scholarly journals Nickel Oxide-Catalyzed Synthesis of 4-Amino-2H-Chromenes: Its Application in Antimicrobial Studies and Towards Protein Docking

2019 ◽  
Vol 31 (5) ◽  
pp. 1049-1056
Author(s):  
A. Neela ◽  
T. Clarina ◽  
V. Rama

This work involves the synthesis of densely functionalized 2-amino-4H-chromenes by domino Knoevenagel-Michael-cyclization reaction of aromatic aldehydes, β-naphthol and malononitrile in the presence of a catalytic amount of a heterogeneous and reusable green NiO nanoparticle at 50 °C. The biogenic nickel oxide nanoparticles are characterized by Fourier transform infrared radiation, X-ray diffraction analysis, scanning electron microscopy and transmission electron microscopy. The synthesized chromenes are characterized by IR, NMR spectra. The synthesized chromene derivatives are studied for microbial inhibition by Kirby-Bauer disc diffusion method using amikacin and flucanazole as positive control. The compounds are found to have good to moderate antimicrobial activities. Their bio evaluation has been carried out with a protein and identified promising ligands for Mycobacterium tuberculosis InhA through molecular docking.

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1137
Author(s):  
Fazal Ur Rehman ◽  
Rashid Mahmood ◽  
Manel Ben Ali ◽  
Amor Hedfi ◽  
Amine Mezni ◽  
...  

This study was planned to synthesize a multifunctional nanomaterial that can effectively encounter the organic pollutants, multidrug-resistant bacteria and reactive free radicals. The Bergenia ciliate (B. ciliate) leaves extract was used as a reducing and capping agent for the synthesis of nickel oxide nanoparticles (NiO NP). The physicochemical properties were studied through X-ray diffractometre (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible and Fourier transform infrared (FTIR) spectroscopies. The highly crystalline monoclinic NiO NPs were synthesized with crystallite size of 27.45 nm. The average particle size derived from TEM micrograph was 49.35 nm whereas the calculated band gap for NiO NPs was 3.78 eV. The photocatalytic study shows that 92.17% of the rhodamine 6G (Rh-6G) was efficiently degraded in the presence of NiO NPs. The agar well diffusion method was applied to examine the antibacterial activity of NiO NPs and the activity was found higher against Gram-negative bacteria (GNB) as compared to Gram-positive bacteria (GPB). The ABTS free radical scavenging activity was also performed, however, the activity was found less than the standard.


2021 ◽  
Vol 09 ◽  
Author(s):  
Vinit Prakash ◽  
Anjana Kumari ◽  
Harpreet Kaur ◽  
Manoj Kumar ◽  
Sumeet Gupta ◽  
...  

Background: Green synthesized nanoparticles from the solvent extract of various plant parts show better biological activities as compared to parent solvent plant extract. Traditionally rhizomes of Picrorhiza kurroa are used to cure various diseases like diarrhea, fever, jaundice, eye infection, skin problems, asthma, arthritis, cancer, diabetes, gastrointestinal problems. Objectives: Present study describes the synthesis of copper nanoparticles from a hydroethanolic extract of P. kurroa rhizomes (CuNPs-Pk) and their evaluation for antimicrobial activities against gram-negative, gram-positive bacterial, and fungal strains. Methods: The solution of copper sulfate and hydroethanolic extract of rhizomes of P. kurroa was mixed with help of a magnetic stirrer at 60°C temperature for 1 h. The blue color of CuSO4.5H2O changed to brownish-black colored copper nanoparticles within 10 minutes. These nanoparticles were centrifuged at 4000 rpm for 20 min, washed with ethanol, followed by deionized water, dried, and were characterized by Ultra violet–visible (UV-Vis) absorption spectra, Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (TEM). Different concentrations of hydroethanolic extract of Picrorhiza kurroa rhizomes (HEEPk), CuNPs-Pk and copper oxide nanoparticles (bare CuO) ranging from 100-400 ppm had been studied against selected bacterial and fungal strains by using the well plate diffusion method. Ciprofloxin and fluconazole were used as standard and Dimethyl sulfoxide (DMSO) as a control for selected strains. Results: The UV–Vis spectral studies confirmed the surface plasmon resonance of green-synthesized CuNPs-Pk. The particle size was found to be 275-285 nm. FTIR analysis of biosynthesis nanoparticles have been confirm the presence of various functional groups (flavonoids, glycosides, tannins, phenols). SEM and TEM of biosynthesized nanoparticles have predicted their spheric al shape and their size (20-40 nm) and These particles have shown effective antimicrobial activities against selected pathogenic organisms viz. Escherichia coli, Staphylococcus aureus, and Aspergillus niger than that of HEEPk and bare CuO. Conclusions: The CuNPs-Pk show effective antimicrobial activities against bacterial and fungal pathogens as compared to HEEPk and bare CuO.


2018 ◽  
Vol 917 ◽  
pp. 167-171 ◽  
Author(s):  
Najmawati Sulaiman ◽  
Yoki Yulizar

Green synthesis of nickel oxide nanoparticles (NiO NPs) usingPhysalisangulataleaf extract (PALE) as weak base sources and stabilizing agents has been reported. Chemical bonding and vibration spectroscopy, crystallographic structure, optical band gap, particle size and microscopic studies of NiO NPs were also investigated. Ni-O vibration modes of NiO NPs were analyzed by FTIR and Raman instrument at ~400 and ~900 cm-1wavenumber. XRD pattern of NiO NPs confirmed cubic crystal structure with space groupFm-3m.Optical band gap of NiO NPs determined by using Tauc plot method was about 3.42 eV. Particle size analyzer showed size distribution of NiO NPs was 64.13 nm which confirm NiO formed in nanoscale. Electron microscopic studies of NiO NPs were observed by using scanning electron microscopy and transmission electron microscopy.


Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 225
Author(s):  
Ahmed M. Naglah ◽  
Mohamed A. Al-Omar ◽  
Abdulrahman A. Almehizia ◽  
Ahmad J. Obaidullah ◽  
Mashooq A. Bhat ◽  
...  

This article aimed to synthesis, spectroscopic, physicochemical characterizations, and catalytic studies on some ofloxacin (OFL) complexes with ruthenium(III) [Ru(III)] metal ions. The Ru(III)-OFL complex, [Ru(OFL)2(Cl)2]Cl and two mixed-ligand complexes, [Ru(OFL)(AA)(H2O)2]Cl2 derived from OFL as the primary ligand and amino acids [AA; either glycine (Gly) or alanine (Ala)] as the secondary ligands, were synthesized and characterized using microanalytical, spectroscopic, and physical techniques including element composition, molar conductivity, infrared, electronic spectra, thermal, X-ray powder diffraction (XRD), Energy dispersive X-ray spectroscopy (EDX), Scanning electron microscopy (SEM), and Transmittance electron microscopy (TEM) analyses. The element analysis data describe the formation of 1:2 [Ru(III):OFL] and 1:1:1 [Ru(III):OFL:AA] complexes. The octahedral geometry of the complexes was confirmed by their magnetic moment and diffused reflectance. Fourier Transform Infrared spectroscopic (FTIR) measurements suggested that the ligands chelated with Ru(III) ions through the nitrogen atoms of the piperazine ring. In vitro antibacterial efficiency of the OFL compounds was evaluated by paper disc diffusion method. Significant antimicrobial activities were observed for some compounds of the series.


2013 ◽  
Vol 63 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Mostafa M. Ghorab ◽  
Zienab H. Ismail ◽  
Awwad A. Radwan ◽  
Mohamad Abdalla

In the present work, interaction of the strategic starting material, methyl 2-isothiocyanatobenzoate (1), with sulfa drugs resulted in the formation of methyl 2-[3-(4-(N-substituted sulfamoyl)phenyl)thioureido] benzoates 2-5, which upon reaction with hydrazine hydrate afforded N-amino derivatives 6-9. Triazoloquinazoline derivatives 10-18 were obtained via reaction of compounds 6-8 with aromatic aldehydes. Also, the reaction of compound 8 with formic acid gave the corresponding triazoloquinazoline derivative 19. Triazinoquinazoline derivatives 22, 23 were obtained via reaction of N-amino derivatives 6 or 8 with ethyl chloroacetate. Interaction of 6 with diethyloxalate yielded triazoloquinazoline 26. The synthesized compounds were screened for their in vitro antimicrobial activities and some of them exhibited promising antibacterial activity compared to ampicillin as positive control. Compounds that revealed significant activity are able to satisfy effectively the proposed pharmacophore geometry.


2015 ◽  
Vol 09 (04) ◽  
pp. 580-586 ◽  
Author(s):  
Priscila de Camargo Smolarek ◽  
Luis Antonio Esmerino ◽  
Ana Cláudia Chibinski ◽  
Marcelo Carlos Bortoluzzi ◽  
Elizabete Brasil dos Santos ◽  
...  

ABSTRACT Objectives: This in vitro study evaluated the antimicrobial effects of commercial toothpastes containing natural compounds. Materials and Methods: The study groups were divided based on the natural compound present in the toothpaste composition: Sorbitol (I), tocopherol (II), mint (III), cinnamon/mint (IV), propolis/melaleuca (V), mint/açai (VI), mint/guarana (VII), propolis (VIII), negative control (IX), and the positive control (X). The antimicrobial properties of the toothpastes were tested using the disk diffusion method against oral pathogens: Streptococcus mutans, Pseudomonas aeruginosa, and Enterococcus faecalis. The resulting inhibition halos were measured in millimeters. Results: The data indicated that the bacteria responded differently to the toothpastes (P < 0.0001). The diameters of the inhibition halos against S. mutans were in decreasing order of efficacy: Propolis/melaleuca > mint/guarana > mint/açai > sorbitol > tocopherol > cinnamon/mint > propolis > mint (P < 0.001 vs. negative control). E. faecalis showed variable responses to the dentifrices in the following order of decreasing efficacy: Mint/guarana > propolis > sorbitol > mint/açai > tocopherol > cinnamon/mint > mint = propolis/melaleuca = negative control. The product with the highest antimicrobial activity was mint/guarana, which was significantly different than propolis/melaleuca, mint, cinnamon/mint, and tocopherol and negative control (P < 0.001). The statistical analysis indicated that propolis, sorbitol, and mint/açai did not show any differences compared to mint/guarana (P > 0.05) and positive control (P > 0.05). P. aeruginosa was resistant to all dental gels tested including positive control. Conclusion: The toothpastes with natural compounds have therapeutic potential and need more detailed searches for the correct clinic therapeutic application. The results from this study revealed differences in the antimicrobial activities of commercial toothpastes with natural compounds.


2019 ◽  
Vol 84 (3) ◽  
pp. 267-275 ◽  
Author(s):  
Chinnaraj Kanagavalli ◽  
Murugesan Sankarganesh ◽  
Raja Dhaveethu ◽  
Manivannan Kalanithi

Novel series of Co(II), Ni(II) and Cu(II) transition metal complexes were synthesized from the Schiff base ligands HL1?HL4 derived from 2-amino-6- nitrobenzothiazole with various aromatic aldehydes, i.e., 4-methylbenzaldehyde, 4- ethylbenzaldehyde, 2-hydroxybenzaldehyde and 4-hydroxybenzaldehyde, respectively. The ligands HL1?HL4 and their metal (II) complexes were characterized by atomic absorption spectroscopy (AAS), magnetic susceptibility and molar conductance measurements, and UV?Vis, FT-IR and NMR spectroscopic techniques. The spectroscopic studies revealed that the complexes of HL1?HL3 coordinated in an octahedral environment and L4 in square planar/tetrahedral geometry. The ligands HL1?HL4 and their metal(II) complexes were screened for their antimicrobial activities against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans. The results suggest that the complexes of HL4 possess greater inhibition activity towards C. albicans. The nonlinear optics (NLO) activities of ligands HL1?HL4 were determined. The obtained results showed that ligands HL1 and HL2 have greater second harmonic generation (SHG) efficiency than HL3and HL4.


2021 ◽  
Vol 9 (6) ◽  
pp. 823-830
Author(s):  
T. Krishnasree ◽  
Pavani Peddi

A unique way, green, cost-effective, and direct fabrication method is proposed for the synthesis of Nickel Oxide Nanoparticles (NPs) in an eco-environmentally way through leaf extract of Suaeda maritima (L.) Dumort. The nickel oxide nanoparticles were synthesized using Nickel (II) nitrate hexahydrate as a metal source and aqueous leaf extract of S. maritima was utilized as a green reducing agent. The formation of NPs was monitored by the change in color in the reaction mixture and the synthesized NPs were characterized using UV-visible spectrophotometer, Fourier Transform infrared (FT-IR) spectroscopy, field emission scanning electron microscope (FE SEM), X-ray diffractometer (XRD), and energy-dispersive X-ray spectroscopy (EDX). Further, the antibacterial activity of synthesized NPs was carried using the agar plate well diffusion method and antioxidant activity by DPPH free radical scavenging activity of the NPs was studied. The UV-visible absorption spectra of nanoparticles show a characteristic maximum absorption peak centered at 397 nm. The functional group analysis by FT-IR confirms the presence of various bio-active functional groups in the synthesized particles. The structural characterization confirms that the particles were Face Centred Cubic lattice structure having IR-regular in shape and rough surface with average atomic weight percentages of 76.3%. The synthesized nanoparticles were found to be potent against the growth of gram-positive (Bacillus subtilis, Staphylococcus aureus) and gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria. In the DPPH assay, the IC 50 values of the synthesized NPs were found to be 28.01 μg/mL which is very close to standard ascorbic acid (22.19 μg/mL) whereas the IC 50 of the aqueous plant leaf extract was found to be 47.30 μg/m confirms that the nanoparticles having enhanced antioxidant activity. From the results of the study it can be concluded that this protocol is simple, rapid, one step, eco-friendly, non-toxic for the synthesis of nickel nanoparticles.


F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 301
Author(s):  
Harlinda Kuspradini ◽  
Sisilia Silau ◽  
Supartini Supartini ◽  
Enih Rosamah ◽  

Pasak Bumi is a local name for a medicinal plant in Kalimantan, Indonesia. It is a famous medicinal plant and commonly used in traditional medicine as an aphrodisiac, as well as in the treatment of malaria. Pasak Bumi is a commercial name for Eurycoma longifolia (Simaroubaceae) plant species. Besides Eurycoma longifolia there are two other plant species also known locally as Pasak Bumi, Rennelia elliptica (Rubiaceae) and Trivalvaria macrophylla (Annonaceae). This study was performed to investigate the antimicrobial activities of the different species of Pasak Bumi and its total phenol contents. The antimicrobial activity of the ethanol extract was determined using the Agar Well Diffusion method at various concentrations while the phenol content was determined by the Folin - Ciocalteu method. The results of the ethanol extract from the different root showed that the T. macrophylla had the highest phenol content, and the highest activity index (AI) was found in the E. longifolia (0.96 at 1000 µg concentration). The results of this study show that the three different Pasak Bumi have potential as antimicrobials against oral pathogen; 1 yeast: Candida albicans, and 3 bacterias: Staphylococcus aureus, Streptococcus mutans, and Streptococcus sobrinus.


2019 ◽  
Vol 7 (7) ◽  
pp. 391-397
Author(s):  
O. Adeyanju ◽  
S. V. Francis ◽  
R. R. Ede ◽  
P.S. Jang ◽  
J.K. Bulus

Elemental analysis, phytochemical screening and antimicrobial activities of aqueous and ethanolic leaf extract of Pilostigma reticulatum (dc) Hochst were studied using paper disc diffusion method against Streptococcus pyogen, Escherichia coli and Salmonella thvpi. Elemental analysis of the plant sample revealed the presence of Ca (1.51 ± 0.01μg/g), Mg (0.43 ± 0.02μg/g). P (0.29 ± 0.01 μg/g), Mn (3.01 ± 0.01 μg/g), Fe (1.04 ± 0.01 μg/g), Zn (1.05 ± 0.02  and Cu was below detectable limit(BDL).The results of the antimicrobial studies indicated that the extracts inhibited the growth of one or more tested pathogens.The ethanolic extract showed a broad spectrum of antimicrobial activity. Phytochemical investigation revealed the presence of tannins, alkaloids, glycosides, flavonoids, carbohydrates and terpenes. Anthraquinone and saponin were not present. Inhibition zone by the extract ranges from 4.0mm to 30mm.The minimum inhibitory concentration (MIC) ranges from 8.0 x102 µg/ml to 1x104 µg/ml. Pilostigma reticulatum leaf may be able to produce antimicrobial agents in drug delivery.


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