Design, Synthesis, and Biological Evaluation of Novel Hybrid Dicaffeoyltartaric/Diketo Acid and Tetrazole-Substituted L-Chicoric Acid Analogue Inhibitors of Human Immunodeficiency Virus Type 1 Integrase

Fourteen analogues of the anti-HIV-1 integrase (IN) inhibitor L-chicoric acid (L-CA) were prepared. Their IC50 values for 3'-end processing and strand transfer against recombinant HIV-1 IN were determined in vitro, and their cell toxicities and EC50 against HIV-1 were measured in cells (ex vivo). Compounds 1-6 are catechol/beta-diketoacid hybrids, the majority of which exhibit submicromolar potency against 3'-end processing and strand transfer, though only with modest antiviral activities. Compounds 7-10 are L-CA/p-fluorobenzylpyrroloyl hybrids, several of which were more potent against strand transfer than 3'-end processing, a phenomenon previously attributed to the beta-diketo acid pharmacophore. Compounds 11-14 are tetrazole bioisosteres of L-CA and its analogues, whose in vitro potencies were comparable to L-CA but with enhanced antiviral potency. The trihydroxyphenyl analogue 14 was 30-fold more potent than L-CA at relatively nontoxic concentrations. These data indicate that L-CA analogues are attractive candidates for development into clinically relevant inhibitors of HIV-1 IN.