目的 采用HPLC-DPPH法评价剑叶龙血树主要成分的抗氧化活性并分析其构效关系。方法 采用HPLC法测定剑叶龙血树中白藜芦醇、龙血素A、龙血素B、紫檀茋、7,4'-二羟基黄酮, 色谱条件:Phenomenex lura C₁₈(250 mm×4.6 mm, 5 μm)色谱柱, 甲醇-乙腈-0.2%磷酸溶液梯度洗脱, 体积流量1.0 mL/min, 柱温35 ℃, 检测波长306 nm。通过对比剑叶龙血树药材溶液加1,1-二苯基-2-三硝基苯肼自由基(DPPH)反应前后的各化合物色谱峰面积衰减情况, 以各化合物峰面积比值计算清除率, 评价各化合物抗氧化活性。结果 二苯乙烯类、二氢查耳酮类成分为剑叶龙血树中主要抗氧化活性成分;抗氧化能力强弱依次为紫檀茋(清除率73.19%) > 白藜芦醇(清除率71.10%) > 龙血素B(清除率39.01%) > 龙血素A(清除率12.14%)。从构效关系上分析, 二苯乙烯类化合物, 当羟基甲基化后, 其抗氧化能力并未减弱;二氢查耳酮类化合物, 苯环上甲氧基取代成对称结构有助于发挥其抗氧化能力;而仅有C-7,4'位羟基取代的黄酮类化合物未显示抗氧化活性。结论 建立的HPLC-DPPH评价方法能量化表达剑叶龙血树中主要抗氧化成分, 为筛选药效指标成分及建立全面谱-效相关质量标准奠定基础。

Objective To evaluate the antioxidant capacity of the main components from Dracaena cochinchinensis by HPLC-DPPH and provide a foundation for "spectrum-effect" quality control standard. Methods The determination was developed on Phenomenex lura C₁₈ column (250 mm × 4.6 mm, 5 μm) with gradient elution of methanol-acetonitril-0.2% H₃PO₄ and the detective wavelength was set at 306 nm. The column temperature was 35 ℃. Results The DPPH free radical scavenging abilities of these five antioxidants were as follows: pterstilbene > resveratrol > luoreirin B > luoreirin A > 7,4'-dihydroxyflavone. The analysis on the structures of the five compounds showed that the hydroxymethylation didn't decrease the antioxidant activities of stilbenes. The symmetry of B ring of dihydrochalcone has the significant effect on the antioxidant activities. However, 7,4'-dihydroxyflavone didn't show the related activity in D. cochinchinensis. Conclusion HPLC-DPPH can not only be used for screening the components with antioxidant potency but also for the purpose of quality evaluation of D. cochinchinensis, and the method proves to be selective, simple, and reproducible.

广西科技攻关项目(0630002-2M, 10124008-15);广西医药产业人才小高地资助项目(0802)