BACKGROUND Synthetic L-ascorbic acid (vitamin C) is widely used as a preservative and nutrient in food and pharmaceutical industries. In the current production method, D-glucose is converted to L-ascorbic acid via several biochemical and chemical steps. The main source of L-ascorbic acid in human nutrition is plants. Several alternative metabolic pathways for L-ascorbic acid biosynthesis are kn...

The biosynthetic pathway of L-ascorbic acid (vitamin C) in plants has been established for several years. However, recent reports describe alternative pathways, revealing a more complex picture of L-ascorbic acid biosynthesis than had been expected. GDP-L-gulose and myo-inositol are proposed as new intermediates in L-ascorbic acid biosynthesis, indicating that part of the animal pathway might a...

1. The effect ofdietary molybdenum on the growth rate and also on ascorbic acid metabolism in rats was studied. An excess of dietary molybdenum resulted in growth retardation and loss of weight. Tolerance to molybdenum was affected by the nature ofthe molybdenum salt administered. 2. Molybdenum ingestion altered certain aspects of ascorbic acid metabolism in rats. The conversion ofD-glucuronola...

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...

When administered to rats, various drugs of widely different chemical structures, for example barbiturates, Chloretone, and paraldehyde, markedly increase the urinary excretion of L-ascorbic acid (1). A previous turnover rate study showed that this increase results from an acceleration in the rate of synthesis of L-ascorbic acid (2), but there is no understanding of the mechanism by which drugs...

l-Ascorbic acid functions as a precursor of oxalic acid in several oxalate-accumulating plants. The present study extends this observation to include Rumex crispus L. (curly dock), Amaranthus retroflexus L. (red root pigweed), Chenopodium album L. (lamb's-quarters), Beta vulgaris L. (sugar beet), Halogeton glomeratus M. Bieb. (halogeton), and Rheum rhabarbarum L. (rhubarb). Several species with...

The influence of L-ascorbic acid at 40 degrees C incubation on the subfragment-1 and rod regions, prepared by chymotryptic digestion of myosin, and myosin was investigated by SDS-polyacrylamide gel electrophoresis and transmission electron microscopy respectively. It was observed that L-ascorbic acid acted more readily on the subfragment-1 region of myosin. Further, circular dichroism measureme...