scholarly journals Manganese(IV) Complexes Derived from Polyfunctional Dihydrazone: Structural, Electrochemical and Antimicrobial Studies

2021 ◽  
Vol 33 (5) ◽  
pp. 1144-1152
Author(s):  
P. Sarma ◽  
P. Mahanta ◽  
D. Basumatary ◽  
C. Medhi

Manganese(IV) complexes viz. [MnIV(nagh)(A)2]·2H2O and [MnIV(nagh)(NN)] have been synthesized from ligand bis(2-hydroxy-1-naphthaldehyde)glutaryldihydrazone (naghH4) and auxiliary ligands, A = H2O (1)/pyridine (2)/2-picoline (3)/3-picoline (4)/ 4-picoline (5) or NN = 2,2′-bipyridine (6)/1,10-phenanthroline (7). The elemental analysis, mass spectral and thermal studies supported the composition of all the manganese(IV) complexes. Structural aspects were determined from magnetic susceptibility, molar conductivity and spectral studies i.e. electronic, electron spin resonance and infrared. Their non-electrolytic nature were determined from molar conductances. Results from studies of magnetic moment, electronic and ESR suggested Mn(IV) ion in six-coordinate octahedral stereochemistry. The ligand coordinated to the metal in enolic form as a tetradentate in an anti-cis configuration as was correlated from IR data. Redox activities and antimicrobial potential against few Gram-positive and Gram-negative bacteria have been investigated for the dihydrazone and some manganese(IV) complexes.

2000 ◽  
Vol 55 (11-12) ◽  
pp. 1030-1034 ◽  
Author(s):  
Gudddadarangavvanahally K. Jayaprakasha ◽  
Pradeep S. Negi ◽  
Sagarika Sikder ◽  
Lingamallu Jagan Mohanrao ◽  
Kurian K. Sakariah

Citrus peels were successively extracted with hexane, chloroform and acetone using a soxhlet extractor. The hexane and chloroform extracts were fractionated into alcohol-soluble and alcohol-insoluble fractions. These fractions were tested against different gram positive and gram negative bacteria. The EtOH-soluble fraction was found to be most effective. Fractionation of EtOH -soluble fraction on silica gel column yielded three polymethoxylated flavones, namely desmethylnobiletin, nobiletin and tangeretin. Their structures were confirm ed by UV, 1H, 13C NMR and mass spectral studies. The findings indicated a potential of these natural compounds as bio preservatives in food applications.


2015 ◽  
Vol 70 (1-2) ◽  
pp. 45-50
Author(s):  
Asu Usta ◽  
Hacer Taşkıran

Abstract N-alkyl substituted 2′,3″-thiazachalcones {3-[(1E)-3-(4-methylthiophene-2-yl)-3-oxoprop-1-en-1-yl]-1-alkyl (C5–12,14) pyridinium bromides} were synthesized by a two-step reaction. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, elemental analysis and mass spectral studies. The synthesized compounds were tested for antibacterial activities and found to be more active against Gram-positive as compared to Gram-negative bacteria.


2012 ◽  
Vol 9 (1) ◽  
pp. 481-486
Author(s):  
K. Anuradha ◽  
R. Rajavel

Novel Cu(II),Ni(II) and VO(II) complexes are synthesized with N1,N4-bis(2-aminobenzylidene)benzene-1,4-diamine (L). Complexes were characterized by elemental analysis, molar conductance, IR, UV and EPR. Spectral studies reveals a square planner geomentry for Cu(II), Ni(II) complexes and square pyramidal for VO(II) complex. The ligand and its complexes were also evaluated against the growth of gram positive bacteria and gram negative bacteria.


2019 ◽  
Vol 31 (5) ◽  
pp. 1087-1090 ◽  
Author(s):  
Pradip P. Deohate ◽  
Roshani S. Mulani

Microwave irradiative synthesis of triazine substituted pyrazoles i.e. (4-benzylideneamino-6-methyl-[1,3,5]-triazin-2-yl)-(5-methyl-2-substituted benzoyl/isonicotinoyl/cinnamoyl-pyrazol-3-yl)-amines have been achieved by the cyclocondensation of N-(4-benzylideneamino-6-methyl-[1,3,5]-triazin-2-yl)-3-oxo butyramide with substituted acid hydrazides. Synthesis of required butyramide was done by reacting 2,4-diamino-6-methyl-[1,3,5]-triazine with benzaldehyde and then condensing the product with ethyl acetoacetate. Structural investigation of synthesized compounds has been done by chemical transformation, elemental analysis and IR, 1H NMR, mass spectral studies. Study of antitubercular and antimicrobial activity of title compounds against some selected Gram-positive and Gram-negative microorganisms was performed to establish the relationship between structure and activity of compound.


2020 ◽  
Vol 49 (3) ◽  
pp. 207-214 ◽  
Author(s):  
Hatem E. Gaffer ◽  
Ismail I. Althagafi

Purpose The purpose of this paper is to synthesize some new azobenzene dyestuffs clubbed with thiazolidinone moiety and their solicitation in dyeing polyester fabrics representing their antibacterial evaluation. Design/methodology/approach Herein, the authors report the synthesis of new thiazolidinone moiety after the coupling of diazotized 4-aminoacetophenone with resorcinol. The newly synthesized dyes were characterized by IR, elemental analysis, mass spectroscopy and proton nuclear magnetic resonance (1H NMR) spectral studies. The characteristics of dyeing of these dyestuffs were evaluated at optimum conditions. Concurrent with dyeing of polyester fabric for synthesized dyes with their antibacterial activity was estimated. Antimicrobial activity of the dyed fabrics at different concentrations was evaluated against gram-positive and gram-negative bacteria. Findings Synthesized azobenzene dyestuffs clubbed with thiazolidinone dyes were applied on polyester fabrics. It was remarked that the modified dyes exhibited better colourfastness properties. Furthermore, the synthesized dyes revealed antimicrobial activity against gram-positive and gram-negative bacteria. Research limitations/implications The synthesized azobenzene dyes for polyester dyeing were not bore earlier. Practical implications The azobenzene dyes were accountable for giving improved colourfastness properties on polyester fabrics. Social implications The synthesized azobenzene derivatives are sensibly expensive and applicable dyes accompanied with good antimicrobial and anticancer activities. Originality/value A common process could be affording textiles of colour and antibacterial assets. The newly synthesized dyes containing thiazolidinone moieties with azobenzene coupler showed interesting disperse colourant for polyester with good antibacterial activity.


Author(s):  
Pooja Pisal ◽  
Meenakshi Deodhar ◽  
Amol Kale ◽  
Ganesh Nigade ◽  
Smita Pawar

Objective: A new series 2-phenyl-3-(substituted benzo[d] thiazol-2-ylamino)-quinazoline-4(3H)-one was prepared by the fusion method by reacting 2-phenyl benzoxazine with 2-hydrazino benzothiazole and it was evaluated for their antimicrobial activity against gram positive, gram negative bacteria and fungi.Methods: Titled compounds were synthesized by fusion reactions. These compounds were evaluated by in vitro antibacterial and antifungal activity using the minimum inhibitory concentration and zone of inhibition methods. The synthesized compounds were characterized with the help of infrared, NMR and mass spectral studies. The benzothiazole moiety and the quinazoline ring have previously shown DNA gyrase inhibition and target related antibacterial activity. Thus, molecular docking studies of synthesized compounds were carried out (PDB: 3G75) to study the possible interaction of compounds with the target. The batch grid docking was performed to determine the probable.Results: These compounds showed significant activity against gram positive and gram negative bacteria as well against the fungi. The compound A5 was found to be active against B. subtilis, P aeruginosa and C. albican at 12.5 µg/ml MIC. The compound A3 was found to be active against all microbial strains selected at 25 and 12.5 µg/ml MIC.Conclusion: Though the relationship between the activities shown by these compounds in, the antimicrobial study is still to be established, the docking studies conducted found to be consistent with antimicrobial results. Thus the results indicate that the designed structure can be a potential lead as an antimicrobial agent.


Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 776
Author(s):  
Joon Ha Lee ◽  
Hoyong Chung ◽  
Yong Pyo Shin ◽  
Mi-Ae Kim ◽  
Sathishkumar Natarajan ◽  
...  

An insect’s innate immune system is the front line of defense against many invading microorganisms. One of the important components of this defense system is antimicrobial peptides (AMPs). Papiliocin is a well-studied antimicrobial peptide (AMP) isolated from the swallowtail butterfly, Papilio xuthus, and it was previously reported to be effective against Gram-positive bacteria, Gram-negative bacteria, and fungi, particularly in drug resistant Gram-negative bacteria. Hence, we aimed to identify novel AMPs from Papilio xuthus using its transcriptome. We immunized the swallowtail butterfly with Escherichia coli, Staphylococcus aureus, Candida albicans, and the total RNA was isolated. De novo transcriptome assembly and functional annotations were conducted, and AMPs were predicted using an in-silico pipeline. The obtained 344,804,442 raw reads were then pre-processed to retrieve 312,509,806 (90.6%) total clean reads. A total of 38,272 unigenes were assembled with the average length of 1010 bp. Differential gene expression analysis identified 584 and 1409 upregulated and downregulated genes, respectively. The physicochemical, aggregation, and allergen propensity were used as filtration criteria. A total of 248 peptides were predicted using our in-house pipeline and the known AMPs were removed, resulting in 193 novel peptides. Finally, seven peptides were tested in vitro and three peptides (Px 5, 6, and 7) showed stronger antimicrobial activity against Gram-negative bacteria and yeast. All the tested peptides were non-allergens. The identified novel AMPs may serve as potential candidates for future antimicrobial studies.


Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 15
Author(s):  
Saeed Ali Syed ◽  
Ahmed Bari ◽  
Mohammed S. Aldughaim ◽  
Md Abdur Rashid ◽  
Mohammad Hossain Shariare ◽  
...  

In recent years, indole derivatives have acquired conspicuous significance due to their wide spectrum of biological activities—antibacterial, antiviral, and anticonvulsant. This compound is derived from naturally grown plants. Therefore, synthesis of a novel “3-(Naphthalen-1-ylimino)indolin-2-one” compound (2) and its analysis using UPLC systems along with antimicrobial assessment was the aim of the current study. Isatin was used as a parent drug for synthesizing compound (2). Liquid Chromatographic analysis was performed using a C18 BEH column (1.7 μm 2.1 × 50 mm) by UPLC systems. Degradation studies were carried out to see whether acid, base, thermal, and oxidizing agents had any impact on the synthesized molecule in stress conditions (100 °C). A lipid-based self-nanoemulsifying formulation was developed and selectivity, specificity, recovery, accuracy, and precision were measured as part of the UPLC system’s validation process. Antimicrobial studies were conducted using gram-positive and gram-negative bacteria. The standard samples were run with a concentration range of 5.0–100.0 μg/mL using the isocratic mobile phase comprising of methanol/water (70/30 %v/v) at 234 nm; good linearity (R2 = 0.9998) was found. The lower limits of detection (LOD) and quantitation (LOQ) of the method were found to be 0.81 μg/mL and 2.5 μg/mL, respectively. The coefficients of variation were found to be less than 2%. The antimicrobial study suggests that compound (2) has a substantial growth effect against gram-negative bacteria. It was successfully synthesized and applied to measure the concentrations in lipid-based dosage form, along with potent antimicrobial activities.


2009 ◽  
Vol 23 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Ghulam Rabbani ◽  
Anvarhusein A. Isab ◽  
Abdul Rahman Al-Arfaj ◽  
Saeed Ahmad ◽  
Muhammad Saleem ◽  
...  

Mercury(II) complexes of thiolates having the general formula [Hg(RS)Cl2]−and [Hg(RS)2] have been prepared and characterized by IR and NMR (1H and13C) spectroscopy (RSH = 2-aminoethanethiol hydrochloride (Aet), cysteine (Cys), thiosalicylic acid (Ts) and 2-mercaptonicotinic acid (Mnt)). The spectral data suggests that the coordination of thiolates to mercury(II) occurs through the sulfur as indicated by the absence of S–H vibrations in IR and significant downfield shifts in the C–S resonance in13C NMR. However, in Mnt complexes, coordination through both sulfur and nitrogen is indicated. Antimicrobial activities of the complexes were evaluated by minimum inhibitory concentration and the results showed that the complexes exhibited a wide range of activities against gram-negative bacteria (E. coli, P. aeruginosa), while moderate activity was observed against a mold,P. citrinum.


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