Picomolar inhibitor of reverse transcriptase featuring significantly improved metabolic stability

Considering the undesirable metabolic stability of our recently identified NNRTI 5(t1/2=96 min)in human liver microsomes,we directed our efforts to improve its metabolic stability by introducing a new favorable hydroxymethyl side chain to the C-5 position of pyrimidine.This strategy provided a series of novel methylol-biphenyl-diarylpyrimidines with excellent anti-HIV-1 activity.The best compound 9g was endowed with remarkably improved metabolic stability in human liver microsomes(t1/2=2754 min),which was about 29-fold longer than that of 5(t1/2=96 min).This compound conferred picomolar inhibition of WT HIV-1(EC50=0.9 nmol/L)and low nanomolar activity against five clinically drug-resistant mutant strains.It maintained particularly low cytotoxicity(CC50=264μmol/L)and good selectivity(SI=256,438).Molecular docking studies revealed that compound 9g exhibited a more stable conformation than 5 due to the newly constructed hydrogen bond of the hydroxymethyl group with E138.Also,compound 9g was characterized by good safety profiles.It displayed no apparent inhibition of CYP enzymes and h ERG.The acute toxicity assay did not cause death and pathological damage in mice at a single dose of 2 g/kg.These findings paved the way for the discovery and development of new-generation anti-HIV-1 drugs.