The utilization of orotic acid for the formation of RNA ~ uracil has been extensively studied in intact animals, tissue slices, and cell suspensions (reviewed in Refs. 5, 31). The mechanism of the utilization, via the initial conversion of orotic acid to uridine nucleotides and the incorporation of uridine nucleotides into polynucleotides, has been partially described in intact animals (13, 17)...

The occurrence of the complete orotic acid pathway for the biosynthesis de novo of pyrimidine nucleotides was demonstrated in the intact cells of roots excised from summer squash (Cucurbita pepo L. cv. Early Prolific Straightneck). Evidence that the biosynthesis of pyrimidine nucleotides proceeds via the orotate pathway in C. pepo included: (a) demonstration of the incorporation of [(14)C]NaHCO...

Radioactive orotic acid incorporation into RNA (de novo pathway of pyrimidine nucleotide synthesis) was considerably lower for rat heart than for rat liver in vivo and in vitro. H uridine ("salvage" pathway) was incorporated into heart RNA to a greater extent than H orotic acid, and the labeling with uridine in the heart exceeded that in the liver. Extracts of heart showed little enzymatic conv...

This investigation was undertaken to correlate the antineoplastic effects of 6-azauridine (AzUR) with the activity of orotic acid metabolism and its inhibition in vitro by AzUR in a series of plasma cell tumors of mice. Although AzUR suppressed tumor growth only moderately and to widely different degrees in different tumors, its antitumor effects in vivo appeared to follow its inhibition of oro...

The process of carcinogenesis following exposure of mice to urethane is demonstrated in the present work to be intimately related to nucleic acid synthesis. Injection of animals with a DNA hydrolysate immediately prior to a single exposure of the animals to urethane markedly reduced the number of pulmonary adenomas initiated. Aminopterin, known to interfere in nucleic acid synthesis (46), poten...

The crystal structure of the title compound, which is also known as vitamin B(13) (systematic name: 2,6-dioxo-1,2,3,6-tetra-hydro-pyrimidine-4-carboxylic acid monohydrate), C(5)H(4)N(2)O(4)·H(2)O, was reported for the first time by Takusagawa & Shimada [Bull. Chem. Soc. Jpn (1973 ▶), 46, 2011-2019]. The present redetermination provides more precise values of the mol-ecular geometry. The asymmet...

Our research group have been working on transistion metal complexes and their activity in the biology field, especially antimicrobial and anticancer properties. Novel pseudohalide ligands with orotic acid and its metal salt Ni(II) have been synthesized and evaluated for their antimicrobial activities by disc diffusion method. The complexes have been characterized by IR, SEM, Raman, P-Xrd and UV...

The present study was conducted to elucidate the metabolic pathways by which enlarged liver size of patients undergoing disorders of orotic acid de novo metabolism and those patients of enlarged liver size induced by di(2-ethyl hexyl) phthalate in rats as animal model. The results showed that rats-treated with orotic acid generated liver triglyceride content 400% higher than that of the control...