Standard Drug Norfloxacin Research Articles

Green Synthesis of Copper Oxide Nanoparticles Using Aerva javanica Leaf Extract and Their Characterization and Investigation of In Vitro Antimicrobial Potential and Cytotoxic Activities.

The development of green technology is creating great interest for researchers towards low-cost and environmentally friendly methods for the synthesis of nanoparticles. Copper oxide nanoparticles (CuO-NPs) attracted many researchers due to their electric, catalytic, optical, textile, photonic, monofluid, and pharmacological activities that depend on the shape and size of the nanoparticles. This investigation aims copper oxide nanoparticles synthesis using Aerva javanica plant leaf extract. Characterization of copper oxide nanoparticles synthesized by green route was performed by three different techniques: X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy, and Scanning Electron Microscopy (SEM). X-ray diffraction (XRD) reveals the crystalline morphology of CuO-NPs and the average crystal size obtained is 15 nm. SEM images showed the spherical nature of the particles and size is lying in the 15–23 nm range. FTIR analysis confirms the functional groups of active components present in the extract which are responsible for reducing and capping agents for the synthesis of CuO-NPs. The synthesized CuO-NPs were studied for their antimicrobial potential against different bacterial as well as fungal pathogens. The results indicated that CuO-NPs show maximum antimicrobial activities against all the selected bacterial and fungal pathogens. Antimicrobial activities of copper oxide nanoparticles were compared with standard drugs Norfloxacin and amphotericin B antibiotics. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of copper oxide nanoparticles were 128 μg/mL against all selected bacterial pathogens. MIC of fungus and minimum fungicidal concentration (MFC) of CuO-NPs were 160 μg/mL. Thus, CuO-NPs can be utilized as a broad-spectrum antimicrobial agent. The cytotoxic activity of the synthesized CuO-NPs suggested that toxicity was negligible at concentrations below 60 μg/mL.

Synthesis and antibacterial activity of novel cinnoline-isoxazole derivatives

Abstract A series of new bioactive cinnoline/ Isoxazole hybrid heterocyclics (7a-p) have been designed and synthesized from cinnoline by applying the regioselective nitrile oxide[1,3]-dipolar cycloadditions. All the synthesised compoundswere screened for their in vitro antibacterial activity. The results of screening revealed that compounds 7f, 7g, 7k, 7l, and 7o are potent antibacterial agents against the Gram- positive bacterial species Bacillus subtilis and Staphylococcus aureus as well as Gram- negative bacterial species Pseudomonas aeruginosa and Escherichia coli. When compared with the standard drug norfloxacin, compound 7k showed more potent antibacterial activity against the all Gram-positive and Gram-negative strains of bacteria. To understand the binding interactions of the most derivatives 7f, 7g, 7k, 7l and 7k molecular docking studies were performed with elastase of Pseudomonas aeruginosa (PDB: 1U4G ). These docking results revealed that this class of compounds have potential antibacterial activity.

In silico docking studies and synthesis of new phosphoramidate derivatives of 6-fluoro-3-(piperidin-4-yl)benzo[d]isoxazole as potential antimicrobial agents

A new class of phosphoramidate derivatives of 6-fluoro-3-(piperidin-4-yl)benzo[d]isoxazole were synthesized in good to excellent yields (78–96%) by an in situ, three-step process. All the synthesized molecules were evaluated for anti-bacterial and anti-fungal activities using in vitro and in silico methods. The results revealed that the compounds 4b, 4d, 4h, 4i, and 4j exhibited the most promising anti-bacterial activity against S. aureus, B. subtilis, K. pneumoniae, S. typhi and P. mirabilis and anti-fungal activity against A. niger and A. flavus when compared with the standard drugs Norfloxacin and Nystatin at concentrations of 25, 50, 75 and 100 µg/mL. The rest of the title compounds have shown moderate activity against all the bacterial and fungal strains. Molecular docking studies revealed that the synthesized compounds have exhibited significant binding modes with high dock scores ranging from −7.2 to −9.5 against 3V2B protein when compared with the standard drugs Norfloxacin (−5.8) and Nystatin (−6.6) respectively. Hence, it is suggested that the synthesized phosphoramidate derivatives of 6-fluoro-3-(piperidin-4-yl)benzo[d]isoxazole will stand as the promising antimicrobial drug candidates in future.

Design, Development and Evaluation of N-Mannich Base Prodrugs of Norfloxacin For In Vitro Release Behavior and Antimicrobial Properties

In this research work, prodrugs of norfloxacin with various benzothiazoles were synthesized and studied for hydrolytic studies at various physiological pH. The results indicated that all of the prodrugs exhibited more and faster hydrolysis mainly in phosphate buffer (pH 7.4) rather than in HCl buffer (pH 1.2). These prodrugs were characterized by FTIR, 1H NMR, mass spectroscopy and physical analysis. The synthesized prodrugs showed better partition coefficient as compared to parent compound, norfloxacin. All of the prodrugs were tested for antimicrobial activity against selected microbial strains. Among the synthesized prodrugs, M1 was found to exhibit significant antibacterial efficacy having MIC 6.25 µg/ml against S. aureus MTCC 96 and prodrug M6 depicted good antibacterial activity (MIC 6.25 µg/ml) against E. coli MTCC 443 when compared with norfloxacin (MIC 10 µg/ml). Prodrugs M2 and M4 showed comparable activity against E. coli MTCC 443 and P. aeruginosa MTCC 1688 respectively to standard drug norfloxacin. The antibacterial activity of prodrug M4 (MIC 25 µg/ml) was found to be better than ciprofloxacin (MIC 50 µg/ml) against S. pyogenus MTCC 442. Moreover, prodrugs M4 and M6 possessed better antifungal activities (MIC 250, 75 µg/ml respectively) against C. albicans MTCC 227 while M2 showed significant potency against A. niger MTCC 282 and A. clavatus MTCC 1323 (MIC 50 µg/ml) compared to standard drug nystatin (MIC 100 µg/ml).

Green synthesis and evaluation of 5-(4-aminophenyl)-4-aryl-4H-1, 2, 4-triazole-3-thiol derivatives

The green synthesis of 5-(4-aminophenyl)-4-aryl-4H-1,2,4-triazole-3-thiol was achieved in four steps, In first step, 4-amino benzoic acid refluxed in ethanol along with catalyst Conc. Sulphuric acid to produce ethyl-4-amino benzoate I. Further compound I refluxed with hydrazine hydrate in ethanol to produce 4-amino benzohydrazide II. Compound II refluxed in ethanolic potassium hydroxide with carbon disulfide to produce 5-(4-aminophenyl)-1,3,4-oxadiazole-2-thiol III. Compound III refluxed in ethanol with different substituted primary aryl amine gave title compounds 5-(4-aminophenyl)-4-aryl-4H-1,2,4-triazole-3-thiol IVa-o. The compounds obtained were identified by FT-IR, 1H-NMR, GC- mass spectroscopy data, and elemental analysis and also screened for in-vivo antimicrobial activity. In vitro antibacterial activity was carried out against organisms like E.coli. K.pneumonia, S.aureus, and B.subtilis as well as in vitro antifungal activity were carried out against organisms like A.niger and S.cerevisiae. In vitro antimicrobial evaluation, the most potent broad spectrum compound IVc, IVd and IVf were found significant agent against standard drug Norfloxacin and Ketoconazole.

A facile synthesis and antimicrobial activity evaluation of sydnonyl-substituted thiazolidine derivatives.

Some new sydnonyl-substituted thiazolidine derivatives were synthesized in high yields by the modified Knoevenagel condensation of 3-aryl-4-formylsydnones with thiazolidine-2,4-dione and 2-thioxo-thiazolidine-4-one, respectively. All the synthesized thiazolidine derivatives were screened by paper-disc method to identify their antimicrobial activities against three bacteria viz. Staphylococcus aureus, Proteus vulgaris and Escherichia coli, and two fungal cultures viz. Aspergillus niger and Penicillium citrinum. The reference drugs were Norfloxacin and Griseofulvin, respectively. The screening data indicated that the tested sydnonyl-substituted thiazolidine derivatives exhibited no obvious antibacterial activity compared with the standard drug Norfloxacin. However, thiazolidine derivatives displayed significant antifungal activities against Penicillium citrinum and Aspergillus niger. Notably, all of the tested compounds showed growth inhibitory activity 1.5-4.4 times higher than that of the standard drug Griseofulvin against the two fungi.

Synthesis, antimicrobial evaluation and QSAR studies of p-amino benzoic acid derivatives

A series of Schiff bases (1-16) and esters (17-27) of p-amino benzoic acid (PABA) was synthesized and its in vitro antimicrobial potential was evaluated by using tube dilution method. Compound 11 was found to be most promising antibacterial agent (pMICbs = 2.11 μM/ml) having antibacterial potential comparable to standard drug norfloxacin (pMICbs = 2.61 μM/ml) and may be taken as a lead compound for the development of novel antibacterial agents. QSAR analysis indicated that electronic parameters, total energy (Te) and energy of lowest unoccupied molecular orbital (LUMO) were found dominant in explaining the antimicrobial activity of synthesized compounds.

Synthesis, Antimicrobial Evaluation and QSAR Studies of 2-chlorobenzoic Acid Derivatives

In the present study, 2-chlorobenzoic acid derivatives were synthesized and evaluated for their antimicrobial activity against Gram-positive bacteria: Staphylococcus aureus, Bascillus subtilis, Gram-negative bacterium Escherichia coli, fungal strains: Candida albicans and Aspergillus niger by tube dilution method. Results of antimicrobial screening indicated that the synthesized compounds exhibited greater antibacterial potential against Gram-negative bacterium (Escherichia coli) than Gram-positive bacteria and the Schiff's bases of 2-chloro benzoic acid were more potent antimicrobial agents than its esters. Compound 6 (pMIC(am)=1.91 µM/ml, pMIC(ec)=2.27 µM/ml) emerged as most potent antimicrobial agent and was found comparable to standard drug norfloxacin (pMIC(ec)=2.61 µM/ml) against Escherichia coli. QSAR studies revealed that the antibacterial, antifungal and the overall antimicrobial activities of the 2-chlorobenzoic acid derivatives were governed by the topological parameters, second order and valence second order molecular connectivity indices ((2)χ and (2)χ(v)).

Mannich bases of 7-piperazinylquinolones and kojic acid derivatives: Synthesis, in vitro antibacterial activity and in silico study

Novel Mannich bases of 7-piperazinylquinolones with kojic acid and chlorokojic acid were designed as new quinolone antibacterials. All compounds showed significant in vitro antibacterial activity against both Gram-positive and Gram-negative bacteria. Particularly, chlorokojic derivative 2b was the most potent compound against Staphylococcus aureus and Pseudomonas aeruginosa (MIC values ≤0.19 μg/mL). Its activity was 4–8 times more than that of standard drug norfloxacin. The molecular docking study of compound 2b further supported the molecular basis of the designed compounds.

Synthesis, characterization, biologically and antioxidant active of some 2-substitued 3,5-dimethyl-4-ethoxy carbonyl pyrrole derivatives

AimsIn recent years there is a tremendous increase of drug resistant pathogens, leading to the design and development of newer antibacterial agents. Various novel carbonyl pyrrole derivatives have been prepared to study on the basis of pharmacological activities in drugs discovery. MethodsThe synthesis of biologically active 2-substituted, 1,2,4-triazole (4a–g), 4-oxadiazole (5a–g) and 4-oxazolidinones (6a–g) starting from 3,5-dimethyl-2,4-diethoxy carbonyl pyrrole (1) are presented in this paper. ResultsThese compounds show antibacterial and antifungal activities when compared with standard drug Norfloxacin and Griseofulvine against Bacterial cultures such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Proteus vulgaris and fungal cultures such as Aspergillus niger and Candida albicans. The structures of the compounds have been confirmed by IR, 1H NMR and Elemental analysis. The compounds 3a, 3c, 4g, 5f, 5g, 6b and 6f (possessing phenyl, 4-methyl, 2-chlorophenyl, 4-nitrophenyl and 3-nitrophenyl) have shown good antioxidant activity within the series of compounds synthesized. ConclusionHence these compounds shall be exploited further for antibacterial activity to attain a potential pharmacophore.

ChemInform Abstract: Synthesis and Evaluation of Some Novel 2,4‐Thiazolidinedione Derivatives for Antibacterial, Antitubercular and Antidiabetic Activities.

AbstractAll of the synthesized thiazolidinedione (IX) and (XI) show promising antibacterial, antitubercular and antidiabetic activities in comparison to the standard drugs norfloxacin, streptomycin and glibenclamide, respectively.

Synthesis, antimicrobial and antiviral evaluation of substituted imidazole derivatives

In the present study, we have synthesized 2-(substituted phenyl)-1 H-imidazole ( 1– 12) and (substituted phenyl)-[2-(substituted phenyl)-imidazol-1-yl]-methanone ( 13– 26) analogues and screened them for their antimicrobial activity against Gram positive, Gram negative and fungal species. The results of antibacterial study indicated that compounds 15, 17 and 24 showed appreciable antibacterial activity and compound 26 emerged as the most potential antifungal agent. The results of SAR studies indicated that the presence of electron withdrawing groups is necessary for the antimicrobial activity of the synthesized compounds. The results of the present study indicated that compounds 15, 17 and 24 might be of interest for the identification of new antimicrobial molecules as their antibacterial activity is equivalent to the standard drug norfloxacin. Further, the antiviral screening of (substituted phenyl)-[2-(substituted phenyl)-imidazol-1-yl]-methanones ( 13– 26) against a panel of viral strains indicated that compounds 16 and 19 can be selected as lead compounds for the development of novel antiviral agents.

Microwave Activated Solid Support Synthesis of New Antibacterial Quinolones

A novel synthesis of 6-fluoro-7-(5-aryl-1,3,4-thiadiazol/oxadiazol-2-yl-sulfanyl)-4-quinolone-3-carboxylic acids from 7-chloro-6-fluoro-4-quinolone-3-carboxylic acid and 5-substituted 1,3,4-thiadiazoles/oxadiazoles on basic alumina under microwave activation is described. All compounds were screened for their in vitro antibacterial activity against B. lichenformis, 2689, K. aerogens 2281, S. typhimurium 2501, E. herbicola 2491, and P. vulgaris 2027 and found to possess activities comparable to that of the standard drug norfloxacin.