Novel Sulfonylamido Benzoxazole Derivatives: Synthesis, Characterisation, Molecular Docking, DFT, and Antimicrobial Activity Investigations.

In this work, numerous novel 2-(p-ethyl/fluorophenyl)-5-[(p-substitutedphenyl)sulfonylamido]benzoxazole derivatives were designed, synthesized, and structurally characterized using H-NMR, C-NMR, mass spectroscopy, and elemental analysis approaches. The antimicrobial activity against several Gram (+) bacteria, Gram (-) bacteria, and fungal species was determined using the in vitro microdilution technique. A molecular docking analysis was performed on all produced compounds utilizing the S.

Benzimidazole and Benzoxazole Derivatives Against Alzheimer's Disease.

Benzimidazole and benzoxazole derivatives are included in the category of medical drugs in a wide range of areas such as anticancer, anticoagulant, antihypertensive, anti- inflammatory, antimicrobial, antiparasitic, antiviral, antioxidant, immunomodulators, proton pump inhibitors, hormone modulators, etc. Many researchers have focused on synthesizing more effective benzimidazole and benzoxazole derivatives for screening various biological activities. In addition, there are benzimidazole and benzoxazole rings as bioisosteres of aromatic rings found in drugs used in the treatment of Alzheimer's disease.

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 and their drug-resistant isolates.

Design, synthesis, molecular docking, density functional theory and antimicrobial studies of some novel benzoxazole derivatives as structural bioisosteres of nucleotides.

A series of some novel 2-(-tert-butylphenyl)-5-(3-substituted-propionamido)benzoxazole derivatives have been designed, synthesized, evaluated for antimicrobial activity and have performed molecular docking studies against penicillin-binding protein 4 (PBP4) and active and allosteric site of PBP2a; were calculated some theoretical quantum parameters and absorption, distribution, metabolism and excretion (ADME) descriptors. acted at minimum inhibitory concentration (MIC) = 8 µg/mL against and their drug-resistant isolates and also formed with GLU145 (1.74 Å) and ILE144 (1.

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.

Synthesis and antimicrobial evaluation of some novel sulfonylamido-benzoxazoles.

A series of 2-(p-substituted phenyl)-5-[(4-substituted phenyl) sulfonylamido]-benzoxazoles were synthesized and tested for their antimicrobial activities. The structures of the new derivatives were elucidated by spectral techniques. The minimum inhibitory concentrations (MIC) of the new benzoxazoles were determined against standard bacterial and fungal strains and drug-resistant isolates and compared to those of several reference drugs.

Synthesis and antimicrobial evaluation of 2-(p-substituted phenyl)-5-[(4-substituted piperazin-l-yl)acetamido]-benzoxazoles.

A series of 2-(p-substituted phenyl)-5-(2-{4-[(p-chloro-fluorophenyl)/phenyl] piperazin-1-yl}acetamido)-benzoxazoles were synthesized and tested for their antimicrobial activities. The structures of the new derivatives were elucidated by spectral techniques. The minimum inhibitory concentrations (MIC) of the new benzoxazoles, along with those of previously synthesized analogues, were determined against standard bacterial and fungal strains and drug-resistant isolates, and compared with those of several reference drugs.

Novel benzoxazoles: synthesis and antibacterial, antifungal, and antitubercular activity against antibiotic-resistant and -sensitive microbes.

A new series of 5-(p-substituted benzamido/phenylacetamido)-2-(p-tert-butylphenyl)benzoxazole derivatives were synthesized and evaluated for their antibacterial, antifungal, and antimycobacterial activities against antibiotic-resistant and -sensitive Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, and Mycobacterium tuberculosis as well as against Candida albicans and Candida krusei. The compounds possessed broad-spectrum activity against all of the tested Gram-positive and Gram-negative bacteria and yeasts, their minimum inhibitory concentrations (MICs) ranging between 16-128 microg/ml. One compound exhibited significant antibacterial activity (16 microg/ml) against an antibiotic-resistant Enterococcus faecalis isolate, having twice the potency of the compared standard drugs vancomycin and gentamycin sulfate.

Synthesis, FT-IR investigation and computational study of 5-[(4-Bromophenyl)acetamido]-2-(4-tert-butylphenyl) benzoxazole.

The synthesis and antimicrobial properties of 5-[(4-Bromophenyl)acetamido]-2-(4-tertbutylphenyl) benzoxazole are reported in the present work. The optimized molecular structure, (1)H NMR, vibrational frequencies, corresponding vibrational assignments of 5-[(4-Bromophenyl)acetamido]-2-(4-tert-butylphenyl) benzoxazole have been investigated experimentally and theoretically using Gaussian09 software package. Potential energy distribution of the normal modes of vibrations was done using GAR2PED program.

Synthesis and antimicrobial activity of novel benzoxazoles.

A series of 2-(p-substituted-benzyl)-5-[[4-(p-chloro/fluoro-phenyl)piperazin-1-yl]acetamido]-benzoxazoles were synthesized in need of new compounds for the fight against microbial pathogens. Their structures were elucidated by spectral techniques. These new derivatives, along with previously synthesized 2-(p-substituted-benzyl)-5-substituted-benzoxazoles, were evaluated for their antibacterial and antifungal activities against standard strains and drug-resistant isolates in comparison with ampicillin, gentamicin sulfate, ofloxacin, vancomycin, fluconazole, and amphotericin B trihydrate.

FT-IR, FT-Raman, SERS and computational study of 5-ethylsulphonyl-2-(o-chlorobenzyl)benzoxazole.

FT-IR, FT-Raman and surface-enhanced Raman scattering spectra of 5-ethylsulphonyl-2-(o-chlorobenzyl)benzoxazole were recorded and analyzed. The vibrational wavenumbers were examined theoretically using the Gaussian09 set of quantum chemistry codes, and the normal modes were assigned by potential energy distribution calculations. The presence of CH(2), SO(2) and CH(3) modes in the SERS spectrum indicates the nearness of the methyl group to the metal surface which affects the orientation and metal molecule interaction.

IR, Raman and SERS spectra of 2-phenoxymethylbenzothiazole.

The FT-IR and FT-Raman spectra of 2-phenoxymethylbenzothiazole were recorded and analyzed. The surface enhanced Raman scattering (SERS) spectrum was recorded in a silver colloid. The vibrational wavenumbers of the compound have been computed using the Hartree-Fock/6-31G* basis and compared with the experimental values.

Synthesis, biological evaluation and 2D-QSAR analysis of benzoxazoles as antimicrobial agents.

A new series of 5(or 6)-nitro/amino-2-(substituted phenyl/benzyl)benzoxazole derivatives were synthesized and evaluated for antibacterial and antifungal activities against Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Candida albicans and their drug-resistant isolate. Microbiological results indicated that the synthesized compounds possessed a broad spectrum of activity against the tested microorganisms at MIC values between > 400 and 12.5 microg/ml.

Some benzoxazoles and benzimidazoles as DNA topoisomerase I and II inhibitors.

Some novel fused heterocyclic compounds of 2, 5-disubstituted-benzoxazole and benzimidazole derivatives, which were previously synthesized by our group, were investigated for their inhibitory activity on both eukaryotic DNA topoisomerase I and II in a cell free system. 2-Phenoxymethylbenzimidazole (17), 5-amino-2-(p-fluorophenyl)benzoxazole (3), 5-amino-2-(p-bromophenyl)benzoxazole (5), 5-nitro-2-phenoxymethyl-benzimidazole (18), 2-(p-chlorobenzyl)benzoxazole (10) and 5-amino-2-phenylbenzoxazole (2) were found to be more potent as eukaryotic DNA topoisomerase I poisons than the reference drug camptothecin having IC(50) values of 14.1, 132.

Synthesis, antimicrobial activity, pharmacophore analysis of some new 2-(substitutedphenyl/benzyl)-5-[(2-benzofuryl)carboxamido]benzoxazoles.

The synthesis and antimicrobial activity of a new series of 2-(substitutedphenyl/benzyl)-5-[(2-benzofuryl)carboxamido]benzoxazole derivatives 3-12 were described. The in vitro antimicrobial activity of the compounds was determined against some Gram-positive, Gram-negative bacteria and fungi and their drug-resistant isolates in comparison with standard drugs. Antimicrobial results indicated that the synthesized compounds possessed a broad spectrum of activity with MIC values 500-15.

Vibrational spectroscopic studies and ab initio calculations of 5-nitro-2-(p-fluorophenyl)benzoxazole.

5-Nitro-2-(p-fluorophenyl)benzoxazole was prepared by heating 2-hydroxy-5-nitro aniline with p-fluorobenzoic acid in polyphosphoric acid. The FT-IR spectrum is recorded and analysed. The vibrational frequencies and corresponding vibrational assignments are examined theoretically using the Gaussian03 set of quantum chemistry codes.

Synthesis and biological activity of some new benzoxazoles.

The synthesis and antimicrobial activity of a new series of 5-ethylsulphonyl-2-(substituted-phenyl/substituted-benzyl and/or phenylethyl)benzoxazole derivatives (3a-3t) except 3a, 3g, 3h, 3k [R.S. Pottorf, N.

Vibrational spectroscopic studies and ab initio calculations of 5-methyl-2-(p-methylaminophenyl)benzoxazole.

FT-IR spectra of 5-methyl-2-(p-methylaminophenyl)benzoxazole was recorded and analysed. The vibrational frequencies of the compound have been computed using the Hartree-Fock/6-31G* basis and compared with the experimental values.

Synthesis and in vitro antimicrobial activity of new 2-[p-substituted-benzyl]-5-[substituted-carbonylamino]benzoxazoles.

Some new 2-(benzyl/p-chlorobenzyl)-5-[(substituted-thienyl/phenyl/phenylthiomethyl/benzyl)carbonylamino]benzoxazole derivatives have been synthesized by reacting 5-amino-2-(benzyl/p-chlorobenzyl)benzoxazoles with appropriate carboxylic acid chlorides. The structures of the synthesized compounds were confirmed by IR, (1)H NMR and MASS spectral data. In vitro antimicrobial activities of the compounds were investigated using twofold serial dilution technique against different two Gram-positive, two Gram-negative bacteria and three Candida spp.

Synthesis and biological evaluation of new N-(2-hydroxy-4(or 5)-nitro/aminophenyl)benzamides and phenylacetamides as antimicrobial agents.

A new series of N-(2-hydroxy-4(or 5)-nitro/aminophenyl)benzamide and phenylacetamide derivatives (1a-1n, 2a-2n) were synthesized and evaluated for antibacterial and antifungal activities against Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, and their drug-resistant isolate. Microbiological results indicated that the compounds possessed a broad spectrum of activity against the tested microorganisms at MIC values between 500 and 1.95 microg/ml.

Vibrational spectroscopic studies and ab initio calculations of 5-methyl-2-(p-fluorophenyl)benzoxazole.

FT-Raman and FT-IR spectra of 5-methyl-2-(p-fluorophenyl)benzoxazole were recorded and analysed. The vibrational frequencies of the compound have been computed using the Hartree-Fock/6-31G* basis and compared with the experimental values.

Induction of apoptosis and necrosis by resistance modifiers benzazoles and benzoxazines on tumour cell line mouse lymphoma L5718 Mdr+cells.

Eighteen new fused heterocyclic compounds of benzazoles and benzoxazines were investigated for induction and inhibition of apoptosis on tumor cells (L5718, mouse lymphoma cell line containing the human mdr-1 gene). For evaluation of apoptosis, the cells were stained with FITC-labelled Annexin-V and propidium iodide and the results were analysed by flow cytometry. Nine of these substances were also checked for reversal of multidrug resistance.

3D-QSAR analysis on benzazole derivatives as eukaryotic topoisomerase II inhibitors by using comparative molecular field analysis method.

Selective topoisomerase II inhibitors have created a great deal of interest in recent years for the design of new antitumoral compounds. 3D-QSAR analysis has been performed on a series of previously synthesized benzoxazole, benzimidazole, and oxazolo(4,5-b)pyridine derivatives, which are screened as eukaryotic topoisomerase II inhibitors, using comparative molecular field analysis (CoMFA) with partial least squares fit to predict the steric and electrostatic molecular field interactions for the activity. The CoMFA study was carried out using a training set of 16 compounds.

Synthesis and antimicrobial activity of some 5-[2-(morpholin-4-yl)acetamido] and/or 5-[2-(4-substituted piperazin-1-yl)acetamido]-2-(p-substituted phenyl)benzoxazoles.

In this study, a series of twelve novel 5-[2-(morpholin-4-yl)acetamido] and/or 5-[2-(4-substituted pip-erazine-1-yl)acetamido]-2-(p-substituted phenyl]benzoxazole derivatives have been synthesized and their structures were confirmed by IR, (1)H NMR, and mass spectral data. These compounds were prepared by reacting 5-(2-chloroacetamido)-2-(4-p-substituted-phenyl)benzoxazoles, which were obtained by using 5-amino-2-[p-substituted-phenyl]benzoxazoles with chloroacetyl chloride, in the presence of morpholine or 1-substituted piperazines. All synthesized compounds 3-14 were tested by using the method of twofold serial dilution technique for in vitro activities against certain strains of Gram-positive, Gram-negative bacteria as well as the yeasts Candida albicans, Candida krusei, and Candida glabrata in comparison with standard drugs.

Synthesis and antimicrobial activity of new 2-[p-substituted-benzyl]-5-[substituted-carbonylamino]benzoxazoles.

A series of 23 new 2-[p-substituted-benzyl]-5-[p-substituted-phenyl/benzyl-carbonylamino]benzoxazole derivatives has been synthesized by reacting 5-amino-2-[p-substituted-benzyl]benzoxazoles with the appropriate carboxylic acid chlorides. The structures of the synthesized compounds were confirmed by IR and (1)H-NMR spectral data. Antimicrobial activities of the compounds were investigated using the twofold serial dilution technique against two gram-positive and two gram-negative bacteria and three Candida species in comparison with standard drugs.