Synthesis, characterization and biological activity of new Ni(II), Pd(II) and Cr(III) complex compounds with chlorhexidine

Six new coordination compounds of Ni(II), Pd(II) and Cr(III) with chlorhexidine, 1,1?-hexamethylenebis[5-(4-chlorophenyl)biguanide], were prepared, characterized and examined for their potential as antimicrobial agents, as well as for their antioxidant activity. The metal complexes correspond to the formulas: [Ni(CHX)]Cl2?2H2O, [Ni(CHX)]Br2?2H2O, [Ni(CHX)](CH3COO)2?C2H5OH, [Pd(CHX)][PdCl4]?2H2O, [Pd(CHX)](CH3COO)2 and [Cr(CHX)Cl2](CH3COO), where CHX = chlorhexidine. Investigations on the in vitro antimicrobial activity of the complexes indicated that all have high activity against the tested bacteria, but are less active against fungi. Among the six complexes, those of Pd(II) showed the highest antibacterial activity, [Pd(CHX)][PdCl4]?2H2O being more active against Gram-positive and Gram-negative bacteria than chlorhexidine diacetate. The antioxidant activity of the metal complexes was investigated by photochemiluminescence and the results showed that the palladium( II) complexes have high antioxidant activities.

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SPS-neutralization in tissue samples for efficacy testing of antimicrobial peptides

BMC Infectious Diseases ◽

10.1186/s12879-019-4700-1 ◽

2019 ◽

Vol 19 (1) ◽

Author(s):

Gabrielle Sherella Dijksteel ◽

Peter H. Nibbering ◽

Magda M. W. Ulrich ◽

Esther Middelkoop ◽

Bouke K. H. L. Boekema

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Peptides ◽

Antimicrobial Agents ◽

Ex Vivo ◽

Residual Activity ◽

Gram Negative Bacteria ◽

Tissue Samples ◽

Gram Negative ◽

Viable Bacteria

Abstract Background Accurate determination of the efficacy of antimicrobial agents requires neutralization of residual antimicrobial activity in the samples before microbiological assessment of the number of surviving bacteria. Sodium polyanethol sulfonate (SPS) is a known neutralizer for the antimicrobial activity of aminoglycosides and polymyxins. In this study, we evaluated the ability of SPS to neutralize residual antimicrobial activity of antimicrobial peptides [SAAP-148 and pexiganan; 1% (wt/v) in PBS], antibiotics [mupirocin (Bactroban) and fusidic acid (Fucidin) in ointments; 2% (wt/wt))] and disinfectants [2% (wt/wt) silver sulfadiazine cream (SSD) and 0.5% (v/v) chlorhexidine in 70% alcohol]. Methods Homogenates of human skin models that had been exposed to various antimicrobial agents for 1 h were pipetted on top of Methicillin-resistant Staphylococcus aureus (MRSA) on agar plates to determine whether the antimicrobial agents display residual activity. To determine the optimal concentration of SPS for neutralization, antimicrobial agents were mixed with PBS or increasing doses of SPS in PBS (0.05–1% wt/v) and then 105 colony forming units (CFU)/mL MRSA were added. After 30 min incubation, the number of viable bacteria was assessed. Next, the in vitro efficacy of SAAP-148 against various gram-positive and gram-negative bacteria was determined using PBS or 0.05% (wt/v) SPS immediately after 30 min incubation of the mixture. Additionally, ex vivo excision wound models were inoculated with 105 CFU MRSA for 1 h and exposed to SAAP-148, pexiganan, chlorhexidine or PBS for 1 h. Subsequently, samples were homogenized in PBS or 0.05% (wt/v) SPS and the number of viable bacteria was assessed. Results All tested antimicrobials displayed residual activity in tissue samples, resulting in a lower recovery of surviving bacteria on agar. SPS concentrations at ≥0.05% (wt/v) were able to neutralize the antimicrobial activity of SAAP-148, pexiganan and chlorhexidine, but not of SSD, Bactroban and Fucidin. Finally, SPS-neutralization in in vitro and ex vivo efficacy tests of SAAP-148, pexiganan and chlorhexidine against gram-positive and gram-negative bacteria resulted in significantly higher numbers of CFU compared to control samples without SPS-neutralization. Conclusions SPS was successfully used to neutralize residual activity of SAAP-148, pexiganan and chlorhexidine and this prevented an overestimation of their efficacy.

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Synthesis, antioxidant and antimicrobial activity of carbohydrazones

Journal of the Serbian Chemical Society ◽

10.2298/jsc161220045b ◽

2017 ◽

Vol 82 (5) ◽

pp. 495-508 ◽

Cited By ~ 9

Author(s):

Aleksandra Bozic ◽

Nenad Filipovic ◽

Irena Novakovic ◽

Snezana Bjelogrlic ◽

Jasmina Nikolic ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antioxidant Activity ◽

Dimethyl Sulphoxide ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Antioxidant Compound ◽

Antioxidant And Antimicrobial Activity ◽

Bacteria And Fungi

Fourteen mono- and bis-carbohydrazone ligands have been synthesized and characterized. Antioxidant activity of the substances was investigated together with possible (E)/(Z) isomerization, and explained on the most active antioxidant compound 4 in various dimethyl sulphoxide?water mixtures. The addition of water to the system was involved in the formation of hydrated molecules which was confirmed in NMR after the addition of D2O. The ligands were tested in vitro against Gram-positive and Gram-negative bacteria and fungi, and their activity was discussed in relation to the structure of investigated carbohydrazone.

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Didymocarpous Pedicellatus R. Br.: Qualitative and Quantitative GCMS Approach for Quality Control in Traditional Poly-Herbal Formulation with In Vitro Antioxidant and Antimicrobial Activity

Oriental Journal Of Chemistry ◽

10.13005/ojc/350220 ◽

2019 ◽

Vol 35 (2) ◽

pp. 648-657 ◽

Cited By ~ 1

Author(s):

Wasim Ahmad ◽

Ennus T. Tamboli ◽

Abuzer Ali ◽

Mohd Amir ◽

S. M. A. Zaidi ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antioxidant Activity ◽

Diffusion Method ◽

Gram Negative Bacteria ◽

Good Precision ◽

Gram Negative ◽

Herbal Formulation ◽

Antioxidant And Antimicrobial Activity ◽

Bacteria And Fungi

A Gas Chromatography and Maas Spectroscopy method was developed and validated for determination and identification of α-humulene in a traditional medicinal herb Didymocarpous pedicellatus R. Br. (DP) (Gesneriaceae) and its poly herbal formulation, Safoof-e-pathar phori (SPP) including their essential oil. Hydrodistillation method were used for the isolation of essential oils from the leaves of DP and SPP herbal formulation. The proposed analysis method was found to be linear r2 = 0.999 in a wide concentration range (0.1-1000 µgmL-1), with good precision (RSD < 2.0%). Antimicrobial activity of α-humulene, DP and SPP oil was assessed by using agar well diffusion method against clinically important Gram-positive, Gram-negative bacteria and fungi. α-Humulene was found to be more active in contrast to Gram-negative bacteria while DP oil and SPP oil were exhibited maximum inhibition against fungal strains. Antioxidant activity of α-humulene, DP oil and SPP oil were determined using 2, 2-diphenyl-1-picryl hydrazyl radical (DPPH) 96 well plate method, which showed antioxidant activity in the following order: standard ascorbic acid (DPPH FRS50 = 2.40 µg) > DP oil (DPPH FRS50 = 3.68 µg) > SPP oil (DPPH FRS50 = 12.54 µg) > and α-humulene (DPPH FRS50 = 36.19 µg).

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Synthesis and characterization of new copper(II) complex compounds with chlorhexidine. Part I

Open Chemistry ◽

10.2478/s11532-010-0028-9 ◽

2010 ◽

Vol 8 (3) ◽

pp. 543-549 ◽

Cited By ~ 5

Author(s):

Mirela Călinescu ◽

Ticuţa Negreanu-Pîrjol ◽

Rodica Georgescu ◽

Octavian Călinescu

Keyword(s):

Antimicrobial Activity ◽

Metal Salt ◽

Complex Compounds ◽

Synthesis And Characterization ◽

Gram Negative Bacteria ◽

Reaction Conditions ◽

Gram Negative ◽

Imine Nitrogen

AbstractThree new copper(II) complex compounds with chlorhexidine diacetate as a ligand have been prepared and characterized by elemental and thermogravimetrical analyses, molar conductances, magnetic susceptibility measurements, infrared, electronic and EPR spectra. The complexes correspond to the formulas: [Cu2(CHX)Cl4]·2C2H5OH, [Cu2(CHX)Br4]·2C2H5OH and [Cu2(CHX)(CH3COO)2] (CH3COO)2·2C2H5OH, where CHX = chlorhexidine, their composition and stereochemistry depending on the reaction conditions and the metal salt used. Chlorhexidine acts as neutral tetradentate NNNN donor, coordinating through the four imine nitrogen atoms. Investigations on antimicrobial activity in vitro show that all the complexes are active against the tested microorganisms, the complex with chloride being more active against Gram negative bacteria than chlorhexidine diacetate..

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SPS-neutralization in tissue samples for efficacy testing of antimicrobial peptides

10.21203/rs.2.12222/v2 ◽

2019 ◽

Author(s):

Gabrielle Dijksteel ◽

Peter Nibbering ◽

Magda Ulrich ◽

Esther Middelkoop ◽

Bouke Boekema

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Peptides ◽

Antimicrobial Agents ◽

Ex Vivo ◽

Residual Activity ◽

Gram Negative Bacteria ◽

Tissue Samples ◽

Gram Negative ◽

Viable Bacteria

Abstract Background Accurate determination of the efficacy of antimicrobial agents requires neutralization of residual antimicrobial activity in the samples before microbiological assessment of the number of surviving bacteria. Sodium polyanethol sulfonate (SPS) is a known neutralizer for the antimicrobial activity of aminoglycosides and polymyxins. In this study, we evaluated the ability of SPS to neutralize residual antimicrobial activity of antimicrobial peptides [SAAP-148 and pexiganan; 1% (wt/v) in PBS], antibiotics [mupirocin (Bactroban) and fusidic acid (Fucidin) in ointments; 2% (wt/wt))] and disinfectants [2% (wt/wt) silver sulfadiazine cream (SSD) and 0.5% (v/v) chlorhexidine in 70% alcohol]. Methods Homogenates of human skin models that had been exposed to various antimicrobial agents for 1 h were pipetted on top of Methicillin-resistant Staphylococcus aureus (MRSA) on agar plates to determine whether the antimicrobial agents display residual activity. To determine the optimal concentration of SPS for neutralization, antimicrobial agents were mixed with PBS or increasing doses of SPS in PBS (0.05-1% wt/v) and then 10^5 colony forming units (CFU)/mL MRSA were added. After 30 min incubation, the number of viable bacteria was assessed. Next, the in vitro efficacy of SAAP-148 against various gram-positive and gram-negative bacteria was determined using PBS or 0.05% (wt/v) SPS immediately after 30 min incubation of the mixture. Additionally, ex vivo excision wound models were inoculated with 10^5 CFU MRSA for 1 h and exposed to SAAP-148, pexiganan, chlorhexidine or PBS for 1 h. Subsequently, samples were homogenized in PBS or 0.05% (wt/v) SPS and the number of viable bacteria was assessed. Results All tested antimicrobials displayed residual activity in tissue samples, resulting in a lower recovery of surviving bacteria on agar. SPS concentrations at ≥0.05% (wt/v) were able to neutralize the antimicrobial activity of SAAP-148, pexiganan and chlorhexidine, but not of SSD, Bactroban and Fucidin. Finally, SPS-neutralization in in vitro and ex vivo efficacy tests of SAAP-148, pexiganan and chlorhexidine against gram-positive and gram-negative bacteria resulted in significantly higher numbers of CFU compared to control samples without SPS-neutralization. Conclusion SPS was successfully used to neutralize residual activity of SAAP-148, pexiganan and chlorhexidine and this prevented an overestimation of their efficacy.

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Synthesis and Evaluation of Some Coumarin Containing Potential Antimicrobial Agents

E-Journal of Chemistry ◽

10.1155/2012/953564 ◽

2012 ◽

Vol 9 (4) ◽

pp. 2493-2500

Author(s):

Sayali D. Kudale ◽

Meenakshi N. Deodhar

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Agents ◽

Gram Negative Bacteria ◽

Schiff’S Bases ◽

Gram Positive ◽

Gram Negative ◽

H Nmr ◽

Nmr Data ◽

Bacteria And Fungi

A series of the Schiff’s bases incorporating coumarin and chalcone moeities, 3-(4-(4-(substituted phenyl)prop-1-ene-3-one) phenylimino) methyl)-4-chloro-2h-chromen-2-one 4(a-g) were synthesized as potential antimicrobial agents. These compounds were characterized on the basis of their spectral (IR,1H NMR) data and evaluated for antimicrobial activity in vitro against gram positive and gram negative bacteria and fungi. Compound 4b was found to be most active with an MIC of 20 µg/mL against all the tested organisms.

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Synthesis and Evaluation of Some Coumarin Based Schiff's Bases as Potential Antimicrobial Agents'

E-Journal of Chemistry ◽

10.1155/2012/791091 ◽

2012 ◽

Vol 9 (4) ◽

pp. 2079-2088 ◽

Cited By ~ 1

Author(s):

Vishakha Bansode ◽

Meenakshi N. Deodhar

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Agents ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

H Nmr ◽

Nmr Data ◽

Bacteria And Fungi

A series of the title compounds 3-(4-(4, 5-dihydro-5-(substituted phenyl)-1H-3-pyrazolyl) phenylimino) methyl)-4-chloro-2H-chromen-2-one 5(a-g) have been synthesized. These compounds were characterized on the basis of their spectral (IR,1H NMR) data and evaluated for antimicrobial activityin vitroagainst gram positive bacteria, gram negative bacteria and fungi. The compound (5b) was found to be the most active with MIC of 20 µg/ml against all the tested organisms.

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Design, Synthesis and Evaluation of Schiff’s Bases of 4-Chloro-3-coumarin aldehyde as Antimicrobial Agents

E-Journal of Chemistry ◽

10.1155/2009/874389 ◽

2009 ◽

Vol 6 (3) ◽

pp. 759-762 ◽

Cited By ~ 12

Author(s):

Shriram Bairagi ◽

Ashok Bhosale ◽

Meenakshi N. Deodhar

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Agents ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Design Synthesis ◽

Gram Negative ◽

H Nmr ◽

Nmr Data ◽

Bacteria And Fungi

4-Chloro-2-oxo-2H-chromene-3-carbaldehyde(2)was reacted with different anilines in rectified spirit as solvent to yield a series of the title compoundsi.e. 4-chloro-3-((substituted-phenylimino) methyl)-2H-chromen-2-one(3a-i). These compounds were charaterised on the basis of their spectral (IR,1H NMR) data and evaluated for antimicrobial activityin vitroagainst gram positive and gram negative bacteria and fungi. Compound3Cwas found to be most active with an MIC of 15 μg /mL against all the tested organisms.

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Synthesis, In Vitro and In Silico Studies of Indolequinone Derivatives against Clinically Relevant Bacterial Pathogens

Current Topics in Medicinal Chemistry ◽

10.2174/1568026620666191223110518 ◽

2020 ◽

Vol 20 (3) ◽

pp. 192-208 ◽

Cited By ~ 1

Author(s):

Talita Odriane Custodio Leite ◽

Juliana Silva Novais ◽

Beatriz Lima Cosenza de Carvalho ◽

Vitor Francisco Ferreira ◽

Leonardo Alves Miceli ◽

...

Keyword(s):

In Silico ◽

Bacterial Infections ◽

Antimicrobial Agents ◽

Mass Spectrometry Analysis ◽

World Health ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Dione Derivative ◽

In Silico Studies

Background: According to the World Health Organization, antimicrobial resistance is one of the most important public health threats of the 21st century. Therefore, there is an urgent need for the development of antimicrobial agents with new mechanism of action, especially those capable of evading known resistance mechanisms. Objective: We described the synthesis, in vitro antimicrobial evaluation, and in silico analysis of a series of 1H-indole-4,7-dione derivatives. Methods: The new series of 1H-indole-4,7-diones was prepared with good yield by using a copper(II)- mediated reaction between bromoquinone and β-enamino ketones bearing alkyl or phenyl groups attached to the nitrogen atom. The antimicrobial potential of indole derivatives was assessed. Molecular docking studies were also performed using AutoDock 4.2 for Windows. Characterization of all compounds was confirmed by one- and two-dimensional NMR techniques 1H and 13C NMR spectra [1H, 13C – APT, 1H x 1H – COSY, HSQC and HMBC], IR and mass spectrometry analysis. Results: Several indolequinone compounds showed effective antimicrobial profile against Grampositive (MIC = 16 µg.mL-1) and Gram-negative bacteria (MIC = 8 µg.mL-1) similar to antimicrobials current on the market. The 3-acetyl-1-(2,5-dimethylphenyl)-1H-indole-4,7-dione derivative exhibited an important effect against different biofilm stages formed by a serious hospital life-threatening resistant strain of Methicillin-Resistant Staphylococcus aureus (MRSA). A hemocompatibility profile analysis based on in vitro hemolysis assays revealed the low toxicity effects of this new series. Indeed, in silico studies showed a good pharmacokinetics and toxicological profiles for all indolequinone derivatives, reinforcing their feasibility to display a promising oral bioavailability. An elucidation of the promising indolequinone derivatives binding mode was achieved, showing interactions with important sites to biological activity of S. aureus DNA gyrase. These results highlighted 3-acetyl-1-(2-hydroxyethyl)-1Hindole- 4,7-dione derivative as broad-spectrum antimicrobial prototype to be further explored for treating bacterial infections. Conclusion: The highly substituted indolequinones were obtained in moderate to good yields. The pharmacological study indicated that these compounds should be exploited in the search for a leading substance in a project aimed at obtaining new antimicrobials effective against Gram-negative bacteria.

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