241 Abstract: All known pyrimidine and pyrimidine-derived secondary producs originate from uracil or its precursor, uracil-6-carboxylic acid. The biosynthesis of these products has been suggested to be uracil detoxication mechanisms. The possible toxic effects of uracil on the germination and growh of Pisum sativum L. cultivar Meteor, Lathyrus tingitanus L. in which pyrimidine-derived secondary...

We studied the effects of 5-ethynyluracil (776C85 and 776C), a potent mechanism-based inactivator of dihydropyrimidine dehydrogenase, on the antitumor efficacy and pharmacokinetics of tegafur (FT), a prodrug of 5-fluorouracil (5-FU), in rats with large s.c. colon carcinoma. Rats were dosed p.o. once daily for 7 days with either FT, FT and uracil in a 1:4 molar ratio (UFT), FT 1 h after 776C (77...

1. Chloramphenicol has a stimulatory effect on the incorporation of radioactive phosphate into the RNA of perfused rat-liver slices, whole liver homogenates or the liver-cell suspensions, and no effect on the incorporation of [(14)C]adenine and [(14)C]uracil into the RNA of the tissue slices. 2. Chloramphenicol completely inhibits the incorporation of labelled adenine and uracil into the RNA of...

The essential oils from two Chinese endemic Meconopsis species, i. e., M. punicea and M. delavayi, were analyzed by using GC-MS for the first time. The major constituents were hexadecanoic acid (16.8%), 1,2-dimethyl naphthalene (11.4%), 1,4-dimethyl naphthalene (6.6%), 1,3-dimethyl-5-ethyl naphthalene (5.9%), and 3-methyl biphenyl (5.6%) for M. punicea, and hexadecanoic acid (9.9%), 1,2-dimethy...