldehyde (DMACA) were from Merck (Darmstadt, Germany). Acetone, ethanol as well as HPLC grade acetonitrile and methanol were purchased from Sigma-Aldrich (St. Louis, MO, USA). LC–MS grade acetonitrile and methanol used for MS analyses were from Fluka (Buchs, Switzerland). MilliQ 18.2 MΩ water (Millipore, Bedford, MA, USA) was also used.
Standard of (−)-epicatechin was obtained from Sigma-Aldrich and (+)-catechin from Carl Roth (Karlsruhe, Germany). Standards of procyanidin B1, procyanidin B2, procyanidin B3, procyanidin C1, (−)-catechin gallate, (−)-gallocatechin, (−)-gallocatechin gallate, (−)-epicatechin gallate, (−)-epigallocatechin and (−)-epigallocatechin gallate were obtained from Extrasynthèse (Genay, France).

Gallocatechin gallate (GCG; HPLC purity > 98%), catechin gallate (CG; HPLC purity > 98%), epicatechin gallate (ECG; HPLC purity > 97.5%), catechin (C; HPLC purity > 99%), gallocatechin (GC; HPLC purity > 98%), and epicatechin (EC; HPLC purity > 99%) were from Extrasynthese (Genay Cedex, France); NADPH and L-idose were from Carbosynth (Compton, England). Bovine serum albumin (BSA), D,L-dithiothreitol (DTT), D,L-glyceraldehyde (GAL), EDTA, glycerol and glutathione (GSH) were purchased from Sigma-Aldrich (Saint Louis, MO, USA); ammonium sulfate, sodium phosphate monobasic were from J.T. Baker (Phillipsburg, NJ, USA); YM10 ultrafiltration membranes were from Merck-Millipore (Darmstadt, Germany). All other chemicals were of a reagent grade.