Abstract
Hexa- and dodecanucleotides containing 7-deaza-2''-deoxy-O6-methylguanosine (m6c7Gd, 2) have been prepared by solid-phase synthesis employing methyl- as well as cyanoethyl phosphoramidites of 2.As the N2-isobuturyl group of protected 2 was difficult to remove after oligonucleotide synthesis the more labile formyl group was introduced. Regioselective N2-formylation was carried out without sugar protection by in-situ hydrolysis of a formamidine intermediate. replacement of dG within the oligomer d(CGCGAATTCGCG) next to dA increased hairpin formation, whereas duplexes were formed if one of the outer dG residues was replaced by m6c7Gd. Tertiary structure changes of the oligomers were detected by comparing the melting curves at 260 and 280 nm or duplex specific cleavage by the endodeoxyribonuclease Eco RI.

This publication has 20 references indexed in Scilit: