RESUMEN

Indole-3-carbaldehyde based novel ligand (E)-2-((1-benzyl-1H-indol-3-yl)methylene)-N-methylhydrazine-1-carbothioamide (MBIHC) and their complexes [(MBIHC)2FeCl2]Cl(C1), [(MBIHC-)2Co] (C2), [(MBIHC-)2Ni] (C3), and [(MBIHC-)2Cu] (C4) have been synthesized. All compounds have been characterized by spectroanalytical techniques. The structure of MBIHC was confirmed by single-crystal X-ray data. The geometry of complexes was determined by spectroscopic and computational studies. In the case of iron complex, ligand MBIHC coordinated to the metal ion in bidentate mode (N and S) while in the case of cobalt, nickel, and copper complexes ligand act as a tridentate ligand (N, S and C). In vitro,antifungal and antibacterial studies of ligand and metal complexes were assayed against C. albicans, C. glabrata, E. coli, and K. pneumoniae pathogens. In antifungal activity, complex C1 exhibited a greater inhibition zone than the other compounds for the both examined fungi C. albicans (24±0.32 mm) and C. glabrata (20±0.16 mm).. However, the antifungal activities of complex C2has shown better activity against both E. coli (25±0.24 mm) and K. pneumoniae (16±0.80 mm) pathogens than the other examined compound.. Complex C2 has found even better than the benchmark drug Ampiciline in case of E. coli. Further, the DFT calculations and molecular docking studies also validate the experimental bioactivity results of examined compounds.

RESUMEN

Poly(ethylene furanoate) (PEF)-based nanocomposites were fabricated with silver (Ag) and titanium dioxide (TiO2) nanoparticles by the in-situ polymerization method. The importance of this research work is to extend the usage of PEF-based nanocomposites with improved material properties. The PEF-Ag and PEF-TiO2 nanocomposites showed a significant improvement in color concentration, as determined by the color colorimeter. Scanning electron microscopy (SEM) photographs revealed the appearance of small aggregates on the surface of nanocomposites. According to crystallinity investigations, neat PEF and nanocomposites exhibit crystalline fraction between 0-6%, whereas annealed samples showed a degree of crystallinity value above 25%. Combining the structural and molecular dynamics observations from broadband dielectric spectroscopy (BDS) measurements found strong interactions between polymer chains and nanoparticles. Contact angle results exhibited a decrease in the wetting angle of nanocomposites compared to neat PEF. Finally, antimicrobial studies have been conducted, reporting a significant rise in inhibition of over 15% for both nanocomposite films against gram-positive and gram-negative bacteria. From the overall results, the synthesized PEF-based nanocomposites with enhanced thermal and antimicrobial properties may be optimized and utilized for the secondary packaging (unintended food-contact) materials.

RESUMEN

We synthesized and characterized two copper(II) complexes: [CuL2Cl]Cl and [CuL'2Cl]Cl, where L = 2,2'-bipyridine and L' = 4,4'-dimethyl-2,2'-bipyridine. We evaluated their photocatalytic hydrocarboxylation properties on a series of synthesized Schiff bases (SBs): (E)-1-(4-((5-bromo-2-hydroxybenzylidene)amino)phenyl)ethanone (SB1), (E)-N-(4-(dimethylamino)benzylidene)benzo[d]thiazol-2-amine (SB2), (E)-4-Bromo-2-((thiazol-2-ylimino)methyl)phenol (SB3), and (E)-4-((5-bromo-2-hydroxybenzylidene)amino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one (SB4). Under mild photocatalytic reaction conditions (room temperature, 1 atm CO2, 30-watt Blue LED light), the derivatives of α-amino acids UAA1-4 were obtained with yields ranging from 5% to 44%. Experimental results demonstrated that [CuL2Cl]Cl exhibited superior photocatalytic efficiency compared to [CuL'2Cl]Cl, attributed to favourable electronic properties. In silico studies revealed strong binding strengths with E. faecalis DHFR (4M7U) for docked Schiff bases (SB) and unnatural α-amino acids (UAAs). In vitro studies further demonstrated significant antimicrobial and antifungal activity for SB2, SB3, and SB4, while none of the synthesized UAAs exhibited such properties, primarily due to the electronic and binding properties of these molecules.Communicated by Ramaswamy H. Sarma.

RESUMEN

Efflux pumps are a relevant factor in antimicrobial resistance. In E. coli, the tripartite efflux pump AcrAB-TolC removes a chemically diverse set of antibiotics from the bacterium. Therefore, small molecules interfering with efflux pump function are considered adjuvants for improving antimicrobial therapies. Several compounds targeting the periplasmic adapter protein AcrA and the efflux pump AcrB have been identified to act synergistically with different antibiotics. Among those, several 4(3-aminocyclobutyl)pyrimidin-2-amines have been shown to bind to both proteins. In this study, we intended to identify analogs of these substances with improved binding affinity to AcrA using virtual screening followed by experimental validation. While we succeeded in identifying several compounds showing a synergistic effect with erythromycin on E. coli, biophysical studies suggested that 4(3-aminocyclobutyl)pyrimidin-2-amines form colloidal aggregates that do not bind specifically to AcrA. Therefore, these substances are not suited for further development. Our study emphasizes the importance of implementing additional control experiments to identify aggregators among bioactive compounds.

Asunto(s)

Proteínas de Escherichia coli , Proteínas de Transporte de Membrana , Proteínas de Transporte de Membrana/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Periplasma/metabolismo , Antibacterianos/farmacología , Antibacterianos/metabolismo , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/metabolismo

RESUMEN

1,3,4-Oxadiazole pharmacophore is still considered a viable biologically active scaffold for the synthesis of more effectual and broad-spectrum antimicrobial agents. Therefore, the present study is based on five 1,3,4-oxadiazole target structures, viz., CAROT, CAROP, CARON (D-A-D-A systems) and NOPON and BOPOB (D-A-D-A-D systems) bearing various bioactive heterocyclic moieties relevant to potential biological activities. Three of the compounds, CARON, NOPON and BOPOB were assessed in-vitro for their efficacy as antimicrobial agents against gram positive (Staphylococcus aureus and Bacillus cereus) and gram negative (Escherichia coli and Klebsiella pneumonia) bacteria; and two fungi, Aspergillus niger and Candida albicans; also, as an anti-tuberculosis agent against Mycobacterium tuberculosis. Most of the tested compounds displayed promising antimicrobial activity, especially CARON which was then analyzed for the minimum inhibitory concentration (MIC) studies. Similarly, NOPON portrayed the highest anti-TB activity among the studied compounds. Consequently, to justify the detected anti-TB activity of these compounds and to recognize the binding mode and important interactions between the compounds and the ligand binding site of the potential target, these compounds were docked into the active binding site of cytochrome P450 CYP121 enzyme of Mycobacterium tuberculosis, 3G5H. The docking results were in good agreement with the result of in-vitro studies. In addition, all the five compounds were tested for their cell viability and have been investigated for cell labeling applications. To conclude, one of the target compounds, CAROT was used for the selective recognition of cyanide ion by 'turn-off' fluorescent sensing technique. The entire sensing activity was examined by spectrofluorometric method and MALDI spectral studies. The limit of detection obtained was 0.14 µM.

Asunto(s)

Antiinfecciosos , Antiinfecciosos/farmacología , Antiinfecciosos/química , Oxadiazoles/farmacología , Hongos , Bacterias , Pruebas de Sensibilidad Microbiana , Antibacterianos/química , Relación Estructura-Actividad , Antifúngicos/química

RESUMEN

Herein we describe the synthesis of a series of nickel(II) complexes (C1-C3) with Schiff bases (HL1-HL3) derived from 4-amino-5-mercapto-3-methyl-1,2,4-triazole and ortho/meta/para-nitrobenzaldehyde having composition [Ni(L)2(H2O)2]. The obtained ligands and their complexes were characterized using physico-chemical techniques viz., elemental analysis, magnetic moment study, spectral (electronic, FT-IR, 1H-NMR) and thermal analysis. The elemental analysis and spectral analysis revealed that Schiff bases behave as monoanionic bidentate ligands towards the Ni(II) ion. Whereas, the magnetic moment study suggested the octahedral geometry of all the Ni(II) complexes. The thermal behavior of the complexes has been studied by thermogravimetric analysis and agrees well with the composition of complexes. Further, the biological activities such as antimicrobial and antifungal studies of the Schiff bases and Ni(II) complexes have been screened against bacterial species (Staphylococcus aureus and Pseudomonas aeruginosa) and fungal species (Aspergillus niger and Candida albicans) activity by MIC method, the results of which revealed that metal complexes exhibited significant antimicrobial activities than their respective ligands against the tested microbial species. Furthermore, the molecular docking technique was employed to investigate the active sites of the selected protein, which indeed helped us to screen the potential anticancer agents among the synthesized ligand and complexes. Further, these compounds have been screened for their in vitro anticancer activity using OVCAR-3 cell line. The results revealed that the complexes are more active than the ligands.

Asunto(s)

Antiinfecciosos , Antineoplásicos , Complejos de Coordinación , Neoplasias Ováricas , Antibacterianos/química , Antiinfecciosos/química , Antifúngicos/química , Antifúngicos/farmacología , Antineoplásicos/química , Antineoplásicos/farmacología , Apoptosis , Benzaldehídos , Línea Celular Tumoral , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Femenino , Humanos , Ligandos , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Níquel/química , Bases de Schiff/química , Espectroscopía Infrarroja por Transformada de Fourier , Triazoles/química , Triazoles/farmacología

RESUMEN

Mastoparan (MP) is an antimicrobial cationic tetradecapeptide with the primary structure INLKALAALAKKIL-NH2. This amphiphilic α-helical peptide was originally isolated from the venom of the wasp Paravespula lewisii. MP shows a variety of biological activities, such as inhibition of the growth of Gram-positive and Gram-negative bacteria, as well as hemolytic activity and activation of mast cell degranulation. Although MP appears to be toxic, studies have shown that its analogs have a potential therapeutic application as antimicrobial, antiviral and antitumor agents. In the present study we have designed and synthesized several new chimeric mastoparan analogs composed of MP and other biologically active peptides such as galanin, RNA III inhibiting peptide (RIP) or carrying benzimidazole derivatives attached to the ε-amino side group of Lys residue. Next, we compared their antimicrobial activity against three reference bacterial strains and conformational changes induced by membrane-mimic environments using circular dichroism (CD) spectroscopy. A comparative analysis of the relationship between the activity of peptides and the structure, as well as the calculated physicochemical parameters was also carried out. As a result of our structure-activity study, we have found two analogs of MP, MP-RIP and RIP-MP, with interesting properties. These two analogs exhibited a relatively high antibacterial activity against S. aureus compared to the other MP analogs, making them a potentially attractive target for further studies. Moreover, a comparative analysis of the relationship between peptide activity and structure, as well as the calculated physicochemical parameters, may provide information that may be useful in the design of new MP analogs.

Asunto(s)

Antiinfecciosos , Venenos de Avispas , Secuencia de Aminoácidos , Antibacterianos/química , Antibacterianos/farmacología , Antiinfecciosos/farmacología , Bacterias Gramnegativas , Bacterias Grampositivas , Péptidos y Proteínas de Señalización Intercelular , Pruebas de Sensibilidad Microbiana , Péptidos/química , Staphylococcus aureus , Relación Estructura-Actividad , Venenos de Avispas/química , Venenos de Avispas/farmacología

RESUMEN

In the present study, five 4-aminophenol derivatives (4-chloro-2-(((4-hydroxyphenyl)imino)methyl)phenol(S-1), 4-((4-(dimethylamino)benzylidene)amino)phenol(S-2), 4-((3-nitrobenzylidene)amino)phenol(S-3), 4-((thiophen-2-ylmethylene)amino)phenol(S-4) and 4-(((E)-3-phenylallylidene)amino)phenol(S-5)) were synthesized and characterized by FT-IR, 1H-NMR, 13C-NMR and elemental analyses. The synthesized compounds were tested for their antimicrobial (Gram-positive and Gram-negative bacteria and Saccharomyces cervesea fungus) and antidiabetic (α-amylase and α-glucosidase inhibitory) activities. All the compounds showed broad-spectrum activities against the Staphylococcus aureus (ATCC 6538), Micrococcus luteus (ATCC 4698), Staphylococcus epidermidis (ATCC 12228), Bacillus subtilis sub. sp spizizenii (ATCC 6633), Bordetella bronchiseptica (ATCC 4617) and Saccharomyces cerevisiae (ATCC 9763) strains. The newly synthesized compounds showed a significant inhibition of amylase (93.2%) and glucosidase (73.7%) in a concentration-dependent manner. Interaction studies of Human DNA with the synthesized Schiff bases were also performed. The spectral bands of S-1, S-2, S-3 and S-5 all showed hyperchromism, whereas the spectral band of S-4 showed a hypochromic effect. Moreover, the spectral bands of the S-2, S-3 and S-4 compounds were also found to exhibit a bathochromic shift (red shift). The present studies delineate broad-spectrum antimicrobial and antidiabetic activities of the synthesized compounds. Additionally, DNA interaction studies highlight the potential of synthetic compounds as anticancer agents. The DNA interaction studies, as well as the antidiabetic activities articulated by the molecular docking methods, showed the promising aspects of synthetic compounds.

Asunto(s)

Aminofenoles/síntesis química , Aminofenoles/farmacología , ADN/química , Aminofenoles/química , Antiinfecciosos/síntesis química , Antiinfecciosos/química , Antiinfecciosos/farmacología , Sitios de Unión , Técnicas de Química Sintética , ADN/metabolismo , Humanos , Hipoglucemiantes/química , Hipoglucemiantes/farmacología , Pruebas de Sensibilidad Microbiana , Conformación Molecular , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Estructura Molecular , Unión Proteica , Bases de Schiff/química , Análisis Espectral , Relación Estructura-Actividad

RESUMEN

In this research work, silica nanoparticles and silica-gentamicin nanostructured solution were synthesized by using the microwave-assisted synthesis, in basic medium, using two silane precursors (tetraethylorthosilicate and octyltriethoxysilane) and the antibiotic (gentamicin sulfate). The prepared materials were characterized through Fourier transform infrared (FTIR) spectroscopy, TGA analysis, transmission electron microscopy (TEM), and atomic force microscopy (AFM) to investigate the morphology and structure. Antimicrobial studies of the silica-gentamicin nanostructured solution versus silica nanoparticles were performed against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. FTIR spectra showed that the gentamicin has been loaded to the silica nanoparticles. AFM analysis showed that the morphology of the silica-gentamicin nanostructured solution has changed, and agglomerations of particles are present at the surface. Antimicrobial testing, performed using the diffusion method through spot inoculation, indicates that the silica-gentamicin nanostructured solution exhibited activity against the resistant strain. The obtained silica-gentamicin solution can be used as biochemical agent for the prevention and treatment of microorganisms which are deposited on different surfaces (e.g., glass, plastic, ceramic).

RESUMEN

A ferrocene-substituted thiobarbituric acid (FT) has been synthesized to explore its photophysical properties and photodynamic and photoantimicrobial chemotherapy activities. FT has an intense metal-to-ligand charge transfer (MLCT) band at ca. 575 nm. The ferrocene moiety of FT undergoes photooxidation to form a ferrocenium species which in turn produces hydroxyl radical in an aqueous environment, which was confirmed via the bleaching reaction of p-nitrosodimethylaniline (RNO). FT exhibits efficient PDT activity against MCF-7 cancer cells with an IC50 value of 5.6 µM upon irradiation with 595 nm for 30 min with a Thorlabs M595L3 LED (240 mW cm-2). Photodynamic inactivation of Staphylococcus aureus and Escherichia coli by FT shows significant activity with log reduction values of 6.62 and 6.16 respectively, under illumination for 60 min at 595 nm. These results demonstrate that ferrocene-substituted thiobarbituric acids merit further study for developing novel bioorganometallic PDT agents.

Asunto(s)

Antibacterianos/farmacología , Compuestos Ferrosos/farmacología , Metalocenos/farmacología , Fármacos Fotosensibilizantes/farmacología , Tiobarbitúricos/farmacología , Antibacterianos/química , Antibacterianos/efectos de la radiación , Escherichia coli/efectos de los fármacos , Compuestos Ferrosos/química , Compuestos Ferrosos/efectos de la radiación , Historia Medieval , Humanos , Radical Hidroxilo/metabolismo , Luz , Células MCF-7 , Metalocenos/química , Metalocenos/efectos de la radiación , Pruebas de Sensibilidad Microbiana , Oxidación-Reducción/efectos de la radiación , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/efectos de la radiación , Staphylococcus aureus/efectos de los fármacos , Tiobarbitúricos/química , Tiobarbitúricos/efectos de la radiación

RESUMEN

Recent years have seen the dynamic development of methods for functionalizing the surface of implants using biomaterials that can mimic the physical and mechanical nature of native tissue, prevent the formation of bacterial biofilm, promote osteoconduction, and have the ability to sustain cell proliferation. One of the concepts for achieving this goal, which is presented in this work, is to functionalize the surface of NiTi shape memory alloy by an atypical glass-like nanocomposite that consists of SiO2-TiO2 with silver nanoparticles. However, determining the potential medical uses of bio(nano)coating prepared in this way requires an analysis of its surface roughness, tribology, or wettability, especially in the context of the commonly used reference coat-forming hydroxyapatite (HAp). According to our results, the surface roughness ranged between (112 ± 3) nm (Ag-SiO2)-(141 ± 5) nm (HAp), the water contact angle was in the range (74.8 ± 1.6)° (Ag-SiO2)-(70.6 ± 1.2)° (HAp), while the surface free energy was in the range of 45.4 mJ/m2 (Ag-SiO2)-46.8 mJ/m2 (HAp). The adhesive force and friction coefficient were determined to be 1.04 (Ag-SiO2)-1.14 (HAp) and 0.247 ± 0.012 (Ag-SiO2) and 0.397 ± 0.034 (HAp), respectively. The chemical data showed that the release of the metal, mainly Ni from the covered NiTi substrate or Ag from Ag-SiO2 coating had a negligible effect. It was revealed that the NiTi alloy that was coated with Ag-SiO2 did not favor the formation of E. coli or S. aureus biofilm compared to the HAp-coated alloy. Moreover, both approaches to surface functionalization indicated good viability of the normal human dermal fibroblast and osteoblast cells and confirmed the high osteoconductive features of the biomaterial. The similarities of both types of coat-forming materials indicate an excellent potential of the silver-silica composite as a new material for the functionalization of the surface of a biomaterial and the development of a new type of functionalized implants.

Asunto(s)

Níquel/química , Prótesis e Implantes , Aleaciones con Memoria de Forma/química , Dióxido de Silicio/química , Plata/química , Titanio/química , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Adhesión Celular/efectos de los fármacos , Células Cultivadas , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Durapatita/química , Durapatita/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/fisiología , Humanos , Ensayo de Materiales/métodos , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Propiedades de Superficie , Humectabilidad

RESUMEN

Single pot green synthesis of silver nanoparticles (AgNPs) was successfully carried out using medicinal plant extract of Acalypha wilkesiana via bottom-up approach. Five imperative operational parameters (pH, contact time, concentration, volume ratio and temperature) pivotal to the synthesis of silver nanoparticles were investigated. The study showed pH 9, 90 min contact time, 0.001 M Ag+ concentration, volume ratio 1:9 (extract: Ag+ solution), and temperature between 90 - 100 °C were important for the synthesis of Acalypha wilkesiana silver nanoparticles (AW-AgNPs). Phytochemical screening confirmed the presence of saponins, flavonoids, phenols and triterpenes for A. wilkesiana. These phytomolecules served as both capping and stabilizing agent in the green synthesis of silver nanoparticles. AW-AgNPs was characterized by UV-Vis Spectroscopy, Fourier Transform Infrared (FTIR) Spectroscopy and Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray (EDX). The surface Plasmon resonance (SPR) was observed at 450 nm which is a characteristic absorbance region of AW-AgNPs formation as a result of the collective oscillation of free electron of silver nanoparticles. FTIR Spectroscopy confirmed the presence of functional groups responsible for bioreduction of Ag+. SEM and TEM results confirmed a well dispersed AW-AgNPs of spherical shape. EDX shows the elemental distribution and confirmed AgNPs with a characteristic intense peak at 3.0 keV. AW-AgNPs showed significant inhibition against selected Gram negative and Gram positive prevailing bacteria. AW-AgNPs can therefore be recommended as potential antimicrobial and therapeutic agent against multidrug resistant pathogens.

RESUMEN

New tailored Cu(II) & Zn(II) metal-based antitumor drug entities were synthesized from substituted benzothiazole o‒vanillin Schiff base ligands. The complexes were thoroughly characterized by elemental analysis, spectroscopic studies {IR, 1H & 13C NMR, ESI-MS, EPR} and magnetic susceptibility measurements. The structure activity relationship (SAR) studies of benzothiazole Cu(II) & Zn(II) complexes having molecular formulas [C30H22CuN5O7S2], [C30H20Cl2CuN5O7S2], [C30H20CuF2N5O7S2], [C30H22N4O4S2Zn], [C30H20Cl2N4O4S2Zn], and [C30H20F2N5O7S2Zn], with CT‒DNA were performed by employing absorption, emission titrations, and hydrodynamic measurements. The DNA binding affinity was quantified by K b and K sv values which gave higher binding propensity for chloro-substituted Cu(II) [C30H20Cl2CuN5O7S2] complex, suggestive of groove binding mode with subtle partial intercalation. Molecular properties and drug likeness profile were assessed for the ligands and all the Lipinski's rules were found to be obeyed. The antimicrobial potential of ligands and their Cu(II) & Zn(II) complexes were screened against some notably important pathogens viz., E. coli, S. aureus, P. aeruginosa, B. subtilis, and C. albicans. The cytotoxicity of the complexes [C30H20Cl2CuN5O7S2], [C30H20CuF2N5O7S2], [C30H20Cl2N4O4S2Zn], and [C30H20F2N5O7S2Zn] were evaluated against five human cancer cell lines viz., MCF‒7 (breast), MIA‒PA‒CA‒2 (pancreatic), HeLa (cervix) and Hep‒G2 (Hepatoma) and A498 (Kidney) by SRB assay which revealed that chloro-substituted [C30H20Cl2CuN5O7S2] complex, exhibited pronounced specific cytotoxicity with GI50 value of 4.8 µg/ml against HeLa cell line. Molecular docking studies were also performed to explore the binding modes and orientation of the complexes in the DNA helix.

Asunto(s)

Antineoplásicos/química , Benzotiazoles/química , Cobre/química , ADN/química , Bases de Schiff/química , Zinc/química , Antiinfecciosos/química , Antiinfecciosos/farmacología , Antineoplásicos/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Humanos , Hidrodinámica , Ligandos , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Estructura Molecular , Análisis Espectral/métodos , Relación Estructura-Actividad

RESUMEN

Hydroxyapatite (HAP) is the main constituent of human bone and teeth. Hydroxyapatite nanoparticles are used for the treatment of various bone infections. Nanohydroxyapatite is a biocompatible material. It is used as a drug carrier for drugs and biomolecules for various diseases. Hydroxyapatite nanoparticles are made into nanocomposite with sodium alginate and polyvinyl alcohol. This nanocomposite is used for the sustained release of drugs. It is characterized by various characterization techniques like XRD, FTIR, TEM, and Raman. Hydroxyapatite nanoparticles are coated initially with polyvinyl alcohol and then coated with sodium alginate. Amoxicillin is used as the model drug. Studies on the drug loading and drug release have been done. The release of the drug is sustained for about 30 days. Antimicrobial studies have shown good activity against pathogens. The zone of inhibition is found to be 18 mm for a concentration of 500 µg against Bacillus subtilis and 16 µg against Klebsiella pneumonia.

RESUMEN

This study presents, for the first-time, the results of a study on the hydrodynamic diameter of essential oils (EOs) of basil and lavender in water, and solutions of EOs of basil (B) and lavender (L) and hydroxyapatite (HAp). The possible influence of basil and lavender EOs on the size of hydroxyapatite nanoparticles was analyzed by Scanning Electron Microscopy (SEM). We also investigated the in vitro antimicrobial activity of plant EOs and plant EOs hydroxyapatite respectively, against Gram-positive bacteria (methicillin-resistant Staphylococcus aureus1144 (MRSA 1144) and S. aureus 1426) and Gram-negative bacteria (Escherichia coli ATCC 25922 and Escherichia coli ESBL 4493). From the autocorrelation function, obtained by Dynamic Light Scattering (DLS) measurements it was observed that basil yielded one peak at an average hydrodynamic diameter of 354.16 nm, while lavender yielded one peak at an average hydrodynamic diameter of 259.76 nm. In the case of HAp nanoparticles coated with basil (HApB) and lavender (HApL) essential oil, the aggregation was minimal. We found that the lavender EO exhibited a very good inhibitory growth activity (MIC values ranging from <0.1% for E. coli reference strain to 0.78% for S. aureus strains). The biological studies indicated that HapL material displayed an enhanced antimicrobial activity, indicating the potential use of HAp as vehicle for low concentrations of lavender EO with antibacterial properties. Flow cytometry analysis (FCM) allowed us to determine some of the potential mechanisms of the antimicrobial activities of EOs, suggesting that lavender EO was active against E. coli by interfering with membrane potential, the membrane depolarization effect being increased by incorporation of the EOs into the microporous structure of HAp. These findings could contribute to the development of new antimicrobial agents that are urgently needed for combating the antibiotic resistance phenomena.

RESUMEN

A series of 3-acetyl-8-methoxycoumarin appended thiosemicarbazones (1-4) was prepared from the reaction of 3-acetyl-8-methoxycoumarin with 4(N)-substituted thiosemicarbazides in a view of ascertaining their biological properties with the change of N-terminal substitution in the thiosemicarbazide moiety. Comprehensive characterization was brought about by various spectral and analytical methods. The molecular structures of all the compounds were determined by single crystal X-ray diffraction analysis. Binding studies with Calf thymus DNA (CT-DNA) and proteins such as Bovine Serum Albumin (BSA) and Human Serum Albumin (HSA) indicated an intercalative mode of binding with DNA and static quenching mechanism with proteins. The compounds cleaved plasmid DNA (pBR322) and acted well as free radical scavengers. A good spectrum of antimicrobial activity was observed against four bacterial and five fungal pathogens. The compounds exhibited profound antiproliferative activity on MCF-7 (human breast cancer) and A549 (human lung carcinoma) cell lines. Assay on human normal keratinocyte cell line HaCaT showed that the compounds were non-toxic to normal cells.

Asunto(s)

Antineoplásicos/farmacología , Cumarinas/farmacología , Bases de Schiff/farmacología , Células A549 , Animales , Antiinfecciosos/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Antioxidantes/farmacología , Bovinos , Proliferación Celular/efectos de los fármacos , Cisplatino/farmacología , Cumarinas/síntesis química , Cumarinas/química , Cristalografía por Rayos X , ADN/metabolismo , Etidio/química , Humanos , Enlace de Hidrógeno , Concentración 50 Inhibidora , Cinética , L-Lactato Deshidrogenasa/metabolismo , Células MCF-7 , Conformación Molecular , Nitritos/metabolismo , Bases de Schiff/síntesis química , Bases de Schiff/química , Espectrometría de Fluorescencia , Espectrofotometría Ultravioleta , Temperatura , Viscosidad

RESUMEN

The drug resistant bacteria and textile contaminations of water cause different sever health problem throughout the world. To overcome this issue, new environmental benign materials and methods are needed. Plant metabolites directed synthesis of nanoparticles is considered eco-friendly and easy in synthesis. Therefore, it was explicit for the synthesis of AgNPs. The prepared AgNPs were evaluated for antibacterial, antioxidant, photo-catalytic and electrochemical degradation properties as well as toxicity of degradation products on aquatic life. X-Ray Photoelectron Spectroscopy (XPS) has been used for analyzing the surface chemistry of prepared AgNPs. The particle size determines the interaction of nanoparticles with pathogens. Both Gram positive and negative bacteria (Escherichia coli and Staphylococcus areous) are used to determine the anti-microbial potency of the green synthesized AgNPs. The synthesized silver nanoparticles showed significant anti-bacterial applications against B. subtilus and S. aureus. The anti-oxidant applications of AgNPs also studied on comparison with vitamin C. The toxicity of the phenolic Azo dyes (PDA) has been studied against Fish, Daphnia and Green Algae. The electrode potential was studied in the electrochemical redox reaction of hydroxy phenol in aqueous media. Simple electrolyte was used to determine the current efficiency. For the stability of electrode multi cyclic voltammetry was also studied during redox reaction, which showed stability under the potential 0.4 to 0.2 V.

Asunto(s)

Antiinfecciosos/química , Antioxidantes/química , Compuestos Azo/química , Nanopartículas del Metal/química , Plata/química , Animales , Antiinfecciosos/farmacología , Antioxidantes/farmacología , Compuestos Azo/toxicidad , Chlorophyta/efectos de los fármacos , Daphnia/efectos de los fármacos , Técnicas Electroquímicas , Electrodos , Peces/metabolismo , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Tecnología Química Verde , Nanopartículas del Metal/toxicidad , Pruebas de Sensibilidad Microbiana , Fenoles/química , Espectroscopía de Fotoelectrones

RESUMEN

Polysaccharides are being extensively employed for the synthesis of silver nanoparticles (Ag NPs) having diverse morphology and applications. Herein, we present a novel and green synthesis of Ag NPs without using any physical reaction conditions. Linseed hydrogel (LSH) was used as a template to reduce Ag+ to Ag0. AgNO3 (10, 20, and 30 mmol) solutions were mixed with LSH suspension in deionized water and exposed to diffused sunlight. Reaction was monitored by noting the change in the color of reaction mixture up to 10 h. Ag NPs showed characteristic ultraviolet-visible (UV/Vis) absorptions from 410 to 437 nm in the case of sunlight and 397-410 nm in the case of temperature study. Transmission electron microscopy images revealed the formation of spherical Ag NPs in the range of 10-35 nm. Face-centered cubic array of Ag NPs was confirmed by characteristic diffraction peaks in powder X-ray diffraction spectrum. Ag NPs were stored in LSH thin films, and UV/Vis spectra recorded after 6 months indicated that Ag NPs retained their texture over the storage period. Significant antimicrobial activity was observed when microbial cultures (bacteria and fungi) were exposed to the synthesized Ag NPs. Wound-healing studies revealed that Ag NP-impregnated LSH thin films could have potential applications as an antimicrobial dressing in wound management procedures.

Asunto(s)

Antiinfecciosos/síntesis química , Lino/química , Tecnología Química Verde/métodos , Nanopartículas del Metal/química , Plata/farmacología , Animales , Antiinfecciosos/farmacología , Vendajes , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Masculino , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Transmisión , Conejos , Plata/química , Cicatrización de Heridas/efectos de los fármacos , Difracción de Rayos X

RESUMEN

A new synthetic methodology of water-soluble gold and silver nanoparticles (AuNPs@TC and AgNPs@TC), using the antibiotic tetracycline (TC) as co-reducing and stabilizing agent, is reported. Both colloids exhibit high water stability. The average sizes obtained were 25±10 and 15±5 nm, respectively. Both composites were tested against TC-resistant bacteria, presenting an increasing antibacterial effect in the case of AgNPs@TC. The sensing towards metal ions was also explored. An interesting and reversible affinity of AuNPs@TC towards AlIII cations in an aqueous system was also observed.

RESUMEN

Hydrazone Schiff bases have been widely explored for their antimicrobial, anticancer, anticonvulsant properties. The aim of the present work is to investigate the spectroscopic, electrochemical, thermal properties, in vitro study of antimicrobial activity and molecular docking studies of the MBHC compound. Slow evaporation solution growth technique was used to grow the single crystal of the MBHC compound. Single crystal X-ray diffraction, FTIR and FT-Raman spectroscopic studies are performed and confirmed the grown MBHC compound. UV-Vis spectroscopy and electrochemical studies deduced the absorption region and HOMO-LUMO band gap value of the compound. Resazurin reduction assay method was utilized to perform antibacterial and antifungal studies which resulted in lesser effectiveness of the MBHC compound compared to the erythromycin and fluconazole tablets. Molecular docking of the MBHC compound with the DNA gyrase protein exhibited the good binding affinity with energy of -43.196kcal/mol and docking score of -6.266 and having good interaction with aminoacids - ASP81 and ARG84.

Asunto(s)

Antiinfecciosos , Bacterias/crecimiento & desarrollo , Candida albicans/crecimiento & desarrollo , Girasa de ADN/química , Hidrazinas , Simulación del Acoplamiento Molecular , Antiinfecciosos/química , Antiinfecciosos/farmacología , Cristalografía por Rayos X , Hidrazinas/química , Hidrazinas/farmacología , Bases de Schiff/química , Bases de Schiff/farmacología