In this study, a new reaction system for quantitative determination of ascorbic acid was introduced. The developed method is based on inhibitory effect of ascorbic acid on the Orange G-bromate system. The change in absorbance was followed spectrophotometrically at 478 nm. The dependence of sensitivity on the reaction variables including reagents concentration, temperature and time was investiga...

Efficiency was examined of microencapsulating L-ascorbic acid by polyglycerol monostearate (PGMS), and changes in the chemical and sensorial aspects of L-ascorbic acid and/or iron-fortified milk during storage were evaluated. The selected core materials were ferric ammonium sulfate and L-ascorbic acid. The highest efficiency (94.2%) of microencapsulation was found with the ratio of 5:1 as the c...

A number of investigations (2, 3, 6, 7, 10) within the past 10 years has demonstrated the significance of determining ascorbic acid in the whole blood or white blood cells in assessing the vitamin C nutriture of individuals. These studies have shown (a) that the blood cells may contain ascorbic acid when there is no vitamin in the serum (2, 3), (b) that scurvy does not appear until the cellular...

Ascorbic acid and nitric oxide are known to play important roles in epilepsy. The aim of present study was to identify the involvement of nitric oxide (NO) in the anticonvulsant effects of ascorbic acid on penicillin-induced epileptiform activity in rats. Intracortical injection of penicillin (500, International Units (IU)) into the left sensorimotor cortex induced epileptiform activity within ...

Previous studies showed that the intact carbon chain of glucose can serve as a precursor for the synthesis of ascorbic acid in the rat (l-3). Evidence for such a precursor relationship came from experiments in which glucose tracers labeled in carbon 1 and carbon 6 were administered to rats, and the L-ascorbic acid isolated from urine was labeled predominantly in carbon 6 and carbon 1, respectiv...

Ascorbic acid is frequently administered intravenously by alternative health practitioners and, occasionally, by mainstream physicians. Intravenous administration can greatly increase the amount of ascorbic acid that reaches the circulation, potentially increasing the risk of oxalate crystallization in the urinary space. To investigate this possibility, we developed gas chromatography mass spec...

Both ascorbic acid and copper were strong prooxidants in the oxidation of linoleate in a buffered (pH 7.0) aqueous dispersion at 37OC. Minimum concentrations at which catalytic activity was detected were 1.3 X 10-7 M for coppcr and 1.8 X 10-6 M for ascorbic acid. For concentrations up to lop3 M, the increase in rate of oxidation with increase in concentration of catalyst was greater for ascorbi...

The biosynthesis of i-ascorbic acid (vitamin C) is not well understood in plants. The ozone-sensitive Arabidopsis thaliana mutant vifamin cl (vfcl; formerly known as sozl) is deficient in ascorbic acid, accumulating approximately 30% of wild-type levels. This deficiency could result from elevated catabolism or decreased biosynthesis. No differences that could account for the deficiency were fou...

It has recently been reported that glucose and its analogues inhibit in vitro ascorbic acid transport across the cell membrane of polymorphonuclear leukocytes and fibroblasts. We have studied the effect of in vivo hyperglycemia on the intracellular ascorbic acid level of mononuclear leukocytes in normal and diabetic human subjects. Administration of an intravenous glucose load resulted in a pro...

Forty-one asthmatic patients in remission were randomly allocated to two treatment groups in a double-blind trial. One group took 1 g, of ascorbic acid as one effervescent tablet once daily and the second group took a matching placebo. The asthmatics were selected from those attending the Asthma Clinic. One criterion for selection was the increase in exacerbation during the rainy season. These ...