铁皮石斛不同部位黄酮碳苷类成分及清除DPPH自由基能力比较研究

目的:对铁皮石斛根、茎、叶和花中黄酮碳苷类成分及抗氧化作用进行比较,为扩大铁皮石斛的药用部位提供实验依据。方法:采用TLC和HPLC及与对照品对照,对铁皮石斛不同部位黄酮类成分种类和含量进行分析;以清除DPPH自由基能力对抗氧化活性进行比较。结果:铁皮石斛茎、叶和花中含有种类相同的黄酮二糖碳苷类成分,并采用对照品指认了共有的8个色谱峰;但各黄酮碳苷的含量有显著差异,叶和花中黄酮碳苷的含量明显高于茎,叶和花HPLC色谱图相似度较高;根中黄酮类成分较少。茎中含有柚皮素,而根、叶和花均不含该成分。铁皮石斛茎和叶对DPPH自由基均有一定的清除作用,叶对DPPH自由基清除能力优于茎。结论:以黄酮碳苷含量及抗氧化活性为指标,铁皮石斛叶和花代替茎入药有一定可能性。该研究为铁皮石斛的综合开发利用提供了前期基础。

Comparative studies on scavenging DPPH free radicals activity of flavone C-glycosides from different parts of Dendrobium officinale

Objective: To study the scavenging DPPH free radicals activity of flavone C-glycosides from different parts of Dendrobium officinale. Method: The types and contents of flavonoids from different parts of D. officinale were analyzed by TLC and HPLC. The antioxidant effect was tested by scavenging DPPH free radicals activity. Result: The stems, leaves and flowers contained the same type of flavone C-A glycosides and 8 common peaks were identified. The content of flavone C-A glycosides was significantly different. The content of flavone C-glycosides in leaves and flowers was higher than that in stems. The flavonoid in roots was less. Stems contained naringenin, which was not identified in root, leave and flower. Both stems and leaves had antioxidant capacity of eliminating DPPH free radicals, of which scavenging DPPH free radicals activity of leaves was better than stems. Conclusion: Considering the content of flavonoid and antioxidant activity leave and flower of D. officinale may substitute stems. The study provides a preliminary basis for the development and utilization of leave and flower of D. officinale.