scholarly journals Synthesis, Characterization and in Vitro Antimicrobial Studies of Ternary Mn(II) Complexes with Isatinphenylhydrazone, Glycine and 8-hydroxyquinoline

2021 ◽  
Vol 37 (5) ◽  
pp. 1146-1151
Author(s):  
Suman Kumari ◽  
Shobhana Sharma ◽  
Seema Seema ◽  
Poonam Yadav ◽  
Mamta Ranka

In our present research work, we have synthesized two ternary metal complexes of Mn(II), complex-I as [Mn(L)(Gly)(Cl)(H2O)] and complex-II as [Mn(L)(Q)(Cl)(H2O)]; where L is Isatinphenylhydrazone (IPH) as primary ligand, whereas glycine (Gly) and 8-hydroxyquinoline (HQ) as secondary ligand in complex-I and II respectively, in 1:1:1 (M : L : Gly or M : L : Q) molar ratios. Above synthesized complexes are employed for characterization using various analytical techniques including elemental analysis, melting point determination, magnetic moment measurements, molar conductance measurements, and spectral techniques (FTIR, UV, 1H NMR) etc. Further, their antimicrobial activities were evaluated against selected bacterial strains i.e., B. subtilis, S. aureus (Gram positive) and P. aeruginosa, E. coli (Gram negative) and fungal strains (T. reesei, A. niger, C. albicans) and found significantly active.

2021 ◽  
Vol 9 (09) ◽  
pp. 900-909
Author(s):  
Anupama Srivastava ◽  
◽  
Shilpi Srivastava ◽  
Om. P. Pandey ◽  
Soumitra K. Sengupta ◽  
...  

Titanium(IV) complexes of type[(η5-C5H5)2TiCl(L)] have been synthesized by the reactions of bis(cyclopentadienyl)titanium(IV)dichloride with Schiff bases (LH) derived by the condensation of 5-(substituted aryl)-2-hydrazino-1,3,4-oxadiazole and indoline-2,3-dione in tetrahydrofuranin the presence oftriethylamine. All these complexes are soluble in PhNO2, DMF and DMSO.The complexes were characterized by elemental analyses, electrical conductance, magnetic susceptibility, UV-Vis, IR, 1H NMR, 13C NMR, XRD and SEM spectral techniques. Low molar conductance values indicate that they are non-electrolytes. The spectral data indicate5-coordinate geometry for the complexes.XRD pattern indicate that the complexes have monoclinic crystal system and particle sizes were found 49.36 nm (nano-size). In vitro antifungal activity of synthesized compounds was evaluated against fungi Aspergillusniger, Aspergillusflavus,ColletotrichumfalcatumandIn vitro antibacterial activity was determined by screening the compounds against gram negative (P. aeruginosa, S.typhi) and gram positive (S. aureus and B.subtilis) bacterial strains using minimum inhibition concentration method (MIC) by serial dilution technique. The titanocene(IV) complexes have higher antimicrobial effect than the parent Schiff bases.


2021 ◽  
Vol 34 (1) ◽  
pp. 183-190
Author(s):  
Mahak Dalal ◽  
Manish Kumar ◽  
K.K. Verma ◽  
Sapana Garg

This article reports the synthesis, characterization and antimicrobial screening of a tridentate 2-[(2-hydroxyphenyl)imino methyl]-1-naphthol ligand (H2AP) and its organotellurium(IV) complexes. Structural characterization of the synthesized ligand and complexes was confirmed by using FT-IR, 1H NMR, 13C NMR, UV-vis, mass spectrometry, molar conductance and elemental analysis. Geometry of all the synthesized compounds has been optimized and their DFT based chemical reactivity descriptors were calculated. DFT and spectral data studies revealed distorted square pyramidal geometry for the tellurium(IV) complexes. In vitro antimicrobial activities of the synthesized ligand and its tellurium(IV)complexes were evaluated against two Gram-positive, two Gram-negative bacterial strains and three fungal strains. The tellurium(IV) complexes exhibited promising activity as compared to the Schiff base ligand.


2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
K. Savithri ◽  
B. C. Vasantha Kumar ◽  
H. K. Vivek ◽  
H. D. Revanasiddappa

A bidentate (N- and O-) imine-based ligand (L1) and its metal complexes of types [CuII(L1)2] (C1), [CuII(L1)(Phen)] (C2), [CoIII(L1)2] (C3), and [CoIII(L1)(Phen)] (C4) (L1 = 2-((E)-(6-fluorobenzo[d]thiazol-2-ylimino)methyl)-4-chlorophenol and phen = 1,10-phenanthroline) were synthesized as potential chemotherapeutic drug candidates. The prepared complexes were structurally characterized by spectral techniques (NMR, FT-IR, LC-MS, EPR, and electronic absorption), thermogravimetric analysis (TGA/DTA), magnetic moment, and CHNO elemental analysis. Spectroscopic studies suggested the distorted octahedral structure for all complexes. In vitro bioassay studies include binding and nuclease activities of the ligand and its complexes with target calf thymus- (CT-) DNA were carried out by employing UV-Vis, fluorescence spectroscopy, viscosity, and gel electrophoresis techniques. The extent of binding propensity was determined quantitatively by Kb and Ksv values which revealed a higher binding affinity for C2 and C4 as compared to C1 and C3. In addition, the scavenging superoxide anion free radical (O∙-2) activity of metal complexes was determined by nitroblue tetrazolium (NBT) light reduction assay. Molecular docking studies with DNA and SOD enzyme were also carried out on these compounds. The antimicrobial study has shown that all the compounds are potential antibacterial agents against Gram-negative bacterial strains and better antifungal agents with respect to standard drugs used.


2010 ◽  
Vol 75 (2) ◽  
pp. 217-228 ◽  
Author(s):  
Dharmpal Singh ◽  
Krishan Kumar ◽  
Ramesh Kumar ◽  
Jitender Singh

A novel series of complexes of the type [M(C28H24N4)X2], where M = Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), X = Cl-, NO3 -, CH3COO- and (C28H24N4) corresponds to the tetradentate macrocyclic ligand, were synthesized by template condensation of 1,8-diaminonaphthalene and diacetyl in the presence of divalent metal salts in methanolic medium. The complexes were characterized by elemental analyses, conductance and magnetic measurements, as well as by UV/Vis, NMR, IR and MS spectroscopy. The low values of the molar conductance indicate non-electrolyte type of complexes. Based on these spectral data, a distorted octahedral geometry may be proposed for all of these complexes. All the synthesized macrocyclic complexes were tested for in vitro antibacterial activity against some pathogenic bacterial strains, viz Bacillus cereus, Salmonella typhi, Escherichia coli and Staphylococcus aureus. The MIC values shown by the complexes against these bacterial strains were compared with the MIC shown by the standard antibiotics linezolid and cefaclor.


Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 703
Author(s):  
Severino Zara ◽  
Giacomo L. Petretto ◽  
Alberto Mannu ◽  
Giacomo Zara ◽  
Marilena Budroni ◽  
...  

The production of saffron spice generates large quantities of plant by-products: over 90% of the plant material collected is discarded, and a consideration fraction of this waste is plant stamens. This work investigated the chemical composition and the antimicrobial activities of the non-polar fraction extracted from four different saffron flower stamens. The chemical composition of ethereal extracts of the saffron stamens was qualitatively assessed by means of gas–chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) analyses. These analyses revealed ethereal extracts to possess a high polyunsaturated fatty acid content. In vitro antibacterial activity of stamen extracts showed no large differences between Gram-positive and Gram-negative bacteria in terms of minimal inhibitory concentration (MIC). In food matrix microbial analysis of the bacterial strains belonging to the main foodborne pathogen species, including Staphylococcus aureus DSM 20231, Escherichia coli DSM 30083, and Listeria monocytogenes DSM 20600, using low-fat UHT milk, revealed a statistically significant reduction in the number of cells (particularly for E. coli and S. aureus with a complete elimination of the population of the two target bacteria following incubation in diethyl ether extracts of saffron stamen (DES) at high concentrations tested, both at 37 °C and 6 °C (for 48 h and 7 days, respectively). A synergic effect was observed when the pathogens were incubated at 6 °C with DES. This work shows these by-products to be excellent sources of bioactive compounds, which could be exploited in high-added-value products, such as food, cosmetics, and drugs.


2021 ◽  
Vol 22 (8) ◽  
pp. 4246
Author(s):  
Muhammad Maqbool ◽  
Qaisar Nawaz ◽  
Muhammad Atiq Ur Atiq Ur Rehman ◽  
Mark Cresswell ◽  
Phil Jackson ◽  
...  

In this study, as a measure to enhance the antimicrobial activity of biomaterials, the selenium ions have been substituted into hydroxyapatite (HA) at different concentration levels. To balance the potential cytotoxic effects of selenite ions (SeO32−) in HA, strontium (Sr2+) was co-substituted at the same concentration. Selenium and strontium-substituted hydroxyapatites (Se-Sr-HA) at equal molar ratios of x Se/(Se + P) and x Sr/(Sr + Ca) at (x = 0, 0.01, 0.03, 0.05, 0.1, and 0.2) were synthesized via the wet precipitation route and sintered at 900 °C. The effect of the two-ion concentration on morphology, surface charge, composition, antibacterial ability, and cell viability were studied. X-ray diffraction verified the phase purity and confirmed the substitution of selenium and strontium ions. Acellular in vitro bioactivity tests revealed that Se-Sr-HA was highly bioactive compared to pure HA. Se-Sr-HA samples showed excellent antibacterial activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus carnosus) bacterial strains. In vitro cell–material interaction, using human osteosarcoma cells MG-63 studied by WST-8 assay, showed that Se-HA has a cytotoxic effect; however, the co-substitution of strontium in Se-HA offsets the negative impact of selenium and enhanced the biological properties of HA. Hence, the prepared samples are a suitable choice for antibacterial coatings and bone filler applications.


2019 ◽  
Vol 2 (1) ◽  
pp. 19
Author(s):  
Murni Halim

A study was carried out to screen for phytochemical constituents and assess the antioxidant and antimicrobial activities of Senna alata and Senna tora leaf extracts. The leaves were first dried at room temperature and 50°C in an oven prior to solvent extraction using ethanol and methanol. The in-vitro qualitative assays showed that both S. alata and S. tora leaf extracts contained bioactive and secondary metabolites components such as tannins, steroids, saponin, terpenoids, glycosides, flavonoids and phenols. The antioxidant activity and capacity test were carried out by conducting free radical of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and Ferric reduction antioxidant plasma (FRAP) assays. Both assays showed S. tora leaf extract has higher antioxidant capacity than S. alata leaf extract. The efficacy of these leaf extracts were tested against skin pathogens through agar well diffusion method. S. alata extract showed an inhibition zone (1.15 – 1.59 mm) against Pseudomonas aeruginosa while S. tora extracts exhibited a strong antimicrobial activity against S. epidermidis (inhibition zone of 12 – 16.94 mm) followed by P. aeruginosa (inhibition zone of 1 – 1.59 mm). Nonetheless, no inhibition zone was observed for S. aureus by both leaf extracts. The phytochemicals and antioxidant constituents as well as inhibitory potential on skin pathogens possessed by S. alata and S. tora leave highlighted their potential utilization in the development of natural drugs or cosmetics to treat skin related diseases or infections.


2019 ◽  
Vol 6 (1) ◽  
pp. 61-70
Author(s):  
Navin Patel ◽  
Sabir Pathan ◽  
Hetal I. Soni

Background: For rapid and sustainable synthesis, microwave irradiation method is serviceable. This present study deals with the preparation of oxadiazole and pyridine bearing 1,2,3,4- tetrahydro pyrimidine derivatives by microwave irradiation. Objective: The present study aims to carry out rapid synthesis of chloro-acetamides of oxadiazoles of Biginelli product and amino cyano derivative of pyridine by microwave-assisted heating. Our efforts are focused on the introduction of chemical diversity in the molecular framework in order to synthesize pharmacologically interesting compounds. Methods:: Microwave irradiation was used for the synthesis of 2-((3-cyano-4-(3,4-dichloro phenyl)- 6-(4-hydroxy-3-methoxyphenyl) pyridin-2-yl) amino)-N-(5-(substituted) -(6-methyl-2-oxo -1,2,3,4- tetrahydro pyrimidin-5-yl)-1,3,4-oxadiazol-2-yl)acetamide by using Biginelli reaction. New structural analogues were confirmed by spectral studies followed by their screening for in vitro antibacterial activity against Staphylococcus aureus, Staphylococcus Pyogenus, Escherichia coli and Pseudomonas aeruginosa bacterial strains and for antifungal activity against Candida albicans, Aspergillus niger and Aspergillus clavatus by micro-broth dilution method. In vitro antimycobacterial activity determined out against (Mycobacterium tuberculosis) H37Rv strain using Lowenstein-Jensen medium. Results: As compared to the conventional method, microwave irradiation method is advantageous for the synthesis of 1,2,3,4-tetrahydropyrimidin derivatives. Potent antimicrobial activities and antitubercular activity were found for some of the compounds. Conclusion: Microwave irradiation method provided an effective way to discover a novel class of antimicrobial and antituberculosis agents. 1,2,3,4-tetrahydropyrimidin derivatives showed improved antimicrobial and good antituberculosis activity.


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Dorian Polo-Cerón

This paper reports the synthesis and detailed characterisation of copper(II) and nickel(II) complexes with tridentate thiosemicarbazone ligands H2L1 and H2L2 derived from 2-acetylpyrazine. The ligands and their metal complexes were characterised by different physicochemical techniques, including elemental and thermogravimetric analysis; UV-Vis, IR, 1H-NMR, and 13C-NMR spectroscopy; molar conductance measurements; and mass spectrometry. The crystal structure of the H2L1 ligand was determined by single crystal X-ray diffraction studies. The spectral data showed that the thiosemicarbazone behaves as an NNS tridentate ligand through the nitrogen atoms of the azomethine group and pyrazine ring and the sulphur atom of the thioamide group. Elemental and thermal analyses indicated that the obtained metal complexes had a 1 : 1 stoichiometry (metal-ligand). The interactions between these complexes and calf thymus DNA (CT-DNA) were studied by electronic absorption and viscosity measurements. The activities of these compounds against oxidative DNA cleavage were examined by agarose gel electrophoresis. Cu(II) and Ni(II) complexes can wind DNA strands through groove interactions and promote strand breakage of the plasmid pmCherry under oxidative stress conditions. Moreover, all the complexes could interact more strongly with DNA than could with the free ligands. Finally, the antibacterial activities of the ligands and their complexes were determined by in vitro tests against Gram-positive bacterial strains (S. aureus ATCC 25923, L. monocytogenes ATCC 19115, and B. cereus ATCC 10876) and Gram-negative bacterial strains (E. coli ATCC 25922, S. typhimurium ATCC 14028, and K. pneumoniae ATCC BAA-2146) using the broth microdilution method. The metal complexes showed greater antimicrobial activities than the precursor ligands against some of the microorganisms.


2007 ◽  
Vol 2007 ◽  
pp. 1-7 ◽  
Author(s):  
Sulekh Chandra ◽  
Smriti Raizada ◽  
Monika Tyagi ◽  
Archana Gautam

A series of metal complexes of Cu(II) and Ni(II) having the general composition[M(L)X2]with benzil bis(thiosemicarbazone) has been prepared and characterized by element chemical analysis, molar conductance, magnetic susceptibility measurements, and spectral (electronic, IR, EPR, mass) studies. The IR spectral data suggest the involvement of sulphur and azomethane nitrogen in coordination to the central metal ion. On the basis of spectral studies, an octahedral geometry has been assigned for Ni(II) complexes but a tetragonal geometry for Cu(II) complexes. The free ligand and its metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties.


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