scholarly journals Insights Into the Mode of Action of the Anti-Candida Activity of 1,10-Phenanthroline and its Metal Chelates

2000 ◽  
Vol 7 (4) ◽  
pp. 185-193 ◽  
Author(s):  
Malachy McCann ◽  
Majella Geraghty ◽  
Michael Devereux ◽  
Denis O'Shea ◽  
James Mason ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Candida Albicans ◽  
Metal Complexes ◽  
Mode Of Action ◽  
Metal Chelates ◽  
Phen Ligand ◽  
Chelating Ligands ◽  
Metal Free ◽  
Highly Active

Metal complexes of malonie acid (metal = Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Ag(I)) were prepared and only the Ag(I) complex inhibited the growth of Candida albicans. Malonate complexes incorporating the chelating 1,10-phenanthroline (1,10-phen) ligand showed a range of activities: good (Mn(II), Cu(II), Ag(I)); moderate (Zn(II)); poor (Co(II), Ni(II)). Metal-free 1,10-phen and Ag(CH3CO2) were also highly active. The metal-free non-chelating ligands 1,7- phenanthroline and 4,7-phenanthroline were inactive and the Cu(II), Mn(II) and Zn(II) complexs of 1,7-phen displayed only marginal activity. Whereas the Cu(II) malonate/1,10-phen complex induces significant cellular oxidative stress the Zn(II) analogue does not.

scholarly journals The newly synthesized thiazole derivatives as potential antifungal compounds against Candida albicans

2021 ◽  
Author(s):  
Anna Biernasiuk ◽  
Anna Berecka-Rycerz ◽  
Anna Gumieniczek ◽  
Maria Malm ◽  
Krzysztof Z. Łączkowski ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Cell Membrane ◽  
Mode Of Action ◽  
Thiazole Derivatives ◽  
Fungal Cell ◽  
Erythrocyte Lysis ◽  
Low Cytotoxicity ◽  
High Antifungal Activity

Abstract Recently, the occurrence of candidiasis has increased dramatically, especially in immunocompromised patients. Additionally, their treatment is often ineffective due to the resistance of yeasts to antimycotics. Therefore, there is a need to search for new antifungals. A series of nine newly synthesized thiazole derivatives containing the cyclopropane system, showing promising activity against Candida spp., has been further investigated. We decided to verify their antifungal activity towards clinical Candida albicans isolated from the oral cavity of patients with hematological malignancies and investigate the mode of action on fungal cell, the effect of combination with the selected antimycotics, toxicity to erythrocytes, and lipophilicity. These studies were performed by the broth microdilution method, test with sorbitol and ergosterol, checkerboard technique, erythrocyte lysis assay, and reversed phase thin-layer chromatography, respectively. All derivatives showed very strong activity (similar and even higher than nystatin) against all C. albicans isolates with minimal inhibitory concentration (MIC) = 0.008–7.81 µg/mL Their mechanism of action may be related to action within the fungal cell wall structure and/or within the cell membrane. The interactions between the derivatives and the selected antimycotics (nystatin, chlorhexidine, and thymol) showed additive effect only in the case of combination some of them and thymol. The erythrocyte lysis assay confirmed the low cytotoxicity of these compounds as compared to nystatin. The high lipophilicity of the derivatives was related with their high antifungal activity. The present studies confirm that the studied thiazole derivatives containing the cyclopropane system appear to be a very promising group of compounds in treatment of infections caused by C. albicans. However, this requires further studies in vivo. Key points • The newly thiazoles showed high antifungal activity and some of them — additive effect in combination with thymol. • Their mode of action may be related with the influence on the structure of the fungal cell wall and/or the cell membrane. • The low cytotoxicity against erythrocytes and high lipophilicity of these derivatives are their additional good properties. Graphical abstract

scholarly journals The Negative Effect of Protein Phosphatase Z1 Deletion on the Oxidative Stress Tolerance of Candida albicans Is Synergistic with Betamethasone Exposure

2021 ◽  
Vol 7 (7) ◽  
pp. 540
Author(s):  
Ágnes Jakab ◽  
Tamás Emri ◽  
Kinga Csillag ◽  
Anita Szabó ◽  
Fruzsina Nagy ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Candida Albicans ◽  
Protein Phosphatase ◽  
Combined Treatment ◽  
Specific Protein ◽  
Ergosterol Biosynthesis ◽  
Acid Oxidation ◽  
Menadione Sodium Bisulfite ◽  
Rnaseq Data ◽  
Negative Effect

The glucocorticoid betamethasone (BM) has potent anti-inflammatory and immunosuppressive effects; however, it increases the susceptibility of patients to superficial Candida infections. Previously we found that this disadvantageous side effect can be counteracted by menadione sodium bisulfite (MSB) induced oxidative stress treatment. The fungus specific protein phosphatase Z1 (CaPpz1) has a pivotal role in oxidative stress response of Candida albicans and was proposed as a potential antifungal drug target. The aim of this study was to investigate the combined effects of CaPPZ1 gene deletion and MSB treatment in BM pre-treated C. albicans cultures. We found that the combined treatment increased redox imbalance, enhanced the specific activities of antioxidant enzymes, and reduced the growth in cappz1 mutant (KO) strain. RNASeq data demonstrated that the presence of BM markedly elevated the number of differentially expressed genes in the MSB treated KO cultures. Accumulation of reactive oxygen species, increased iron content and fatty acid oxidation, as well as the inhibiting ergosterol biosynthesis and RNA metabolic processes explain, at least in part, the fungistatic effect caused by the combined stress exposure. We suggest that the synergism between MSB treatment and CaPpz1 inhibition could be considered in developing of a novel combinatorial antifungal strategy accompanying steroid therapy.

Cathodic Corrosion Activated Fe-based Nanoglass as Highly-Active and -Stable Oxygen Evolution Catalyst for Water Splitting

2021 ◽  
Author(s):  
Kaiyao Wu ◽  
Fei Chu ◽  
Yuying Meng ◽  
Kaveh Edalati ◽  
Qingsheng Gao ◽  
...  
Keyword(s):  
Water Splitting ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Amorphous Alloys ◽  
Precious Metal ◽  
Active Sites ◽  
Metal Free ◽  
Highly Active ◽  
Stable Oxygen ◽  
Surface Active

Transition metal-based amorphous alloys have attracted increasing attention as precious-metal-free electrocatalysts for oxygen evolution reaction (OER) of water splitting due to their high macro-conductivity and abundant surface active sites. However,...

Development of silica-supported frustrated Lewis pairs: highly active transition metal-free catalysts for the Z-selective reduction of alkynes

2016 ◽  
Vol 6 (3) ◽  
pp. 882-889 ◽  
Author(s):  
Kai C. Szeto ◽  
Wissam Sahyoun ◽  
Nicolas Merle ◽  
Jessica Llop Castelbou ◽  
Nicolas Popoff ◽  
...  
Keyword(s):  
Transition Metal ◽  
Lewis Acid ◽  
Selective Reduction ◽  
Frustrated Lewis Pairs ◽  
Acid Base ◽  
Metal Free ◽  
Highly Active ◽  
Active Transition ◽  
Lewis Pairs

Supported Lewis acid/base systems based have been prepared and characterized.

Electrodeposition of catalytically active polyporphyrin films of metal complexes of amino-substituted tetraphenylporphyrins

2018 ◽  
Vol 22 (12) ◽  
pp. 1047-1053 ◽  
Author(s):  
Mariya V. Tesakova ◽  
Mitar Lutovac ◽  
Vladimir I. Parfenyuk
Keyword(s):  
Metal Complexes ◽  
Quartz Crystal ◽  
Film Growth ◽  
Metal Free ◽  
Porphyrin Ligand ◽  
Catalytically Active ◽  
Microscopy Method ◽  
Scanning Electron Microscopy Method ◽  
Electron Microscopy Method ◽  
Scanning Electron

The process of electrodeposition of polyporphyrin films based on amino-substituted tetraphenylporphyrins and their metal complexes (CuT([Formula: see text]-NH[Formula: see text]Ph)P, FeClT([Formula: see text]-NH[Formula: see text]Ph)P, MnClT([Formula: see text]-NH[Formula: see text]Ph)P) has been studied by the quartz crystal microbalance method. The surfaces of the films have been characterized by the scanning electron microscopy method and the number of electrons taking part in porphyrin electropolymerization has been determined. It has been established that the most intensive film growth is observed for the metal-free porphyrin ligand. The obtained polyporphyrin films have been analyzed for the catalytic ability in oxygen electroreduction reactions.

scholarly journals RECENTES APLICAÇÕES DO ORGANOFOTOCATALISADOR 1,2,3,5-TETRAQUIS(CARBAZOL-9-IL)-4,6- DICIANOBENZENO EM TRANSFORMAÇÕES QUÍMICAS

Química Nova ◽  
2020 ◽  
Author(s):  
Lucas Pugnal ◽  
Emanuele Pissinati ◽  
Karina Quaglio ◽  
Márcio Paixão
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Chemical Transformations ◽  
Redox Potentials ◽  
Research Groups ◽  
Organic Fluorophores ◽  
Metal Free ◽  
Polypyridine Complexes ◽  
Distinguished Research

RECENT APPLICATIONS OF THE ORGANIC PHOTOCATALYST 1,2,3,5-TETRAKIS(CARBAZOL-9-YL)- 4,6-DICIANOBENZENE IN CHEMICAL TRANSFORMATIONS. Ruthenium and iridium polypyridine complexes are among the most employed photocatalysts described in literature. The broad applicability is due to the redox potentials and long half-life times of the excited state which these molecules presented. The pursuit for metal-free alternatives has been intensified in the last few years, therefore, many organic fluorophores were successfully employed as photocatalysts. Among them, 1,2,3,5-tetrakis(carbazol-9-yl)- 4,6-dicianobenzene (4CzIPN) recently drawn attention of the community, and it’s been widely employed by distinguished research groups. Recent studies have shown that this catalyst do not only present similar properties to transition metal complexes, but also, its synthesis can be accomplished more easily and less expensive when compared with the metallic photocatalysts above mentioned. Therefore, 4CzIPN constitutes a metal-free alternative to replace transition metal complexes in conventional photochemical protocols. Moreover, it’s as a powerful ally in the development of new photochemical approaches. In this work, we aim to summarize recent applications of 4CzIPN as catalyst in the emerging field of redox photocatalysis.

scholarly journals Amalgamation of Novel Schiff Base Ligand and Its Transition Metal Complexes and Their Biological Activity

2019 ◽  
pp. 1-13
Author(s):  
B. Akila ◽  
A. Xavier
Keyword(s):  
Antibacterial Activity ◽  
Schiff Base ◽  
Metal Complexes ◽  
Elemental Analysis ◽  
Schiff Base Ligand ◽  
Electronic Spectroscopy ◽  
Antioxidant Properties ◽  
Salmonella Typhi ◽  
Metal Chelates ◽  
Schiff Base Complexes

Schiff base synthesized from 2-hydroxy-1-naphthaldehyde and 2-2’ (ethylene dioxy) bis ethylenediamine (L1) and its Metal complexes, [M (II) (L)6](where M= Mn(II), Ru(III), Cu(II)and V(V) L= Schiff base moiety), have been prepared and characterized by elemental analysis, spectroscopic measurements (infrared, electronic spectroscopy, 1H-NMR, EPR and Mass spectroscopy ). Elemental analysis of the metal complexes was suggested that the stoichiometry ratio is 1:1 (metal-ligand). The electronic spectra suggest an octahedral geometry for MC1and MC2 Schiff base complexes and distorted octahedral for MC3 and MC4 complexes. The Schiff base and its metal chelates have been screened for their invitro test antibacterial activity against three bacteria, gram-positive (Staphylococcus aureus) and gram-negative (Klebsiella pheneuammonia and Salmonella typhi). Two strains of fungus (Aspergillus niger and Candida albicans). The metal chelates were shown to possess more anti fungal activity compare then antibacterial activity and antioxidant properties. The complexes are highly active than the free Schiff-base ligand.    

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