Phytochemical Changes in Aerial Parts of Hypericum perforatum at Different Harvest Stages

Hypericum perforatum is a perennial herb that produces anti- depression metabolite hypericin (Hyp) as well as flavonoids and poly phenols . In order to find the optimization of harvest stage to increase bioactive compounds production , the levels of Hyp , flavonoids and poly phenols as well as antioxidant capacity were evaluated by the assays of high performance liquid chromatography (HPLC), NaNO 2-AlCl 3-NaOH and Folin-Ciocalteu as well as 1, 1-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP), respectively. The results showed that there was no difference in antioxidant capacity of extracts from aerial parts between floral budding stage (FBS) and blooming stage (BS) , while significant decrease was observed at fruit set stage (FSS) compared to BS (P ＜ 0.05). On a per plant basis, biomass and the levels of Hyp , flavonoids and poly phenols in aerial parts decreased during harvest stages , even if bioactive compounds contents i n flower reache d the highest at BS on a dry weight basis . These findings indicated that the optimization of harvest stage of H. perforatum should be at FBS.