Anti-hepatitis B virus activity of new pyrimidine and adenine peptide nucleic acid analogues.

A number of N-substituted thymine and adenine derivatives, 2a, b and 3a, b, were synthesized by the coupling reaction of 1-bromo-2,2-diethoxyethane with the corresponding base. The corresponding peptide nucleic acid (PNA) analogues, N-substituted ethylamino-3-hydroxypropanoate derivatives 5a, b and ethylamino-3-hydroxybutanoate derivatives 6a, b, were synthesized from the corresponding 2-[3,4-dihydro-5-methyl-2,4-dioxopyrimidin-1(2H)-yl]-acetaldehyde (3a) and 2-[6-amino-4H-purin-9(5H)-yl]-acetaldehyde (3b), respectively. The synthesized compounds were tested for their antiviral activity against hepatitis B virus (HBV). The plaque reduction infectivity assay was used to determine the virus count reduction as a result of the treatment with the tested compounds.