Evaluation of In Silico and In Vitro Antidiabetic Properties of 4-(Hydroxysubstituted Arylidene)-2-Phenyloxazol-5(4 H)-one Derivatives

Abstract

Oxazolones are heterocyclic molecules characterized by a five-membered ring containing both nitrogen and oxygen atoms. It is a significant pharmacophore for therapies as well as a synthon for many physiologically active compounds. Since diabetes is a chronic disease that affects how the body metabolizes sugars, the major focus of this study was to evaluate the antidiabetic properties of synthetic 4-( Hydroxysubstituted arylidene)-2-phenyloxazol-5(4 H )-one derivatives in silico and in vitro. Derivatives were synthesized by the Erlenmeyer and Justus method with slight modifications. Structures of the derivatives were confirmed by physical, FTIR, ¹H NMR, ¹³C NMR, and HRMS data. Mainly, the antidiabetic properties were determined via α-amylase inhibitory activity, α-glucosidase inhibitory activity, glycation inhibitory activity, glucose uptake by yeast cell assay, and kinetic studies. The ability of synthesized compounds in the inhibition of α-amylase and α-glucosidase, drug-likeness model score evaluations, possible adverse effects, and ADMET profiles were also investigated by in silico studies. The results indicate that 5e exhibits the highest inhibition toward α-amylase enzyme with a mixed inhibition, while 5b showed the highest inhibition toward α-glucosidase enzyme with a mixed inhibition pattern in the presence of acarbose as the standard drug. In the protein glycation inhibitory assay, 5e demonstrated strong inhibition at higher concentrations, surpassing quercetin. Maximum potential to transport glucose across the cell membrane of Saccharomyces cerevisiae was shown by 5e. Under in silico studies, 5e showed the highest drug-likeness score and the highest affinity for the α-amylase enzyme, while 5d showed the highest affinity toward the α-glucosidase enzyme. These results show a good correlation between in vitro and in silico studies for 5e. Overall, results from both in vitro and in silico studies suggest that the increment of the number of hydroxyl groups in the structure may enhance the activity of 5e and the potential of synthesized oxazol-5(4H)-one derivatives with hydroxyl groups attached to the phenyl ring as promising candidates for the treatment of diabetic mellitus. Further, it suggests that more research is required to validate the efficacy and mechanisms of action of these compounds.

Scheme 1. Erlenmeyer Synthesis of 4-(Hydroxysubstituted Arylidene)-2-Phenyloxazol-5(4H)-One (5a–5e)

Figure 1

Lineweaver–Burk plot of 5e against α-amylase enzyme at different concentrations of substrate (starch).

Figure 2

Lineweaver–Burk plot of 5b against α-glucosidase at different concentrations of substrate (p-NPG).

Figure 3

Glucose uptake % by Saccharomyces cerevisiae in the presence of the derivatives. Metformin was used as the standard drug. Data expressed in mean SD ±, n = 3.

Figure 4

Overlaid fluorescence emission spectra of the 5c (A), 5d (B), and 5e (C). (1) BSA + Fruc, (2) BSA + Fruc + 5c/5d/5e (100 ppm), (3) BSA + Fruc + 5c/5d/5e (200 ppm), (4) BSA + Fruc + 5c/5d/5e (400 ppm), (5) BSA + Fruc + 5c/5d/5e (800 ppm), (6) BSA + Fruc + 5c/5d/5e (1600 ppm), (7) BSA only, (8) Fructose only.

Figure 5

Comparison of percentage inhibition of fluorescent AGEs by 5c (A), 5d (B), 5e (C) and Quercetin.

Figure 6

Amino acid interaction diagrams between human pancreatic α-amylase enzyme and compounds 5a (A), 5b (B), 5c (C), 5d (D), and 5e (E).

Figure 7

Amino acid interaction diagrams between human α-glucosidase enzyme and compounds 5a (A), 5b (B), 5c (C), 5d (D), and 5e (E).