The electron spin resonance (ESR) spectrum of erythrocytes of a health male volunteer exhibited 2 min after intravenous administration of 1g of ascorbic acid a considerable increase in spin concentration and an new signal at about g-2.005 which we previously had found to correlate to the semidehydroascorbate (SDA) radical and which is not identical with the O2 radical. Moreover, the vitamin C c...

Krug AW, Völker K, Dantzler WH, Silbernagl S. Why is D-serine nephrotoxic and -aminoisobutyric acid protective?. Am J Physiol Renal Physiol 293: F382–F390, 2007. First published April 11, 2007; doi:10.1152/ajprenal.00441.2006.—D-Serine selectively causes necrosis of S3 segments of proximal tubules in rats. This leads to aminoaciduria and glucosuria. Coinjection of the nonmetabolizable amino aci...

Humans are unable to synthesise ascorbate (Vitamin C) due to the lack of a functional gulonolactone oxidase (Gulo), the enzyme that catalyses the final step in the biosynthesis pathway. Ascorbate is a vital micronutrient required for many biological functions, including as a cofactor for metalloenzymes that regulate the transcription factor hypoxia-inducible factor-1 (HIF-1), which governs cell...

Subterranean clover (Trifolium subterraneum L. cv Seaton Park) was grown in solution cultures containing adequate nitrogen both with and without Cu. After Cu deficiency had developed, Cu(2+) was added to some deficient plants and Cu content, protein content, and activities of three Cu metalloenzymes (diamine oxidase [EC1.4.3.6], ascorbate oxidase [EC1.10.3.3] and o-diphenol oxidase [EC1.10.3.1]...