Substituted N-{3-[(1,1-dioxido-1,2-benzothiazol-3-yl)(phenyl)amino]propyl}benzamide analogs as potent Kv1.3 ion channel blockers. Part 2

Discovery of KV 1.3 ion channel inhibitors: Medicinal chemistry approaches and challenges

The KV 1.3 voltage-gated potassium ion channel is involved in many physiological processes both at the plasma membrane and in the mitochondria, chiefly in the immune and nervous systems. Therapeutic targeting KV 1.3 with specific peptides and small molecule inhibitors shows great potential for treating cancers and autoimmune diseases, such as multiple sclerosis, type I diabetes mellitus, psoriasis, contact dermatitis, rheumatoid arthritis, and myasthenia gravis. However, no KV 1.3-targeted compounds have been approved for therapeutic use to date. This review focuses on the presentation of approaches for discovering new KV 1.3 peptide and small-molecule inhibitors, and strategies to improve the selectivity of active compounds toward KV 1.3. Selectivity of dalatazide (ShK-186), a synthetic derivate of the sea anemone toxin ShK, was achieved by chemical modification and has successfully reached clinical trials as a potential therapeutic for treating autoimmune diseases. Other peptides and small-molecule inhibitors are critically evaluated for their lead-like characteristics and potential for progression into clinical development. Some small-molecule inhibitors with well-defined structure-activity relationships have been optimized for selective delivery to mitochondria, and these offer therapeutic potential for the treatment of cancers. This overview of KV 1.3 inhibitors and methodologies is designed to provide a good starting point for drug discovery to identify novel effective KV 1.3 modulators against this target in the future.

An insight into the synthesis, crystal structure, geometrical modelling of crystal morphology, Hirshfeld surface analysis and characterization ofN-(4-methylbenzyl)benzamide single crystals

A versatile approach for the synthesis ofN-(4-methylbenzyl)benzamide, C15H15NO, using CuI as catalyst has been reported. Single crystals of the synthesized compound were grown using the slow evaporation solution technique. The crystal structure of theN-(4-methylbenzyl)benzamide crystals has been determined by single-crystal X-ray diffraction. The compound crystallizes in an orthorhombic lattice, noncentrosymmetric space groupPna21. The crystal structure is stabilized by intermolecular N—H...O hydrogen bonds and weak C—H...π interactions to form layers parallel to theaaxis. A user-friendly approach based on centre of mass propagation vector theory was used to predict the crystal morphology. The framework developed here utilizes the concept of intermolecular bond strength to discern the crystal morphology. Fourier transform IR, NMR and high-resolution mass spectrometry analytical techniques were used for the identification of functional groups and confirmation of the structure of the title compound. All of the intermolecular interactions present in the crystal structure, including the C—H...π, C—H...O and N—H...O interactions, were investigated and confirmed by molecular Hirshfeld surface analysis. From linear optical spectroscopy, the transmittance, optical band gap and UV cutoff wavelength were determined. The photoluminescence emission spectrum was recorded for a grown crystal. Dielectric measurements were performed at room temperature for various frequencies. The mechanical strength of the (001) plane of the title compound was measured using the Vickers micro-hardness technique. A piezo-coefficient of 15 pC N−1was found along the (001) plane of the title crystals. The thermal stability and melting point were also investigated. In addition, density functional theory simulations were used to calculate the optimized molecular geometry and the UV–vis spectrum, and to determine the highest occupied molecular orbital/lowest unoccupied molecular orbital energy gap. The results show thatN-(4-methylbenzyl)benzamide is a potential candidate for multifunctional optical and piezoelectric crystals.

Cu(I)-catalyzed N,N'-diarylation of natural diamines and polyamines with aryl iodides

The Cu(I)-catalyzed N,N’-diarylation of natural diamines and polyamines such as putrescine, cadaverine, spermine, spermidine and their homologues is described. Aryl iodides bearing electron-donating and electron-withdrawing groups have been employed in the study. The CuI/2-(isobutyryl)cyclohexanone/DMF catalytic system has found to be more efficient in the diarylation of diamines and spermine while the CuI/L-proline/EtCN system proved to be preferable for the diarylation of other tri- and tetraamines like spermidine, norspermidine and norspermine.

Crystal structure of 4-methyl-N-[2-(piperidin-1-yl)eth-yl]benzamide monohydrate

In the title compound, C15H22N2O·H2O, the dihedral angle between the planes of the piperidine and benzene rings is 31.63 (1)°. The piperidine ring adopts a chair conformation. The water solvent mol-ecule is involved in inter-species O-H⋯O, O-H⋯N, N-H⋯O and weak C-H⋯O hydrogen-bonding inter-actions, giving rise to chains extending along [010].

Novel Kv1.3 blockers for immunosuppression: WO2012155199

A recent patent application from Bionomics/Merck Serono describes novel compounds as blockers of the voltage-gated Kv1.3 ion channel. The blockade of this channel shows great promise as a new therapeutic target for the treatment of autoimmune disorders such as multiple sclerosis, psoriasis, diabetes and rheumatoid arthritis. The generic claim of this patent refers to a new chemotype of Kv1.3 blockers based on an amide core with potent IC50's which are potentially within the nanomolar range. This article briefly reviews the chemistry and biology found in the patent and compares it with previous discoveries in the field.

N-(2-Oxo-2-phenyl-acet-yl)benzamide

In the title compound, C(15)H(11)NO(3), the two essentially planar benzaldehyde groups [maximum deviations = 0.0487 (12) and 0.0205 (10) Å] are inclined at a dihedral angle of 72.64 (6)° with respect to each other. The bridging C-C-N-C torsion angle is 22.58 (18)°. In the crystal, inter-molecular bifurcated acceptor N-H⋯O and C-H⋯O hydrogen bonds link inversion-related mol-ecules into dimers incorporating R(1) (2)(7) and R(2) (2)(8) ring motifs. The crystal structure is further stabilized by weak inter-molecular C-H⋯π inter-actions.