Of 142 purines, purine nucleosides, and analogues tested for inhibition of growth of Escherichia coli B Hill, 45 were active. Of these, 27 were evaluated for inhibition of other E. coli lines, including those resistant to 6-thioguanine, 2-fluoroadenosine, 2,6-diaminopurine, or 6-mercaptopurine. Most toxic to the parent lines were 2-fluoroadenosine, 2-fluoroadenine, 2-fluoro-5'-deoxyadenosine, a...

7.11.5.1 Thermal and Photochemical Reactions 405 7.11.5.2 Reactions with Electrophiles 406 7.11.5.2.1 N-Alkylation 406 7.11.5.2.2 C-Allcylation and arylation 408 7.11.5.2.3 Reaction with diazonium ions 409 7.11.5.2.4 Oxidation of ring atoms 409 7.11.5.2.5 Halogenation 410 7.11.5.2.6 Metal complexes 410 7.11.5.3 Reactions with Nucleophiles 411 7.11.5.3.1 Reduction 411 7.11.5.3.2 Amination and hy...

The chemical changes occurring during embryonic development have been studied by several workers (l-3). In the hen’s egg there is very little nucleic acid present, whereas a considerable synthesis of both desoxypentose nucleic acid (DNA) and ribose nucleic acid (RNA) occurs in the embryo (4-6). Recently, methods for the determination of purines and pyrimidines in small amounts of tissue have be...