Huifang Zhang,Xiaofang Li,Ke Wu,Mengke Wang,Pu Liu,Xinsheng Wang,Ruixue Deng
Paeonia ostiiis a traditional medicinal plant popularly used in China. This study intended to evaluate the antioxidant properties and the chemical components of the flavonoid-rich extracts from the flowers ofP. ostii. The results showed that the flavonoid-rich extracts from the flowers ofP. ostiihad strong scavenging capacities on 2,2′-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS), hydroxyls, superoxide anions, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals in a dose-dependent manner. Five flavonoids, dihydrokaempferol (1), apigenin-7-O-β-d-glucoside (2), apigenin-7-O-β-d-neohesperidoside (3), kaempferol-7-O-β-d-glucopyranoside (4), and kaempferol-3-O-β-d-glucopyranosyl-7-O-β-d-glucopyranoside (5), were isolated from the flavonoid-rich extracts of the flowers ofP. ostii. High-performance liquid chromatography (HPLC) analysis revealed that compounds3and4were abundant in theP. ostiiflower and in flavonoid-rich extracts. The main components of the flower ofP. ostiiare flavonoids. The high antioxidant activity of the flavonoid-rich extracts may be attributed to the high content of flavonoids. The five isolated flavonoids were the primary antioxidant ingredients, and may play important roles in the strong antioxidant activities of this flower. Based on the obtained results, the flower ofP. ostiicould be a potential source of natural antioxidants in food and pharmaceutical applications.Keywords:flavonoids of peony flower;Paeonia ostii;natural antioxidant;chemical constituents
Parameter effects and kinetics of ultrasound assisted ionic liquid mediated hydro-distillation (UILHD) were investigated. An ionic liquid 1-ethyl-3-methylimidazolium bromide ([C2C1im]Br) was employed both as a substrate under sonication and as an additive during distillation. Paeonia suffruticosa Andr. ‘Jitsugetsu Nishiki’, a widely cultivated ornamental plant in China, was selected as a case study. The optimal condition of UILHD was [C2C1im]Br concentration of 10 %, ultrasonic power of 400 W and pretreatment duration of 20 min. Under such a condition, the extraction equilibrium could be basically reached at 35 min of distillation. The kinetics obeyed pseudo-first-order equation. Calculated values of maximum essential oil yield and first-order rate constant were 1.53 g and 0.117 min-1, respectively. The main essential oil components of flowers of P. suffruticosa Andr. ‘Jitsugetsu Nishiki’ were 1,3,5-trimethoxybenzene (16.6 %), tricosane (8.7 %), nerol (8.6 %), nonadecane (6.4 %) and nonanal (5.5 %). The most abundant chemical class was non-terpene hydrocarbons (44.6 %) followed by non-terpene oxygenated compounds (31.2 %) and oxygenated terpenes (22.2 %). UILHD proved to be a promising technique for efficient isolation of essential oils.
危险品化学品经营许可证（带存储）