Pietro Monforte

Discovery of 2,3-diaryl-1,3-thiazolidin-4-ones as potent anti-HIV-1 agents

Design, synthesis and anti-HIV activity of a series of 2,3-diaryl-1,3-thiazolidin-4-ones are reported. Some derivatives proved to be highly effective in inhibiting HIV-1 replication at nanomolar concentrations thereby acting as non-nucleoside HIV-1 RT inhibitors (NNRTIs). SAR studies evidenced that the nature of the substituents at the 2 and 3 positions of the thiazolidinone nucleus largely influenced the in vitro anti-HIV activity of this new class of potent antiviral agents.

Design, Synthesis, Structure-Activity Relationships, and Molecular Modeling Studies of 2,3-Diaryl-1,3-thiazolidin-4-ones as Potent Anti-HIV Agents

Starting from 1H,3H-thiazolo[3,4-a]benzimidazoles (TBZs), we performed the design, synthesis, and the structure-activity relationship studies of a series of 2,3-diaryl-1,3-thiazolidin-4-ones. Some derivatives proved to be highly effective in inhibiting HIV-1 replication at nanomolar concentrations with minimal cytotoxicity, thereby acting as nonnucleoside HIV-1 RT inhibitors (NNRTIs). Computational studies were used to delineate the ligand-RT interactions and to probe the binding of the ligands to HIV-1 RT.

Synthesis and anti-hIV activity of 1-(2,6-difluorophenyl)-1H,3H-thiazolo[3,4-a]benzimidazole structurally-related 1,2-substituted benzimidazoles.

The synthesis of 1,2-substituted benzimidazoles is reported. These novel derivatives share chemical similarities with 1-aryl-1H,3H-thiazolo[3,4-a]benzimidazoles, a class of HIV-1 NNRTIs studied widely. All compounds prepared were tested in MT-4 cells to explore their potential anti-HIV activity and were found to be less potent than 1-(2,6-difluorophenyl)-1H,3H-thiazolo[3,4-a]benzimidazole (TBZ).

Synthesis and anti-HIV activity of 2,3-diaryl-1,3-thiazolidin-4-(thi)one derivatives

Several 2,3-diaryl-1,3-thiazolidine-4-thione derivatives and 2,3-diaryl-1,3-thiazolidin-4-ones bearing a methyl group at C-5 position have been synthesized and tested as anti-HIV agents. The results of the in vitro tests showed that some of them proved to be effective inhibitors of HIV-1 replication.

Synthesis and anti-HIV activity of 2,3-diaryl-1,3-thiazolidin-4-ones

Several 1,3-thiazolidin-4-ones bearing a 2,6-dihalophenyl group at C-2 and a variously substituted phenyl ring at N-3 have been synthesized and tested as anti-HIV agents. The results of the in vitro tests showed that some of them proved to be effective inhibitors of HIV-1 replication.

Anti-HIV agents: design and discovery of new potent RT inhibitors

This paper reports our work in the field of nonnucleoside RT inhibitors (NNRTIs). On the basis of extensive studies on 1H,3H-thiazolo[3,4-a]benzimidazole derivatives (TBZs) followed by structure-activity relationship (SAR) considerations and molecular modeling, the design and synthesis of a series of 2,3-diaryl-1,3-thiazolidin-4-ones have been performed. Some derivatives proved to be highly effective in inhibiting human immunodeficiency virus type-1 (HIV-1) replication at nanomolar concentrations with minimal toxicity, acting as reverse transcriptase (RT) inhibitors. Computational studies were used in order to probe the binding of our ligands to HIV-1-RT.

Efficient 3D database screening for novel HIV-1 IN inhibitors.

We describe the use of pharmacophore modeling as an efficient tool in the discovery of novel HIV-1 integrase (IN) inhibitors. A three-dimensional hypothetical model for the binding of diketo acid analogues to the enzyme was built by means of the Catalyst program. Using these models as a query for virtual screening, we found several compounds that contain the specified 3D patterns of chemical functions. Biological testing shows that our strategy was successful in searching for new structural leads as HIV-1 IN inhibitors.

Synthesis and biological activity of novel 1H,3H-thiazolo[3,4-a]benzimidazoles: non-nucleoside human immunodeficiency virus type 1 reverse transcriptase inhibitors.

Using a known human immunodeficiency virus type 1 (HIV-1) nonnucleoside reverse transcriptase inhibitor (NNRTI), 1-(2,6-difluorophenyl)-1H,3H-thiazolo[3,4-a]benzimidazole (TBZ NSC 625487) as the lead structure for drug design, a series of novel 1H,3H-thiazolo[3,4-a]benzimidazole derivatives substituted on the benzene-fused ring was prepared. Their in vitro anti-HIV-1 activity, as well as their inhibitory effects on the viral reverse transcriptase, were evaluated. The structure-activity relationships for these compounds are described and the results suggest that the apolar binding pocket of RT, into which the NNRTIs must fit, can accommodate only groups with a limited size and shape.

Structural Features and Anti-Human Immunodeficiency Virus (HIV) Activity of the Isomers of 1-(2′,6′-Difluorophenyl)-1H,3H-Thiazolo[3,4-a]Benzimidazole, a Potent Non-Nucleoside HIV-1 Reverse Transcriptase Inhibitor

The structural features, including the absolute configuration, of the enantiomers of 1-(2′,6′-difluorophenyl)-1H,3H-thiazolo[3,4-a]benzimidazole (TBZ; NSC 625487), the lead compound of a new class of human immunodeficiency virus type 1 (HIV-1) non-nucleoside reverse transcriptase inhibitors (NNRTIs), are described. Diffractometric analysis revealed that TBZ, like other NNRTIs, assumes a butterfly-like conformation in which the phenyl ring at C1 is in an orthogonal orientation relative to the thiazolobenzimidazole system, and the 2′,6′-fluorine atoms form two intramolecular hydrogen bonds with H1 and one of the methylene protons at C3, respectively. The stereochemistry in solution, as confirmed by lanthanide shift reagent-assisted ‘H NMR, paralleled the situation present in the solid state. The in vitro anti-HIV activity of the two enantiomers was also evaluated and the results obtained showed that the R-(+) is more active than the S-(−) isomer in inhibiting HIV-1 replication. Resistance and cross-resistance to other NNRTIs as well as inhibitory effects on HIV-1 reverse transcriptase activity are also reported.

Synthesis and in vitro antitumour activity evaluation of 1-aryl-1H,3H-thiazolo[4,3-b]quinazolines.

A series of 1H,3H-thiazolo[4,3-b]quinazolines (2a-i) were synthesized and evaluated for their in vitro antitumour activity against ca. 60 human tumour cell lines. They exhibited moderate (2c, 2d, 2f and 2g) to strong (2a, 2b, 2e, 2h and 2i) cell-growth inhibition at a concentration of 10(-4) M, but weak activity at lower concentrations. Only 1-(2,6-dichlorophenyl)-1H,3H-thiazolo[4,3-b]quinazoline (2h) possesses a significant growth inhibitory activity on 22 cell lines at a concentration of 10(-5) M.