Purines can be found in a multitude of naturally occurring compounds with a range of functions. This thesis describes the design and synthesis of purines and structurally related pyrazolopyrimidine derivatives intended for biological applications. Pyrazolopyrimidines are structurally related to purines and are used as scaffolds for ATP-competitive protein kinase inhibitors. A pyrazolopyrimidine...

The complex question of the biosynthetic origin of nucleic acid purines has been approached from a number of directions. The elaboration of the over-all picture for a single organism has obvious advantages, and the experiments reported here represent a study in that direction with Lactobacillus casei as the test organism. Extensive information regarding purine utilization by L. casei is availab...

The considerations which prompted an investigation of the r61e of folic acid in formate metabolism were discussed in an earlier paper (1) in which it was reported that rats deficient in this vitamin incorporated less of a standard dose of CY4-formate into certain amino acids and heme than did rats fed folic acid. There is abundant microbiological evidence to indicate an interrelationship betwee...

A purine-requiring mutant (strain W-11) of Escherichia coli strain K-12, has been shown to synthesize 5-aminoimidazole riboside precursors (Love and Gots, 1955). This strain was thought to lack the enzymes responsible for the conversion of aminoimidazole ribotide to purines. On the basis of information on the biosynthesis of purines carried out with enzyme systems from pigeon liver (Buchanan et...

A purine-requiring mutant (strain W-11) of Escherichia coli strain K-12, has been shown to synthesize 5-aminoimidazole riboside precursors (Love and Gots, 1955). This strain was thought to lack the enzymes responsible for the conversion of aminoimidazole ribotide to purines. On the basis of information on the biosynthesis of purines carried out with enzyme systems from pigeon liver (Buchanan et...

Calcium-dependent release of purines was previously demonstrated in cultures of chick retinal cells stimulated with high potassium concentrations but there is no evidence for an exocytotic mechanism of adenosine release from presynaptic terminals. Here we show that activation of NMDA or alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)/kainate glutamate ionotropic receptors promotes a...

The synthesis of 2- and 6-trifluoromethylated purines and 1-deazapurines was performed by formal [3 + 3]-cyclization reactions of 5-aminoimidazoles with a set of trifluoromethyl-substituted 1,3-CCC- and 1,3-CNC-dielectrophiles. The corresponding fluorinated nucleosides were synthesized by glycosylation of 9-unsubstituted purines and 1-deazapurines with peracetylated β-ribose, β-glucose, and rha...

The pattern of formate-Cl4 incorporation by Ehrlich ascites tumor cells has been found to be remarkably different in vitro from the pattern of incorporation in vivo (3-5). Thus, after incubation of cells with formate-Cl4 in vitro, the specific activity of the DNA thymine was 10 to 30 times higher than that of the DNA purines. In contrast, after incorporation of formateCl4 by these cells in viva...