Hans Emtenäs

Design and evaluation of pilicides: potential novel antibacterial agents directed against uropathogenic Escherichia coli.

Design and evaluation of Pilicides : Potential novel antibacterial agents directed against Uropathogenic Escherichia coli

Efficient microwave assisted synthesis of optically active bicyclic 2-pyridinones via Δ2-thiazolines

A new efficient synthesis of optically active bicyclic 2-pyridiones has been developed using microwave irradiation. The synthesis is a two-step procedure via Δ2-thiazolines, which only requires a 3 + 2 min reaction time compared to 2 days when using conventional heating. The optimized conditions proved to be suitable for the synthesis of a small library in excellent yields and with limited racemizations.

Discovery of AZD6642, an Inhibitor of 5-Lipoxygenase Activating Protein (FLAP) for the Treatment of Inflammatory Diseases

A drug discovery program in search of novel 5-lipoxygenase activating protein (FLAP) inhibitors focused on driving a reduction in lipophilicity with maintained or increased ligand lipophilic efficiency (LLE) compared to previously reported compounds led to the discovery of AZD6642 (15b). Introduction of a hydrophilic tetrahydrofuran (THF) ring at the stereogenic central carbon atom led to a significant shift in physicochemical property space. The structure-activity relationship exploration and optimization of DMPK properties leading to this compound are described in addition to pharmacokinetic analysis and an investigation of the pharmacokinetic (PK)-pharmacodynamic (PD) relationship based on ex vivo leukotriene B4 (LTB4) levels in dog. AZD6642 shows high specific potency and low lipophilicity, resulting in a selective and metabolically stable profile. On the basis of initial PK/PD relation measured, a low dose to human was predicted.

Identification and design of a novel series of MGAT2 inhibitors

[Acyl CoA]monoacylglycerol acyltransferase 2 (MGAT2) is of interest as a target for therapeutic treatment of diabetes, obesity and other diseases which together constitute the metabolic syndrome. In this Letter we report our discovery and optimisation of a novel series of MGAT2 inhibitors. The development of the SAR of the series and a detailed discussion around some key parameters monitored and addressed during the lead generation phase will be given. The in vivo results from an oral lipid tolerance test (OLTT) using the MGAT2 inhibitor (S)-10, shows a significant reduction (68% inhibition relative to naїve, p<0.01) in plasma triacylglycerol (TAG) concentration.

Stereoselective synthesis of optically active bicyclic β-lactam carboxylic acids that target pilus biogenesis in pathogenic bacteria

Optically active bicyclic beta-lactams were synthesized, starting from 2-H-delta 2-thiazolines and Meldrums acid derivatives. Several methods to accomplish an ester hydrolysis without damaging the beta-lactam framework were investigated. A rapid CsOH saponification of the beta-lactam methyl esters was developed and protonation of the Cs-carboxylates by Amberlite (IR-120 H+) afforded a series of bicyclic beta-lactam carboxylic acids. Moreover, a convenient method for the synthesis of 2-H-delta 2-thiazolinecarboxylic acid methyl ester 2 was developed. Bicyclic beta-lactam carboxylic acids 7a-g and aldehydes 4a-d were screened for their affinity to the bacterial periplasmic chaperone PapD using a surface plasmon resonance technique. beta-Lactams substituted with large acyl substitutents showed better binding to the chaperone than the native C-terminal peptide PapG 8, demonstrating that bicyclic beta-lactams constitute a new class of potential bacterial chaperone inhibitors.

Lactam sulfonamides as potent inhibitors of the Kv1.5 potassium ion channel

A series of lactam sulfonamides has been discovered and optimized as inhibitors of the Kv1.5 potassium ion channel for treatment of atrial fibrillation. In vitro structure-activity relationships from lead structure C to optimized structure 3y are described. Compound 3y was evaluated in a rabbit PD-model and was found to selectively prolong the atrial effective refractory period at submicromolar concentrations.

Stereoselective synthesis of Ψ[CH2O] pseudodipeptides and conformational analysis of a PheΨ[CH2O]Ala containing analogue of the drug desmopressin

A method for synthesis of XaaΨ[CH2O]Ala/Gly pseudodipeptides in good yields and excellent diastereoselectivity from azido alcohols and (R)-2-chloropropionic acid or tert-butyl bromoacetate has been developed. Insertion of one of the pseudodipeptide building blocks in the peptide drug desmopressin revealed that methylene ether isosteres may have only a minor influence on the secondary structure of peptides.

Isoindolinone compounds active as Kv1.5 blockers identified using a multicomponent reaction approach

A series of isoindolinone compounds have been developed showing good in vitro potency on the Kv1.5 ion channel. By modification of two side chains on the isoindolinone scaffold, metabolically stable compounds with good in vivo PK profile could be obtained leaving the core structure unsubstituted. In this way, low microsomal intrinsic clearance (CLint) could be achieved despite a relatively high logD. The compounds were synthesized using the Ugi reaction, in some cases followed by Suzuki and Diels-Alder reactions, giving a diverse set of compounds in a small number of reaction steps.

Design, Synthesis and Biological Evaluation of Pilicides: Inhibitors of Pilus Assembly in Pathogenic Bacteria

Due to bacterial resistance, there is a constant struggle to get new treatments for bacterial diseases. A wide range of pathogenic gram-negative bacteria such as E. coli, K. pneumonia and Y. Pestis assembles hair-like adhesive protein filaments called pili on their surfaces. These organelles mediate attachment to the host-cell during microbial invasion. The stabilization and transportation of pilus subunits through the periplasmic compartment by a periplasmic chaperone is crucial in pilus assembly. Inhibition of the chaperone/subunit complex, thus preventing pilus assembly, appears to be a good target for development of a new antibacterial drug.