夏枯草生殖生长期总黄酮积累规律及抗氧化活性研究

通过测定夏枯草生殖生长期各阶段不同器官的总黄酮含量,揭示夏枯草各器官总黄酮的积累规律。采用70%乙醇超声波提取,后用等体积的乙酸乙酯、正丁醇和水萃取,得到乙酸乙酯、正丁醇和水提取物,以BHT为对照,研究不同溶剂提取物的抗氧化活性。结果表明:夏枯草根、茎、叶中的黄酮含量随着生长进程而升高,至终花期达到最高;花穗中的黄酮含量在花盛期最高;各器官相比,叶中黄酮含量最高。夏枯草不同溶剂提取物及对照BHT清除DPPH.的能力高低次序为:乙酸乙酯提取物>正丁醇提取物>BHT>水提物,清除.OH的能力高低次序为:BHT>乙酸乙酯提取物>正丁醇提取物>水提物,并且不同溶剂提取物的抗氧化活性与其总黄酮含量呈较显著的相关性。夏枯草总黄酮具有良好的抗氧化活性,可在夏枯草花终期或果穗干枯期采集叶或全草提炼加工。

Accumulation of Total Flavonoids at Reproductive Stage and Antioxidant Activity of Prunella vulgaris Linn.

The research was aimed to investigate the accumulation of total flavonoids in different organs and antioxidant activities in different extracts of Prunella vulgaris Linn.,which would provide theoretical basis for further research.The total flavonoids contents in different organs during different periods were measured at reproductive stage.Total flavonoids content was investigated by spectrometric method.The powder of P.vulgaris was extracted with 70% ethanol(in water,v/v) using ultrasonic extraction,and then the filtrate was extracted followed with ethyl acetate,n-butanol and water at equal volume.The extracts of different solvents could be gotten.The antioxidant activities of different extracts were evaluated and BHT was used as a positive control.The results showed that:the total flavonoids content of roots,steams and leaves of P.vulgaris increased with plant growth and reached the peak at flower-perished period,while that of the spikes reached the peak at flowers-blooming period.The total flavonoids content of leaves was the highest one among all the organs.Scavenging abilities on DPPH· of the extracts and BHT were in descending order:ethyl acetate>n-butanol>BHT>water.Scavenging abilities on ·OH of the extracts and BHT were in descending order:BHT>ethyl acetate>n-butanol>water.There was strong correlation between antioxidant activity and total flavonoids content in different extracts of P.vulgaris.The flavonoids of P.vulgaris have great antioxidant activity,and they can be obtained by processing the leaves or the whole herb which were collected in flower-perished period or spike-dry period.