A series of thiol-nucleophiles, captopril, l-cysteine, and tiopronin, were introduced to the degradation reaction of grape seed extracts and the eight new bioactive flavan-3-ol derivatives were observed. Then, these derivatives were successfully separated and prepared in large quantity by high-speed counter-current chromatography (HSCCC) and semi-preparative HPLC under the optimized separation conditions. The appropriate two solvent systems consisted of n-hexane–ethyl acetate–methanol–water (0.05:1.5:0.5:1.2, v/v/v/v) and n-hexane–ethyl acetate–water (1:10:10, v/v/v) with head–tail mode were used for HSCCC two-step separation of captopril degradation products. N-butanol–ethyl acetate–methanol–water (2:4:0.5:6, v/v/v/v) with a combination of tail–head and head–tail elution modes in HSCCC run of l-cysteine degradation products, and n-hexane–ethyl acetate–methanol–water (0.15:1.6:0.4:1, v/v/v/v) was applied with head–tail and tail–head elution modes in HSCCC separation of tiopronin degradation products. The structures of these derivatives were confirmed by MS and ¹H NMR analysis. Moreover, a systematic comparison of antioxidant activity of all the eleven degradation products was first implemented and found that most of the derivatives had stronger antioxidant activity than free catechins.

中文翻译：

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高速逆流色谱法从原花青素中分离抗氧化剂黄烷-3-醇硫代共轭物

将一系列硫醇亲核试剂卡托普利，1-半胱氨酸和硫普罗宁引入葡萄籽提取物的降解反应中，并观察到八个新的生物活性黄烷-3-醇衍生物。然后，在优化的分离条件下，通过高速逆流色谱（HSCCC）和半制备型HPLC成功分离并大量制备了这些衍生物。适当的2个溶剂体系包括了正己烷-乙酸乙酯-甲醇-水（0.05：1.5：0.5：1.2，V / V / V / V）和正-己烷-乙酸乙酯-水（一点10分10秒， v / v / v）带头–尾模式用于HSCCC卡托普利降解产物的两步分离。N-丁醇-乙酸乙酯-甲醇-水（2：4：0.5：6，V / V / V / V）与尾的组合-头和头-在HSCCC运行尾洗脱模式1-半胱氨酸降解产物，和正-己烷-乙酸乙酯-甲醇-水（0.15：1.6：0.4：1，v / v / v / v）与头施加-尾，尾-在硫普罗宁降解产物HSCCC分离头洗脱模式。这些衍生物的结构通过MS和¹确证。1 H NMR分析。此外，首先对所有11种降解产物的抗氧化活性进行了系统比较，发现大多数衍生物比游离儿茶素具有更强的抗氧化活性。