Chemical Synthesis Of Proanthocyanidin B2 And Its Content In Grapes Seeds Of Multiple Varieties

As an important part of the grapes, seeds accounts for 4-7% of the total fruit. Eight procyanidin dimers B1-B8 and their epigallocatechin gallate(ECG) were separated and identified from grape seeds.In this study, epicatechin was used to synthesize--procyanidin dimer B2 by benzylation, activation and deprotection. The final product was analyzed by mass spectrogram analysis(MS) and nuclear magnetic resonance(NMR). Qualitative and quantitative analysis of procyanidin dimer B2 in the grape seeds from 4 different grape varieties was achieved by high performance liquid chromatography(HPLC).The main results showed as follows:1. The final product procyanidin dimer B2 was achieved by organic synthesis by using epicatechin as the raw material, the yield of procyanidin dimer B2 was 80.5%. Structure was characterized by mass spectrogram analysis(MS) and nuclear magnetic resonance(NMR).2. HPLC characterization was used to analyzed the purity of procyanidin dimer B2. The results indicated that the purity of the target product is 90.37%.3. In addition, HPLC was used to analyze the procyanidin dimer B2 in seeds from 4 different grape varieties: ’Cabernet Sauvignon’, ’Beibinghong’, ’Meili’ and ’Ecolly’. The results showed that the content of procyanidin dimer B2 was 1.8511mg/g in ’Cabernet Sauvignon’, it was 1.2322mg/g in ’Beibinghong’, it was respectively 0.7464mg/g and 0.2988mg/g in ’Meili’ and ’Ecolly’, the differences in the four grapes were significant.Organic synthesis had higher efficiency and less damage of the structure of procyanidin dimer B2. Organic synthesis can meet different needs, it has great value in business and scientific research.