1,4-Naphthoquinone thiazole urea hybrids bearing morpholine/piperazine: synthesis, crystal structure, aldose reductase and α-glycosidase enzyme inhibition, molecular docking, and electrochemical interaction with dsDNA.

Abstract

In this study, new 1,4-naphthoquinone thiazole urea hybrids bearing morpholine (3a-d) or piperazine (3e-h) moiety were synthesized in 76-89 % yields and characterized by ¹H NMR, ¹³C NMR, FT-IR, HRMS, and elemental analysis. The stereochemistry of 3d was determined by single crystal x-ray diffraction study. We evaluated the inhibitory potential of these compounds 3a-h on aldose reductase (ALR2) and α-glycosidase enzyme (α-GLY) activity. Our results indicate that these compounds substantially inhibit ALR2 at micromolar doses, with inhibition constants (K_Is) between 0.79 and 2.20 μM and inhibit α-GLY K_I between 0.67 and 2.82 μM. Molecular docking simulations were utilized to elucidate inhibitory effects and establish structure-activity relationships for the synthesized compounds. DNA interaction studies are of great importance for the synthesis of new drugs and for studying the behavior and mechanisms of action of synthesized drug molecules. Herein, the interaction of 3d selected as a model compound with ct-dsDNA was investigated in the solution phase by the electrochemical method of differential pulse voltammetry (DPV). The decrease in the peak current value of 3d after the addition of the DNA solution confirmed the interaction. Limits of detection (LOD) and quantification (LOQ) for the interaction were found to be 0.099 ppm and 0.327 ppm in the concentration range of 0.348 ppm to 0.739 ppm, respectively. To determine the binding constant, cyclic voltammetry (CV) was utilized and found to be 8.6 × 10² M^-1. Additionally, the type of interaction between the 3D molecule and DNA was investigated and supported by molecular docking and Fourier transformed infrared spectroscopy (FTIR).