叠鞘石斛联苄类化合物的大孔树脂纯化工艺优选及抗氧化活性考察

目的：优选叠鞘石斛联苄类化合物的大孔树脂纯化工艺条件并考察其体外抗氧化活性。方法：以静态饱和吸附量和洗脱率为指标，通过静态吸附-洗脱试验筛选大孔树脂型号。采用单因素试验考察上样液质量浓度、上样量、乙醇体积分数、洗脱剂用量、上样流速及洗脱流速对纯化工艺的影响，通过体外抗氧化试验考察联苄类化合物的体外抗氧化能力。结果：HPD-300型树脂纯化联苄类化合物的效果最好，其最佳纯化工艺条件为上样液质量浓度9.04 g·L^-1，上样量1.25 BV，上样流速0.5 mL·min^-1，加水和70%乙醇各5 BV以1.0 mL·min^-1的流速洗脱。纯化后联苄类化合物纯度达67.07%，较纯化前提高了4.25倍。联苄类化合物的纯化物和粗提物对超氧阴离子自由基的抗氧化活性以半数抑制浓度（IC₅₀）表示分别为0.408，0.985 g·L^-1，对羟自由基的IC₅₀依次为7.856，7.827 g·L^-1。结论：HPD-300型大孔吸附树脂对叠鞘石斛联苄类化合物的纯化效果较好，纯化物的体外抗氧化能力有所提高。

Optimization of Purification Technology for Bibenzyl Compounds from Dendrobium aurantiacum by Macroporous Resin and Investigation of its Antioxidant Activity

Objective: To optimize purification process of bibenzyl compounds from Dendrobium aurantiacum with macroporous resin and investigate its antioxidant ability before and after being purified. Method: With static adsorption capacity and elution ratio as indexes,five types of macroporous resin(X-5,HPD-300,D-101,AB-8 and S-8) were used to purify bibenzyl compounds by static adsorption-elution test.Single factor tests were adopted to investigate effects of the concentration of sample solution,the largest sample volume,ethanol concentration and other factors on purification process of bibenzyl compounds,and antioxidant ability of bibenzyl compounds was determined. Result: HPD-300 type of macroporous resin was selected,its optimum purification process was as follows:the concentration of sample solution 9.04 g·L^-1,the largest sample volume of 1.25 BV,sampling flow rate at 0.5 mL·min^-1,separately eluted with 5 BV water and 70% ethanol at flow rate of 1.0 mL·min^-1. Under these conditions,purity of bibenzyl compounds could reach 67.07%,which increased 4.25 times by compared with unpurified.IC₅₀ of refined and crude bibenzyl compounds for superoxide anion radical were 0.408 and 0.985 g·L^-1,but they were 7.856 and 7.827 g·L^-1 for hydroxyl radical,respectively. Conclusion: HPD-300 type of macroporous resin had an excellent purification effect for bibenzyl compounds of D. aurantiacum,its purity and antioxidant ability were improved remarkably.