ISSN:
1573-8388
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Summary The CD spectra of 5-bromine-substituted derivatives of nucelotides of uracil and cytosine, namely the ribo- and 2′-deoxyribonucleoside 5′-monophosphates, have been obtained in neutral, acid, alkaline, and alcoholic solutions. Three CEs have been recorded in the 220–300 nm region, corresponding to π-π* transitions in the B2u, B1u, and E1ua bands. It has been concluded that an intramolecular hydrogen bond exists between 0–2 and the 2′-hydroxyl in the 5-bromine-substituted ribonucleotides of uridine and cytidine. A transition of the conformational type localized at a pH equal to the pK value of the heterocyclic base has been detected for 5-bromo-UMP and UMP. On comparing the main characteristic of the CD spectra of the compounds investigated with the spectra of the unbrominated analogs given in the literature, it has been concluded that the halogenation of a pyrimidine base in position 5 does not fundamentally change the ratio of the most probable rotational stereomers, and the compounds investigated have the anti conformation in solution.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00570791
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