Discovery of a Novel Potent and Selective Calcium Release-Activated Calcium Channel Inhibitor: 2,6-Difluoro-N-(2'-methyl-3'-(4-methyl-5-oxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)-[1,1'-biphenyl]-4-yl)benzamide. Structure-Activity Relationship and Preclinical Characterization.

The role of calcium release-activated calcium (CRAC) channels is well characterized and is of particular importance in T-cell function. CRAC channels are involved in the pathogenesis of several autoimmune diseases, making it an attractive therapeutic target for treating inflammatory diseases, like rheumatoid arthritis (RA). A systematic structure-activity relationship study with the goal of optimizing lipophilicity successfully yielded two lead compounds, 36 and 37. Both compounds showed decent potency and selectivity and a remarkable pharmacokinetic profile. Further characterization in in vivo RA models and subsequent histopathological evaluation of tissues led to the identification of 36 as a clinical candidate. Compound 36 displayed an excellent safety profile and had a sufficient safety margin to qualify it for use in human testing. Oral administration of 36 in Phase 1 clinical study in healthy volunteers established favorable safety, tolerability, and good target engagement as measured by levels of IL-2 and TNF-α.

Impact of patient counseling on treatment adherence behavior and quality of life in maintenance hemodialysis patients.

Life in end-stage renal disease (ESRD) is miserable; food and fluid restrictions are mandatory due to impaired renal function. Patient involvement forms a key role in the management of ESRD. Hence, a direct impact of patient counseling on treatment adherence and quality of life (QOL) could be established, which forms the basis of this study. We conducted a prospective interventional study of 10 months, where the ESRD-Adherence Questionnaire and Kidney Disease QOL (KDQOL) data were used to study the effect of patient counseling. A total of 121 patients enrolled in the study with mean age of 62.14 ± 11.41 years. The adherence factors indicated that 97% were adherent to dialysis sessions, followed by 67.77% toward diet and 60.33% toward fluid. On assessing the influence of counseling on QOL and adherence to various factors affecting ESRD, a positive correlation could be observed, which indicates the impact of pharmacist intervention in improving the QOL and patient compliance, thus the need for periodic counseling was established as an effective way to improve health-related QOL and awareness in ESRD.

Inhibition of Golgi mannosidase II with mannostatin A analogues: synthesis, biological evaluation, and structure-activity relationship studies.

Mannostatin and aminocyclopentitetrol analogues with various substitutions at the amino function were synthesized. These compounds were tested as inhibitors of human Golgi and lysosomal alpha-mannosidases. Modification of the amine of mannostatin had only marginal effects, whereas similar modifications of aminocyclopentitetrol led to significantly improved inhibitors. Ab initio calculations and molecular docking studies were employed to rationalize the results. It was found that mannostatin and aminocyclopentitretrol could bind to Golgi alpha-mannosidase II in a similar mode to that of the known inhibitor swainsonine. However, due to the flexibility of the five-membered rings of these compounds, additional low-energy binding modes could be adopted. These binding modes may be relevant for the improved activities of the benzyl-substituted compounds. The thiomethyl moiety of mannostatin was predicted to make favorable hydrophobic interactions with Arg228 and Tyr727 that would possibly account for its greater inhibitory activity.

A surface exposed O-linked galactose residue destabilises the structure of a folded helix-loop-helix dimer.

A 42-residue glycopeptide Tn-15 and the corresponding reference polypeptide Thr-15 were designed and synthesized to provide a model system for the study of how glycosylation affects the stability of a molten globule-like protein. Tn-15 and Thr-15 fold into hairpin helix-loop-helix motifs that dimerise to form four-helix bundles and the only difference between the sequences is that Tn-15 carries an O-linked N-acetylgalactosamine residue at the side chain of threonine-15 whereas the sequence Thr-15 is unglycosylated. An analysis of the mean residue ellipticities at 222 nm of the two polypeptides and of the alpha-H chemical shift deviations from random coil values showed that glycosylation reduced the helical content of the polypeptides and increased the dissociation constant of the helix-loop-helix dimer to form monomers. The pH dependencies of the helical content of Tn-15 and Thr-15 differed as that of Thr-15 was largely unaffected by pH in the range from pH 4 to pH 10, whereas Tn-15 lost almost half of the helical content at pH 4 upon raising the pH to 10. No single amino acid residue was found to ionize in a way that could explain the observed pH dependence of Tn-15. The temperature dependence of the mean residue ellipticity of Tn-15 revealed a surprising decrease in helicity at 278 K in comparison with that at 293 K, reminiscent of cold denaturation, that was not observed for the reference four-helix bundle Thr-15.

Synthesis of Some Copper(II)-Chelating (Dialkylamino)pyridine Amphiphiles and Evaluation of Their Esterolytic Capacities in Cationic Micellar Media.

Three new (dialkylamino)pyridine (DAAP)-based ligand amphiphiles 3-5 have been synthesized. All of the compounds possess a metal ion binding subunit in the form of a 2,6-disubstituted DAAP moiety. In addition, at least one ortho-CH(2)OH substituent is present in all the ligands. Complex formation by these ligands with various metal ions were examined under micellar conditions, but only complexes with Cu(II) ions showed kinetically potent esterolytic capacities under micellar conditions. Complexes with Cu(II) were prepared in host comicellar cetyltrimethylammonium bromide (CTABr) media at pH 7.6. Individual complexes were characterized by UV-visible absorption spectroscopy and electron paramagnetic resonance spectroscopy. These metallomicelles speed the cleavage of the substrates p-nitrophenyl hexanoate or p-nitrophenyl diphenyl phosphate. To ascertain the nature of the active esterolytic species, the stoichiometries of the respective Cu(II) complexes were determined from the kinetic version of Job's plot. In all the instances, 2:1 complex ligand/Cu(II) ion are the most kinetically competent species. The apparent pK(a) values of the Cu(II)-coordinated hydroxyl groups of the ligands 3, 4, and 5, in the comicellar aggregate, are 7.8, 8.0, and 8.0, respectively, as estimated from the rate constant vs pH profiles of the ester cleavage reactions. The nucleophilic metallomicellar reagents and the second-order "catalytic" rate constants toward esterolysis of the substrate p-nitrophenyl hexanoate (at 25 degrees C, pH 7.6) are 37.5 for 3, 11.4 for 4, and 13.8 for 5. All catalytic systems comprising the coaggregates of 3, 4, or 5 and CTABr demonstrate turnover behavior in the presence of excess substrate.