No abstract

Nucleosides and their analogues are an important, well-established class of clinically useful medicinal agents that exhibit antiviral and anticancer activity. Thus, our research group has focused on the synthesis of new nucleoside derivatives that could be tested for their broad-spectrum biological activity. In this study, two new series of nucleoside derivatives were synthesized from uridine (1) through facile two-step reactions using the direct acylation method, affording 5’-O-acyl uridine derivatives in good yields. The isolated uridine analogs were further transformed into two series of 2’,3’-di-O-acyl derivatives bearing a wide variety of functionalities in a single molecular framework to evaluate their antimicrobial activity. The new synthesized compounds were characterized through physicochemical, elemental and spectroscopic analysis, and all were screened for their in vitro antimicrobial activity against selected human and plant pathogenic strains. The test compounds revealed moderate to good antibacterial and antifungal activities and were more effective against fungal phytopathogens than against bacterial strains, while many of them exhibited better antimicrobial activity than standard antibiotics. Minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) tests against all microorganisms were also conducted for five compounds based on their activity (6, 11, 13, 16, and 17). In addition, all the derivatives were optimized using density functional theory (DFT) B3LYP/6-31g+(d,p) calculations to elucidate their thermal and molecular orbital properties. A molecular docking study was performed using the human protein 5WS1 to predict their binding affinity and modes, and ADMET and SwissADME calculations confirmed the improved pharmacokinetic properties of the compounds. Besides, structure–activity relationship (SAR), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) studies were also performed. Thus, the improvement of the bioactivity of these compounds is expected to significantly contribute to the design of more antimicrobial agents for therapeutic use in the future.

In recent, millions of people are living with the human immunodeficiency virus type 1 (HIV-1), which causes acquired immunodeficiency syndrome. HIV-1 reverse transcriptase (RT) is one of the main viral targets for HIV-1 inhibition. Pyrimidine nucleoside derivative, 3′-azido-3′-deoxythymidine (AZT) is a highly active nucleoside inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT). In this work, hydroxyl (-OH) groups of cytidine structure were modified with different aliphatic and aromatic groups to get 5´-O-acyl- and 2´,3´-di-O-acyl derivatives and then employed for molecular modeling, molecular docking, biological prediction, and pharmacological studies. Herein, we relate the optimization of cytidine and its acylated analogues applying density functional theory (DFT) with B3LYP/3-21G level theory to explore their thermochemical and molecular electrostatic potential (MEP) properties. Prediction of activity spectra for substances (PASS) indicated promising antiviral, anti-carcinogenic, and antifungal functionality of these cytidine esters compared to the antibacterial activities. To support this observation, their cytotoxic prediction and molecular docking studies have been performed against HIV-1 reverse transcriptase (RT) (PDB: 3V4I). Most of the molecules studied out here could bind near the crucial catalytic binding site, Tyr181, Ile94, Ile382, Lys374, Val381, Val90, and Tyr34 of the HIV-1 reverse transcriptase (RT), and the molecules were surrounded by other active site residues like Gln332, Trp406, Asn265, Gly93, His96, Pro95, and Thr165. Finally, these novel molecules were analyzed for their pharmacokinetic properties which expressed that the combination of in silico ADMET prediction, toxicity prediction, and drug-likeness had shown a promising result. The study discusses the performance of molecular docking to suggest the novel molecules active against resistance mutants of RT and/or recombinant strains of HIV-1.