Pyrimidine metabolism in microorganisms.

Improved Techniques in Paper Chromatography of Carbohydrates

Publisher Summary This chapter discusses the three main reasons for the chemical modification of nucleic acids that are available on modifying agents. These agents are used for inactivations of various kinds, for directed functional changes of nucleic acids in vivo and for the elucidation, through resulting modification, of structural and functional characteristics peculiar to synthetic or native polynucleotides. Some of these agents are useful for one, two, or all three of these purposes. One of the few agents that serve all three of them is formaldehyde. It is widely used as an inactivator of viruses to obtain vaccines and is reported to exert a cytostatic (carcinostatic) effect. It is also one of the most promising mutagenic agents affecting multicellular organisms. Formaldehyde is used extensively in structural and functional studies of nucleic acids as an agent not so much for causing denaturation as for preventing renaturation, and as a fixator of nucleic acids and nucleoproteins in electron microscope and sedimentation investigations. Recently, some progress in the structural study of formaldehyde interaction products with nucleotides and nucleic acids has been made. The chapter emphasizes on the evidence for the formation of various structures and the molecular mechanisms of biological and other effects of formaldehyde.

Reactions of nucleic acids and nucleoproteins with formaldehyde.

An evaluation of film detection methods for weak β-emitters, particularly tritium

The proton has been the nucleus of choice for NMR studies of macromolecules because it is ubiquitous; it provides the highest sensitivity; its resonances can be identified with types of amino and nucleic acids by means of experiments utilizing proton spin-spin interaction and chemical shift; and, most important, proton NMR yields distance information via the nuclear Overhauser effect (NOE). Many of these advantages are lost for larger biopolymers (molecular weight more than 15 kDa) for which the line width is considerably greater than the proton-proton spin-spin interaction. The spin-spin interaction is then useless or difficult to use for assignment; and furthermore the proton line width and the number of proton resonances both increase in proportion to the molecular weight, thereby increasing the problem of resonance overlap to an intolerable degree.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033583500004029

Proton-detected heteronuclear edited and correlated nuclear magnetic resonance and nuclear Overhauser effect in solution

Synthesis of 5-Substituted Pyrimidines via Formaldehyde Addition1

SummaryA procedure for the application of filter paper partition chromatography to the separation of both volatile and non-volatile organic acids with chain lengths of about eight carbons or less is described. The potassium hydroxamate derivatives of the organic acids are prepared by reacting the methyl ester with about a two-fold excess of a mixture of potassium hydroxide and hydroxylamine in methyl alcohol. The hydroxamate derivatives obtained from about 10−6 mole of each of the esters are applied to the filter paper, the chromatogram developed with suitable solvents, and then sprayed with ferric chloride to make the derivatives visible as purple spots on a yellow background. Isobutyric acid and phenol gave the best results of the solvents tried for two-dimensional chromatograms of the dicarboxylic acids. RF values for a number of hydroxamate derivatives are given for several solvents.

Robert M. Fink

Papers

Synthesis of 5-Substituted Pyrimidines via Formaldehyde Addition1

Application of filter paper partition chromatography to qualitative analysis of volatile and non-volatile organic acids.

Utilization of radiocarbon from thymidine and other precursors of ribonucleic acid in Neurospora crassa.

Radiocarbon and Filter-Paper Partition Chromatography.

Transmission of .pi. interactions through .sigma. bonds in tricyclo[4.4.2.01,6]dodeca-3,8-diene-11,12-dione and its tetrahydro derivative