Synthesis and biological evaluation of mixed phosphonate derivatives of substituted acyclonucleoside phosphonates

In order to find structural optimization strategy for substituted mixed phosphonates of acyclonucleoside phosphonates, mono L-amino acid ester, mono NSAID carboxylic ester prodrugs of adefovir was used as lead compound. Based on the structural features of abacavir and alamifovir, sub-structure combination method was used to introduce substituted phenylthio or amino fragments at 6-position of purine ring. Therefore, purine ring substituted acyclonucleside phosphonate mixed phosphonate ester derivatives( 9a-9l )were designed and synthesized, and their structures were confirmed by ¹H NMR, ESI-MS, and ESI-HRMS. HepG2. 2. 2. 15 and HK-2 cell line were used for in vitro anti-HBV activity and renal cell toxicity evaluation models, respectively. Several compounds exhibited anti-HBV activity, of which compound 9a displayed the most potent antiviral activity with higher selectivity index(EC₅₀ 0. 48 μmol/L, SI 763. 72), lower renal cell toxicity, and higher chemical and enzymatic stability, making it a potential anti-HBV candidate for further investigation.