نتایج جستجو برای: 2 2 diphenyl 1 picrylhydrazyl dpph

تعداد نتایج: 3940654  

Journal: :Food chemistry 2015
Tsun-Thai Chai Meng-Tee Kwek Hean-Chooi Ong Fai-Chu Wong

This study aimed to isolate a potent antiglucosidase and antioxidant fraction from Stenochlaena palustris. Extraction was performed with hexane, chloroform, ethyl acetate, methanol, and water. Antiglucosidase, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and ferric reducing antioxidant power (FRAP) assays found methanol extract (ME) to be the most active. Water fraction (WF) of ME was a stro...

2016
KHALIDA AL-AzAwI

3-((4-(dimethylamino)benzylidene)amino)-2-methylquinazolin-4(3H)-one (3), 3-((4hydroxybenzylidene)amino)-2-methylquinazolin-4(3H)-one (4), 2-methyl-3-(pyrrolidin-2-ylideneamino) quinazolin-4(3H)-one (5) and 3,3'-((1,4-phenylenebis(methanylylidene)) bis(azanylylidene))bis(2methylquinazolin-4(3H)-one) (6) derived from 3-amino-2-methylquinazolin-4(3H)-one have been synthesized and characterized by...

Journal: :Molecules 2014
Lin Hu Na-Na Chen Qun Hu Cui Yang Qing-Song Yang Fang-Fang Wang

A novel dimer of piceatannol glycoside, named rheumaustralin (1) was isolated from the underground parts of the ethnomedicinal plant Rheum austral (Polygonaceae) collected from Tibet together with 17 known compounds, including rheumin (2), 2,5-dimethyl-7-hydroxychromone (3), 2,5-dimethylchromone-7-O-β-D-glucopyranoside (4), 7-hydroxy-2-(2'-hydroxypropyl)-5-methylchromone (5), torachrysone (6) t...

2009
M. R. Saha S. M. R. Hasan R. Akter M. M. Hossain M. S. Alam M. A. Alam M. E. H. Mazumder

In the present study, antioxidant potential of the methanol extract of the leaves of Mimusops elengi Linn. was evaluated by using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay, reducing power and total antioxidant capacity. The extract showed significant activities in all antioxidant assays compared to the reference antioxidant ascorbic acid in a dose dependent manner. In DPPH scavengi...

Journal: :Bulletin of the Chemical Society of Japan 1972

Journal: :Molecules 2015
Tjaša Prevc Alenka Levart Irena Kralj Cigić Janez Salobir Nataša Poklar Ulrih Blaž Cigić

The reactivity of tocopherols with 2,2-diphenyl-1-picrylhydrazyl (DPPH) was studied in model systems in order to establish a method for quantifying vitamin E in plant oils. The method was optimized with respect to solvent composition of the assay medium, which has a large influence on the course of reaction of tocopherols with DPPH. The rate of reaction of α-tocopherol with DPPH is higher than ...

Journal: :Molecules 2015
Anamaria D P Alexiou Carla C Decandio Sabrina da N Almeida Marcelo J P Ferreira Paulete Romoff Reginaldo C Rocha

A new trinuclear oxo-centered chromium(III) complex with formula [Cr3O(CH3CO2)6(L)(H2O)2] (L = 5-hydroxyflavone, known as primuletin) was synthetized and characterized by ESI mass spectrometry, thermogravimetry, and 1H-NMR, UV-Vis, and FTIR spectroscopies. In agreement with the experimental results, DFT calculations indicated that the flavonoid ligand is coordinated to one of the three Cr(III) ...

Journal: :Zeitschrift fur Naturforschung. C, Journal of biosciences 1997
P Basnet T Matsuno R Neidlein

We evaluated free radical scavenging activity of the water, methanol and chloroform extracts of propolis in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and xanthine-xanthine oxidase (XOD) generated superoxide anion assay systems. The free radical scavenging activity guided fractionation and chemical analysis led to the isolation of a new compound, propol (3-[4-hydroxy-3-(3-oxo-but-1-enyl)...

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