Preparative separation of grape skin polyphenols by high-speed counter-current chromatography

Abstract

To develop an efficient method for large preparation of various individual polyphenols from white grape skins (Fernão Pires; Vitis vinifera) by preparative high-speed counter-current chromatography (HSCCC) and preparative-HPLC, an optimized preparative HSCCC condition with two-phase solvent system composed of Hex-EtOAc-H2O (1:50:50, v/v) was used to separate grape skin polyphenols into various fractions. Both the tail-head and head-tail elution modes were used with a flow rate of 3.0ml/min and a rotary speed of 950rpm. Afterwards, a preparative-HPLC separation was applied to isolate individual polyphenols in each of the fractions from HSCCC. Total of 7 fractions (Fraction A to G) were obtained from grape skin extract by HSCCC. After preparative-HPLC isolation, fifteen individual compounds were obtained, most of which presented high yields and purity (all over 90%). The HSCCC method followed with preparative-HPLC appeared to be convenient and economical, constituting an efficient strategy for the isolation of grape skin polyphenols.

Keywords: (+)-Catechin (PubChem CID: 107957); (+)-Catechin-phloroglucinol derivative (PubChem CID: 14009031); (−)-Epicatechin (PubChem CID: 72276); Astilbin (PubChem CID: 119258); Grape skins; HPLC separation; High-speed counter-current chromatography; Phloroglucinol (PubChem CID: 359); Polyphenols; Procyanidin B1 (PubChem CID: 11250133); Procyanidin B1 3-gallate (PubChem CID: 72193635); Procyanidin B2 (PubChem CID: 122738); Procyanidin B3 (PubChem CID: 146798); Procyanidin B4 (PubChem CID: 147299); Procyanidin C1 (PubChem CID: 169853); trans-Coutaric acid (PubChem CID: 57517924).