高级搜索

白茶柱层析分离过程中化学组分含量与弹性蛋白酶抑制活性的变化

Chemical Compositions and Elastase-inhibition Activities of Column Separation Eluents of White Tea Extract

    摘要
  • 摘要:
    目的 测定白茶水提物经大孔吸附树脂分离后的弹性蛋白酶抑制活性与化学组分含量变化，为白茶有效活性部位及其组分的提纯制备与综合利用提供基础数据。
    方法 以XAD-4离子交换大孔树脂为吸附剂，对白茶水提取物（E0）进行上柱吸附，同步收集流出液（E1），再依次用0.5 mol·L−1 NaCl和1 mol·L−1 HCl混合酸溶液（1∶40，V/V）、纯水和85%乙醇洗脱，分别收集流出液E2、E3和E4，测定柱分离过程中各流出液的茶多酚（Tea polyphenols, TP）、总黄酮（Total flavonoids, TFls）、咖啡碱（Caffeine, CAF）、没食子酸（Gallic acid, GA）和儿茶素类（EGCG、GCG、EC、C、EGC、GC、ECG、CG）等化学组分含量，并评价其对猪胰弹性蛋白酶（Porcine pancreatic elastase, PPE）的荧光猝灭效果，以及分析二者相关性。
    结果 白茶提取物（E0）及其4个柱流出液（E1、E2、E3、E4）化学组分测定结果表明，TP和TFls含量排序为E0＞E1＞E4＞E2＞E3，且E0、E1、E4相互间差异显著（P＜0.05）；CAF含量为E0＞E4＞E1＞E2＞E3，除E1与E2差异不显著外，其余相互间均差异显著（P＜0.05）；GA、GC、EGC、C含量为E0＞E1＞E4，EGCG、EC、GCG、ECG、CG为E0＞E4＞E1，且相互间均分别达到显著差异（P＜0.05）。PPE荧光猝灭活性试验表明，E0、E1和E4对PPE的荧光猝灭率分别为46.0%、29.3%和26.0%，且相互间达到显著差异。皮尔逊相关性分析表明，样品对PPE的荧光猝灭率与其TP、TFls含量的相关系数均达到0.99，呈极显著正相关（P＜0.01），与CAF、GA和儿茶素类组分呈正相关，但不显著。
    结论 与E0相比，E4中各化学组分均显著降低，荧光猝灭活性也显著降低。白茶对PPE的荧光猝灭活性与其多酚、总黄酮含量密切相关，推测白茶中具有PPE抑制活性的功能物质基础是多酚、总黄酮。

     

    Abstract:
    Objective Chemical composition and elastase-inhibition activity of the water extract of white tea were analyzed for determination of active ingredients in the column separation eluents.
    Method The spray-dried powder of boiling water-extracted Baimudan White Tea was dissolved in 400 mL of distilled water at the concentration of 5 mg·mL−1 (E0) to pass through an XAD-4 ion exchange macroporous resin as adsorbent to collect the eluent (E1) followed by using three different mobile phases of the mixed solutions of 0.5 mol·L−1 NaCl and 1 mol·L−1 HCl (1∶40, v/v), distilled water, and 85% ethanol to collect eluents E2, E3, and E4, respectively. Chemicals, including tea polyphenols (TP), total flavonoids (TFls), caffeine (CAF), gallic acid (GA), and catechins (i.e., GC, EGC, C, EGCG, EC, GCG, ECG, and CG), were analyzed to correlate with the fluorescence quenching effects on porcine pancreatic elastase (PPE) of E0 as well as the 4 eluents.
    Result The contents of TP, TFls, and WSS in E0 and the eluents ranked as E0>E1>E4>E2>E3, with those of E0, E1, and E4 significantly differed from one another (P<0.05). That of CAF ranked as E0>E4>E1>E2>E3 with significant differences, except between E1 and E2 (P<0.05). Those of GA, GC, EGC, and C ranked as E0>E1>E4, while EGCG, EC, GCG, ECG, and CG ranked as E0>E4>E1, all significantly differed from one another (P<0.05). The PPE fluorescence quenching rates of the eluents in a constant volume significantly differentiated in the order of E0 (46.0%)>E1 (29.3%)>E4 (26.0%). A significant positive Pearson correlation was observed between the quenching rate and TP or TFls content with a coefficient of 0.99 (P<0.01) but not significant between that and CAF, GA, or CAF content.
    Conclusion On an XAD-4 ion exchange macroporous resin, the Baimudan White Tea extract was sent to collect several eluents that included E1 from the first elution, then E2 from flashing with 0.5 mol·L−1 NaCl and 1 mol·L−1 HCl mixed 1∶40 v/v acidic solutions, E3 from washing with distilled water, and E4 from eluting with 80% ethanol. The last eluent contained significantly fewer chemicals with lower quenching activities than E0. Among the chemicals, polyphenols and total flavonoids closely related to the PPE quenching and were speculated as the key contributor of the bioactivity of the tea extract.

     

    • HTML全文
    • 参考文献(29)
    • 相关文章
    • 施引文献
  • 资源附件(0)

/

返回文章
返回