Novel proanthocyanidin dimer analogues with the C-ring-opened diaryl-propan-2-gallate structural unit and enhanced antioxidant activities

作者：Chen Jinyu; Xu Ze; Zhu Wei; Nie Rongzu; Li Chun-mei^*

来源：Journal of Functional Foods, 2016, 21: 290-300.

DOI：10.1016/j.jff.2015.12.023

• New dimer analogues
• Preparation
• Antioxidant activity
• Persimmon

This study aimed to establish an approach for preparing new representative proanthocyanidin oligomers from persimmon for further structure-activity relationship study. Persimmon tannins (with a mean degree of polymerization of 23.7) were depolymerized, using 0.1 M methanolic HCl, with (+)-catechin and (-)-epigallocatechin gallate as chain breakers. Normal phase high-performance liquid chromatography (NP-HPLC) coupled with reversed phase high-performance liquid chromatography mass spectrometry (RP-HPLC-MS) method was used to analyse the degradation products. Four B-type and one A -type dimers were tentatively identified. In addition, three dimer analogues, 1-(3',4'-dihydroxypheny1)-3-(2 '',4 '',6 ''-trihydroxyphenyl)propan-2-ol-(epi)catechin dimer (B-type) and 1-(3',4',5'-trihydroxypheny1)3-(2 '',4 '',6 ''-trihydroxypheny1)-propan-2-gallate-(epi)gallocatechin-3-gallate dimers (A- and B-type), were reported for the first time. Three different assays were employed to evaluate the antioxidant capacities of the new dimer analogues. Our results revealed that the formation of the C-ring-opened diaryl-propan-2-gallate structural unit on dimer analogues enhanced their antioxidant abilities in aqueous systems for the first time. This research provided a workable approach for preparing novel dimeric proanthocyanidins for further structure activity relationship study.

• 出版日期2016-3
• 单位华中农业大学