The antitumor activity of 5-fluorouracil (FUra) against ascites Sarcoma 180 was significantly enhanced by coadministration of guanosine, and slightly by adenosine, but not by cytidine or uridine. In advanced ascites Sarcoma 180, guanosine also enhanced the action of FUra, but adenosine, uridine, and cytidine did not. The potentiation of antitumor activity by guanosine was reversed by addition o...

The aim of this investigation was to test the hypothesis that extracellular guanosine regulates extracellular adenosine levels. Rat preglomerular vascular smooth muscle cells were incubated with adenosine, guanosine, or both. Guanosine (30 μmol/l) per se had little effect on extracellular adenosine levels. Extracellular adenosine levels 1 h after addition of adenosine (3 μmol/l) were 0.125 ± 0....

The self-association of guanosine, cytidine, and adenosine and base pairing between guanosine, cytidine, adenosine, and uridine in dimethyl sulfoxide have been investigated by the variation of their 15N NMR chemical shifts with concentration and temperature. Guanosine, cytidine, and adenosine all showed evidence of self-association by hydrogen bonding. In guanosine/cytidine mixtures, a hydrogen...

Guanosine is a purine nucleoside with important functions in cell metabolism and a protective role in response to degenerative diseases or injury. The past decade has seen major advances in identifying the modulatory role of extracellular action of guanosine in the central nervous system (CNS). Evidence from rodent and cell models show a number of neurotrophic and neuroprotective effects of gua...

We studied the incorporation of 14C-labeled guanosine into riboflavin under conditions precluding the metabolic conversion of guanosine compounds to free guanine. For this purpose we isolated a mutant BM 2 of Salmonella typhimurium deficient in the enzymes IMP dehydrogenase, purine nucleoside phosphorylase, and purine nucleotide pyrophosphorylase. The mutant incorporated [ribose-14C]guanosine i...

The stereochemical course of the reaction catalyzed by the soluble form of bovine lung guanylate cyclase has been investigated using [alpha-18O]guanosine 5'-triphosphate (Rp diastereomer) and guanosine 5'-O-(1-thiotriphosphate) (Sp diastereomer) as substrates. The product from the 3-thiomorpholino-1',1'-dioxide sydnonimine-stimulated enzymatic cyclization of [alpha-18O] guanosine 5'-triphosphat...

•Guanosine quadruplex hydrogels were modified with ligand 1 enabling Eu(III) binding •Two of the gels both exceptionally stable and partially self-healable •Eu(III)-centered circularly polarized luminescence was observed for one hydrogel •The helical nature guanosine quadruplexes influenced Eu(III)-centered CPL The formation bio-inspired healable lanthanide luminescent is detailed. These materi...

Misonidazole, after reduction to the hydroxylamine derivative, was found to react with guanosine in aqueous solution at pH 7. The guanosine product was isolated and was assigned a structure having a new 5-membered ring with a -CHOH-CHOH-linkage between the N-1 and N-2 positions of guanine. Removal of the sugar residue from the guanosine product by acid hydrolysis resulted in the corresponding g...