建立了定量核磁共振法测定山楂提取物中原花青素含量及聚合度的分析方法。以邻苯二甲酸氢钾为内标，氘代二甲基亚砜为溶剂进行1H-NMR谱图分析。根据内标质量WR、样品质量WD、内标物H-4、H-5的吸收峰面积AR (δ 7.529)、原花青素分子的H-6、H-8吸收峰面积A6,8 (δ 5.787, 5.702)以及末端表儿茶素单元H-4e的峰面积Ae (δ 2.362)，按公式 计算不同批次制备的山楂提取物中原花青素的平均聚合度，按公式 计算不同批次制备的山楂提取物中原花青素的含量。方法评价结果表明：原花青素在0.4~24 mg/mL范围内线性关系良好（r=0.9996），加标回收率为104.6%。采用开发的方法对不同批次制备的山楂提取物中原花青素的含量及其聚合度进行了测定，其含量分别为42.1%和44.2%，平均聚合度为3.0和3.4。

An analytical method to determine the content and the mean degree of polymerization (mDP) of the procyanidins in Chinese hawthorn extract was developed using quantitative nuclear magnetic resonance spectrometry (qNMR). 1H-NMR spectra were recorded using DMSO-d6 (dimethyl sulfoxide-d6) as the solvent and potassium biphthalate as the internal standard. According to the weight of the internal standard WR, the weight of sample WD, the absorption peak area AR（δ 7.529）of H-4 and H-5 from the internal standard, the absorption peak area A6,8（δ 5.787，5.702）of H-6 and H-8 from procyanidins, and the peak area Ae（δ 2.362）of H-4e at the end of the epicatechin unit, the mDP and content of the procyanidins in hawthorn extracts prepared from different batches were calculated based on the equations N = A6,8/Ae - 1 and C = (144 N + 1) A6,8 WR/51 (N + 1) ARWD ×100%, respectively. The results showed that there was a good linearity (r = 0.9996) within the range of 0.4~24 mg/mL and the average recovery was 104.6%. This method was applied to determine the content and mDP of procyanidins in hawthorn extract samples from two batches. The contents were 42.1% and 44.2% respectively; and the mDP values were 3.0 and 3.4, respectively.

河北省自然科学基金（C2015204187）；国家自然科学基金项目（31071494）；河北省自然科学基金项目（C2011204093）