作者:Robert H. Hudson、Mykhaylo Goncharenko、Andrew P. Wallman、Filip Wojciechowski
DOI:10.1055/s-2005-868503
日期:——
We report the first example of alkylation of underivatized xanthine with chloroacetic acid to yield a separable mixture of N 7- and N 9-(methylenecarboxyl)xanthine and its conversion to a peptide nucleic acid monomer compatible with Fmoc-based oligomerization chemistry. Additionally, we have simultaneously prepared the N 7 - and N 9-PNA monomers of guanine by alkylation of 2-N-isobutyrylguanine which were subsequently separated. Molecular modeling of the nucleobase base triplets indicates that N 7-xanthine and N 7-guanine form isomorphous triplets with adenine and guanine, respectively. We also show that polyamides containing N 7-xanthine are compatible with triple-helix formation.