The effects of formycin (7-amino-3-(/3-D-ribofuranosyl)pyrazolo(4,3-d)-pyrimidine), an adenosine analog, on purine metabolism in Ehrlich ascites tumor cells were studied. Purine biosynthesis de novo was blocked by formycin through inhibition of phosphoribosylpyrophosphate synthesis, and this did not occur in cells which did not phosphorylate formycin. This analog had no significant effect on ad...

The effect of salinity on ammonium-assimilation enzymes, as well as on the enzymes of purine catabolism, was studied in root nodules of common bean plants grown in an environmentally controlled chamber. Salt treatments (0, 25, 50 and 100 mM) were applied during the vegetative period, when the symbiosis was well established. Four harvests were made, two during the vegetative and two during the r...

Alcohol Dehydrogenase 5 Is a Source of Formate for De Novo Purine Biosynthesis in HepG2 Cells Sajin Bae, James Chon, Martha S Field, and Patrick J Stover 499 Activation of Nrf2-Antioxidant Signaling by 1,25-Dihydroxycholecalciferol Prevents Leptin-Induced Oxidative Stress and Inflammation in Human Endothelial Cells Thaisa M Teixeira, Danielly C da Costa, Angela C Resende, Christophe O Soulage, ...

2-Amino-3-functionally substituted thiophene de­ rivatives are important intermediates to the phar­ maceutically important thieno[2,3-d]pyrimidines [2]. These thiophene derivatives were available from the procedures published by K. Gewald [3, 4] via either the reaction of a-methylene ketones with active methylene nitriles in presence of elementary sulphur of from a-mercaptoketones and active me...

H om oconjugation energies in vacuo have been calculated for pyridine N -oxide (PyO) and its 4-methyl(4 PicO) and 4-nitro(4-N O :PyO) de­ rivatives with the use o f the C N D O /2 m ethod. C om parison with the experim ental hom oconjuga­ tion constants in some aprotic solvents reveals the opposite order o f the stability o f hom ocom plexes than could be expected based on the calculated hom oc...