Diaryl hydrazones as multifunctional inhibitors of amyloid self-assembly.

The design and application of an effective, new class of multifunctional small molecule inhibitors of amyloid self-assembly are described. Several compounds based on the diaryl hydrazone scaffold were designed. Forty-four substituted derivatives of this core structure were synthesized using a variety of benzaldehydes and phenylhydrazines and characterized. The inhibitor candidates were evaluated in multiple assays, including the inhibition of amyloid ß (Aß) fibrillogenesis and oligomer formation and the reverse processes, the disassembly of preformed fibrils and oligomers. Because the structure of the hydrazone-based inhibitors mimics the redox features of the antioxidant resveratrol, the radical scavenging effect of the compounds was evaluated by colorimetric assays against 2,2-diphenyl-1-picrylhydrazyl and superoxide radicals. The hydrazone scaffold was active in all of the different assays. The structure-activity relationship revealed that the substituents on the aromatic rings had a considerable effect on the overall activity of the compounds. The inhibitors showed strong activity in fibrillogenesis inhibition and disassembly, and even greater potency in the inhibition of oligomer formation and oligomer disassembly. Supporting the quantitative fluorometric and colorimetric assays, size exclusion chromatographic studies indicated that the best compounds practically eliminated or substantially inhibited the formation of soluble, aggregated Aß species, as well. Atomic force microscopy was also applied to monitor the morphology of Aß deposits. The compounds also possessed the predicted antioxidant properties; approximately 30% of the synthesized compounds showed a radical scavenging effect equal to or better than that of resveratrol or ascorbic acid.

Novel heteroaromatic organofluorine inhibitors of fructose-1,6-bisphosphatase.

A broad group of compounds including substituted pyrazoles, pyrroles, indoles, and carbazoles were screened to identify potential inhibitor lead compounds of fructose-1,6-bisphosphatase (FBPase). Best inhibitors are (1H-indol-1-yl)(4-(trifluoromethyl)phenyl)methanone, ethyl 3-(3,5-dimethyl-1H-pyrrol-2-yl)-4,4,4-trifluoro-3-hydroxybutanoate, 3,5-diphenyl-1-(3-(trifluoromethyl) phenyl)-1H-pyrazole, and ethyl 3,3,3-trifluoro-2-hydroxy-2-(1-methyl-1H-indol-3-yl)propanoate. The IC50 values (3.1, 4.8, 6.1, and 11.9 microM) were comparable to that of AMP, the natural inhibitor of murine FBPase (IC50 of 4.0 microM). Docking programs were utilized to interpret the experiments.

Sonochemical asymmetric hydrogenation of isophorone on proline modified Pd/Al2O3 catalysts.

The sonochemical asymmetric hydrogenation of isophorone (3,3,5-trimethyl-2-cyclohexenone) by proline-modified Pd/Al2O3 catalysts is described; presonication of a commercial Pd/Al2O3-proline catalytic system resulted in highly enhanced enantioselectivities (up to 85% ee).