Abstract

Purification of total flavonoids from Ginkgo biloba flowers (GBF) extracts were studied using six resins. Adsorption-desorption experiments indicated that polyamide resin is the most suitable resin. The optimal purification process of total flavonoids of GBF was as follows: a loading concentration of 5.85 mg/mL, a loading volume of 1 bed volume (BV), a loading flow rate of 2 BV/h, a water volume of 2.67 BV, and a desorption solution of 40% ethanol. Under these conditions, the maximum purity of total flavonoids was 37.1 ± 1.1%. The antioxidant activity of purified flavonoids was further evaluated in vitro. It showed that the 40% ethanol purified fraction (Fr. B) group had the strongest antioxidant activity of the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity concentration for 50% of maximal effect (EC₅₀, 145.4 ± 13.8 µg/mL) and ferric reducing ability (2.5 ± 0.2 mM FeSO₄ equivalent mg⁻¹Fr. B). In addition, at the concentration of 160 µg/mL, the Fr. B strikingly increased the viability rate of hydrogen peroxide stimulated PC-12 cells to normal levels (***p < 0.001). This method provides a basis for the application and development of GBF resources. It indicated that the purified GBF flavonoids can be used as a source of potential antioxidant.

摘要

使用六种树脂对银杏叶 (GBF) 提取物中总黄酮的纯化进行了研究。吸附-解吸实验表明聚酰胺树脂是最合适的树脂。GBF总黄酮的最佳纯化工艺为：上样浓度5.85 mg/mL，上样体积1床体积（BV），上样流速2 BV/h，水量2.67 BV，和40%乙醇的脱附溶液。在这些条件下，总黄酮的最大纯度为 37.1 ± 1.1%。在体外进一步评估了纯化的类黄酮的抗氧化活性。结果表明，40% 乙醇纯化组分（Fr. B）组具有最强的 2, 2-二苯基-1-苦基肼 (DPPH) 自由基清除活性浓度的抗氧化活性，达到最大效果的 50% (EC 50 , _145.4 ± 13.8 µg/mL) 和铁还原能力 (2.5 ± 0.2 mM FeSO ₄当量 mg ⁻¹ Fr. B)。此外，在 160 µg/mL 的浓度下，Fr。B 将过氧化氢刺激的 PC-12 细胞的存活率显着提高至正常水平 ( ***p  < 0.001)。该方法为GBF资源的应用开发提供了依据。这表明纯化的 GBF 类黄酮可用作潜在抗氧化剂的来源。