Imidazole Ring Opening of 7-Methylguanosine at Physiological pH |
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| Authors: | G Barbarella V Tugnoli M Zambianchi |
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| Institution: | 1. Istituto dei Composti del Carbonio Contenenti Eteroatomi e loro Applicazioni, Consiglio Nazionale Ricerche , Via della Chimica 8, 40064, Ozzano E., Bologna, Italy;2. Dipartimento di Biochimica, Sezione di Chimica e Propedeutica Biochimica, Facolta′ di Medicina e Chirurgia , Universita′ di Bologna , Via Selmi 2, 40126, Bologna, Italy |
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| Abstract: | Abstract It is shown by carbon-13 NMR that the only product of the imidazole ring-opening of 7-methyl-guanosine at physiological pH is 2-amino-6-hydroxy-5-N-methylformamido-4-(N-β-ribofurano-sylamino)pyrimidine and that, contrary to previous results, the hydrolysis of the glycosylic bond at pH=7.2 is a much slower process than the ring opening. The ring opened formamidopyrimidine derivative is a very mobile molecule existing under different conformations depending on the solvent, and in water it is capable of giving different kinds of aggregates. Possible biochemical implications of these results are discussed. |
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