The hydrolyses of .alpha.-D-ribose and -glucose 1-phosphates

Abiotic production of sugar phosphates and uridine ribonucleoside in aqueous microdroplets

“…As the mass spectrometry cannot distinguish between the two optical isomers, d - and l -sugars, we tested if there was any transformation of the optical isomeric forms during the phosphorylation in microdroplets. The specific rotations, [α] D 20 , of d -ribose and d -ribose-1-phosphate are −25.0° and +39.8°, respectively ( 35 , 36 ). The [α] D 20 of the solution collected from the reaction between d -ribose and ribose-1-phosphate in microdroplets was measured to be −21.1° by a polarimeter.…”

Toward a Detailed Understanding of Base Excision Repair Enzymes: Transition State and Mechanistic Analyses of N-Glycoside Hydrolysis and N-Glycoside Transfer

“…7,12,107,108 (The sole known exception 46,64 is discussed below.) Thus, The ribofuranosyl oxacarbenium ion is expected to be more stable than the glucopyranosyl oxacarbenium ion, based on the higher reactivity of O-ribosides 7 and sugar 1-phosphates, 118 and therefore more prone to proceed through D N *A N mechanisms. Nonetheless, the nonenzymatic hydrolyses of the AMP 27 and NAD +41 had A N D N mechanisms, though hydrolysis of dAMP appears to be stepwise.…”

Defining a process operating window for the synthesis of 5-methyluridine by transglycosylation of guanosine and thymine

“…Although the enzymes PNP and UP both show activity below pH 7, lower guanosine conversion and 5-MU yields were observed. The lower 5-MU yield may possibly be attributed in part to the decomposition of R-1-P under acidic conditions (Bunton and Humeres, 1969). Within the broad pH 7-10 window available for performing the reaction, the pH range 7.5 to 8.5 was chosen for subsequent experiments.…”