The present research investigation was aimed at the evaluation of antioxidant activities of methanolic (70%) extracts of whole plant of Pentanema vestitum and fruits of Pistacia integerrima, Withiana somniferra and Withiana coagulans on scavenging of 2, 2-diphenyl-2-picrylhydrazyl (DPPH) free radical. The rank of order of free antioxidant activity of the selected plants was; P. integerrima > P....

The oxidation of ascorbic acid (Vitamin C) is a very important redox reaction, as it has interesting biological properties and is also a powerful reductant. Ascorbic acid is a lactone with a 2,3-endiol group. The enolic group imparts acidity to the molecule; the enol group at position 3 has a pKa of 4.1 and the enol at position 2 has a pKa of 11.6. It is very effective as a reducing agent and i...

Changes in quality, total ascorbic acid, reduced ascorbic acid and dehydroascorbate in fresh cut ‘Selva’ strawberries (Fragariu x anana~~a Duch.) held for 7 days and ‘Fuyu’ persimmons (Diospyros kuki L.) held for 8 days at 5°C in air or controlled atmospheres were evaluated. Various atmospheres had significantly different effects on the color, pH, and titratable acidity of the fruits. The two f...

Hypertension is associated with low plasma ascorbic acid levels and impaired endothelial function. Recent evidence suggests that increased vascular oxidative stress contributes to the pathophysiology of endothelial dysfunction and hypertension. We recently showed that chronic oral ascorbic acid therapy lowers blood pressure in hypertensive patients. We hypothesized that it would also improve en...

A cross-sectional study of the 979 nonsmoking women and men aged 20-29 years who participated in the Toronto Nutrigenomics and Health Study from 2004 to 2008 was conducted to determine the prevalence of serum ascorbic acid (vitamin C) deficiency and its association with markers of chronic disease in a population of young Canadian adults. High performance liquid chromatography was used to determ...

Ascorbic acid (1), a natural antioxidant, was modified by employing transglycosylation activity of Bacillus stearothermophilus maltogenic amylase with maltotriose and acarbose as donor molecules to enhance its oxidative stability. The transglycosylation reaction with maltotriose as donor created mono- and di-glycosyl transfer products with an alpha-(1,6)-glycosidic linkage. In addition, two aca...

Liakakos, D., Ikkos,. D. G., Vlachos, P., Ntalles, K., and Coulouris, Ch. (1974). Archives of Disease in Childhood, 49, 400. Effect of ascorbic acid on urinary hydroxyproline of children receiving corticosteroids. Oral administration of ascorbic acid, 0 * 5 g every 8 hours for a period of 4 days, had no effect on the urinary hydroxyproline excretion of 7 healthy children aged 8 to 14 years. Whe...

Abstract In this study ameliorative effects of ascorbic acid (0.5 mM) on onion (Allium cepa L. cv. Red Azarshahr) under copper stress (Cu: 6.5 μM) were studied. Fresh weights of leaves and roots were reduced in seven week old plants under excess copper condition. Cu stress also reduced membrane stability index in leaves. There was a considerable increase in H2O2 content and lipid peroxidation i...

The kinetics and mechanism of metal ion catalysis in the oxidation of ascorbic acid have been the subject matter of several studies. The catalytic oxidation of ascorbic acid in the presence of Cu(II) and Fe(I'.|I) ions and their complexes in aqueous medium have been reportedl-6. As has been mentioned in the previous chapter, among the various metal complexes synthesised, only the Cu(]I) complex...

The C-8 position of deoxyguanosine (dGuo) was hydroxylated by ascorbic acid in the presence of oxygen (O2) in 0.1 M phosphate buffer (pH 6.8) at 37 degrees C. Addition of hydrogen peroxide (H2O2) remarkably enhanced this hydroxylation. The Udenfriend system [ascorbic acid, FeII, ethylenediaminetetraacetic acid (EDTA) and O2] was also effective for hydroxylation of dGuo in high yield. Guanine re...