Search

Made available in DSpace on 2022-05-01T03:58:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 A silver(I) complex with succinic acid in the form of succinate is presented. Chemical characterization confirms the molecular composition Ag2C4H4O4 for the complex. Infrared spectra suggest a bidentate coordination of both carboxylate groups of succinates to the two Ag(I) ions. Density functional theory (DFT) studies were used in the structures of succinic acid and Ag(I) succinate complex with coordination formula [Ag2(C4H4O4)] in order to optimize them to their minimum energy. The studies confirmed that each carboxylate group of the succinate anion is coordinated to one silver atom by the two oxygen in a bidentate mode and the bond lengths O···Ag theoretically determined range from 2.325 to 2.338 Å. The complex [Ag2(C4H4O4)] showed in vitro antibacterial activity against the bacterial strains of Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa complex. Anti-Mycobacterium tuberculosis analyses were also performed and the [Ag2(C4H4O4)] complex was shown to be active over M. tuberculosis H37Rv strain with MIC90 of 23.94 μg mL-1 while succinic acid itself showed a value higher than 25.00 μg mL-1. University of Araraquara Graduate Program in Biotechnology in Regenerative Medicine and Medicinal Chemistry University of Araraquara Medicine Course São Paulo State University Institute of Chemistry São Paulo State University School of Pharmaceutical Sciences University of Campinas Institute of Chemistry Federal University of Tocantins Chemistry Collegiate São Paulo State University Institute of Chemistry São Paulo State University School of Pharmaceutical Sciences

Made available in DSpace on 2021-06-25T10:50:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Myrcia bella is a medicinal plant used for the treatment of diabetes, hemorrhages, and hypertension in Brazilian folk medicine. Considering that plant extracts are attractive sources of new drugs, the aim of the present study was to verify the influence of incorporating 70% hydroalcoholic of M. bella leaves in nanostructured lipid systems on the mutagenic and antifungal activities of the extract. In this work, we evaluated the antifungal potential of M. bella loaded on the microemulsion against Candida sp for minimum inhibitory concentration, using the microdilution technique. The system was composed of polyoxyethylene 20 cetyl ether and soybean phosphatidylcholine (10%), grape seed oil, cholesterol (10%: proportion 5/1), and purified water (80%). To investigate the mutagenic activity, the Ames test was used with the Salmonella Typhimurium tester strains. M. bella, either incorporated or free, showed an important antifungal effect against all tested strains. Moreover, the incorporation surprisingly inhibited the mutagenicity presented by the extract. The present study attests the antimicrobial properties of M. bella extract, contributing to the search for new natural products with biological activities and suggesting caution in its use for medicinal purposes. In addition, the results emphasize the importance of the use of nanotechnology associated with natural products as a strategy for the control of infections caused mainly by the genus Candida sp. University of Araraquara (UNIARA) Department of Biological Sciences and Health São Paulo State University (UNESP) Department of Biological Sciences Faculty of Science São Paulo State University (UNESP) Department of Biological Sciences School of Pharmaceutical Sciences, Campus Araraquara São Paulo State University (UNESP) Department of Drugs and Medicines School of Pharmaceutical Sciences, Campus Araraquara University of Brasilia Nanobiotechnology Laboratory Department of Genetics and Morphology University of Araraquara Department of Biological Sciences and Health UNIARA Carlos Gomes 1338, Rua Carlos Gomes, 1217 São Paulo State University (UNESP) Department of Biological Sciences Faculty of Science São Paulo State University (UNESP) Department of Biological Sciences School of Pharmaceutical Sciences, Campus Araraquara São Paulo State University (UNESP) Department of Drugs and Medicines School of Pharmaceutical Sciences, Campus Araraquara

Copper(II)–sulfonamide–(N^N) complexes are a promissing class of compounds resulting from the combination of bioactive organic drugs with the Cu–(N^N) motif. Here, we expand on the studies of three of such compounds that we had previously reported to be effective metallonucleases with promising antiproliferative activities. Since the compounds were previously shown to interact with DNA mostly in a non-covalent form, in this study we investigated their interactions with specific nucleotides to evaluate possible ligand replacement and preferential purine or pyrimidine base binding. Results showed partial ligand dissociation followed by non-preferential nucleotide binding in the conditions of mass spectrometric experiments. Additional biophysical studies of the interaction between the complexes and serum albumin, which is an important class of carriers of metallodrugs in plasma were performed and described for the first time here. Fluorescence spectroscopy indicated binding of the compounds to albumin, while dynamic light scattering (DLS) and circular dichroism (CD) data indicated no significant alteration of protein secondary structure or agglomeration. The compounds showed no protease activity on serum albumin or on lysozyme, a smaller protein, even in the presence of a reducing agent. The absence of protease activity is an important factor when it is considered the compounds can be transported by serum albumin and, when combined with data we reported previously, also indicates that DNA is more prone to cleavage by the compounds. Since both sulfonamides and copper(II) complexes have antibacterial effects, here we investigated the antibacterial activity of the complexes on three prevalent bacterial strains (Staphylococcus aureus, Escherichia coli and Psedomonas aeruginosa) with results indicating that the compounds are more active towards the Gram-positive S. aureus strain. The combination of the Cu–(N^N) motif with synergic sulfonamide ligands leads to metallonucleases with potential application in various biological endpoints.

Three platinum(II) complexes containing amantadine (atd), rimantadine (rtd) and memantine (mtn) as ligands were synthesized and characterized by chemical and spectroscopic methods. The crystal data revealed the coordination formula [PtCl2(ligand)(DMSO)] for the three complexes. The stability studies of the complexes by 1H nuclear magnetic resonance (NMR) spectroscopy revealed a ligand exchange of the DMSO ligand in the coordination sphere by deuterated DMSO-d6 used as solvent. The 195Pt NMR of the complexes confirmed the presence of one platinum species in solution and the chemical shifts are consistent with the coordination sphere observed in the crystallographic studies. Theoretical studies of complexes and ligands were also performed and combined with the experimental data to support the structural features of the synthesized compounds. The in vitro antibacterial activity assays showed that free ligands rimantadine and memantine were able to inhibit the growth of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa bacterial strains, while amantadine was inactive. Their respective Pt(II) complexes, on the other hand, showed to be more active over Gram-positive bacteria than the Gram-negative ones, with the platinum(II) memantine complex (Pt-mtn) being the most active one. Biophysical assays suggest that the Pt(II) complexes interact with CT-DNA and alter its B-form, as observed by CD spectroscopy. The interaction of the three complexes with bovine serum albumin was also evidenced by fluorescence spectroscopy, which revealed that the platinum(II) rimantadine complex (Pt-rtd) is the most reactive of this series.

Bacterial cellulose (BC) production can be performed using a static or stirred culture method. In the static culture method, the BC is obtained presents three-dimensional thinner network structures and excellent mechanical properties. In the agitated culture method, BC is produced in the form of fibrous granules or threads with a lower degree of polymerization, mechanical resistance, and crystallinity than the films formed in static fermentation. Compared with BC membranes, sphere-like BC (SBC) cultured under agitated conditions showed advantages for adsorption due to its larger surface area. The objectives of this work were to obtain SBC, by the bacterial strain Komagataeibacter hansenii ATCC 23769, in agitated cultivation, using media containing different carbon sources carbon sources, such as fructose (FRU), glucose and sucrose (MS1), sucrose (Y) and glucose (Z and HS), aiming to produce supports for sustained release of rifampicin (RIF). SBC has been produced under agitation at 130 rpm and 25°C. SBC obtained were processed to remove bacteria and residues from the culture media and lyophilized. The SBC characterizations were performed by Fourier transform infrared spectroscopy (FTIR), Field emission gun-scanning electron microscopy (FEG-SEM), thermogravimetric analysis (TGA) and by derivative thermogravimetry (DTG). The SBC produced were impregnated with antibiotic RIF and tested for the sustained release capacity of this drug by diffusion method and Frans cell kinetics. SBC that the best results for all tests were produced in FRU, Z and MS1 media, respectively. The results demonstrate the potential of the SBC to contribute to the design of new drug delivery systems with biomedical applications.

Made available in DSpace on 2021-06-25T10:56:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-15 Platinum complexes have received special attention due to their biological properties with emphasis on the antitumor and antibacterial activities. In this manuscript, we report the synthesis of a novel water-soluble Pt(II) complex with the amino acid deoxyalliin (S-allyl-L-cysteine, sac), [Pt(sac)2], and its characterization by a set of chemical and spectroscopic techniques besides its preliminary antibacterial activity assays. Elemental and high-resolution mass spectrometric data (ESI-MS) indicated its 1:2 metal/ligand molar composition, with the molecular formula [Pt(C6H10NO2S)2]⋅H2O. The crystal structure of the complex was solved by single-crystal X-ray diffraction studies, where the two molecules of deoxyalliin were shown to be coordinated to the metal in a bidentate N,S-mode and in a trans-configuration. The 1H, 13C and 195Pt nuclear magnetic resonance (NMR) results and the infrared spectroscopic data reinforced the N,S-coordination of deoxyalliin to the metal. The coordination mode of the ligand was supported by density functional theory (DFT) calculations. The antibacterial activity of the complex was preliminarily evaluated by the minimum inhibitory concentration (MIC) assay. The experiments were performed for the complex and the free ligand over Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacterial strains. The [Pt(sac)2] complex did not show inhibitory effect in bacterial growth even at the highest concentration of 3.75 mmol L−1 considered in the present study. Institute of Chemistry University of Campinas – UNICAMP, P.O. Box 6154 Faculty of Pharmaceutical Sciences University of Campinas – UNICAMP Chemistry Collegiate Federal University of Tocantins-UFT, Campus Gurupi, PO Box 66 Institute of Chemistry Federal University of Goiás – UFG, Campus Samambaia Graduate Program in Biotechnology Regenerative Medicine and Medicinal Chemistry University of Araraquara - UNIARA Department of Analytical Physicochemical and Inorganic Chemistry Institute of Chemistry – São Paulo State University - UNESP Department of Analytical Physicochemical and Inorganic Chemistry Institute of Chemistry – São Paulo State University - UNESP

Made available in DSpace on 2020-12-12T02:49:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-11-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The aims of this work were to evaluate the antibacterial and antiproliferative potential in vitro of the metal complex with 4-aminobenzoic acid (Ag-pABA) and a drug delivery system based on bacterial cellulose (BC-Ag-pABA). The Ag-pABA complex was characterized by elemental analysis, high resolution mass spectrometry and single-crystal X-ray diffraction techniques, which indicated a 1:2 metal/pABA composition plus a nitrate ion coordinated to silver by the oxygen atom, with the coordination formula [Ag (C7H7NO2)2(NO3)]. The coordination of pABA to the silver ion occurred by the nitrogen atom. The in vitro antibacterial activity of the complex evaluated by minimum inhibitory concentration assays demonstrated the effective growth inhibitory activity against Gram-positive, Gram-negative biofilm producers and acid-alcohol resistant Bacillus. The antiproliferative activities against a panel of eight tumor cells demonstrated the activity of the complex with a significant selectivity index (SI). The DNA interaction capacity and the Ames Test indicated the absence of mutagenicity. The BC-Ag-pABA composite showed an effective capacity of sustained release of Ag-pABA. The observed results validate further studies on its mechanisms of action and the conditions that mediate the in vivo biological effects using animal models to confirm its safety and effectiveness for treatment of skin and soft tissues infected by bacterial pathogens, urinary tract infections and cancer. University of Araraquara – UNIARA Institute of Chemistry University of Campinas – UNICAMP Faculty of Pharmaceutical Sciences University of Campinas – UNICAMP São Paulo State University – UNESP School of Pharmaceutical Sciences Faculty of Medical Sciences University of Campinas – UNICAMP São Paulo State University – UNESP School of Pharmaceutical Sciences FAPESP: , 2015/09833-0 CAPES: 001 FAPESP: 019/03049-7 FAPESP: 13/07276-1 FAPESP: 2014/06779-2 FAPESP: 2015/20882-3 FAPESP: 2016/07729-4 FAPESP: 2017/16278-9 FAPESP: 2017/19243-1 FAPESP: 2018/00163-0 FAPESP: 2018/02344-2 FAPESP: 2018/12062-4 FAPESP: 2018/12590-0 FAPESP: 2018/25512-8 CNPq: 300968/2016-7 CNPq: 407822/2018

Made available in DSpace on 2018-12-11T17:37:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-10-15 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Komagataeibacter rhaeticus, a bacterium isolated from Kombucha tea, was used to produce bacterial cellulose (BC) through its cultivation in a static sugarcane molasses (SCM) supplemented-culture medium (totally or partially), as an alternative carbon source. BC membranes were characterized by different physicochemical analysis using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission gun-scanning electron microscopy (FEG-SEM), thermogravimetry analysis (TGA) and PeakForce quantitative nanomechanics atomic force microscopy (PeakForce (QNM-AFM)). FTIR, XRD and TGA results suggest great similarity among all membranes produced by distinct culture media. Although the glucose (F1) and SCM (F6) media presented the lowest BC yield, all SCM-supplemented culture media (from F2 to F5) showed BC yield values similar to the HS culture medium (F0). FEG-SEM analysis showed that as higher SCM concentrations on culture media higher dense nanofibers network could be prepared. Quantitative nanomechanical results obtained by AFM technique corroborate FEG-SEM analysis besides show smoother and more flexible BC membranes as a function of the increasing of the SCM concentrations. The modification of the carbon source of the culture medium with an important by-product of Brazilian agroindustry appears as a viable alternative to reduce cost of BC production (of up to 20.06%) besides increase the possibilities of industrial scale BC preparation. University of Araraquara – UNIARA Interdisciplinary Laboratory of Advanced Materials Centro de Ciências da Natureza – CNN Universidade Federal do Piauí – UFPI Institute of Chemistry – São Paulo State University – UNESP Group ‘Materials + Technologies’ (GMT) Department of Chemical and Environmental Engineering Faculty of Engineering Gipuzkoa University of the Basque Country (UPV/EHU), Plaza Europa 1 Faculty of Engineering Vitoria-Gasteiz University of the Basque Country (UPV/EHU), C/Nieves Cano 12 Laboratório de Pesquisa Desenvolvimento & Inovação, Apis Flora Ind. Coml. Ltda, Ribeirão Preto Institute of Chemistry – São Paulo State University – UNESP

The search for modulating ligand substitution reaction in gold complexes is essential to find new active metallo compounds for medical applications. In this work, a new linear and hydrosoluble goldI complex with tris-(2-carboxyethylphosphine) (AuTCEP). The two phosphines coordinate linearly to the metal as solved by single crystal X-ray diffraction. Complete spectroscopic characterization is also reported. In vitro growth inhibition (GI50) in a panel of nine tumorigenic and one non-tumorigenic cell lines demonstrated the complex is highly selective to ovarium adenocarcinoma (OVCAR-03) with GI50 of 3.04 nmol mL−1. Moreover, non-differential uptake of AuTCEP was observed between OVCAR-03 (tumor) and HaCaT (non-tumor) two cell lines. Biophysical evaluation with the sulfur-rich biomolecules showed the compound does not interact with two types of zinc fingers, bovine serum albumin, N-acetyl- l -cysteine and also l -histidine, revealing to be inert to ligand substitution reactions with these molecules. However, AuTCEP demonstrated to cleave plasmidial DNA, suggesting DNA as a possible target. No antibacterial activity was observed in the strains evaluated. Besides, it inhibits 15% of the activity of a mixture of serine-β-lactamase and metallo-β-lactamase from Bacillus cereus in the enzymatic activity assay, similarly to EDTA. These results suggest AuTCEP is selective to metallo-β-lactamase but the cell uptake is hindered, and the compound does not reach the periplasmic space of Gram-positive bacteria. The unique inert behavior of AuTCEP is interesting and represent the modulation of the reactivity through coordination chemistry to decrease the toxicity associated with AuI complexes and its lack of specificity, generating very selective compounds with unexpected targets.

Palladium(II) and platinum(II) complexes with a hydrazide derivative of ibuprofen (named HIB) were synthesized and characterized by chemical and spectroscopic methods. Elemental and thermogravimetric analyses, as well as ESI-QTOF-MS studies for both complexes, confirmed a 1:2:2 metal/HIB/Cl− molar ratio. The crystal structure of the palladium(II) complex was solved by single crystal X-ray diffractometric analysis, which permitted identifying the coordination formula [PdCl2(HIB)2]. Crystallographic studies also indicate coordination of HIB to the metal by the NH2 group. Nuclear magnetic resonance and infrared spectroscopies reinforced the coordination observed in the crystal structure and suggested that the platinum(II) complex presents similar coordination modes and structure when compared with the Pd(II) complex. The complexes had their structures optimized with the aid of DFT methods. In vitro antiproliferative assays showed that the [PdCl2(HIB)2] complex is active over ovarian cancer cell line OVCAR-03, while biophysical studies indicated its capacity to interact with CT-DNA. The complexes were inactive over Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa bacterial strains.

Made available in DSpace on 2018-11-26T17:42:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) In this work, for the first time bacterial cellulose (BC) hydrogel membranes were used for the fabrication of antimicrobial cellulosic nanocomposites by hydrothermal deposition of Cu derivative nanoparticles (i.e. Cu(0) and CuxOy species). BC-Cu nanocomposites were characterized by FTIR, SEM, AFM, XRD and TGA, to study the effect of hydrothermal processing time on the final physicochemical properties of final products. XRD result show that depending on heating time (3-48 h), different CuxOy phases were achieved. SEM and AFM analyses unveil the presence of the Cu(0) and copper CuxOy nanoparticles over BC fibrils while the surface of 3D network became more compact and smother for longer heating times. Furthermore, the increase of heating time placed deleterious effect on the structure of BC network leading to decrease of BC crystallinity as well as of the on-set degradation temperature. Notwithstanding, BC-Cu nanocomposites showed excellent antimicrobial activity against E. coli, S. aureus and Salmonella bacteria suggesting potential applications as bactericidal films. Univ Fed Piaui, Dept Quim, Campus Minist Petronio Portela, BR-64049550 Teresina, PI, Brazil Univ Estadual Paulista, Inst Quim Araraquara, Dept Quim Geral & Inorgan, Rua Prof Francisco Degni,55, BR-14800060 Araraquara, SP, Brazil Centro Univ Araraquara, Lab Biopolimeros & Biomat BIOPOLMAT, Rua Carlos Gomes,1217, BR-14801320 Araraquara, SP, Brazil Univ Basque Country UPV EHU, Dpto Ingn Quim & Medio Ambiente, Escuela Politecn Donostia San Sebastian, Pza Europa 1, Donostia San Sebastian 20018, Spain Univ Luterana Brasil, Programa Posgrad Genet & Toxicol Aplicada, Ave Farroupilha,8001,Predio 01, BR-92450900 Canoas, RS, Brazil Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Carlos, SP, Brazil Univ Estadual Paulista, Inst Quim Araraquara, Dept Quim Geral & Inorgan, Rua Prof Francisco Degni,55, BR-14800060 Araraquara, SP, Brazil FAPESP: 2015/ 09833-0 FAPESP: 2016/06612-6

A ternary copper(II) complex with sulfamethizole (SMZ, C9H10N4O2S2) and 1,10-phenantroline (phen), [Cu(SMZ)2(phen)], and a silver(I) complex with sulfamethizole, Ag-SMZ, are presented. Elemental analyses indicate a 2:1:1 SMZ/copper/phen composition for the [Cu(SMZ)2(phen)] complex and a 1:1 silver/SMZ composition for the Ag-SMZ complex. Mass spectrometric analyses permitted identifying the [Cu(SMZ)2(phen)+H]+ and [Ag(SMZ)+H]+ ions at m/z 782.0297 and m/z 378.9371, respectively, confirming the proposed compositions. Theoretical isotopic patterns match with the experimental ones for the copper and silver complexes. 1H and {15N,1H} HMBC nuclear magnetic resonance (NMR), and infrared (IR) spectroscopic measurements evidence the coordination of sulfamethizole to silver(I) by the SO2-N group, and indicate the participation of the 5-membered heterocyclic ring 5-methyl-1,3,4-thiadiazole in coordination. The [Cu(SMZ)2(phen)] crystal structure was determined by single crystal X-ray diffractometry, attesting the N-coordination of sulfamethizole to copper(II) by the nitrogen of the 5-methyl-1,3,4-thiadiazole heterocyclic ring. Electronic paramagnetic resonance (EPR) indicates a square pyramidal geometry around the copper(II) ion for the [Cu(SMZ)2(phen)] complex. Biological studies showed the antibacterial activity of the Ag-SMZ and [Cu(SMZ)2(phen)] complexes over Gram-positive and Gram-negative bacteria. Both complexes have shown to be more active against Gram-negative Pseudomonas aeruginosa ATCC bacterial strain, with minimum inhibitory concentration (MIC) values of 0.41 mmol L−1 for the silver(I) complex and 1.60 mmol L−1 for the copper(II) complex.

The present article describes the synthesis and biological studies in vitro of a novel silver complex with furosemide (Ag-FSE). Elemental, thermal and mass spectrometric analysis indicated a 1:1 metal/ligand composition, with the molecular formula AgC 12 H 10 ClN 2 O 5 S. Infrared and nuclear magnetic resonance studies suggest coordination of the ligand to the silver ion by the oxygen atoms of the carboxylate group. Additional Density Functional Theory (DFT) studies led to the proposition of the structure of the Ag-FSE complex. The antibacterial activities of the complex were primarily evaluated by antibiogram assays using the disc diffusion method and minimum inhibitory concentrations (MIC). Moreover, the mutagenicity of the complex was also evaluated to ensure that it is safe for subsequent application. The Ag-FSE complex has shown a significant in vitro antibacterial activity against Gram-positive Staphylococcus aureus (ATCC 25923), Gram negative Escherichia coli (ATCC 25922) and Pseudomonas aeruginosa (ATCC 27853), and yeast Candida albicans (ATCC 90028). The absence of a mutagenic activity of Ag-FSE against Salmonella Typhimurium bacterial strains in the Ames assay is an extremely important finding for its future use as a drug in medicine.

Neste trabalho, foi realizada a sintese de complexos de Ag(I) e Cu(II) com sulfametazina. Os complexos foram caracterizados por analise elementar, espectroscopia no infravermelho, analise termica, ressonância magnetica nuclear e espectrometria de massas. A atividade antibacteriana dos complexos foi avaliada pelo ensaio de determinacao da concentracao inibitoria minima (CIM) e a interacao dos compostos com biomoleculas foi analisada por eletroforese.

The coordination chemistry and antimicrobial profiles of three copper(II) complexes with 2-(imidazole-2-yl)heteroaryl ligands, named impy, impz and impm, have been investigated. Based on X-ray structure determination the complexes present square planar geometry with coordination formulas [CuCl2(impx)], where x = y, z or m. Elemental analysis and mass spectrometric results are in agreement with the proposed compositions. Vibrational spectroscopy and molecular modeling provided further evidences that the [CuCl2(impz)] complex, which did not have its structure solved by X-ray diffraction, adopts a similar geometry of the other two complexes. Electronic spectroscopic data indicated that all three ligands led to a hypsochromic shift of the d-d band when compared to CuCl2·2H2O and that the electronic structure of the ligands are significantly altered upon coordination to Cu(II). Electronic paramagnetic resonance studies in solution showed that the compounds present similar coordination environments. The MIC values of the complexes over E. coli and S. aureus was 17.8 μmol·mL−1, thus no distinction was found between the complexes and the tested strain. The complexes were inactive over three tested fungal strains under the considered experimental conditions.

A silver(I) complex with the antitumor drug 5-fluorouracil was synthesized and characterized by a set of chemical and spectroscopic techniques. Elemental, thermogravimetric and mass spectrometric analyses indicate a 3:2 metal/ligand composition, with minimal formula Ag3(C4HFN2O2)(C4H2FN2O2). Solid-state NMR and IR spectroscopic studies suggest that coordination to silver(I) occurs by the nitrogen atoms N1 and N3, and by oxygen atom O2 of the ligand. The in vitro antiproliferative assays show the higher activity of the silver(I) complex with 5-fluorouracil when compared to the free drug against ovarian multidrug resistant (NCI/ADR-RES) and colon (HT29) tumor cell lines, with 50% growth inhibition (GI50) values of 0.36 and 0.34 μg mL−1, respectively. Gel electrophoresis assay indicated that the silver(I) complex does not interact with pIRES DNA plasmid. The compound also presented higher activity than cisplatin against a variety of tumor cell lines. The compound was also assayed over Gram-positive (Staphyloccocus aureus) and −negative (Escherichia coli and Pseudomonas aeruginosa) bacterial strains and the MIC values show its activity over the considered microorganisms at high concentrations.

The present work describes the synthesis, structural characterization and antibacterial assays of two silver(I) complexes with the sulfa drugs sulfisoxazole (SIZH) and sulfadimethoxine (SDMXH). Chemical analyses and high resolution mass spectrometric studies led to 1:1 metal/ligand compositions, suggesting the minimal formulas AgC11H12O3N3S·H2O for Ag–SIZ and AgC12H13O4N4S for Ag–SDMX. Infrared and solution state NMR spectroscopic measurements indicated ligand coordination to Ag(I) by the nitrogen atoms of the SO2N and NH2 groups in Ag–SIZ, whereas for Ag–SDMX the coordination of the ligand to Ag(I) occurs by the SO2N group and one of the nitrogen atoms of the pyrimidine ring. The proposed coordination modes were confirmed by X-ray diffraction studies and showed the formation of dimeric structures in both cases. The Ag–SDMX complex shows the classical bridging mode of coordination, in which the silver ions bridge between the nitrogen atom of the sulfonamide group of one ligand and the nitrogen atom of the pyrimidine ring of the second ligand, while for the Ag–SIZ complex coordination occurs by the nitrogen atoms of the NH2 and SO2N groups. Antibacterial assays indicated that Ag–SIZ and Ag–SDMX complexes are effective against Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacterial strains, being the Ag–SDMX complex more active than the Ag–SIZ one. These results are an indicative that the ligand structures and dissimilar coordination modes of the sulfonamides may be associated to the antibacterial activities of the complexes.

A silver complex with the sulfonamide sulfameter, also known as sulfamethoxydiazine (SMTR), was prepared and characterized. Chemical analyses were consistent with the [Ag(C11H11N4O3S)] composition (AgSMTR), while conductivity measurements in DMSO indicated a non-electrolyte behavior of the complex in this solvent. High-resolution ESI(+)-QTOF mass spectrometric experiments revealed the presence of the [Ag(C11H11N4O3S)+H]+ and [Ag2(C11H11N4O3S)2+H]+ species in solution. Infrared and NMR spectroscopies indicated coordination of the ligand to the metal by the nitrogen atoms of the sulfonamide group and of the pyrimidine ring. The structure of AgSMTR was solved by powder X-ray diffraction technique using the Rietveld method. The solved structure confirms the formation of a dimer, where each silver ion is coordinated by one of the nitrogen atoms of the pyrimidine ring, the nitrogen of the sulfonamide group and by an oxygen atom from the sulfonyl group. An argentophilic interaction of 2.901(1) A is present in this dimeric structure. The AgSMTR complex was assayed over Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacterial strains, and it was found that the compound is 8 times more active over the Gram-negative bacteria in DMSO solution, with MIC values in the micromolar range.

Bacterial cellulose (BC) produced by some bacteria, among them Gluconacetobacter xylinum, which secrets an abundant 3D networks fibrils, represents an interesting emerging biocompatible nanomaterial. Since its discovery BC has shown tremendous potential in a wide range of biomedical applications, such as artificial skin, artificial blood vessels and microvessels, wound dressing, among others. BC can be easily manipulated to improve its properties and/or functionalities resulting in several BC based nanocomposites. As example BC/collagen, BC/gelatin, BC/Fibroin, BC/Chitosan, etc. Thus, the aim of this review is to discuss about the applicability in biomedicine by demonstrating a variety of forms of this biopolymer highlighting in detail some qualities of bacterial cellulose. Therefore, various biomedical applications ranging from implants and scaffolds, carriers for drug delivery, wound-dressing materials, etc. that were reported until date will be presented.

The emergence of bacterial strains resistant to antibiotics, such as the sulfonamides (sulfa drugs), is currently a case of concern. The synthesis of metal complexes using well-known antibacterial agents and bioactive metals has proven to be an excellent strategy in the development of new and more active metallodrugs. Herein, we report the synthesis, structural characterization and antibacterial analysis of new gold(I) and silver(I) complexes with the sulfa drug sulfasalazine (ssz). Elemental, thermal and high-resolution mass spectrometric measurements indicated a 1:1:1 Au/ssz/Ph3P molar composition for the gold(I) complex (Ph3P - triphenylphosphine), while for the silver(I) complex the molar composition was 1:1 Ag/ssz. Solution state NMR and infrared spectroscopic data suggest that ssz coordinates to silver(I) and gold(I) by the oxygen atoms of the deprotonated carboxylic group. The coordination mode of the carboxylate was supported by density functional theory (DFT) calculations, which reinforces a monodentate coordination for the gold(I) complex and a bridged bidentate mode for the silver(I) one, with the molecular formulas [(Ph3P)Au(ssz)] and [Ag(ssz)]2, respectively. Antibacterial activity assays indicated the sensitivity of Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacterial strains to [Ag(ssz)]2 and [(Ph3P)Au(ssz)] complexes, while the free ligand was not able to inhibit the growth of any tested bacteria. The non-interaction of the complexes with deoxyribonucleic acid (DNA) was also demonstrated, which suggests that this biomolecule is not a preferential target for the compounds.

Polynuclear copper(II) complexes with nalidixic acid hydrazones derivatives containing 2-imidazolyl (h2imi, complexes 1A and 1B), 4-imidazolyl (h4imi, complexes 2A and 2B), salicyl (hsali, complex 3) and 1H-pyrrolyl (hpyrr, complex 4) units were synthesized and characterized by chemical and spectroscopic methods. Crystallographic studies of complex 1B, [Cu3(h2imi−)2Cl4], show that coordination of hydrazones to Cu(II) occurs by tridentate modes of the type κ3(O,N,N′) as well as bidentate modes of the type κ2(O′,N″). For complexes 2A and 4, EPR data are compatible with a trinuclear structure, based on an antiferromagnetic coupling between copper centers that is stronger at low temperature. Complexes 1A, 2A, 3 and 4 had their antiproliferative activities evaluated in vitro against a panel of tumor cells by determination of GI50 values. Complexes 3 (GI50 = 1.14 μM, SI = 4.52) and 4 (GI50 = 2.72 μM, SI = 6.06) were more active and selective against 786-0 cell lines than doxorubicin (GI50 = 85.0 μM, SI = 5·10−3). Complex 1A presented high selectivity indexes against glioma (U251, GI50 = 2.53 μM, SI = 60.9) and multiple drugs resistance ovarian (NCI/ADR-RES GI50 = 1.69 μM, SI = 91.4) cell lines when compared to doxorubicin and cisplatin. DNA gel electrophoresis (pIRES DNA) and cell-cycle arrest (NCI/ADR-RES cell line) assays were performed with complex 1A. The obtained results suggest that the mechanism of action of complex 1A does not involve DNA interaction and complex 1A seems to be a cell cycle non-specific drug.

This work describes the synthesis of bilayer bacterial cellulose membranes (BCs) produced by Gluconacetobacter hansenii ATCC 23769 in culture media with different carbon sources (sugarcane molasses, syrup and fructose) as well as their retention capacity and sustained release of the antibacterial agent ceftriaxone. Scanning electronic microscopy analysis showed that BCs produced in all culture media exhibit a double layer and three-dimensional fiber network obtained in only one step. Elemental and thermogravimetric analyses, Fourier transform infrared spectroscopy and X-ray diffraction show that the BC membranes are composed of pure cellulose. In particular, the BC produced in sugarcane molasses medium presented a three-dimensional network structure of the bilayer with high-density fiber entangling, which was responsible for the largest holding capacity and sustained release of the antibiotic ceftriaxone in relation to Staphylococcus aureus bacterial strains. This behavior shows the potential of applying such BC membranes in wound dressings as a sustained support to release different antibiotics to treat skin infections.

Made available in DSpace on 2018-12-11T17:37:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-10-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The bis-(1,10-phenanthroline)copper(I) complex, [Cu(I)(phen)2]+, was the first copper-based artificial nuclease reported in the literature. The biological and ligand-like properties of sulfonamides make them good candidates for fine-tuning the reactivity of the [Cu(phen)2] motif with biomolecules. In this context, we developed three novel copper(II) complexes containing the sulfonamides sulfameter (smtrH) and sulfadimethoxine (sdmxH) and (N^N)-bidentate ligands (2,2′-biyridine or 1,10-phenantroline). The compounds were characterized by chemical and spectroscopic techniques and single-crystal X-ray crystallography. When targeting plasmid DNA, the phen-containing compounds [Cu(smtr−)2(phen)] (1) and [Cu(sdmx−)2(phen)] (2) demonstrated nuclease activity even in the absence of reducing agents. Addition of ascorbic acid resulted in a complete cleavage of DNA by 1 and 2 at concentrations higher than 10 μM. Experiments designed to evaluate the copper intermediates involved in the nuclease effect after reaction with ascorbic acid identified at least the [Cu(I)(N^N)2]+, [Cu(I)(sulfa)(N^N)]+ and [Cu(I)(sulfa)2]+ species. The compounds interact with DNA via groove binding and intercalation as verified by fluorescence spectroscopy, circular dichroism (CD) and molecular docking. The magnitude and preferred mode of binding are dependent on the nature of both N^N ligand and the sulfonamide. The potent nuclease activity of compounds 1 and 2 are well correlated with their antiproliferative and anti-M. tuberculosis profiles. The results presented here demonstrated the potential for further development of copper(II)-sulfonamide-(N^N) complexes as multipurpose metallodrugs. Institute of Chemistry University of Campinas UNICAMP Biological and Health Sciences Department University of Araraquara UNIARA School of Pharmaceutical Sciences São Paulo State University UNESP Faculty of Pharmaceutical Sciences University of Campinas UNICAMP Chemical Biological and Agricultural Pluridisciplinary Research Center (CPQBA) University of Campinas – UNICAMP Department of Physiological Sciences Piracicaba Dental School University of Campinas UNICAMP School of Pharmaceutical Sciences São Paulo State University UNESP CNPq: 140466/2014-2 FAPESP: 2015/09833-0 FAPESP: 2015/20882-3 FAPESP: 2015/25114-4 CNPq: 442123/2014-0

AIMS Obtain varieties of Gluconacetobacter hansenii from original strain ATCC 23729 with greater efficiency to produce bacterial cellulose (BC) membrane with better dry mass yield for application as support of sustained antimicrobials' drug release. METHODS AND RESULTS Application of different chemical and physical conditions (pH, temperature and UV light exposure) to obtain different G. hansenii varieties with high capacity to produce BC membranes. Characterization of the G. hansenii variants was performed by scanning electron microscopy (SEM) and optical microscopy of the colony-forming units. BC membrane produced was characterized by SEM, infrared spectroscopy and X-ray diffraction. The BC produced by variants isolated after incubation at 35°C showed elevated dry mass yield and high capacity of retention and sustained release of ceftriaxone antibiotic with the produced BC by original G. hansenii ATCC 23769 strain subjected to incubation at 28°C and with commercial BC. CONCLUSION The application of different chemical and physical conditions constitutes an important method to obtain varieties of micro-organisms with dissimilar metabolism advantageous in relation to the original strain in the BC production. SIGNIFICANCE AND IMPACT OF THE STUDY These results demonstrate the importance of in vivo studies for the application, in medicine, of BC membranes as support for antimicrobial-sustained release for the skin wound treatment.

The sulfa drug sulfadoxine (SFX) reacted with Ag+ ions in aqueous solution, affording a new silver(I) complex (AgSFX), which was fully characterized by chemical, spectroscopic and structural methods. Elemental, ESI-TOF mass spectrometric and thermal analyses of AgSFX suggested a [Ag(C12H13N4O2S)] empirical formula. Infrared spectroscopic measurements indicated ligand coordination to Ag(I) through the nitrogen atoms of the (deprotonated) sulfonamide group and by the pyrimidine ring, as well as through oxygen atom(s) of the sulfonamide group. These hypotheses were corroborated by 13C and 15N SS-NMR spectroscopy and by an unconventional structural characterization based on X-ray powder diffraction data. The latter showed that AgSFX crystallizes as centrosymmetric dimers with a strong Ag⋯Ag interaction of 2.7435(6) A, induced by the presence of exo-bidentate N,N′ bridging ligands and the formation of an eight-membered ring of [AgNCN]2 sequence, nearly planar. Participation of oxygen atoms of the sulfonamide residues generates in the crystal a 1D coordination polymer, likely responsible for its very limited solubility in all common solvents. Besides the analytical, spectroscopic and structural description, the antibacterial properties of AgSFX were assayed using disc diffusion methods against Escherichia coli and Pseudomonas aeruginosa (Gram-negative), and Staphylococcus aureus (Gram-positive) bacterial strains. The AgSFX complex showed to be active against Gram-positive and Gram-negative bacterial strains, being comparable to the activities of silver sulfadiazine.

The present work describes the synthesis and spectroscopic characterization of two silver(I) complexes with the sulfonamides sulfathiazole (AgC9H8N3O2S2, Ag-SFT) and sulfamethoxazole (AgC10H10N3O3S, Ag-SFM). Elemental analyses indicate a 1:1 metal/ligand composition for both complexes. Spectroscopic techniques such as 1H, 15N NMR and IR evidence the coordination of both ligands to silver through the nitrogen atom of the sulfonamide group, and also indicate the participation of the 5-membered N-heterocyclic ring in the coordination. The Ag-SFT crystal structure was solved by X-ray powder diffraction and indicates the formation of a dimeric structure with silver bridging between two ligand molecules. Biological studies showed the antibacterial activity of Ag-SFT and Ag-SFM complexes against Gram-positive and Gram-negative bacterial strains, with MIC values ranging from 3.45 to 6.90 mmol L−1 for the sulfathiazole complex and 1.74 to 13.9 mmol L−1 for the sulfamethoxazole complex. The complexes have shown to be more active against Gram-negative bacterial strains.

Made available in DSpace on 2020-12-12T02:31:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Universidade Estadual de Campinas ASCRS Research Foundation Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) This manuscript presents three silver(I) complexes with fluoroanthranilic acid (fa) isomers, [Ag(4fa)]n, [Ag(5fa)]n and [Ag(6fa)]n, which were named as Ag4fa, Ag5fa and Ag6fa, respectively. The 1:1 metal/ligand molar composition of the complexes was determined by elemental, thermal and high-resolution mass spectrometric (ESI(+)-MS) analyses. Infrared and 1H, 13C and {15N,1H} nuclear magnetic resonance spectroscopy evidenced the coordination of the fluoroanthranilic acid isomers to silver via the nitrogen atom of the amino group and by the oxygen atoms of the carboxylate group. The structure of the Ag5fa complex was determined by single crystal X-ray diffraction analysis. The complex forms an extended polymeric structure organized in layers with coordination by the amino and carboxylate moieties. Antibacterial activity assays showed that the silver complexes were active against M. tuberculosis (MIC90 between 2.6 and 4.2 µg/mL) and also over S. aureus, B. cereus, E. coli and P. aeruginosa (MIC = 62.25 µg/mL) strains. The complexes have also shown in vitro cytotoxicity over cancer cell lines and selectivity (SI) especially against epithelial colorectal adenocarcinoma cells (IC50 = 2.1 µg/mL and SI > 3). Also, the silver complexes are non-mutagenic, which is essential when considering the development of new bioactive compounds for therapeutic purposes. Inorganic Chemistry Department Institute of Chemistry University of Campinas – UNICAMP, P.O. Box 6154 Biological and Health Sciences Department University of Araraquara – UNIARA School of Pharmaceutical Sciences São Paulo State University – UNESP School of Pharmaceutical Sciences São Paulo State University – UNESP FAPESP: 2017/16278-9 FAPESP: 2017/25995-6 FAPESP: 2018/00163-0 FAPESP: 2018/12062-4 FAPESP: 2018/14512-7 CNPq: 407012/2018-4

Silver(I) complexes with amantadine (atd) and memantine (mtn) were synthesized and characterized. Elemental, thermogravimetric and mass spectrometric analyses indicated a 1:2 metal/ligand ratio, with the molecular composition AgC20H34N2·NO3 for Ag–atd and AgC24H42N2·NO3·H2O for Ag–mtn. The crystal structures of the silver(I) complexes were determined by single crystal X-ray diffractometric studies and show the coordination of amantadine and memantine to the Ag(I) ion by the nitrogen atom of the NH2 group. The spectral analysis by infrared and 1H, 13C and {15N,1H} nuclear magnetic resonance (NMR) spectroscopies confirmed the coordination sites of the ligands to the silver ions. Computational studies revealed modes of vibration and bond lengths similar to those found experimentally. The in vitro antibacterial activity assays showed that amantadine is not active over the tested strains while memantine showed a low activity against Staphylococcus aureus and Pseudomonas aeruginosa. On the other hand, the complexes had a pronounced antibacterial activity over the same strains with minimum inhibitory concentration (MIC) values in the micromolar range. Biophysical assays based on fluorescence spectroscopy indicated that the silver(I) complexes interact weakly with bovine serum albumin, while agarose gel electrophoresis and competitive binding experiments revealed that the compounds interact with DNA by non-covalent interactions.

A new palladium(II) complex with the amino acid L-tryptophan (Pd-TRP) was synthesized in aqueous solution and characterized by chemical and spectroscopic methods. Elemental, ESI-QTOF mass spectrometric, and thermal analyses of the solid compound permitted proposing the [Pd(C11H11N2O2)2] · 2H2O composition. Infrared, Raman, and UV-Vis spectroscopic data indicate the coordination of the ligand to Pd(II) through monodentate oxygen of carboxylate and through nitrogen of the amino group. The 1H and 13C NMR spectroscopic data confirm coordination through the carboxylate, while 15N NMR data confirm coordination of nitrogen of NH2. Density functional theory studies confirmed nitrogen and oxygen coordination to palladium(II) as a minimum of the potential energy surface with calculations of the hessians showing no imaginary frequencies. Biological studies were performed to provide information concerning the antibacterial activities of the compound. The Pd-TRP complex was shown to be active against Gram-positive and ...

A novel silver(I) complex with nimesulide (NMS) of composition AgC13H11N2O5S was synthesized and characterized by chemical and spectroscopic measurements, density functional theory (DFT) studies and biological assays. Infrared (IR), ESI-QTOF-mass spectrometric (MS) analyses and 1H, 13C and [1H–15N] nuclear magnetic resonance (NMR) studies indicate that NMS acts as a bidentate ligand, being coordinated to Ag(I) through the nitrogen and one of the oxygen atoms of the sulphonamide group. The proposed structure based on the experimental data was confirmed as a minimum of the potential energy surface (PES) with the calculation of the hessians, showing no imaginary frequencies. Also, the theoretical IR spectra of the free ligand and of the silver(I) complex (Ag–NMS) are in a good agreement with the experimental data. Theoretical Time-Dependent DFT (TD-DFT) studies confirmed that the observed transitions in the UV–Vis spectra of the NMS and Ag–NMS are due to π–π∗ transitions. The antibacterial activity of Ag–NMS was evaluated by an antibiogram assay, using the disk diffusion method. The complex showed an effective antibacterial activity against Staphylococcus aureus (Gram-positive), and Escherichia coli and Pseudomonas aeruginosa (Gram-negative) pathogenic bacterial cells.

Two new metal complexes of penicillamine (Pen), with molecular formulas [Ag(C5H10O2NS)]·H2O and [Au(C5H10O2NS)], were synthesized by the reaction of the ligand with, respectively, silver nitrate and potassium dicyanoaurate(I) salts in aqueous solutions. Analytical characterizations of the complexes were based on elemental (C, H, N and S), thermal (TG-DTA) and electrospray ionization mass spectrometry (ESI-MS) analyses. Solid-state 13C nuclear magnetic resonance (SSNMR) and infrared (IR) spectroscopic measurements indicate coordination of Pen to Ag(I) or Au(I) through the sulfur atom. Studies based on density functional theory (DFT) confirmed that Pen acts as an S-donor ligand to Au(I) or Ag(I). Thermal decompositions of the silver(I) and gold(I) complexes start at temperatures near 50 °C, leading to the formation of Ag0 and Au0 at 700 °C and 500 °C, respectively. Both complexes are just slightly soluble in common solvents such as water, methanol, ethanol, acetonitrile, hexane and dimethylsulfoxide. An antibiogram assay was performed by the disc diffusion method. The AgPen complex showed antibacterial activities against Escherichia coli and Pseudomonas aeruginosa bacterial strains.

In this article, synthesis of a palladium(II) complex with 2-mercaptothiazoline in aqueous solution is presented. Composition of the complex was defined as 1 : 2 (metal : ligand). Infrared and solid-state nuclear magnetic resonance indicate ligand coordination to Pd(II) through nitrogen of thiazole ring and sulfur of thiol. ESI–QTOF–mass spectrometric analysis shows primarily the dimeric form in solution. An antibiogram assay of the complex was performed by the disc diffusion method. The compound did not show antibacterial activity against the considered bacterial cells in the tested concentrations.

A new silver(I) complex with N-acetyl- l -cysteine (NAC) of composition AgC5H8NO3S·H2O was synthesized and characterized by a set of chemical and spectroscopic measurements. Solid-state 13C nuclear magnetic resonance (SSNMR) and infrared (IR) analyses indicate the coordination of the ligand to Ag(I) through the sulfur atom. The Ag–NAC complex is slightly soluble in dimethyl sulfoxide. It is insoluble in water, methanol, ethanol, acetone and hexane. Antibacterial activity of the silver complex with N-acetyl- l -cysteine (Ag–NAC) was evaluated by antibiogram assays using the disc diffusion method. The compound showed an effective antibacterial activity against Staphylococcus aureus (Gram-positive), Escherichia coli and Pseudomonas aeruginosa (Gram-negative) bacterial cells. Biological analysis for evaluation of a potential cytotoxic effect of Ag–NAC was performed using HeLa cells derived from human cervical adenocarcinoma. The complex presented a significant cytotoxic activity, inducing 80% of cell death at a concentration of 200 μmol L−1.

Nuclear magnetic resonance studies, molecular modeling and antibacterial assays of the palladium(II) complex with S-allyl-L-cysteine (deoxyalliin) are presented. Studies based on solid and solution 13C and 15N nuclear magnetic resonance (NMR) spectroscopy confirmed that the palladium(II) complex preserved the same structural arrangement in both states, with no modifications on coordination sphere when dissolved in water. Density functional theory (DFT) studies stated that the trans isomer is the most stable one. Antibacterial activities of S-allyl-L-cysteine and its palladium(II) complex were evaluated by antibiogram assays using the disc diffusion method. The palladium(II) complex showed an effective antibacterial activity against Staphylococcus aureus (Gram-positive), Escherichia coli and Pseudomonas aeruginosa (Gram-negative) bacterial cells.

A new platinum(II) complex with methionine sulfoxide was synthesized and characterized by chemical and spectroscopic techniques. Elemental analyses, mass spectrometric measurements (electrospray ionization quadrupole time-of-flight mass spectrometry), and thermal analyses of the solid compound fit the composition [(C5H10NO3S)Pt(µ-Cl)2Pt(C5H10NO3S)] · 2.5H2O. Infrared spectroscopic data indicate coordination of the ligand to Pt(II) through the nitrogen of NH2 and the sulfur of the S=O group. 1H-15N nuclear magnetic resonance spectroscopic data confirm nitrogen coordination. Antibacterial activities were evaluated by antibiogram assays using the disc diffusion method. The platinum(II) complex showed antibacterial activity against Gram-negative Pseudomonas aeruginosa bacterial cells.

A new gold(I) complex with N-acetyl-L-cysteine was synthesized and characterized by chemical and spectroscopic techniques. The elemental and thermal analyses of the solid compound fit to the composition AuC5H8NO3S · 0.75H2O. Solid-state 13C-nuclear magnetic resonance (SSNMR) and infrared (IR) analyses indicate the coordination of the ligand to Au(I) through sulfur. The insolubility of the complex in both polar and non-polar solvents supports a polymeric structure. The antibacterial activity of the complex was evaluated by antibiogram assays using the disc diffusion method. The compound showed effective antibacterial activity against Staphylococcus aureus (Gram positive) and Escherichia coli (Gram negative) bacterial cells.

O presente trabalho discute os recentes avanços na biossíntese e na produção de celulose bacteriana (CB) pela gram-negativa, aeróbia e aceto-ácida Gluconacetobacter. xylinus. A CB se difere de seu par vegetal, principalmente devido ao seu caráter de fibras nanométricas, contra o caráter micrométrico da vegetal, são extruídas através da parede celular de G. xylinus, com isso sua estrutura macroscópica é mecanicamente e fisicamente mais resistente, abrindo grandes oportunidades de aplicações tecnológicas e biológicas, muito além das obtidas pela celulose vegetal. O desafio atual está no aumento da produção de CB, que se debruça num maior entendimento de sua biossíntese para que seja possível uma posterior manipulação genético-bioquímica oriundas do recente avanço na biologia molecular e nos bioprocessos. São relacionados trabalhos utilizando a CB como base para produção de compósitos como também o que a está sendo feito de mais atual com este material biológico.The present paper discusses the recent advances about the biosynthesis and production of bacterial cellulose (BC), from gram-negative, aerobic and acetic acid Gluconcetobacter xylinus (Gx). The BC differs from his vegetal pair, mainly due his feature of nanometric fibers, as opposed to micrometric feature of vegetal cellulose, are extruded through the cellular wall of Gx, thereby the macroscopic structure of BC is mechanically and physically more resistant, open big opportunities of biological and technological applications, apart from that obtained by vegetal cellulose. The actual challenge is in the grown of production of BC, which deals a superior understanding of his biosynthesis, to makes possible a later genetic-biochemical manipulation derived from recent advances in molecular biology. Are related works using the BC for production of composites and also what is being done of more actual with this biological material.

New ternary copper(II) complexes of sulfathiazole (SFT, C9H8N3O2S2) or nimesulide (NMS, C13H11N2O5S) and 2,2′-bipyridine (bipy) were synthesized, and characterized by chemical and spectroscopic techniques. Elemental analyses indicated a 2:1:1 sulfonamide/copper/bipy composition for both complexes. Mass spectrometric measurements permitted identifying the molecular ions [Cu(SFT)2(bipy)+H]+ and [Cu(NMS)2(bipy)+H]+ at m/z 728 and 835, respectively, confirming the proposed compositions. Crystal structure of the [Cu(SFT)2(bipy)] complex was solved by powder X-ray diffraction analysis (PXRD), attesting that the Cu(II) ion is hexacoordinated in a distorted octahedral geometry. Each SFT molecule coordinates to the metal ion by the nitrogen atoms of the SO2–N group and of the heterocyclic ring. The coordination sphere is completed by a bipyridine. Electronic paramagnetic resonance (EPR) studies were carried out for the [Cu(NMS)2(bipy)] complex, indicating a tetragonal environment around the metal ion. It was suggested that NMS coordinates to Cu(II) by the nitrogen and oxygen atoms of the SO2–N group, which was confirmed by infrared spectroscopic studies. Biological studies showed the antibacterial activity of both Cu-SFT and Cu-NMS complexes, with the minimum inhibitory concentration (MIC) values ranging from 0.10 to 0.84 mmol L−1 against Gram-negative bacteria for [Cu(SFT)2(bipy)], and from 1.50 to 3.00 mmol L−1 against Gram-positive and -negative bacteria for [Cu(NMS)2(bipy)].

Tissue engineering is an interdisciplinary scientific field that seeks to restore or improve the biological functions of damaged tissue or unable to perform its function. Some biomaterials are used...

Bacterial cellulose (BC) is a very interesting biopolymers to biomedical application, including drug delivery system, due to unique characteristics as such as high degree purity and of porosity, relative high permeability to liquid and gases, high holding water capacity, tensile strength and randomly oriented three-dimensional fiber network. Several authors described the use of BC membranes or copolymers to use as drug delivery system. The aim of the present mini-review was to show the wide and vantages application of the BC and its copolymers for use as controlled drug delivery system.

The study and development of polymers for pharmaceutical and biomedical use has been increasing due to their peculiar properties that contribute for the improvement of the life quality, such as the polymers used in regenerative medicine and in drug release systems. The development of new polymer based materials and its composites depends on several steps, such as the synthesis approach, the extraction, the composition, the influence of their properties on the specific applications, and others. This review describes the use of conventional and new polymers with potential application in pharmaceutical and biomedical fields, highliting the properties that allow them to be useful for such pourposes.

The use of metal complexes in medicine dates back to the 16th century. Nowadays one of the best examples of a metal-based drug used in medicine is silver-sulfadiazine (SSD). This compound is used t...