کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1220162 | 1494545 | 2016 | 11 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Novel proanthocyanidin dimer analogues with the C-ring-opened diaryl-propan-2-gallate structural unit and enhanced antioxidant activities Novel proanthocyanidin dimer analogues with the C-ring-opened diaryl-propan-2-gallate structural unit and enhanced antioxidant activities](/preview/png/1220162.png)
• Five proanthocyanidin dimers were obtained by depolymerizing PT40 using (+)-catechin and EGCG as chain breakers.
• Three dimer analogues with the C-ring-opened structural unit were tentatively identified and reported for the first time.
• The formation of the C-ring-opened diaryl-propan-2-gallate unit on dimer analogues enhanced their antioxidant potency.
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′-dihydroxyphenyl)-3-(2′′,4′′,6′′-trihydroxyphenyl)propan-2-ol-(epi)catechin dimer (B-type) and 1-(3′,4′,5′-trihydroxyphenyl)-3-(2′′,4′′,6′′-trihydroxyphenyl)-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.
Journal: Journal of Functional Foods - Volume 21, March 2016, Pages 290–300