Investigation of anti-diabetic potential and molecular simulation studies of dihydropyrimidinone derivatives

In an attempt to find new targets for α-amylase and α-glucosidase for the treatment of type 2 diabetes mellitus, the present study aims in determining the anti-diabetic potential of synthesized dihydropyrimidinone derivatives. The in vitro α-glucosidase and α-amylase inhibitory activity was performed and the molecular docking analysis of the ligand in the active binding site of target protein was determined. The results revealed significant percent inhibition of α-glucosidase by the compound 6-benzyl-4-(4-hydroxyphenyl)-3,4,6,7-tetrahydro-1H-pyrrolo[3,4-d]pyrimidine-2,5-dione (compound A). The active compound showed 81.99% inhibition when compared to standard ascorbic acid having percent inhibition 81.18%. The IC₅₀ of active compound (A) showed to be 1.02 µg/ml. The molecular docking analysis revealed that the ligand bound to the active binding site of protein with the lowest binding energy of -7.9 kcal/mol that was also significantly similar to standard having -7.8 kcal/mol binding energy. The molecular dynamic simulation studies also revealed stable binding of ligand in the active binding site of protein with low RMSD of 1.7 Å similar to the protein RMSD 1.6Å In conclusion, the study revealed a potential new target against α-glucosidase to treat type 2 diabetes mellitus.

Discovery of a naturally occurring broad-spectrum inhibitor against gut bacterial β-glucuronidases from Ginkgo biloba

Gut bacterial β-glucuronidases (GUS) play an important role in deconjugation of various O-glucuronides, which are tightly linked with the drug-induced intestinal toxicity. Increasing evidence has indicated that inhibition of bacterial GUS could alleviate GUS-associated intestinal toxicity, but the potent and broad-spectrum inhibitors against multiple bacterial GUS have been rarely reported. This study aimed to find potent and broad-spectrum GUS inhibitors from Ginkgo biloba. It was found that amentoflavone displayed relatively strong inhibition on three GUS including CpGUS, SpasGUS and EcGUS. Further investigations demonstrated that amentoflavone could inhibit GUS-mediated PNPG hydrolysis in a dose-dependent manner with IC₅₀ values of 2.36 μM, 2.88 μM and 3.43 μM for CpGUS, SpasGUS and EcGUS, respectively. Inhibition kinetic studies showed that amentoflavone functioned as a non-competitive inhibitor against all tested GUS with K_i values of less than 2 μM. Docking simulations indicated that amentoflavone could tightly bind on allosteric sites of three GUS mainly via hydrogen bonding interactions, and the number of hydroxyl groups of amentoflavone played crucial roles in these interactions. Collectively, our findings suggested that amentoflavone was a potent broad-spectrum inhibitor against bacterial GUS, which can be used as a promising lead compound for developing novel agents to alleviate GUS-associated intestinal toxicity.