690 



INDEX 



representation of, 451 



stability to acids, 117 



synthesis of, 125, 126, 130 



thiouracil and, 103 



thymidine phosphorylase and, 605 



thymine estimation and, 304 



ultraviolet absorption of 123, 499, 503, 

 507 

 Uracil-4-carboxylic acid, see Orotic acid 

 Uracil-5-carboxylic acid, 101 

 Uracil deoxyriboside, 139, 157 



occurrence of, 14 



ultraviolet absorption of, 504, 509 

 Uranyl chloride, ribonuclease assay and, 



566-567 

 Urea, 



deoxypentose nucleic acid and, 332, 

 529 



formation from guanine, 122 



formation from pyrimidines, 86, 120, 

 121, 123, 619, 623 



formation from uric acid, 618 



nucleoprotein and, 319 



paper chromatography and, 251 

 Ureas, 



purine synthesis and, 132, 133, 134 



pyrimidine synthesis and, 125, 126, 

 129-130 

 Urease, barbiturase and, 623 

 Ureidomethylenecyanoacetate, pyrimi- 

 dine synthesis and, 129 

 Ureidomethylenemalonate, pyrimidine 



synthesis and, 129 

 Ureidosuccinic acid, 



formation of, 620, 621 

 Ureidosuccinic acid, ring-closure of, 621 

 Uric acid, 13, 82, 84, 94 



dehydrogenation of, 618 



formation, 609 



gout and, 96 



indole-hydrochloric acid reaction and, 

 298 



8-methylxanthine formation and, 119 



occurrence of, 96 



oxidation of, 121-123 



paper chromatography of, 253 



permanganate oxidation of, 616 



purine synthesis and, 130 



reduction of, 119, 120 



ultraviolet light and, 123, 136 



xanthine oxidase inhibition and, 612 



Uric acid riboside, 159 



occurrence of, 96 



nucleoside hydrolase and, 607 



paper chromatography of, 253 

 Uricase, 96, 123, 609, 614 



history, 614-615 



inhibitors, 619 



intracellular localization of, 625 



mechanism of action, 



decarboxylation reaction, 616, 618 

 intermediary product, 616-618 

 oxidation reaction, 615-616 



optimal pH of, 618-619 



specificity of, 618 

 Uridine, 12, 100, 138, 140, 157, 594, 622 



borate complex, electrophoresis of, 283 



cationic exchangers and, 219 



dissociation constants of, 459 



formation from cytidine, 143, 144 



ionization of, 272 



methylation of, 145 



paper chromatography of, 255 



phosphate linkages, 413-415 



phosphorolysis of, 602, 604, 605 



reduction of, 141 



reaction with hydrazines, 144 



spectrophotometric estimation of, 200- 

 202 



structure, x-ray diffraction and, 454 



synthesis of, 155-156 



trityl derivatives of, 146 



ultraviolet absorption of, 123, 509, 518 

 Uridine benzyl phosphate 6, ribonuclease 



and, 430 

 Uridine diphosphate, 



coenzymes and, 187 



diesterase and, 434 



ion-exchange of, 230-231, 232 



production of, 434-435 



transphosphorylation and, 626 



ultraviolet absorption of, 513 

 Uridine diphosphate glucose, 



hydrolysis of, 186-187 



paper chromatography and, 264 



ribose in, 13 



structure of, 98-99 

 Uridine ethyl phosphate a, ribonuclease 



and, 430 

 Uridine-5'-ethyl phosphate, 176 

 Uridine hydrolase. 



