Synthesis and different biological activities of novel benzoxazoles

Design, Synthesis, and Anti-Fungal Evaluation of Heterocyclic Benzoxazole Derivatives

In order to discover more promising anti-fungal agents, a series of benzoxazole family was synthesized by PPA-catalyzed condensation and a Raney nickel/hydrazine reduction. Altogether 45 compounds were obtained in good to excellent yields and characterized by FT-IR, NMR, MS, and X-ray crystal diffraction. Moreover, the biological activity against eight phytopathogenic fungi was investigated. All in all, most of these compounds bear moderate antifungal activities. Among them, three candidates show the strongest activities, compound 4ac, 4bc provided over 50% inhibition rate against five fungi. Especially, the inhibitory rate of compound 4ah on Mycosphaerella melonis reached 76.4%.

Synthesis, antimicrobial activity, density functional modelling and molecular docking with COVID-19 main protease studies of benzoxazole derivative: 2-(p-chloro-benzyl)-5-[3-(4-ethly-1-piperazynl) propionamido]-benzoxazole

This study contains synthesis, antimicrobial activity, density functional modelling and molecular docking studies of benzoxazole derivative: 2-(p-chloro-benzyl)-5-[3-(4-ethly-1-piperazynl) propionamido]-benzoxazole. The synthetic procedure of investigated compound is given in detail. The newly synthesized benzoxazole compound and standard drugs were evaluated for their antimicrobial activity against some Gram-positive, Gram-negative bacteria and fungus C. albicans and their drug-resistant isolates. The benzoxazole compound has been characterized by using ¹H-NMR, IR and MASS spectrometry and elemental analysis techniques. The molecular structure of the compound in the ground state has been modelling using density functional theory (DFT) with B3LYP/6-311++g(d,p) level. The molecular docking of 2-(p-chloro-benzyl)-5-[3-(4-ethly-1-piperazynl) propionamido]-benzoxazole with COVID-19 main protease has been also performed by using optimized geometry and the experimentally determined dimensional structure of the main protease (M-pro) of COVID-19.

Transition Metal Exchanged Hydroxyapatite/Fluorapatite Catalysts for C-C and C-N Bond Forming Reactions

Transition metal (Cu, Zn, Rh, Pd) exchanged hydroxyapatite (HAP)/fluorapatite (FAP) materials have been synthesized by ion-exchange method resulting in incorporation of the metal ions in the HAP/FAP structure. C-C and C-N bond forming reactions are important in synthetic organic chemistry as these organic transformations are very critical. Transition metal exchanged FAP provides an efficient catalytic system for N-arylation of haloarenes and Suzuki and Heck coupling of haloarenes. By designing such catalytic materials, our group has developed synthetic methods which allow higher product yields and easy separation with the use of a small amount of catalyst in a shorter reaction time. This account addresses the work carried out in last two decades in the area of C-C and C-N bond forming reactions using transition metal exchanged fluorapatite.

Novel pyranopyrazole derivatives comprising a benzoxazole core as antimicrobial inhibitors: Design, synthesis, microbial resistance and machine aided results

From a medical point of view lot of existing antibiotics became unusable because microbial gained strong antibiotic resistance. The combination of two compounds in one core may lead to kill such type of pathogens. Herein, we developed pyranopyrazole derivatives comprising benzoxazole moiety by green approach strategy and studied their antimicrobial performance on four bacteria and two fungi. As a result, most of the compounds delivered reliable toxicity to kill the pathogens. In those,6aexhibited considerable activity against the microbial pathogens. Moreover,compounds 6d, 6l,and6nshowed prominent antibacterial activity. In addition, molecular docking studies of docked compounds revealed the strong bonding interaction with DNA-Gyrase and were docked into the intercalation location of DNA of the DNA-gyrase complex. The molecule bounded to the DNA stabilized by the H bonds, hydrophobic interactions, and π-π interaction. In addition, the linked 5-chlorobenazoxazole structure stabilized by the DT-8 and DG2009 of the F chain with pi-pi interactions. From the computer-aided results, it was observed that compound6a demonstrated maximum docking score -10.0 kcal/mole towards DNA-gyrase. Overall, this investigation suggested that these biologically active compounds can be utilized as leads for preclinical studies with the goal of developing newer antimicrobial drugs.

Biological evaluation and docking studies of some benzoxazole derivatives as inhibitors of acetylcholinesterase and butyrylcholinesterase

A series of 2,5-disubstituted-benzoxazole derivatives (1–13) were evaluated as possible inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The results demonstrated that the compounds exhibited a broad spectrum of AChE and BChE inhibitory activity ranging between 6.80% and 90.21% except one compound which showed no activity against AChE at the specified molar concentration. Another derivative displayed a similar activity to that of reference drug (galanthamine) for inhibition of AChE and BChE. In addition, molecular docking of the compounds into active site of AChE was performed using recombinant human AChE (PDB ID: 4ey6) in order to understand ligand–protein interactions.