Design, synthesis, and anti-TMV bioactivities of nucleobase phosphonate analogs

GRAPHICAL ABSTRACT ABSTRACT A series of novel nucleobase derivatives and their analogues possessing diethoxyphosphoryl scaffolds were synthesized through four-step reactions and screened for their antiviral activity toward tobacco mosaic virus (TMV). Preliminary bioassays suggested that some of these simple structures displayed appreciable anti-TMV activity in vivo. Among them, compound (diethoxyphosphoryl)methyl 4-[2-(1H-benzo[d][1,2,3]triazol-1-yl)acetamido]-benzoate (a-3) exerted the strongest chemotherapeutic and protective effects against TMV with the rates of 52.8 and 72.2% at the dosage of 500 µg/mL, respectively, which were comparable with those of the commercial agricultural antiviral agent ningnanmycin (54.2 and 70.2%). Molecular docking with TMV helicases revealed that compound a-3 had strong interactions with receptor amino acid residues. Given the facile synthetic route and significant chemotherapeutic and protective potentials, compound a-3 could be further studied and exploited as a promising antiviral candidate.