Combining Machine Learning and Molecular Dynamics to Predict P-Glycoprotein Substrates.

The efflux transporter P-glycoprotein (P-gp) is responsible for the extrusion of a wide variety of molecules, including drug molecules, from the cell. Therefore, P-gp-mediated efflux transport limits the bioavailability of drugs. To identify potential P-gp substrates early in the drug discovery process, models have been developed based on structural and physicochemical descriptors.

Enzymatic Late-Stage Oxidation of Lead Compounds with Solubilizing Biomimetic Docking/Protecting groups.

Late-stage functionalization of lead compounds is of high interest in drug discovery since it offers an easy access to metabolites and derivatives of a lead compound without the need to redesign an often long multistep synthesis. Owing to their high degree of chemoselectivity, biocatalytic transformations, enzymatic oxidations in particular, are potentially very powerful because they could allow the synthesis of less lipophilic derivatives of a lead compound. In the majority of cases, enzymatic oxidations have been used in an empirical way as their regioselectivity is difficult to predict.

Discovery of Novel Aminotetralines and Aminochromanes as Selective and Competitive Glycine Transporter 1 (GlyT1) Inhibitors.

The glycine transporter 1 (GlyT1) has emerged as a key novel target for the treatment of schizophrenia. Herein, we report the synthesis and biological evaluation of aminotetralines and aminochromanes as novel classes of competitive GlyT1 inhibitors. Starting from a high-throughput screening hit, structure-activity relationship studies led first to the discovery of aminotetralines displaying high GlyT1 potency and selectivity, with favorable pharmacokinetic properties.

De Novo Design, Synthesis, and Biological Evaluation of 3,4-Disubstituted Pyrrolidine Sulfonamides as Potent and Selective Glycine Transporter 1 Competitive Inhibitors.

The development of glycine transporter 1 (GlyT1) inhibitors may offer putative treatments for schizophrenia and other disorders associated with hypofunction of the glutaminergic N-methyl-d-aspartate (NMDA) receptor. Herein, we describe the synthesis and biological evaluation of a series of 3,4-disubstituted pyrrolidine sulfonamides as competitive GlyT1 inhibitors that arose from de novo scaffold design. Relationship of chemical structure to drug-drug interaction (DDI) and bioactivation was mechanistically investigated.

Emerging technologies for metabolite generation and structural diversification.

Multiple technologies have emerged for structural diversification and efficient production of metabolites of drug molecules. These include expanded use of enzymatic and bioorganic transformations that mimic biological systems, biomimetic catalysis and electrochemical techniques. As this field continues to mature the breadth of transformations is growing beyond simple oxidative processes due in part to parallel development of more efficient catalytic methods for functionalization of unactivated scaffolds.

Orally active thrombin inhibitors. Part 1: optimization of the P1-moiety.

The synthesis and SAR of novel nanomolar thrombin inhibitors with the common backbone HOOC-CH(2)-d-cyclohexylalanyl-3,4-dehydroprolyl-NH-CH(2)-aryl-C(=NH)NH(2) are described together with their ecarin clotting time (ECT) prolongation as measure for thrombin inhibition ex vivo. The aryl P1-moiety mimicking the arginine part of the d-Phe-Pro-Arg derived thrombin inhibitors turned out to be a key component for in vitro potency and in vivo activity. Optimization of this part led to compounds with improved antithrombin activity in rats and dogs after oral administration compared to the recently launched anticoagulant melagatran.

Orally active thrombin inhibitors. Part 2: optimization of the P2-moiety.

Synthesis and SAR of orally active thrombin inhibitors of the d-Phe-Pro-Arg type with focus on the P2-moiety are described. The unexpected increase in in vitro potency, oral bioavailability, and in vivo activity of inhibitors with dehydroproline as P2-isostere is discussed. Over a period of 24h the antithrombin activity of the most active inhibitors with IC(50)s in the nanomolar range was determined in dogs demonstrating high thrombin inhibitory activity in plasma and an appropriate duration of action after oral administration.

Synthesis and SAR of highly potent dual 5-HT1A and 5-HT1B antagonists as potential antidepressant drugs.

Novel 5-HT(1) autoreceptor ligands based on the N-4-aryl-piperazinyl-N'-ethyl-5,6,7,8-tetrahydropyrido[4', 3':4,5]thieno[2,3-d]pyrimidin-4(3H)-one core are described. Aiming at antidepressants with a novel mode of action our objective was to identify potent antagonists showing balanced affinities and high selectivity for the 5-HT(1A) and 5-HT(1B) receptors. Strategies for the development of dual 5-HT(1A) and 5-HT(1B) antagonists based on 1 and 2 as leads and the corresponding results are discussed.

D-Phe-Pro-Arg type thrombin inhibitors: unexpected selectivity by modification of the P1 moiety.

Synthesis of thrombin inhibitors and their binding mode to thrombin is described. Modification of the P1 moiety leads to an increased selectivity versus trypsin. The observed selectivity is discussed in view of their thrombin-inhibitor complex X-ray structures.

Solid-phase synthesis of endothelin receptor antagonists.

A new solid-phase synthesis for ET receptor antagonists suitable for automation is presented. A support bound 2-hydroxybutyric acid derivative was converted to the corresponding ether derivatives using 4-halo-2-methylsulfonylpyrimidines. Subsequent Suzuki coupling with various aryl boronic acids gave the desired antagonists in good yields and purities.

Design and synthesis of 1,5- and 2,5-substituted tetrahydrobenzazepinones as novel potent and selective integrin alphaVbeta3 antagonists.

The design and synthesis of novel integrin alpha(V)beta(3) antagonists based on a 1,5- or 2,5-substituted tetrahydrobenzaezpinone core is described. In vitro activity of respective compounds was determined via alpha(V)beta(3) binding assay, and selected derivatives were submitted to further characterization in functional cellular assays. SAR was obtained by modification of the benzazepinone core, variation of the spacer linking guanidine moiety and core, and modification of the guanidine mimetic.

Solid-phase synthesis of thrombin inhibitors.

A newly developed convergent solid-phase synthesis provides efficient access to thrombin inhibitors of the D-Phe-Pro-Arg type. Members of the synthesized libraries inhibited thrombin with IC(50)s in the nanomolar range.

Synthesis of highly potent and selective hetaryl ureas as integrin alpha(V)beta3-receptor antagonists.

Solid-phase synthesis and SAR of integrin alpha(V)beta3-receptor antagonists containing a urea moiety as non-basic guanidine mimetic are described. The most potent compounds exhibited IC(50) values towards alpha(V)beta3 in the nanomolar range and high selectivity versus related integrins like alpha(IIb)beta3. For selected examples efficacy in functional cellular assays is demonstrated.

Synthesis and SAR of N-substituted dibenzazepinone derivatives as novel potent and selective alpha(V)beta(3) antagonists.

Synthesis and SARs of new integrin alpha(V)beta(3) antagonists based on an N-substituted dibenzazepinone scaffold are described. Variation of spacer and guanidine mimetic led to potent compounds exhibiting an IC(50) towards alpha(V)beta(3) in the nanomolar range, high selectivity versus integrin alpha(IIb)beta(3) and efficacy in functional cellular assays.

Amine Additives Greatly Expand the Scope of Asymmetric Hydrosilylation of Imines.

Slow addition of a primary amine to the reaction mixture greatly increases the scope of the titanium-catalyzed asymmetric reduction of imines 1. An important added feature of this method is that chiral secondary amines 2 can be obtained in much higher optical purity (up to 99 % ee) than would be predicted from the E:Z ratios of the starting imines 1.