Abstract
Treatment of guanosine with n-propylnitrosourea yields 7-n-propylguanine (after acid hydrolysis) but O6-isopropylguanosine. Similarly, injection of [3H]di-n-propylnitrosamine into Sprague--Dawley rats resulted in isolation of 7-n-propylguanine from RNA, but O6-isopropylguanosine. The amounts of the different adducts indicate that attack at both N-7 and O6 of guanine proceed by bimolecular substitution (otherwise significant levels of 7-isopropylguanine should have been seen), but the observed rearrangement indicates that the transition state for reaction at O6 may be much looser than that for reaction at N-7.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Alkylation
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Animals
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Chemical Phenomena
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Chemistry
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Chromatography, Thin Layer
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Guanine / analogs & derivatives*
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Guanine / isolation & purification
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Guanine / metabolism
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Guanosine / analogs & derivatives*
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Guanosine / isolation & purification
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Guanosine / metabolism*
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Liver / metabolism
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Male
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Nitrosamines / pharmacology*
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Nitrosourea Compounds / metabolism
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RNA / analysis
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Rats
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Rats, Inbred Strains
Substances
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Nitrosamines
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Nitrosourea Compounds
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Guanosine
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N-nitroso(di-n-propyl)amine
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7-n-propylguanine
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Guanine
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RNA
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propylnitrosourea
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O-isopropylguanosine