Paeonia ostii is 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 of P. ostii. The results showed that the flavonoid-rich extracts from the flowers of P. ostii had 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 of P. ostii. High-performance liquid chromatography (HPLC) analysis revealed that compounds 3 and 4 were abundant in the P. ostii flower and in flavonoid-rich extracts. The main components of the flower of P. ostii are 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 of P. ostii could be a potential source of natural antioxidants in food and pharmaceutical applications.

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Abstract:In the course of screening natural products for antibacterial activities, a total acetone extract of the seed cake of Paeonia rockii showed significant effects against bacterial strains. Bioactivity-guided fractionation of the EtOAc-soluble fraction of the total acetone extract resulted in the isolation and identification of five resveratrol trimers, including rockiiol C (1), gnetin H (2), suffruticosol A (3), suffruticosol B (4) and suffruticosol C (5). The relative configuration of these compounds was elucidated mainly by comprehensive 1D and 2D-NMR experiments. Compound 1 was a new compound. All isolated compounds exhibited strong antibacterial activities against Gram-positive bacteria.

A hot downer reactor of 4.5 m in height and 13 mm in inner diameter was built to examine its performance in the deep catalytic cracking (DCC) process. The experimental results show that the downer reactor can significantly improve the selectivity of desired products in comparison with the commercial riser adopting the same feed and catalyst: the yields of propylene and gasoline increase by 3.71 and 7.30 wt %, respectively, while the yields of dry gas and coke reduce by 6.77 and 1.98 wt %, respectively. The "close to plug flow" pattern of the gas and solids in the downer makes it a desirable reactor for the DCC process.

Introduction The Paeonia ostii T. Hong & J. X. Zhang seed shell, characterised by a high content of oligostilbenes, is one of the two most important by‐products in the preparation of seed oil. Oligostilbenes are considered characteristic constituents of the genus Paeonia, and can be used in fingerprinting to determine the geographical origin and the quality of raw materials. Objective To develop and optimise a simple and reproducible high‐performance liquid chromatography diode array detection (HPLC‐DAD) method for the simultaneous determination of seven oligostilbenes in P. ostii seed shell from different geographical areas, and to associate the cultivation area. Methodology A validated HPLC method coupled with a DAD detector was performed for the detection and determination of target compounds in the samples. Optimal chromatographic conditions were achieved using an Agilent Zorbax Eclipse SB‐AQ‐C18 column and a gradient elution with acetonitrile and potassium dihydrogen phosphate solution. Results The proposed quantitative method showed appropriate accuracy and precision, and was successfully applied to the routine analysis of seven oligostilbenes and the quality evaluation of 50 P. ostii seed shell samples. There were significant differences between the contents of the seven oligostilbenes in different samples (P < 0.01). Conclusion The results demonstrated that the oligostilbenes were main secondary metabolites in the P. ostii seed shells, and the content of seven components in P. ostii seed shells sourced from different cultivation areas in China was different.