The negative environmental and social impacts of food waste accumulation can be mitigated by utilizing bio-refineries' approach where food waste is revalorized into high-value products, such as prodigiosin (PG), using microbial bioprocesses. The diverse biological activities of PG position it as a promising compound, but its high production cost and promiscuous bioactivity hinder its wide application. Metal ions can modulate the electronic properties of organic molecules, leading to novel mechanisms of action and increased target potency, while metal complex formation can improve the stability, solubility and bioavailability of the parent compound.
View Article and Find Full Text PDFRecognizing that metal ions play an important role in modifying the pharmacological properties of known organic-based drugs, the present manuscript addresses the complexation of the antifungal agent voriconazole (vcz) with the biologically relevant silver(I) ion as a strategy for the development of new antimycotics. The synthesized silver(I) complexes with vcz were characterized by mass spectrometry, IR, UV-Vis and NMR spectroscopy and single-crystal X-ray diffraction analysis. The crystallographic results showed that complexes {[Ag(vcz)(HO)]CHSO} (1), {[Ag(vcz)]BF} (2) and {[Ag(vcz)]PF} (3) have polymeric structures in the solid state, in which silver(I) ions have a distorted tetrahedral geometry.
View Article and Find Full Text PDFInspired by the emergence of resistance to currently available antifungal therapy and by the great potential of metal complexes for the treatment of various diseases, we synthesized three new silver(I) complexes containing clinically used antifungal azoles as ligands, [Ag(ecz)]SbF (1, ecz is econazole), {[Ag(vcz)]SbF} (2, vcz is voriconazole), and [Ag(ctz)]SbF (3, ctz is clotrimazole), and investigated their antimicrobial properties. The synthesized complexes were characterized by mass spectrometry, IR, UV-vis and H NMR spectroscopy, cyclic voltammetry, and single-crystal X-ray diffraction analysis. In the mononuclear complexes 1 and 3 with ecz and ctz, respectively, the silver(I) ion has the expected linear geometry, in which the azoles are monodentately coordinated to this metal center through the N3 imidazole nitrogen atom.
View Article and Find Full Text PDFis an opportunistic, Gram-negative bacterium, involved in severe infections associated with cystic fibrosis, pneumonia, burn wounds, ocular diseases, and immunosuppressive illnesses, and is a major cause of intrahospital infections. This bacterium is also one of the most commercially and biotechnologically significant microorganisms, since it can produce valuable biomolecules which represent a rich source of potential drug candidates. On the other hand, metal complexes have been used in medicine for both therapeutic and diagnostic purposes since ancient times.
View Article and Find Full Text PDFDimethyl 6-(pyrazine-2-yl)pyridine-3,4-dicarboxylate (py-2pz) was used as a ligand for the synthesis of new copper(ii) and silver(i) complexes, [CuCl(py-2pz)] (1), [Cu(CFSO)(HO)(py-2pz)]CFSO·2HO (2), [Ag(py-2pz)]PF (3) and {[Ag(NO)(py-2pz)]·0.5HO} (4). The complexes were characterized by spectroscopic and electrochemical methods, while their structures were determined by single crystal X-ray diffraction analysis.
View Article and Find Full Text PDFIn a search for novel antimicrobial metal-based therapeutic agents, mononuclear gold(III) complexes 1-7 of the general formula [AuCl(azole)], where azole stands for imidazole (im, 1), 1-isopropylimidazole (ipim, 2), 1-phenylimidazole (phim, 3), clotrimazole (ctz, 4), econazole (ecz, 5), tioconazole (tcz, 6) and voriconazole (vcz, 7) were synthesized, characterized and biologically evaluated. In all complexes, the corresponding azole ligand is monodentately coordinated to the Au(III) the imidazole or triazole nitrogen atom, while the remaining coordination sites are occupied by chloride anions leading to the square-planar arrangement. antimicrobial assays showed that the complexation of inactive azoles, imidazole, 1-isopropylimidazole and 1-phenylimidazole, to the Au(III) ion led to complexes 1-3, respectively, with moderate activity against the investigated strains and low cytotoxicity on the human normal lung fibroblast cell line (MRC-5).
View Article and Find Full Text PDFThree new silver(I) complexes [Ag(NO)(tia)(HO)] (), [Ag(CFSO)(1,8-naph)] () and [Ag(1,8-naph)(HO)](PF) (), where tia is thianthrene and 1,8-naph is 1,8-naphthyridine, were synthesized and structurally characterized by different spectroscopic and electrochemical methods and their crystal structures were determined by single-crystal X-ray diffraction analysis. Their antimicrobial potential was evaluated against four bacterial and three species, and the obtained results revealed that these complexes showed significant activity toward the Gram-positive Gram-negative and the investigated species with minimal inhibitory concentration (MIC) values in the range 1.56-7.
View Article and Find Full Text PDFFive novel copper(ii) complexes with pyridine-4,5-dicarboxylate esters as ligands, [Cu(NO)(py-2tz)(HO)]NO (1), [Cu(NO)(py-2metz)(HO)] (2), [Cu(NO)(py-2py)(HO)]·HO (3), [CuCl(py-2tz)] (4) and [CuCl(py-2metz)] (5) (py-2tz is dimethyl 2-(thiazol-2-yl)pyridine-4,5-dicarboxylate, py-2metz is dimethyl 2-(4-methylthiazol-2-yl)pyridine-4,5-dicarboxylate and py-2py is dimethyl 2,2'-bipyridine-4,5-dicarboxylate), were synthesized and structurally characterized by different spectroscopic and electrochemical methods. The structure of these complexes was determined by single-crystal X-ray diffraction analysis, confirming the bidentate coordination mode of the corresponding pyridine-4,5-dicarboxylate ester to the Cu(ii) ion through the nitrogen atoms. The antimicrobial potential of copper(ii) complexes 1-5 was assessed against two bacterial and two Candida species.
View Article and Find Full Text PDFCopper(II) and zinc(II) complexes with clinically used antifungal drug fluconazole (fcz), {[CuCl(fcz)]5HO}, , and {[ZnCl(fcz)]·2CHOH}, , were prepared and characterized by spectroscopic and crystallographic methods. The polymeric structure of the complexes comprises four fluconazole molecules monodentately coordinated via the triazole nitrogen and two chlorido ligands. With respect to fluconazole, complex showed significantly higher antifungal activity against and .
View Article and Find Full Text PDFA series of mononuclear gold(iii) complexes of the general formula [AuCl(diazanaphthalene)], where diazanaphthalene is quinazoline (qz, 1), phthalazine (phtz, 2), 1,5-naphthyridine (1,5-naph, 3), 1,6-naphthyridine (1,6-naph, 4) or 1,8-naphthyridine (1,8-naph, 5), were prepared and fully characterized. The complexes 1-5 consist of discrete monomeric species with the Au(iii) cation in a square planar coordination geometry surrounded by three chloride anions and one diazanaphthalene ligand. Crystallographic studies indicate the presence of an extended 4 + 1 or 4 + 2 geometry around the square planar [AuCl(diazanaphthalene)] center due to Au⋯Cl and Au⋯N interactions.
View Article and Find Full Text PDFNew dinuclear silver(i) complexes with N,N',N'',N'''-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane (tpmc), [Ag2(NO3)(tpmc)]NO3·1.7H2O (1), [Ag2(CF3SO3)2(tpmc)] (2), and [Ag2(tpmc)](BF4)2 (3) were synthesized and characterized by NMR (1H and 13C), IR and UV-Vis spectroscopy, cyclic voltammetry and molar conductivity measurements. The molecular structures of the complexes were determined by single-crystal X-ray diffraction analysis.
View Article and Find Full Text PDFThree novel Zn(II) complexes, [ZnCl(qz)] (1), [ZnCl(1,5-naph)] (2) and [ZnCl(4,7-phen)] (3), where qz is quinazoline, 1,5-naph is 1,5-naphthyridine and 4,7-phen is 4,7-phenanthroline, were synthesized by the reactions of ZnCl and the corresponding N-heterocyclic ligand in 1:2 molar ratio in ethanol at ambient temperature. The characterization of these complexes was done by NMR, IR and UV-Vis spectroscopy, and their crystal structures were determined by single-crystal X-ray diffraction analysis. Complexes 1 and 3 are mononuclear species, in which Zn(II) ion is tetrahedrally coordinated by two nitrogen atoms belonging to two qz or 4,7-phen ligands, respectively, and by two chloride anions, while complex 2 is a 1D coordination polymer that contains 1,5-naph as bridging ligand between two metal ions.
View Article and Find Full Text PDF1,2-Bis(4-pyridyl)ethane (bpa) and 1,2-bis(4-pyridyl)ethene (bpe) were used for the synthesis of polynuclear silver(I) complexes, {[Ag(bpa)]NO} (), {[Ag(bpa)]CFSO HO} () and {[Ag(bpe)]CFSO} (). In complexes , the corresponding nitrogen-containing heterocycle acts as a bridging ligand between two Ag(I) ions. antimicrobial activity of these complexes, along with the ligands used for their synthesis, was evaluated against the broad panel of Gram-positive and Gram-negative bacteria and fungi.
View Article and Find Full Text PDFInfections of the cow udder leading to mastitis and lower milk quality are one of the biggest problems in the dairy industry worldwide. Unfortunately, therapeutic options for the treatment of cow mastitis are limited as a consequence of the development of pathogens that are resistant to conventionally used antibiotics. In the search for agents that will be active against cow mastitis associated pathogens, in the present study, five new silver(i) complexes with different chelating pyridine-4,5-dicarboxylate types of ligands, [Ag(NO)(py-2py)] (1), [Ag(NO)(py-2metz)] (2), [Ag(CHCN)(py-2py)]BF (3), [Ag(py-2tz)]BF (4) and [Ag(py-2metz)]BF (5), py-2py is dimethyl 2,2'-bipyridine-4,5-dicarboxylate, py-2metz is dimethyl 2-(4-methylthiazol-2-yl)pyridine-4,5-dicarboxylate and py-2tz is dimethyl 2-(thiazol-2-yl)pyridine-4,5-dicarboxylate, were synthesized, structurally characterized and assessed for in vitro antimicrobial activity using both standard bioassay and clinical isolates from a contaminated milk sample obtained from a cow with mastitis.
View Article and Find Full Text PDFNew polynuclear silver(I) complexes with 1,5-naphthyridine (1,5-naph), [Ag(NO)(1,5-naph)] (Ag1), [Ag(CFCOO)(1,5-naph)] (Ag2) and [Ag(CFSO)(1,5-naph)] (Ag3) were synthesized by the reaction of the corresponding silver(I) salt and 1,5-naph in ethanol at room temperature. These complexes were characterized by NMR, IR and UV-Vis spectroscopy, while their crystal structures were determined by single-crystal X-ray diffraction analysis. In all these complexes, 1,5-naph acts as a bridging ligand between two Ag(I) ions, while the remaining coordination sites are occupied by oxygen atom(s) of the corresponding anion.
View Article and Find Full Text PDFFive novel silver(I) complexes with 4,7-phenanthroline (4,7-phen), [Ag(NO-O)(4,7-phen-μ-N4,N7)] (1), [Ag(ClO-О)(4,7-phen-μ-N4,N7)] (2), [Ag(CFCOO-O)(4,7-phen-μ-N4,N7)] (3), [Ag(HO)(4,7-phen)](SbF) (4) and {[Ag(HO)(4,7-phen-μ-N4,N7)](BF)} (5) were synthesized, structurally elucidated and biologically evaluated. These complexes showed selectivity towards Candida spp. in comparison to the tested bacteria and effectively inhibited the growth of four different Candida species, particularly of C.
View Article and Find Full Text PDFMononuclear silver(I) complexes with 1,7-phenanthroline (1,7-phen), [Ag(NO-O,O') (1,7-phen-N7)] (1) and [Ag(1,7-phen-N7)]X, X = ClO (2), CFSO (3), BF (4) and SbF (5) were synthesized and structurally characterized by NMR (H and C), IR and UV-Vis spectroscopy and ESI mass spectrometry. The crystal structures of 1, 3 and 4 were determined by single-crystal X-ray diffraction analysis. In all these complexes, 1,7-phen coordinates to the Ag(I) ion in a monodentate fashion via the less sterically hindered N7 nitrogen atom.
View Article and Find Full Text PDFDinuclear platinum(II) complexes, [{Pt(en)Cl}(-qx)]Cl·2HO (), [{Pt(en)Cl}(-qz)](ClO) (), and [{Pt(en)Cl}(-phtz)]Cl·4HO (), were synthesized and characterized by different spectroscopic techniques. The crystal structure of was determined by single-crystal X-ray diffraction analysis, while the DFT M06-2X method was applied in order to optimize the structures of . The chlorido Pt(II) complexes were converted into the corresponding aqua species , and their reactions with an equimolar amount of Ac-L-Met-Gly and Ac-L-His-Gly dipeptides were studied by H NMR spectroscopy in the pH range 2.
View Article and Find Full Text PDFGold(III) complexes with 1,7- and 4,7-phenanthroline ligands, [AuCl(1,7-phen-κN7)] (1) and [AuCl(4,7-phen-κN4)] (2) were synthesized and structurally characterized by spectroscopic (NMR, IR and UV-vis) and single-crystal X-ray diffraction techniques. In these complexes, 1,7- and 4,7-phenanthrolines are monodentatedly coordinated to the Au(III) ion through the N7 and N4 nitrogen atoms, respectively. In comparison to the clinically relevant anti-angiogenic compounds auranofin and sunitinib, gold(III)-phenanthroline complexes showed from 1.
View Article and Find Full Text PDFTwo dinuclear palladium(II) complexes, [{Pd(en)Cl}(μ-pz)](NO) and [{Pd(en)Cl}(μ-pydz)](NO), have been synthesized and characterized by elemental microanalysis and spectroscopic (H and C NMR, IR and UV-vis) techniques (en is ethylenediamine; pz is pyrazine and pydz is pyridazine). The square planar geometry of palladium(II) metal centers in these complexes has been predicted by DFT calculations. The chlorido complexes were converted into the corresponding aqua complexes, [{Pd(en)(HO)}(μ-pz)] and [{Pd(en)(HO)}(μ-pydz)], and their reactions with N-acetylated l-histidylglycine (Ac-l-His-Gly) and l-methionylglycine (Ac-l-Met-Gly) were studied by H NMR spectroscopy.
View Article and Find Full Text PDFGold(iii) complexes with different l-histidine-containing dipeptides, [Au(Gly-l-His-N,N,N3)Cl]Cl·3HO (1a), [Au(Gly-l-His-N,N,N3)Cl]NO·1.25HO (1b), [Au(l-Ala-l-His-N,N,N3)Cl][AuCl]·HO (2a), [Au(l-Ala-l-His-N,N,N3)Cl]NO·2.5HO (2b), [Au(l-Val-l-His-N,N,N3)Cl]Cl·2HO (3), [Au(l-Leu-l-His-N,N,N3)Cl]Cl (4a) and [Au(l-Leu-l-His-N,N,N3)Cl][AuCl]·HO (4b), have been synthesized and structurally characterized by spectroscopic (H NMR, IR and UV-vis) and single-crystal X-ray diffraction techniques.
View Article and Find Full Text PDFFive silver(I) complexes with aromatic nitrogen-containing heterocycles, phthalazine (phtz) and quinazoline (qz), were synthesized, characterized and analyzed by single-crystal X-ray diffraction analysis. Although different AgX salts reacted with phtz, only dinuclear silver(I) complexes of the general formula {[Ag(X-O)(phtz-N)]2(μ-phtz-N,N')2} were formed, X=NO3(-) (1), CF3SO3(-) (2) and ClO4(-) (3). However, reactions of qz with an equimolar amount of AgCF3SO3 and AgBF4 resulted in the formation of polynuclear complexes, {[Ag(CF3SO3-O)(qz-N)]2}n (4) and {[Ag(qz-N)][BF4]}n (5).
View Article and Find Full Text PDFInterest in antimicrobial gold complexes originated from the work of Robert Koch at the end of 19th century, who demonstrated that potassium dicyanidoaurate(I), K[Au(CN)2], showed activity against Mycobacterium tuberculosis, a causative agent of tuberculosis. Subsequently, a large number of gold(I) and gold(III) complexes have been evaluated as possible antimicrobial agents against a broad spectrum of bacteria, fungi and parasites. The first part of the present review article summarizes the results achieved in the field of antibacterial and antifungal activity of gold(I) and gold(III) complexes.
View Article and Find Full Text PDFIntroduction: Urinary prostate-specific antigen (uPSA) can be used as additional parameter of benign prostatic hyperplasia (BPH) progression.
Materials And Methods: From January 2001 to December 2011, uPSA was determined in 265 patients with benign prostate. Based on total prostate volume (TPV), the patients with benign prostate were divided in two groups: TPV < 31 mL and TPV ≥ 31 mL.
The present review article highlights recent findings in the field of gold(III) complexes with amino acids, peptides and proteins. The first section of this article provides an overview of the gold(III) reactions with amino acids, such as glycine, alanine, histidine, cysteine and methionine. The second part of the review is mainly focused on the results achieved in the mechanistic studies of the reactions between gold(III) and different peptides and structural characterization of gold(III)-peptide complexes as the final products in these reactions.
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