Synthesis and Properties of Nucleic Acid Analogues Consisting of a Benzene−Phosphate Backbone

The synthesis and properties of a nucleic acid analogue consisting of a benzene−phosphate backbone
are described. The building blocks of the nucleic acid analogue are composed of bis(hydroxymethyl)benzene residues connected to nucleobases via the biaryl-like axis. Stabilities of the duplexes were
studied by thermal denaturation. It was found that the thermal stabilities of the duplexes composed
of the benzene−phosphate backbone are highly dependent on their sequences. The duplexes with
the benzene−phosphate backbone comprised of the mixed sequences were thermally less stable
than the natural DNA duplexes, whereas that composed of the homopyrimidine and homopurine
sequences was thermally and thermodynamically more stable than the corresponding natural DNA
duplex. It was suggested that the analogues more efficiently stabilize the duplexes in a B-form
duplex rather than in an A-form duplex. Thus, the duplexes consisting of the benzene−phosphate
backbone, especially composed of the homopyrimidine and homopurine sequences, may offer a novel
structural motif useful for developing novel materials applicable in the fields of bio- and
nanotechnologies.