Design and Synthesis of Highly Potent HIV-1 Protease Inhibitors Containing Tricyclic Fused Ring Systems as Novel P2 Ligands: Structure-Activity Studies, Biological and X-ray Structural Analysis.
Ghosh, A.K., R Nyalapatla, P., Kovela, S., Rao, K.V., Brindisi, M., Osswald, H.L., Amano, M., Aoki, M., Agniswamy, J., Wang, Y.F., Weber, I.T., Mitsuya, H.(2018) J Med Chem 61: 4561-4577
- PubMed: 29763303 
- DOI: https://doi.org/10.1021/acs.jmedchem.8b00298
- Primary Citation of Related Structures:  
6CDJ, 6CDL - PubMed Abstract: 
The design, synthesis, and biological evaluation of a new class of HIV-1 protease inhibitors containing stereochemically defined fused tricyclic polyethers as the P2 ligands and a variety of sulfonamide derivatives as the P2' ligands are described. A number of ring sizes and various substituent effects were investigated to enhance the ligand-backbone interactions in the protease active site. Inhibitors 5c and 5d containing this unprecedented fused 6-5-5 ring system as the P2 ligand, an aminobenzothiazole as the P2' ligand, and a difluorophenylmethyl as the P1 ligand exhibited exceptional enzyme inhibitory potency and maintained excellent antiviral activity against a panel of highly multidrug-resistant HIV-1 variants. The umbrella-like P2 ligand for these inhibitors has been synthesized efficiently in an optically active form using a Pauson-Khand cyclization reaction as the key step. The racemic alcohols were resolved efficiently using a lipase catalyzed enzymatic resolution. Two high resolution X-ray structures of inhibitor-bound HIV-1 protease revealed extensive interactions with the backbone atoms of HIV-1 protease and provided molecular insight into the binding properties of these new inhibitors.
Organizational Affiliation: 
Department of Chemistry and Department of Medicinal Chemistry , Purdue University , 560 Oval Drive , West Lafayette , Indiana 47907 , United States.