The excited-state dynamics of the purine free base and 9-methylpurine are investigated using experimental and theoretical methods. Femtosecond broadband transient absorption experiments reveal that excitation of these purine derivatives in aqueous solution at 266 nm results primarily in ultrafast conversion of the S2(ππ*) state to the vibrationally excited (1)nπ* state. Following vibrational an...

Examination of various purine-requiring mutants of Escherichia coli strain B revealed that one strain, B-35-2, blocked in the conversion of 5-amino-1-(5’-phosphoribosyl)-4-imidazole carboxamide to inosine 5’-phosphate, possessed markedly elevated levels of inosine 5’-phosphate dehydrogenase and xanthosine 5’-phosphate aminase when grown under conditions of purine limitation (1). In contrast, an...

The present experiment was carried out to study the endogenous losses of purine and pyrimidine derivatives from pregnant sows. Three pregnant and three non-pregnant Large White x Landrace sows were fed on a purine-free diet composed of starch, glucose, sucrose and vegetable oil, with casein as the protein source. The experiment began, for the six animals, after diagnosis of pregnancy and was di...

haloalkyl purines i.e. 2,6-diamino-8-(chloromethyl) purine 10; 2, 6-diamino-x- (chloromethyl) purine 17; 2,6-diamino-8-(chloropropylp) urine 18; were synthesized by two distinct but facile methods. the n-alkylating potential of 2, 6-diamino-8- (chloromethyl) purine was investigated. the following products 2,6-diamino-8-(nbenzyl- n-methyl) purine 11; 2,6-diamino-8-(4-nitro anilinomethyl) purine ...

A versatile method for the synthesis of chiral 1,4-disubstituted-1,2,3-triazole derivatives starting from easily accessible naturally occurring D-or L-amino acids as chiral synthons is described. The amino acids were converted into azido alcohols, followed by copper catalyzed [3+2] cycloaddition reactions between the azido alcohols and methyl propiolate and subsequent ester aminolysis with prim...

Previous experiments have shown that when hypoxanthine is synthesized de novo from formate, glycine, and CO2 in extracts or homogenates of pigeon liver these substrates are utilized for purine synthesis in the molecular ratio of 2: 1: 1 (1). Formate is the precursor of carbon atoms 2 and 8 of the purine base; glycine, of atoms 4, 5, and 7; and CO2 of atom 6 (2, 3). The present problem originate...

A facile method for the introduction of various substituents at the C-6 position of guanosine and 2'-deoxyguanosine is reported. In a simple, 1-step transformation, tert-butyldimethylsilyl protected guanosine and 2'-deoxyguanosine were converted to the O(6)-(benzotriazol-1-yl) derivatives via reaction with 1H-benzotriazol-1-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP) and 1,8-...