Structure–activity relationship of HIV-1 protease inhibitors containing α-hydroxy-β-amino acids. Detailed study of P1 site (original) (raw)

Discovery and optimization of nonpeptide HIV-1 protease inhibitors

Bioorganic & Medicinal Chemistry, 1996

Several small, achiral nonpeptide inhibitors of H1V-I protease with low micromolar activity were identified by mass screening of the Parke-Davis compound library. Two of the compounds, structurally similar, were both found to be competitive and reversible inhibitors [compound 1, 4-hydroxy-3-(3-phenoxypropyl)-l-benzopyran-2-one: K, = 1.0 p.M; compound 2, 4-hydroxy-6-phenyl-3-(phenylthio)-pyran-2-one: K~ = 1.1 ~tM]. These inhibitors were chosen as initial leads for optimization of in vitro inhibitory activity based on molecular modeling and X-ray crystallographic structural data. While improvements in inhibitory potency were small with analogues of compound 1, important X-ray crystallographic structural information of the enzyme-inhibitor complex was gained. When bound, 1 was found to displace H20301 in the active site while hydrogen bonding to the catalytic Asps and Ile50 and Ilel50. "[he pyranone group of compound 2 was found to bind at the active site in the same manner, with the 6-phenyl and the 3-phenylthio occupying P1 and PI', respectively. The structural information was used to develop design strategies to reach three or four of the internal pockets, P2-P2'. This work led to analogues of diverse structure with high potency (IC50 < 10 nM) that contain either one or no chiral centers and remain nonpeptidic. The highly potent compounds possess less anti-HIV activity in cellular assays than expected, and current optimization now focuses on increasing cellular activity. The value of the HIV-1 protease inhibitors described is their potential as better pharmacological agents with a different,pattern of viral resistance development, relative to the peptidic inhibitors in human clinical trials.

Aminodiol HIV Protease Inhibitors. Synthesis And Structure−Activity Relationships Of P1/P1‘ Compounds: Correlation between Lipophilicity and Cytotoxicity

Journal of Medicinal Chemistry, 1996

A series of novel aminodiol inhibitors of HIV protease based on the lead compound 1 with structural modifications at P 1 ′ were synthesized in order to reduce the cytotoxicity of 1. We have observed a high degree of correlation between the lipophilicity and the cytotoxicity of this series of inhibitors. It was found that appropriate substitution at the para position of the P 1 ′ phenyl group of 1 resulted in the identification of equipotent (both against the enzyme and in cell culture) compounds (10l, 10m, 10n, and 15c) which possess significantly decreased cytotoxicity.

Design and synthesis of inhibitors for the HIV-1 protease

1994

A variety of phosphonamidate-containing peptides were synthesised as potential inhibitors of the HIV-1 protease. These transition state analogues were designed using known sequences from HIV-1 protease substrates and incorporated a unique Phe-Pro scissile bond mimic in an attempt to achieve selectivity over the mammalian aspartic proteases. Such compounds were found to be moderate inhibitors of the HiV-1 protease possessing iCgo values in the 1-100 pM range, both in in vitro and in vivo assays. However, the phosphonamidate methyl ester analogues showed a marked ability to enter ceils and this feature was highlighted in the 1:1 ratio of in vivo/ in vitro iCso values (generally for peptidic inhibitors, this ratio is 10-10000 fold higher, indicating poor cell uptake properties). Optimisation of the methyl ester analogues was attempted by alteration of the binding residues flanking either side of the phosphonamidate moiety. However, such alterations had only a small effect on inhibitor ...

Design of HIV-1 Protease Inhibitors Active on Multidrug-Resistant Virus

Journal of Medicinal Chemistry, 2005

On the basis of structural data gathered during our ongoing HIV-1 protease inhibitors program, from which our clinical candidate TMC114 9 was selected, we have discovered new series of fused heteroaromatic sulfonamides. The further extension into the P2′ region was aimed at identifying new classes of compounds with an improved broad spectrum activity and acceptable pharmacokinetic properties. Several of these compounds display an exceptional broad spectrum activity against a panel of highly cross-resistant mutants. Certain members of these series exhibit favorable pharmacokinetic profiles in rat and dog. Crystal structures and molecular modeling were used to rationalize the broad spectrum profile resulting from the extension into the P2′ pocket of the HIV-1 protease.

INHIBITORS OF HIV-1 PROTEASE: A Major Success of Structure-Assisted Drug Design 1

Annual Review of Biophysics and Biomolecular Structure, 1998

Retroviral protease (PR) from the human immunodeficiency virus type 1 (HIV-1) was identified over a decade ago as a potential target for structure-based drug design. This effort was very successful. Four drugs are already approved, and others are undergoing clinical trials. The techniques utilized in this remarkable example of structure-assisted drug design included crystallography, NMR, computational studies, and advanced chemical synthesis. The development of these drugs is discussed in detail. Other approaches to designing HIV-1 PR inhibitors, based on the concepts of symmetry and on the replacement of a water molecule that had been found tetrahedrally coordinated between the enzyme and the inhibitors, are also discussed. The emergence of drug-induced mutations of HIV-1 PR leads to rapid loss of potency of the existing drugs and to the need to continue the development process. The structural basis of drug resistance and the ways of overcoming this phenomenon are mentioned.

Design and synthesis of HIV-1 protease inhibitors. Novel tetrahydrofuran P2/P2′-groups interacting with Asp29/30 of the HIV-1 protease. Determination of binding from X-ray crystal structure of inhibitor protease complex

Bioorganic & Medicinal Chemistry, 2003

A series of novel HIV-1 protease inhibitors based on two pseudosymmetric dipeptide isosteres have been synthesized and evaluated. The inhibitors were designed by incorporating Nphenyloxazolidinone-5-carboxamides into the hydroxyethylene and (hydroxyethyl)hydrazine dipeptide isosteres as P2 and P2′ ligands. Compounds with (S)-phenyloxazolidinones attached at a position proximal to the central hydroxyl group showed low nM inhibitory activities against wildtype HIV-1 protease. Selected compounds were further evaluated for their inhibitory activities against a panel of multidrug-resistant protease variants and for their antiviral potencies in MT-4 cells. The crystal structures of lopinavir (LPV) and two new inhibitors containing phenyloxazolidinone-based ligands in complex with wild-type HIV-1 protease have been determined. A comparison of the inhibitor-protease structures with the LPV-protease structure provides valuable insight into the binding mode of the new inhibitors to the protease enzyme. Based on the crystal structures and knowledge of structure-activity relationships, new inhibitors can be designed with enhanced enzyme inhibitory and antiviral potencies.

Structure of a non-peptide inhibitor complexed with HIV-1 protease. Developing a cycle of structure-based drug design

The Journal of biological chemistry, 1993

A stable, non-peptide inhibitor of the protease from type 1 human immunodeficiency virus has been developed, and the stereochemistry of binding defined through crystallographic three-dimensional structure determination. The initial compound, haloperidol, was discovered through computational screening of the Cambridge Structural Database using a shape complementarity algorithm. The subsequent modification is a non-peptidic lateral lead, which belongs to a family of compounds with well characterized pharmacological properties. This thioketal derivative of haloperidol and a halide counterion are bound within the enzyme active site in a mode distinct from the observed for peptide-based inhibitors. A variant of the protease cocrystallized with this inhibitor shows binding in the manner predicted during the initial computer-based search. The structures provide the context for subsequent synthetic modifications of the inhibitor.