The second series of flexible shape-modified nucleosides is introduced. The "fleximers" feature the purine ring systems split into their individual imidazole and pyrimidine components. This structural modification serves to introduce flexibility to the nucleoside while still retaining the elements essential for recognition. As a consequence, these structurally innovative nucleosides can more re...

AN ECOLOGICALLY RELEVANT SOIL EXTRACTION PROCEDURE SEPARATED TWO TYPES OF MOLECULES IMPORTANT FOR BACTERIA: flavonoids and small hydrophilic organic compounds. Two flavonoids, identified previously as inducers of nodulation genes in Rhizobium meliloti, were detected in rhizosphere soil from alfalfa (Medicago sativa L.). In addition, biologically significant quantities (micromoles per kilogram) ...

Unnatural nucleosides have been explored to expand the properties and the applications of oligonucleotides. This paper briefly summarizes nucleic acid analogs in which the base is modified or replaced by an unnatural stacking group for the study of nucleic acid interactions. We also describe the nucleoside analogs of a base pair-mimic structure that we have examined. Although the base pair-mimi...

A rigid molecular clip comprising bisphosphonate binding sites and aromatic sidewalls forming an electron-rich cavity is able to distinguish between nucleosides and nucleotides in aqueous solution. Neutral nucleosides as well as antibiotics derived thereof are drawn into the unpolar interior of the cleft and lead to substantial upfield-shifts in the H NMR spectrum. Nucleoside drugs can therefor...

We report computed cross sections for the elastic scattering of slow electrons by the pyrimidine bases of DNA, thymine and cytosine, and by the associated nucleosides, deoxythymidine and deoxycytidine. For the isolated bases, we carried out calculations both with and without the inclusion of polarization effects. For the nucleosides, we neglect polarization effects but estimate their influence ...

Using Vorbrüggen's protocol, reaction of persilylated uracil with xylofuranose derivatives having 3beta-oxy-3alpha-alkyl substitution produced both alpha- and beta-nucleosides. Only the beta-nucleosides were formed from substrates having the reverse stereochemistry at C-3 or lacking the 3-alkyl substituent. Participation of the 3beta-oxy substituent in stabilizing the incipient C-1 carbonium io...

Studies on the cellular metabolism of endogenous nucleosides and structurally related analogs are facilitated by the thin-layer chromatographic (TLC) separation of nucleotides, Complex mixtures of ribosyl and deoxyribosyl nucleotides can be separated by ascending two-dimensional TLC on PEI-cellulose anion-exchange layers”“. Nucleoside mono-, diand triphosphates are first separated in one dimens...

The synthesis of the title 2'-deoxyadenosine derivatives bearing bipyridine, phenanthroline or terpyridine ligands and their corresponding RuII-complexes in position 8 linked via acetylene or phenylene tethers was accomplished through cross-coupling reactions. The Suzuki-Miyaura reactions of boronic acids or the Sonogashira reactions of terminal acetylene derivatives of oligopyridine ligands we...