Synthesis and anti-HIV activity of alkylated quinoline 2,4-diols

Naturally occurring quinolone alkaloids, buchapine (1) and compound 2 were synthesized as reported in literature and evaluated for anti-HIV potential in human CD4+ T cell line CEM-GFP, infected with HIV-1_NL4.3 virus by p24 antigen capture ELISA assay. The compounds 1 and 2 showed potent inhibitory activity with IC₅₀ value of 2.99 and 3.80 μM, respectively. Further, 45 alkylated derivatives of quinoline 2,4-diol were synthesized and tested for anti-HIV potential in human CD4+ T cell line CEM-GFP. Among these, 13 derivatives have shown more than 60% inhibition. We have identified three most potent inhibitors 6, 9 and 23; compound 6 was found to be more potent than lead molecule 1 with IC₅₀ value of 2.35 μM and had better therapeutic index (26.64) as compared to AZT (23.07). Five derivatives 7, 19a, 19d, 21 and 24 have displayed good noticeable anti-HIV activity. All active compounds showed higher CC₅₀ values which indicate that they have better therapeutic indices.