Recent results from non-basic glycosidase inhibitors: How structural diversity can inform general strategies for improving inhibition potency

Synthesis and bio-evaluation of newer dihydropyridines and tetrahydropyridines based glycomimetic azasugars

This study presents the synthesis and bio-evaluation of new triazolylated dihydropyridine and tetrahydropyridine azasugar scaffolds (F1-14). Azasugar glycomimetics are the synthetic substances that mimic the structural and functional characteristics of natural carbohydrates showcasing promising potential as therapeutic agents for diabetes. The α-glucosidase inhibitory activity of synthesized final compounds were evaluated against the commercially available α-glucosidase enzyme. Majority of the screened compounds displayed excellent inhibition with IC50 values ranging from 2.12 to 75.11 μM, when compared to the standard drug Acarbose. Particularly, compound F5 with IC50 value of 2.12 μM was found to be the most active compound among the series. Further molecular docking studies of selected ligands were performed to investigate the binding interactions with enzyme active sites. Their specific binding patterns have been analysed with the binding sites of Saccharomyces cerevisiae α-glucosidase. These findings suggest these candidates as the potential leads for the anti-diabetic activity.

Advancement in chiral heterocycles for the antidiabetic activity

For the synthesis and development of pharmaceuticals, chirality is an important structural component. Chiral heterocyclic compounds have annoyed the interest of synthetic chemists who are working to create useful and efficient techniques for these molecules. As indicated by the expanding number of chiral drugs created in the last two decades, the link between chirality and pharmacological activity has become more important in the pharmaceutical and biopharmaceutical industries. Approximately 65% of currently used drugs are chiral, and many of them are promoted as racemates in many circumstances. There are a growing number of new chiral heterocyclic compounds with important biological properties and intriguing uses in medical chemistry and drug discovery. In this study, we review current breakthroughs in chiral heterocycles and their different physiological activities that have been published in the last year (from 2010 to early 2023). This study focuses on the current trends in the use of chiral heterocycles in drug design and the creation of several powerful and competent candidates for diabetic illnesses.

The dual role of fucosidases: tool or target

Regular intake of fucosylated oligosaccharides has been associated with several benefits for human health, particularly for new-borns. Since these biologically active molecules can be found naturally in human milk, research efforts have been focused on the alternative synthetic routes leading to their production. In particular, utilization of fucosidases to perform stereoselective transglycosylation reactions has been widely investigated. Other reasons that bring these enzymes to the spotlight are their role in viral infections and cancer proliferation. Since their involvement in the pathogenesis of these diseases have been widely described, fucosidases have become a target in newly developed therapies. Finally, activity disorders of biologically important fucosidases can lead to health problems such as fucosidosis. What is common for both mechanisms is the interaction between the enzyme and substrates in and around the active site. Therefore, this review will analyse different substrate structures that have been tested in terms of their interaction with fucosidases active sites, either in synthesis or inhibition reactions. The published results will be compared from this perspective.

Multivalent Pyrrolidine Iminosugars: Synthesis and Biological Relevance

Recently, the strategy of multivalency has been widely employed to design glycosidase inhibitors, as glycomimetic clusters often induce marked enzyme inhibition relative to monovalent analogs. Polyhydroxylated pyrrolidines, one of the most studied classes of iminosugars, are an attractive moiety due to their potent and specific inhibition of glycosidases and glycosyltransferases, which are associated with many crucial biological processes. The development of multivalent pyrrolidine derivatives as glycosidase inhibitors has resulted in several promising compounds that stand out. Herein, we comprehensively summarized the different synthetic approaches to the preparation of multivalent pyrrolidine clusters, from total synthesis of divalent iminosugars to complex architectures bearing twelve pyrrolidine motifs. Enzyme inhibitory properties and multivalent effects of these synthesized iminosugars were further discussed, especially for some less studied therapeutically relevant enzymes. We envision that this comprehensive review will help extend the applications of multivalent pyrrolidine iminosugars in future studies.

Design and synthesis of novel benzimidazole-iminosugars linked a substituted phenyl group and their inhibitory activities against β-glucosidase

A series of novel benzimidazole-iminosugars linked a (substuituted) phenyl group on benzene ring of benzimidazole 5(a-p) and 6(a-p) have been rationally designed and conveniently synthesized through Suzuki coupling reaction in high yields. All compounds have been evaluated for their inhibitory activities against β-glucosidase (almond). Six compounds 5d, 6d, 6e, 6i, 6n, and 6p showed more significant inhibitory activities with IC₅₀ values in the range of 0.03-0.08 μM, almost 10-fold improved than that of the parent analogue 4, and much higher than that of the positive control castanospermine. The additional phenyl ring and the electron donating groups on it would be beneficial for the activity. Compounds 6d, 6n, and 4 had been chosen to be tested for their inhibition types against β-glucosidase. Interestingly, three compounds have different inhibition types although they had very similar structure. Their K_i values were calculated to be 0.02 ± 0.01 μM, 0.02 ± 0.01 μM, and 0.66 ± 0.14 μM, respectively. The equilibrium dissociation constant (K_D) for 6d, 6n, and 4 and β-glucosidase was 0.04 μM, 0.03 μM and 0.45 μM by the ITC-based assay, respectively. Molecular docking work suggests that such benzimidazole-iminosugars derivatives might bind to the active site of β-glucosidase mainly through hydrogen bonds, the additional phenyl ring towards the solvent-exposed region played an important effect on their inhibitory activity against β-glucosidase.