Hit optimization studies of 3-hydroxy-indolin-2-one analogs as potential anti-HIV-1 agents.

In the current study, twenty-two compounds based upon 3-hydroxy-3-(2-oxo-2-phenylethyl)indolin-2-one nucleus were designed, synthesized and in vitro evaluated for HIV-1 RT inhibition and anti-HIV-1 activity. Compounds 3d, 5c and 5e demonstrated encouraging potency against RT enzyme as well as HIV-1 in low micromolar to nanomolar concentration with good to excellent safety index. Structure activity relationship studies revealed that halogens such as bromo or chloro at 5th the position of oxindole ring remarkably enhanced the potency against RT. Moreover, methoxy or chloro groups at the ortho position of phenyl ring also significantly favored RT inhibition activity. Seven compounds (3b, 3c, 3d, 3e, 5b, 5c and 5e) with better anti-HIV-1 potency were tested against the mutant HIV-1K103N strain. The putative binding mode, as well as interaction patterns of the best active compound 5c with wild HIV-1 RT were studied via docking studies.

Synthesis and study of anti-HIV-1 RT activity of 5-benzoyl-4-methyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one derivatives.

In the present study, a series of fourteen 5-benzoyl-4-methyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one derivatives were designed, synthesized and characterized by appropriate spectral analysis. Further, titled compounds were in-vitro screened against wild HIV-1 RT enzyme using ELISA based colorimetric assay, in which four compounds significantly inhibited the RT activity with IC50≤25µM. Moreover, two significantly active compounds of the series, A10 and A11 exhibited IC50 values 8.62 and 6.87µM respectively, during the in-vitro assay. Structure Activity Relationship (SAR) studies were performed for the synthesized compounds in order to estimate the effect of substitution pattern on the RT inhibitory potency. The cytotoxicity of the synthesized compounds was evaluated against T lymphocytes. Further, putative binding modes of the significantly active (A11) and the least active (A4) compounds with wild HIV-1 RT were also investigated using docking studies.

Molecular Docking and Molecular Dynamics Simulation Based Approach to Explore the Dual Inhibitor Against HIV-1 Reverse Transcriptase and Integrase.

BACKGROUND: HIV integrase (IN) and reverse transcriptase (RT) are key enzymes for the replication of HIV-1. DNA polymerase and ribonuclease H (RNase H) are the two catalytic domains of HIV-1 RT which are validated as drug targets because of their essence for replication. IN and RNase H domain of RT shares striking structural similarity; it contains conserved DDE triad (two aspartates and one glutamate) and a pair of divalent Mg2+/Mn2+ ions at their catalytic core domain. OBJECTIVE: To search for novel compounds with dual inhibition of IN and RNase H for the drug development against both wild and drug-resistant strains of HIV. METHODS: In the present work, attempts have been made to search compounds against both IN and the RNase H domain of RT. Using structure-based virtual screening approach; Asinex database of small molecules was screened against the viral IN. Top thirty ranked hits obtained, were further evaluated against RNase H domain of RT using Extra Precision (XP) mode of Glide docking. Furthermore, eleven common potential hits were observed which were subjected to the in-silico prediction of drug-likeness properties. Later on, molecular dynamics simulation was performed for the best common active hit (AS6), in the complex with selected enzymes. RESULT: In silico screening of Asinex database compounds against IN and RNase H resulted in total seven compounds namely AS3, AS5, AS6, AS15, AS17, AS18, and AS20 having dual inhibition activity. CONCLUSION: This study warrants the dual inhibition activity of AS6 against IN and RNase H confirms its anti-HIV activity.

Design, synthesis and evaluation of diarylpiperazine derivatives as potent anti-tubercular agents.

Molecular hybridization is an emerging approach to design novel ligands by combination of two or more pharmacophoric subunits of known bioactive compounds. In the present study, we have designed a novel series of diarylpiperazine analogues, synthesized, characterized using FTIR, (1)H NMR, Mass, Elemental analysis and evaluated their in-vitro anti-tubercular activity. Among the reported sixteen diarylpiperazines, eleven analogues exhibited significant anti-tubercular activity against Mycobacterium tuberculosis H37Rv strain with MIC values below 6.25 µg/mL and good selectivity index. Structure activity relationship studies concluded that, ortho-para directing group (except para chloro) substitution on ortho and para position of piperazine attached phenyl ring favored anti-tubercular activity.

Design and synthesis of tetrahydrophthalimide derivatives as inhibitors of HIV-1 reverse transcriptase.

BACKGROUND: Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are one of the key components in highly active anti-retroviral therapy because of their high specificity and less toxicity. NNRTIs inhibit reverse transcriptase enzyme by binding to the allosteric site, which is 10Å away from the active site. Rapid emergence of resistance is the major problem with all anti-HIV agents. Hence, there is continuous need to develop novel anti-HIV agents active against both drug sensitive and resistance strains. RESULTS: All the 16 synthesized 2-(1,3-dioxo-3a,4-dihydro-1H-isoindol-2(3H,7H,7aH)-yl)-N-(substitutedphenyl) acetamide 4(a-p) analogs were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, mass spectroscopy, and elemental analysis. Lipinski rule of five parameters and molecular parameters like solubility, drug likeness, and drug score were derived for designed analogs using online servers like Molinspiration and Osiris property explorer. Synthesized compounds were evaluated for their HIV-1 reverse transcriptase inhibitor activity by HIV-1 RNA-dependent DNA polymerase activity assay at 2 and 20 µM concentrations. CONCLUSIONS: Among the 16 synthesized compounds, 4a, 4b, 4f, 4g, 4k, and 4l showed weak reverse transcriptase inhibitor activity at 20 µM concentration. For the designed compounds, there was no correlation observed between molecular modeling and in vitro studies.