Synthesis of several pryrazolo[4,3-e][1,2,4]-triazines is described. The absorption spectrum of some 5-substituted derivatives was found to extend to the visible region. These compounds were found to inhibit some enzymes of purine metabolism, like xanthine oxidase or bacterial purine-nucleoside phosphorylase with Ki values in the 10(-3) -10(-5) M range.

Cardiorespiratory and biochemical indicators typically used by contemporary elite athletes seem to have limited applicability. According to some recent studies, purine metabolism better reflects exercise response and muscle adaptation in this group. We propose using purine derivatives, especially plasma hypoxanthine concentration, as indicators of training status in consecutive training phases ...

Interest in electrochemical analysis of purine nucleobases and few other important purine derivatives has been growing rapidly. Over the period of the past decade, the design of electrochemical biosensors has been focused on achieving high sensitivity and efficiency. The range of existing electrochemical methods with carbon electrode displays the highest rate in the development of biosensors. M...

A series of 11 new substituted 1,5-dihydro-4,1-benzoxazepine derivatives was synthesised to study the influence methyl group in 1-(benzenesulphonyl) moiety, replacement purine by benzotriazole bioisosteric analogue, and introduction a bulky substituent at position 6 purine, on biological effects. Their inhibition against isolated HER2 studied structure–activity relationships have been confirmed...

Various derivatives of adenosine were prepared by acylation of adenosine (6-amino-9-(bD-ribofuranosyl)purine (1) with different molar equivalents of acetic anhydride and/or pivaloyl chloride in pyridine. Compounds 6-acetylamino-9-[(2,3,5-tri-O-acetyl)-b-Dribofuranosyl]purine (3), 6-amino-9-[(2,3,5-tri-O-acetyl)-b-D-ribofuranosyl]purine (4), and 6-pivaloylamino-9-[(2,3,5-tri-O-pivaloyl)-b-D-ribo...

Eight ruminally cannulated lactating cows from a study on the effects of dietary rumen degraded protein (RDP) on production and N metabolism were used to compare 15N, total purines, amino acid (AA) profiles, and urinary excretion of purine derivatives (PD) as microbial markers for quantifying the flow of microbial protein at the omasal canal. Dietary RDP was gradually decreased by replacing sol...

Numerous basic studies have reported on the neuroprotective properties of several purine derivatives such as caffeine and uric acid (UA). Epidemiological also shown inverse association appropriate intake or serum urate levels with neurodegenerative diseases Alzheimer disease (AD) Parkinson’s (PD). The well-established mechanisms UA involve adenosine A2A receptor antagonism antioxidant activity,...

This study examined the in ̄uence of dietary variation on the usefulness of urinary spot purine derivatives (PD) collected at three periods (8:00±9:30, 14:00±15:30 and 20:00±21:30 hours) as predictors of intake by cattle. Diets comprised teff (Eragrotis tef) straw, fresh and dried napier grass and fresh napier grass supplemented with 1.5 (as fed) of dry alfalfa hay. Variation in dry matter intak...