Highly Galloylated Tannin Fractions from Witch Hazel (Hamamelis virginiana) Bark: Electron Transfer Capacity, In Vitro Antioxidant Activity, and Effects on Skin-Related Cells

2008 ◽  
Vol 21 (3) ◽  
pp. 696-704 ◽  
Author(s):  
Sonia Touriño ◽  
Daneida Lizárraga ◽  
Anna Carreras ◽  
Sonia Lorenzo ◽  
Vanessa Ugartondo ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Electron Transfer ◽  
Witch Hazel ◽  
Electron Transfer Capacity ◽  
In Vitro Antioxidant Activity

scholarly journals Evaluation of the Antioxidant Activity of Cis/Trans-N-Phenyl-1,4,4a,5,8,8a-Hexahydro-3,1-Benzoxazin-2-Imines

Antioxidants ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 197 ◽  
Author(s):  
Guadalupe Firpo ◽  
María L. Ramírez ◽  
Martín S. Faillace ◽  
Maria dos R. Mendes de Brito ◽  
Ana P. S. Correia Lima e Silva ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Electron Transfer ◽  
Hydroxyl Radicals ◽  
Ex Vivo ◽  
Antioxidant Properties ◽  
Comprehensive Analysis ◽  
Biologically Active ◽  
Acetyl Cholinesterase ◽  
In Vitro Antioxidant Activity

The growing interest in the chemistry of unsaturated ring-fused 1,3-heterocycles, in this particular case 1,3-oxazines, arise in part from their versatile pharmacological applications. In the present article, the evaluation of the in vitro and ex vivo antioxidant activity of two cyclohexene-fused oxazines is discussed. The in vitro antioxidant activity was evaluated by trapping the ABTS and hydroxyl radicals as well as the inhibition of the enzyme acetyl-cholinesterase and hemolysis of erythrocytes by 2,2’-Azobis(2-amidinopropane) dihydrochloride (AAPH). The results suggest that both unsaturated 1,3-oxazines are auspicious sources of biologically active compounds with good antioxidant properties. In addition, a comprehensive analysis of the interaction between these heterocycles with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radicals, as well as the measurements of redox potential, provided evidence for a mechanism of antioxidant activity that takes place through electron transfer (ET) processes.

In vitro antioxidant activity and tannin content of Echium italicum L.

Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
N Niciforovic ◽  
S Solujic ◽  
V Mihailovic ◽  
D Pavlovic-Muratspahic
Keyword(s):  
Antioxidant Activity ◽  
Tannin Content ◽  
In Vitro Antioxidant Activity

Physicochemical characterization and in vitro antioxidant activity of hyaluronic acid produced by Streptococcus zooepidemicus CCT 7546

2021 ◽  
pp. 1-10
Author(s):  
Wilza Kímilly Vital de Paiva ◽  
Waleska Rayane Dantas Bezerra de Medeiros ◽  
Cristiane Fernandes de Assis ◽  
Everaldo Silvino dos Santos ◽  
Francisco Caninde de Sousa Júnior
Keyword(s):  
Antioxidant Activity ◽  
Hyaluronic Acid ◽  
Physicochemical Characterization ◽  
Streptococcus Zooepidemicus ◽  
In Vitro Antioxidant Activity

scholarly journals Green One-Pot Synthesis of Coumarin-Hydroxybenzohydrazide Hybrids and Their Antioxidant Potency

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1106
Author(s):  
Marko R. Antonijević ◽  
Dušica M. Simijonović ◽  
Edina H. Avdović ◽  
Andrija Ćirić ◽  
Zorica D. Petrović ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Electron Transfer ◽  
Density Functional ◽  
Electron Transfer Reaction ◽  
Hydrogen Atom Transfer ◽  
Special Importance ◽  
Theory Approach ◽  
One Pot ◽  
Antioxidant Potency

Compounds from the plant world that possess antioxidant abilities are of special importance for the food and pharmaceutical industry. Coumarins are a large, widely distributed group of natural compounds, usually found in plants, often with good antioxidant capacity. The coumarin-hydroxybenzohydrazide derivatives were synthesized using a green, one-pot protocol. This procedure includes the use of an environmentally benign mixture (vinegar and ethanol) as a catalyst and solvent, as well as very easy isolation of the desired products. The obtained compounds were structurally characterized by IR and NMR spectroscopy. The purity of all compounds was determined by HPLC and by elemental microanalysis. In addition, these compounds were evaluated for their in vitro antioxidant activity. Mechanisms of antioxidative activity were theoretically investigated by the density functional theory approach and the calculated values of various thermodynamic parameters, such as bond dissociation enthalpy, proton affinity, frontier molecular orbitals, and ionization potential. In silico calculations indicated that hydrogen atom transfer and sequential proton loss–electron transfer reaction mechanisms are probable, in non-polar and polar solvents respectively. Additionally, it was found that the single-electron transfer followed by proton transfer was not an operative mechanism in either solvent. The conducted tests indicate the excellent antioxidant activity, as well as the low potential toxicity, of the investigated compounds, which makes them good candidates for potential use in food chemistry.

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