Compounds with the ability to scavenge reactive oxygen species (ROS) and inhibit tyrosinase may be useful for treatment prevention from ROS-related diseases. The number location of phenolic hydroxyl flavonoids will significantly influence inhibition activity. Phenolic is indispensable antioxidant activity flavonoids. Isoeugenol, shikonin, baicalein, rosmarinic acid, dihydromyricetin have respectively one, two, three, four, or five hydroxyls. different molecular structures similar structure...

Extraction temperature influences the total phenolic content (TPC), flavonoid (TFC) of medicinal plant extracts to a great extend. TPC and TFC are principle activity constituents present in plant. The effects extraction on TPC, free radical-scavenging capacity Gynura divaricata leaf worth study.Folin-Ciocalteu aluminum chloride colorimetric assay were used determine at different temperatures. antioxidant measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH),...

Optimization of total flavonoid compound (TFC) extraction from Gynura medica leaf was investigated using response surface methodology (RSM) in this paper. The conditions were 30–60% (v/v) ethanol concentration (X1), 85–95 °C temperature (X2) and 30–50 (v/w) liquid-to-solid ratio (X3). Statistical analysis the experiments indicated that significantly affected TFC (p < 0.01). Box-Behnken experiment design showed polynomial regression models good agreement with experimental results,...

Pharmacognosy Magazine,2011,7,26,101-108.DOI:10.4103/0973-1296.80666Published:May 2011Type:Original ArticleAuthors:Chunpeng Wan, Yanying Yu, Shouran Zhou, Shuge Tian, and Shuwen Cao Author(s) affiliations:Chunpeng Wan1, Yu2, Zhou3, Tian4, Cao5 1State Key Laboratory of Food Science Technology, Nanchang University, Nanchang-330047, Jiangxi, China 2Department Chemistry, - 330 031, 3Jiangxi University Traditional Chinese Medicine, 006, 4Xinjiang Famous Prescription Formulas, Urumqi 830 011,...

Polyurea spraying is a new temporary support technology that can significantly enhance the mechanical properties of coal. However, mechanism interactions between polymer coating and coal unclear. In this study, No. 4 non-stick from Mengcun Coal Mine polyurea material were used to conduct experiments numerical simulations. The tests simulations examine role sprayed in formation residual strength unloading rebound after brittle failure results showed presence had significant impact on behavior...

Background: Acute liver damage is primarily induced by one of several causes, among them viral exposure, alcohol consumption, and drug immune system issues. Agents with the ability to inhibit tyrosinase protect against DNA caused reactive oxygen species (ROS) may be therapeutically useful for prevention or treatment ROS-related diseases. Methods: This investigation examined hepatoprotective effects phloretin isonicotinyl hydrazone (PIH) on D-galactosamine (D-GalN)-induced acute in Kunming...

With increases in mining depth and intensity, disasters such as stress concentration, slab failure, coal body dynamic outbursts at the coal–rock interface have become more serious. Therefore, it is important to analyze stress–strain behavior of combinations explore deterioration process failure characteristics combinations. In this study, we used field survey, theoretical analysis, numerical simulation methods microstructure influence interlayer thickness on composite body. The results show...

During froth treatment, a water-in-diluted bitumen emulsion is obtained. The emulsified water contains chloride ions that form hydrochloric acid in downstream oil processing, leading to catalyst deactivation and equipment corrosion. Emulsified water, drops smaller than 10 μm, cannot be effectively removed by gravity settling centrifugation below 2 wt %. In this work, filter-coalescer was used promote the coalescence separation of water-in-bitumen emulsion. larger (>300 μm) exiting coalescer...

With the aim to find out structural features for tyrosinase inhibitory activity, effects of seven paeonol analogues on diphenolase mushroom tyrosinase, interaction between inhibitors and copper ions, antioxidant activity by DPPH radical were investigated. These had suggested remarkable inhibition toward tyrosinase. Among them, (a) exhibited strongest (IC50 =0.21 mM) as well showed potent scavenging radical. The kinetics revealed that was a mixed-type inhibitor, 2′-hydroxy acetophenone (c),...

To study the chemical constituents of Daphne odora var. margirmta.The compounds were isolated and purified by column chromatography silica gel, ODS, Sephadex LH-20, their structures identified UV, 1H-NMR, 13C-NMR, MS CD spectroscopic methods.Ten elucidated as wikatrols B (1), kaempferol (2), daphnodorin (3), D2 (4), A (5), C (6), D1 (7), I (8), daphnetin (9), daphnoretin (10).Compounds 1,2,4 obtained from this plant for first time,and compound 1 was firstly genus Daphne.

It is crucial to understand the scaling behaviors of acoustic emissions (AEs) preceding damage localization in order predict failures brittle solids under compression. Yet, effect length scale on complex interplay between initiation, propagation, and coalescence pre-existing fracture networks corresponding AE poorly understood. In this study, we perform laboratory compressional experiments naturally fractured rocks at four sample sizes from 50 300 mm whose strength generally exhibits a...