Design, synthesis, docking studies and biological screening of 2-thiazolyl substituted -2,3-dihydro-1H-naphtho[1,2-e][1,3]oxazines as potent HIV-1 reverse transcriptase inhibitors

Abstract

1,3-oxazine nucleus and thiazolyl group features prominently in many biologically important natural products as well as bioactive molecules. A series of novel 2-thiazolyl substituted-2,3-dihydro-1H-naphtho [1,2-e][1,3]oxazine derivatives were designed and synthesized based on their structure-activity relationships (SARs) from 2-naphthol, substituted thiazolyl amines and formalin through ring closure by one-pot three component reaction. These derivatives were first evaluated for their inhibitory effect on HIV-1 Reverse Transcriptase (RT) enzyme activity. Out of 14 compounds, 4 showed potent inhibition of HIV-1 RT activity at significantly low concentration. Docking studies of these molecules revealed their high affinity binding to several amino acids of HIV-1 RT which are less sensitive to point mutations. Furthermore, anti-HIV activity of these molecules was analysed in a CD4⁺ T cell-line, which indicates that Therapeutic Index (TI) of some of these compounds is better than Zidovudine and Efavirenz, known HIV-1 RT inhibitors. Taken together, our studies report for the first time some novel naphthoxazine derivatives with significant TI, which is through inhibition of HIV-1 RT activity.

Keywords: Anti-HIV; CD4+ T cell-line; Efavirenz; Naphthoxazine derivatives.