New α-galactosidase-inhibiting aminohydroxycyclopentanes

A Supramolecular Gel-Based Protocol for the Detection of α-Glycosidases for Screening Potential Drugs

α-Glycosidases are carbohydrate-digesting enzymes that catalyze the hydrolysis of α-1,4-glycopyranoside bonds from oligosaccharides and disaccharides. α-Glucosidase is an important biomarker for the diagnosis of type-II diabetes, Azoospermia and Pompe diseases. Additionally, the mutations in α-galactosidase lead to Fabry disease. Inhibitors targeting these enzymes are prescribed as anti-diabetic medications and as effective chaperones for Fabry disease. Comprehending the function - regulation of α-glycosidases requires accurate quantification methods. In this work, we highlight the design of a simple luminescent 'turn-on' assay for sensing these two α-glycosidases in a supramolecular TbCh hydrogel matrix using 1-α-glycosides as pro-sensitizers. The protocol offers a cost-effective method for selectively sensing α-glycosidases in the detection limit of the subnanomolar range. Importantly, the developed enzyme sensors functioned as a platform for rapid screening of drug molecules based on their inhibition potency. Therefore, the protocol is useful for facilitating the advancement of therapeutics and diagnostics targeting this important class of enzymes.

Synthesis and glycosidase inhibition of 3,4,5-trihydroxypiperidines using a one-pot amination-cyclisation cascade reaction

Trihydroxypiperidines are a therapeutically valuable class of iminosugar. We applied a one-pot amination-cyclisation cascade reaction to synthesise 3,4,5-trihydroxypiperidine stereoisomers in three steps from commercially available pentoses and in excellent overall yields. Using our methodology, the yields of the syntheses of meso-1, meso-2 and 3L are the highest reported to date. The synthetic methodology was readily extended to the three-step synthesis of N-alkyl derivatives by replacing the ammonia nitrogen source with a primary amine. The trihydroxypiperidines and N-alkyl analogues were screened for enzyme inhibitory activity using Fabrazyme (Fabry disease), GCase (Gaucher's disease), Agrobacterium sp. β-glucosidase, and Escherichia coli β-galactosidase. N-Phenylethyl 3,4,5-trihydroxypiperidine (N-phenylethyl-1-(3R,4R,5S)-piperidine-3,4,5-triol) showed good inhibitory activity of Fabrazyme (Ki = 46 μM). This activity was abolished when the N-phenylethyl group was removed or replaced with a non-aromatic alkyl chain.