ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The syntheses of 7-deaza-N6-methyladenine N9-(2′-deoxy-β-D-ribofuranoside) (2) as well as of 8-aza-7-deaza-N6-methyladenine N8- and N9-(2′-deoxyribofuranosides) (3 and 4, resp.) are described. A 4,4′-dimeth-oxylritylation followed by phosphitylation yielded the methyl phosphoramidites 12-14. They were employed together with the phosphoramidite of 2′-deoxy-N6v-methyladenosine (15) in automated solid-phase oligonucleotide synthesis. Alternating or palindromic oligonucleotides derived from d(A-T)6 or d(A-T-G-C-A-G-A*-T-C-T-G-C-A) but containing one methylated pyrrolo[2,3-d]pyrimidine or pyrazolo[3,4-d]pyrimidine moiety in place of a N6-methylaminopurine (A*) were synthesized. Melting experiments showed that duplex destabilization induced by a N6-Me group of 2′-deoxy-N6-methyladenosine is reversed by incorporation of 8-aza-7-deaza-2′-deoxy-N6-meihyladenosine, whereas 7-deaza-2′-deoxy-N6-methyladenostne decreased the Tm value further. Regiospecific phosphodiester hydrolysis of d(A-T-G-C-A-G-m6A-T-C-T-G1-C-A) by the endodeoxyribonuclease Dpn I, yielding d(A-T-G-C-A-G-m6A) and d(pT-C-T-G-C-A), was prevented when the residue c7m6Ad (2), c7m6z8Ad (3), or c7m6z8Ad′ (4) replaced m6Ad (1) indicating that N(7) of N6-methyladenine is a proton-acceptor site for the endodeoxyribonuclease.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19890720503
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