Design and synthesis of a DNA-like structure composed of alkynyl C-nucleotide with 2-aminopyrimidin-4-one as a nucleobase

– A heterocyclic compound, 2-aminopyrimidin-4-one, was found to be a new candidate of a non-natural nucleobase that forms a novel base pair by self-dimerization. 2-Aminopyrimidin-4-one was connected to a deoxyribose through an acetylene linkage. The non-natural nucleoside was derivatized to its phosphoramidite that could be subjected to a conventional solid-phase DNA synthesis. The solid-phase auto-synthesis successfully afforded a non-natural DNA-like oligomer bearing 2-aminopyrimidin-4-one as a nucleobase. The synthetic oligomer exhibited reversible formation of a higher-order structure that would be a duplex like natural DNA. The present study means creation of a novel artificial DNA-like system with unordinary odd numbers of genetic alphabets.