Inhibitors of cholesterol biosynthesis. 1. 3,5-Dihydroxy-7-(N-imidazolyl)-6-heptenoates and -heptanoates, a novel series of HMG-CoA reductase inhibitors

Direct Catalytic Asymmetric Synthesis of Oxindole-Derived δ-Hydroxy-β-ketoesters by Aldol Reactions

Direct asymmetric synthesis of δ-hydroxy-β-ketoesters was accomplished via regio- and enantioselective aldol reactions of β-ketoesters with isatins catalyzed by cinchona alkaloid thiourea derivatives. The C-C bond formation of the reactions occurred only at the γ-position of the β-ketoesters. Reaction progress monitoring and product stability analyses under the conditions that included the catalyst indicated that the γ-position reaction products were formed kinetically. Various δ-hydroxy-β-ketoesters bearing 3-alkyl-3-hydroxyoxindole cores relevant to the development of bioactive molecules were synthesized.

Synthesis, characterization and application of Ni0.5Zn0.5Fe2O4 nanoparticles for the one pot synthesis of triaryl-1H-imidazoles

Ni_0.5Zn_0.5Fe₂O₄ nanopowder, as a highly efficient and heterogeneous catalyst, was employed for the synthesis of 2,4,5-triaryl substituted imidazoles.

Structure-Based Rational Quest for Potential Novel Inhibitors of Human HMG-CoA Reductase by Combining CoMFA 3D QSAR Modeling and Virtual Screening

3-Hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR) catalyzes the formation of mevalonate. In many classes of organisms, this is the committed step leading to the synthesis of essential compounds, such as cholesterol. However, a high level of cholesterol is an important risk factor for coronary heart disease, for which an effective clinical treatment is to block HMGR using inhibitors like statins. Recently the structures of catalytic portion of human HMGR complexed with six different statins have been determined by a delicate crystallography study (Istvan and Deisenhofer Science 2001, 292, 1160-1164), which established a solid basis of structure and mechanism for the rational design, optimization, and development of even better HMGR inhibitors. In this study, three-dimensional quantitative structure-activity relationship (3D QSAR) with comparative molecular field analysis (CoMFA) was performed on a training set of up to 35 statins and statin-like compounds. Predictive models were established by using two different ways: (1) Models-fit, obtained by SYBYL conventional fit-atom molecular alignment rule, has cross-validated coefficients (q2) up to 0.652 and regression coefficients (r2) up to 0.977. (2) Models-dock, obtained by FlexE by docking compounds into the HMGR active site, has cross-validated coefficients (q2) up to 0.731 and regression coefficients (r2) up to 0.947. These models were further validated by an external testing set of 12 statins and statin-like compounds. Integrated with CoMFA 3D QSAR predictive models, molecular surface property (electrostatic and steric) mapping and structure-based (both ligand and receptor) virtual screening have been employed to explore potential novel hits for the HMGR inhibitors. A representative set of eight new compounds of non-statin-like structures but with high pIC(50) values were sorted out in the present study.

Three-dimensional quantitative structure (3-D QSAR) activity relationship studies on imidazolyl and N-pyrrolyl heptenoates as 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) inhibitors by comparative molecular similarity indices analysis (CoMSIA)

A comparative molecular similarity indices analysis (CoMSIA) of a set of 29 imidazolyl and N-pyrrolyl heptenoates have been performed to find out the structural requirements for 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) inhibitory activity. The HMG like side chain, a common moiety of statins, was used to align the molecules. The results guide to design new chemical entities with high potency.

Synthesis and biological activity of methanesulfonamide pyrimidine- and N-methanesulfonyl pyrrole-substituted 3,5-dihydroxy-6-heptenoates, a novel series of HMG-CoA reductase inhibitors

A novel series of methanesulfonamide pyrimidine- and N-methanesulfonyl pyrrole-substituted 3,5-dihydroxy-6-heptenoates were synthesized and evaluated for their ability to inhibit the enzyme HMG-CoA reductase in vitro. Monocalcium bis(+)-7-[4-(4-fluorophenyl)-6-isopropyl-2-(N-methyl-N- methanesulfonylaminopyrimidin)-5-yl]-(3R,5S)-dihydroxy-(E)-6-he ptenoate (3a, S-4522) was selected as a candidate for further evaluation. Compound 3a was approximately four times more potent than lovastatin sodium salt (in inhibiting HMG-CoA reductase in vitro (IC50 = 11 nM). Compound 3a was shown to be the most potent cholesterol biosynthesis inhibitor in this series (IC50 = 1.12 nM) in rat isolated hepatocytes; its inhibitory activity was approximately 100 times more potent than pravastatin.

7-(Disubstituted thiazolyl)-3,5-dihydroxy-6-heptenoic/heptanoic acid derivatives as HMG-CoA reductase inhibitors

A series of disubstituted thiazoles, functionalized with the essential 3,5-dihydroxy-6-heptenoic or heptanoic chain, were prepared and evaluated for their ability to inhibit the enzyme HMG-CoA reductase in vitro. All the synthesized compounds 46-61 showed a moderate inhibitory potency.