青藏高原狭果茶藨子黄酮纯化工艺及抗氧化活性研究

以青藏高原产的狭果茶藨子为原料,研究其黄酮纯化工艺及抗氧化活性。通过静态吸附试验对D101、D218、D315、HPD-600、AB-8这5种大孔树脂进行筛选,考察上样浓度、上样量、上样流速以及洗脱剂浓度、洗脱流速对狭果茶藨子黄酮吸附和解吸性能的影响,确定最佳树脂类型和纯化工艺条件;以羟自由基、超氧阴离子自由基、DPPH自由基、ABTS自由基清除率和金属螯合能力为考察指标,评价纯化前后狭果茶藨子黄酮的抗氧化能力。黄酮纯化工艺研究结果表明:AB-8大孔树脂对狭果茶藨子黄酮的纯化效果较好,其对黄酮吸附率达93.01%,解吸率达73.54%;在上样浓度12 mg/mL、上样量40 mL、上样流速2.0 mL/min以及洗脱液乙醇浓度60%、洗脱流速2.0 mL/min条件下,狭果茶藨子黄酮纯度从6.09%提高到46.43%。抗氧化试验结果表明:狭果茶藨子黄酮有较强的羟自由基、超氧阴离子自由基、DPPH自由基、ABTS自由基清除能力及金属螯合能力,经过AB-8大孔树脂纯化后其抗氧化活性显著增强,其中对DPPH自由基、羟自由基清除能力及金属螯合能力尤为突出,作用效果甚至强于同浓度下传统抗氧化剂Vc,其对DPPH自由基的清除率最高可达94.08%,金属螯合率最高达81.27%,说明狭果茶藨子黄酮具备开发成新型天然抗氧化剂的潜力。

Purification Process and Antioxidant Activity of Flavonoids from Ribes Stenocarpum Maxim in Qinghai-Tibet Plateau

Using Ribes stenocarpum Maxim produced in the Qinghai-Tibet plateau as raw material,the purification process and antioxidant activity of flavonoids were studied.Five macroporous resins such as D101,D218,D315,HPD-600 and AB-8 were screened by static adsorption test.The effects of sample concentration,sample volume,sample flow rate,eluent concentration and flow rate on the adsorption and desorption properties of flavonoids from Ribes stenocarpum Maxim were investigated to determine the optimal resin type and purification process conditions.The antioxidant activity of flavonoids from Ribes stenocarpum Maxim before and after purification was evaluated by hydroxyl free radical,superoxide anion free radical,DPPH free radical,ABTS free radical scavenging rate and metal chelating ability.Study on the purification process of flavonoids showed that AB-8 macroporous resin had better purification effect on the flavonoids of Ribes stenocarpum Maxim with adsorption rate of 93.01% and desorption rate of 73.54%.Under the conditions of 12 mg/mL sample concentration,40 mL sample volume,2.0 mL/min sample flow rate,60% ethanol concentration and 2.0 mL/min elution flow rate,the purity of Ribes stenocarpum Maxim flavone increased from 6.09% to 46.43%.The results of antioxidant test showed that Ribes stenocarpum Maxim flavonoids had strong scavenging ability of hydroxyl free radical,superoxide anion free radical,DPPH free radical,ABTS free radical and metal chelating ability,after being purified by AB-8 macroporous resin,its antioxidant activity was significantly enhanced,especially the scavenging ability to DPPH radical and hydroxyl radical and the metal chelating ability,and its effect was even stronger than that of the traditional antioxidant Vc at the same concentration,the scavenging rate of DPPH radical reached 94.08%,and the metal chelating rate reached 81.27%,indicating that the flavonoids from Ribes stenocarpum Maxim had potential to be developed into new natural antioxidant.