2,2-Diphenyl-1-picrylhydrazyl-ultra-high performance liquid chromatography-Q-time-of-flight mass spectrometry (DPPH-UPLC-Q-TOF/MS), as a rapid and efficient means, now was used for the first time to screen antioxidants from Selaginella doederleinii. The nine biflavone compounds were screened as potential antioxidants. The biflavones were structurally identified and divided into the three types,...

Phytochemical investigation of the aqueous extract of Pithecellobium clypearia afforded one novel compound, clypearoside A (1), and one new stereoisomer, (-)-(2S,3S)-epigallocatechin-7-gallate (2) and four known ones (3-6). Their structures were elucidated on the basis of spectroscopic data, especially 2D NMR, HRESIMS and ECD spectra. Compounds 2-4 showed strong activity against DPPH (diphenylp...

In continuation of our study the in vitro antioxidant activity of some novel quinoxaline derivatives was investigated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method with respect to ascorbic acid. To determine the antioxidant activity, a number of substituted indoxyls (3A-G), cyclic ketones (2A-G), and quinoxalines (1A-G) were synthesized by both microwave and conventional heating methods. The p...

A xanthone, 1,3,6,7-tetrahydroxy-xanthone (compound (1)) had been isolated from Garcinia benthami Pierre. The isolation was conducted through the chromatography technique and spectroscopy methods by spectroscophyc: mass spectrometry (LC-MS), infra red (IR), UV, 1H-NMR, 13C-NMR (1D and 2D-NMR). Antioxidant activity test by using DPPH (1,1diphenyl-2-picrylhydrazyl) method from the isolated compou...

BACKGROUND The potential of ascorbic acid and two botanical decoctions, green tea and cat's claw, to limit cell death in response to oxidants were evaluated in vitro. METHODS Cultured human gastric epithelial cells (AGS) or murine small intestinal epithelial cells (IEC-18) were exposed to oxidants - DPPH (3 microM), H2O2 (50 microM), peroxynitrite (300 microM) - followed by incubation for 24 ...

OBJECTIVES The objective of this study is to investigate the effects of Salviae Miltiorrhizae Radix hot aqueous extract on nitric oxide (NO) and prostaglandin E2 (PGE2 ) production and on 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical scavenging in macrophages. METHODS Salviae Miltiorrhizae Radix(300 g) was heated at 100℃ with distilled water (2 L) for 4 hours. The extract was filtered an...

OBJECTIVES Potato (Solanum tuberosum L.), as a whole food, contains high levels of vitamins and important antioxidants including phenolic acids, carotenoids and flavonoids. The objective of this study was to determine the total phenolic content and antioxidant activities of three common potatoes (Solanum tuberosum) cultivars in Iran i.e., Savalan, Agria and Sante. MATERIALS AND METHODS Phenol...

A challenge in recent years has been the rational use of forest and agriculture residues for the production of bio-fuel, biochemical, and other bioproducts. In this study, potentially useful compounds from pyrolytic lignins were identified by HPLC-MS/MS and untargeted metabolomics. The metabolites identified were 2-(4-allyl-2-methoxyphenoxy)-1-(4-hydroxy-3-methoxyphenyl)-1-propanol, benzyl benz...

The time evolution of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH*) concentration in four solvents (methanol, ethanol, propanol, and acetonitrile) during its reduction by three flavanones containing an isolated p-catechol group (taxifolin, eriodyctiol, and fustin) as well as the time evolution of the mass spectra of the reaction mixture has been determined by spectrophotometry and liquid mass s...

Purpose: To investigate the physicochemical properties and DPPH radical scavenging activity of gallic acid–lecithin complex Methods: The complex of gallic acid with lecithin was prepared by solvent method. The physicochemical properties of the complex were investigated by ultraviolet-visible spectrometry (UV), infrared spectrometry (IR), scanning electron microscopy (SEM), differential scanning...