UPLC快速测定石崖茶中5个黄酮类化合物含量及其体外抗氧化活性评价

目的: 建立石崖茶中山茶苷A、山茶苷B、表儿茶素、槲皮苷和芹菜素5个黄酮类成分超高效液相色谱(UPLC)测定方法,初步评价石崖茶的体外抗氧化活性。 方法: 采用Waters Acquity BEH(2.1 mm×100 mm,1.7 μm)色谱柱,水-乙腈作流动相,梯度洗脱,流速0.35 mL·min^-1,检测波长280 nm(0~1.5 min)用于检测表儿茶素,330 nm(1.5~2.5 min和3.0~7.0 min)检测山茶苷A、山茶苷B和芹菜素,254 nm(2.5~3.0 min)检测槲皮苷,柱温40℃,分析时间7 min。采用1,1-二苯基-2-苦基苯肼(DPPH)和2,2-联氮基-双-(3-乙基苯并噻唑啉-6-磺酸)二氨盐(ABTS)法测定石崖茶63%乙醇提取物的抗氧化活性。 结果: 山茶苷A、山茶苷B、表儿茶素、槲皮苷和芹菜素的线性范围分别为120.0~600.0,2.5~18.0,50.0~480.0,1.0~ 3.5,1.5~7.5 ng(r≥0.9996);平均加样回收率分别为98.03%,98.26%,100.8%,98.48%,100.2%;精密度、重复性和稳定性良好,RSD均小于2%。石崖茶抗氧化活性较维生素C弱,抗氧化活性与含测指标成分不呈相关性。 结论: 石崖茶具有一定抗氧化活性。该UPLC方法操作简便,检测结果准确,可为石崖茶的质量标准研究提供依据。

Objective: To develop a ultra performance liquid chromatography(UPLC)method for determination of five flavonoids(camellianin A,camellianin B,epicatechin,quercetin and apigenin)in leaves of Adinandra nitida Merr.ex Li,as well as the evaluation of their antioxidant activities in vitro by 1,1-diphenyl-2-picrylhydrazyl(DPPH)and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt(ABTS)radical. Methods: The separation was performed on a Waters Acquity BEH(2.1 mm×100 mm,1.7 μm)column,the mobile phase was water-acetonitrile with gradient elution,at a flow rate of 0.35 mL·min^-1.A diode array detector with the wavelength of 280 nm(0-1.5 min)was used to monitor epicatechin,330 nm(1.5-2.5 min,3.0-7.0 min)to monitor camellianin A,camellianin B and apigenin,and 254 nm(2.5-3.0 min)to monitor quercetin,detective temperature: 40℃,analysis time: 7 min. Results: The linear ranges of camellianin A,camellianin B,epicatechin,quercetin and apigenin were 120.0-600.0,2.5-18.0,50.0-480.0,1.0-3.5 and 1.5-7.5 ng(r≥0.9996),respectively.The mean recoveries were 98.03%,98.26%,100.8%,98.48% and 100.2%.The accuracy,precision and stability were satisfactory with RSD less than 2%.A.nitida leaves exhibited less antioxidant capacities compared with ascorbic acid.There were no relationship between the content of flavonoids and the antioxidant activities of A.nitida leaves. Conclusion: A.nitida leaves had antioxidant activity.The UPLC method is simple,accurate and helpful to quality control of A.nitida leaves.