Malcolm MacCoss

Variation of 1J(C1′, H1′) with glycosidic bond conformation of pyrimidine nucleosides

1J(C1′, H1′) magnitudes of a series of pyrimidine cyclonucleosides are found to vary quantitatively with glycosidic bond conformation. Measurements of J(C1′, H1′) in pyrimidine nucleosides and nucleotides can be used to determine the range of allowed syn and anti conformations.

Nucleic acid related compounds. 20. Sugar, base doubly modified nucleosides at the 5′-terminal “cap” of mRNAs and in nuclear RNA

Abstract N 6, O 2′-Dimethyladenosine (III) has recently been reported to occur adjacent to the modified guanosine at the 5′-terminal “cap” of a number of mRNAs and in nuclear RNA. The possible presence of N 6, N 6, O 2′-trimethyladenosine (V) in adenovirus mRNA “caps” has been suggested on the basis of labeled methyl distribution between sugar and base fractions. Methylation of 2′- O -methyladenosine (I) gave N 1, O 2′-dimethyladenosine hydroiodide (II) which was rearranged to give III. Sugar methylation of 6-chloropurine riboside (IV) followed by replacement of chloro with dimethylamine gave V plus its O 3′-isomer (VI). Thin layer chromatography systems which cleanly resolve II, III, and V have been devised. Adenosine aminohydrolase (E.C. 3.5.4.4) deaminates III slowly, but has no effect on V. Identifying spectral data are tabulated.

The enzymatic synthesis of ATP analogues

Abstract The enzymatic synthesis of selected adenosine 5′-triphosphate analogues from their respective 5′-monosphosphates has been achieved using phosphoenolpyruvate synthetase. Adenosine 5′-monophosphate analogues altered at positions 1,6,7,8 or 9 of the purine ring, or at the ribose 2′- or 3′-positions are substrates with 30% conversion to the nucleoside 5′-triphosphate.