Department of Chemical Engineering, School of Chemistry and Chemical Engineering , Chongqing University , Chongqing 401331 , PR China.
J Agric Food Chem. 2018 Sep 5;66(35):9291-9300. doi: 10.1021/acs.jafc.8b02478. Epub 2018 Aug 21.
Red radish was extracted by methanol to obtain crude radish procyanidin extracts. The purity of procyanidin (PP) and procyanidin dimers (PD) of crude radish procyanidin extracts under different ratios of methanol to radish was optimized to achieve the best extraction performance. Then the crude radish procyanidin extracts was, respectively, processed six macroporous resins separation to separate radish procyanidin oligomers (RPO) and polymers (RPP). Depolymerization of radish procyanidin polymers (RPP) into oligomers was then conducted. N-Acetylneuraminate lyase (NAL) was first used as the enzyme to depolymerize RPP. The depolymerization yield (DY) under different depolymerized conditions was also investigated. Results showed the DY of RPP would achieve 53.24 ± 0.35% at the best conditions. Then the high-purity procyanidin dimers was prepared by depolymerized procyanidin oligomers and PRO. Additionally, the chemical structure of the preparative radish procyanidin dimers was elucidated by high-resolution mass spectrometry and one- and two-dimensional NMR.
红白萝卜经甲醇提取得到原萝卜低聚原花青素提取物。为获得最佳提取效果，优化了不同甲醇与萝卜比例下原萝卜低聚原花青素提取物中原花青素（PP）和原花青素二聚体（PD）的纯度。然后，将原萝卜低聚原花青素提取物分别用 6 种大孔树脂进行分离，分离出萝卜低聚原花青素（RPO）和聚合物（RPP）。然后将萝卜低聚原花青素聚合物（RPP）解聚成低聚物。首先使用 N-乙酰神经氨酸酶（NAL）作为酶解聚 RPP。研究了不同解聚条件下的解聚产率（DY）。结果表明，在最佳条件下，RPP 的 DY 可达 53.24±0.35%。然后通过解聚低聚原花青素和 PRO 制备高纯度的原花青素二聚体。此外，通过高分辨质谱和一维及二维 NMR 阐明了制备的萝卜原花青素二聚体的化学结构。
