Efficient Green Synthesis, Anticancer Activity, and Molecular Docking Studies of Indolemethanes Using a Bioglycerol-Based Carbon Sulfonic Acid Catalyst.

Indolemethane derivatives are significant molecules in the study of N-heterocyclic chemistry. Herein, we designed and developed a highly efficient green synthesis of indolemethane compounds using a recyclable biodegradable glycerol-based carbon solid acid catalyst under solvent-free conditions at room temperature for 5 min with excellent yields. The synthesized compounds were subjected to cytotoxic activity against prostate (DU145), hepatocellular carcinoma (HepG2), and melanoma (B16) cell lines. The highest cytotoxicity effects were found with 1k (1.09 µM) and 1c (2.02 µM) against DU145, followed by 1a, 1d, 1f, 1n, and 1m between 5.10 and 8.18 µM concentrations. The anticancer activity is validated using molecular docking simulations, and comparing binding energies with the standard drug doxorubicin suggests that the title compounds are well fitted into the active site pocket of the target molecules..

Precise Sn-Doping Modulation for Optimizing CdWO4 Nanorod Photoluminescence.

The cadmium tungstate rods have been given much attention due to their potential for usage in numerous luminescent applications. We have prepared single crystalline Sn-doped Cd1-xSnxWO4 (where x = 0, 1, 3, and 5%) nanorods (NRDs) and characterized them using refined X-ray diffraction and TEM analysis, revealing a monoclinic phase and a crystallite size that decreased from 62 to 38 nm as Sn concentration increased. Precise Sn doping modulation in CdWO4 NRDs causes surface recombination of electrons and holes, which causes the PL intensity to decrease as the Sn content rises. The chromaticity diagram shows that an increase in the Sn content caused a change in the emission color from sky blue to light green, which was attributed to the increased defect density. The photoluminescence time decay curve of all samples fit well with double-order exponential decay, and the average decay lifetime was found to be 1.11, 0.93, and 1.16 ns for Cd1-xSnxWO4, x = 0, 1, and 5%, respectively. This work provides an understanding of the behavior of Sn-doped CdWO4 NRDs during electron transitions and the physical nature of emission that could be used in bio-imaging, light sources, displays, and other applications.

One-pot hydrothermal preparation and defect-enhanced photocatalytic activity of Bi-doped CdWO4 nanostructures.

In the field of photocatalysis, the suppression of electron-hole recombination through various defects has been an emerging trend to enhance photocatalytic activity. The separation efficiency of electron-hole recombination of well-explored wolframite structured monoclinic CdWO4, prepared using the one-pot hydrothermal method, was further improved by Bi3+ doping in CdWO4. Studies using the partial density of states illustrated that Bi 6s and 6p orbitals altered the electronic band structure to the extent of lowering the band gap, resulting in more photon absorption. The positron annihilation lifetime studies unveiled the formation of cluster defects such as oxygen (V0o, Vo1+, Vo2+) along with cadmium vacancies () in Bi-doped CdWO4. The coexistence and synergy of more adsorption sites of V0o, Vo1+, Vo2+, VCd for dye and O2 molecules, suitable oxide/redox band potentials, the modified electronic band structure especially owing to W-O1-Bi-O2-W linkages, together with high surface area endowed Bi-doped CdWO4 to form ˙O2- radicals played a predominant role in the methyl orange degradation. All the experimental findings demonstrated conclusively that Bi3+ doping at Cd2+ facilitated CdWO4 to exhibit superior photocatalytic activity.

Room Temperature Magnetic Memory Effect in Cluster-Glassy Fe-doped NiO Nanoparticles.

The Fe-doped NiO nanoparticles that were synthesized using a co-precipitation method are characterized by enhanced room-temperature ferromagnetic property evident from magnetic measurements. Neutron powder diffraction experiments suggested an increment of the magnetic moment of 3d ions in the nanoparticles as a function of Fe-concentration. The temperature, time, and field-dependent magnetization measurements show that the effect of Fe-doping in NiO has enhanced the intraparticle interactions due to formed defect clusters. The intraparticle interactions are proposed to bring additional magnetic anisotropy energy barriers that affect the overall magnetic moment relaxation process and emerging as room temperature magnetic memory. The outcome of this study is attractive for the future development of the room temperature ferromagnetic oxide system to facilitate the integration of spintronic devices and understanding of their fundamental physics.

In Situ FTIR Spectroscopic Monitoring of the Formation of the Arene Diazonium Salts and its Applications to the Heck-Matsuda Reaction.

This study depicts the use of a fiber-optic coupled Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) probe for the in-depth study of arene diazonium salt formation and their utilization in the Heck-Matsuda reaction. The combination of these chemical reactions and in situ IR spectroscopy enabled us to recognize the optimum parameters for arene diazonium salt formation and to track the concentrations of reactants, products and intermediates under actual reaction conditions without time consuming HPLC analysis and the necessity of collecting the sample amid the reaction. Overall advantages of the proposed methodology include precise reaction times as well as identification of keto enol tautomerization in allylic alcohols supporting the 'path a' elimination mechanism in the Heck-Matsuda reaction.

Molecular Design, Synthesis, and Biological Evaluation of 2-Hydroxy-3-Chrysino Dithiocarbamate Derivatives.

A series of 2-hydroxy-3-chrysino dithiocarbamate derivatives (3a-k) were designed, synthesized, and characterized for their structure determination by 1H NMR, 13C NMR, and HRMS (ESI) spectral data. They were screened for their in vitro biological activities against a panel of selected bacterial and fungal strains. These antimicrobial studies indicate that some of the analogues manifested significant activity compared to standard drugs. Among the synthetic analogues (3a-k), compounds 3d, 3f, and 3j exhibited very good antibacterial activity and compounds 3d, 3f, and 3h showed very good antifungal activity compared to the standard drugs penicillin and itrazole, respectively. The compounds 3e, 3g, and 3h showed moderate antibacterial activity and the compounds 3j and 3k showed moderate antifungal activity. Molecular docking studies were performed and the experimental antimicrobial screening results were also correlated with the binding energy values obtained by molecular docking. The synthesized chrysin analogues (3a-k) have obeyed Lipinski's "rule of five" and have drug-likeness.

Study of microwave effects on the lipase-catalyzed hydrolysis.

The effect of microwave heating on lipase-catalyzed reaction remains controversial. It is not clear whether the reaction rate enhancements are purely due to thermal/heating effects or to non-thermal effects. Therefore, quantitative mass spectrometry was used to conduct accurate kinetic analysis of lipase-catalyzed hydrolysis of triolein by microwave and conventional heating. Commercial lipases from Candida rugosa (CRL), Porcine Pancreas (PPL), and Burkholderia cepacia (BCL) were used. Hydrolysis reactions were performed at various temperatures and pH levels, along with various amounts of buffer and enzymes. Hydrolysis product yields at each time point using an internal-standard method showed no significant difference between microwave and conventional heating conditions when the reaction was carried out at the same temperature. CRL showed optimum catalytic activity at 37 °C, while PPL and BCL had better activities at 50 °C. The phosphate buffer was found to give a better hydrolysis yield than the Tris-HCl buffer. Overall results prove that a non-thermal effect does not exist in microwave-assisted lipase hydrolysis of triolein. Therefore, conventional heating at high temperatures (e.g., 50 °C) can be also used to accelerate hydrolysis reactions.

Hydrolysis of Letrozole catalyzed by macrocyclic Rhodium (I) Schiff-base complexes.

Ten mononuclear Rhodium (I) complexes were synthesized by macrocyclic ligands having N4 and N2O2 donor sites. Square planar geometry is assigned based on the analytical and spectral properties for all complexes. Rh(I) complexes were investigated as catalysts in hydrolysis of Nitrile group containing pharmaceutical drug Letrozole. A comparative study showed that all the complexes are efficient in the catalysis. The percent yields of all the catalytic reaction products viz. drug impurities were determined by spectrophotometric procedures and characterized by spectral studies.

Functionalized magnetic iron oxide (Fe3O4) nanoparticles for capturing gram-positive and gram-negative bacteria.

The development of nanotechnology in biology and medicine has raised the need for conjugation of nanoparticles (NPs) to biomolecules. In this study, magnetic and functionalized magnetic iron oxide nanoparticles were synthesized and used as affinity probes to capture Gram-positive/negative bacteria. The morphology and properties of the magnetic NPs were examined by transmission electron microscopy, Fourier transform infrared spectroscopy, and zeta potential measurements. Furthermore, this study investigated the interaction between functionalized magnetic nanoparticles and Gram positive/negative bacteria. The positively and negatively charged magnetic nanoparticles include functionalities of Fe3O4, SiO2, TiO2, ZrO2, poly ethyleneimine (PEI) and poly acrylic acid. Their capture efficiencies for bacteria were investigated based on factors such as zeta potential, concentration and pH value. PEI particles carry a positive charge over a range of pH values from 3 to 10, and the particles were found to be an excellent candidate for capturing bacteria over such pH range. Since the binding force is mainly electrostatic, the architecture and orientation of the functional groups on the NP surface are not critical. Finally the captured bacteria were analyzed using matrix-assisted laser desorption/ionization mass spectrometry. The minimum detection limit was 10(4) CFU/mL and the analysis time was reduced to be less than 1 hour. In addition, the detection limit could be reduced to an extremely low concentration of 50 CFU/mL when captured bacteria were cultivated.

Quantification of genetically modified soya using strong anion exchange chromatography and time-of-flight mass spectrometry.

Stable-isotope dimethyl labeling was applied to the quantification of genetically modified (GM) soya. The herbicide-resistant gene-related protein 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) was labeled using a dimethyl labeling reagent, formaldehyde-H2 or -D2. The identification and quantification of CP4 EPSPS was performed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The CP4 EPSPS protein was separated from high abundance proteins using strong anion exchange chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Then, the tryptic peptides from the samples and reference were labeled with formaldehyde-H2 and formaldehyde-D2, respectively. The two labeled pools were mixed and analyzed using MALDI-MS. The data showed a good correlation between the peak ratio of the H- and D-labeled peptides and the GM soya percentages at 0.5, 1, 3, and 5 %, with R (2) of 0.99. The labeling reagents are readily available. The labeling experiments and the detection procedures are simple. The approach is useful for the quantification of GM soya at a level as low as 0.5 %.

Evaluating the potential nonthermal microwave effects of microwave-assisted proteolytic reactions.

Microwave-assisted proteolytic digestion methods have evolved into a highly effective approach and serve as an alternative to conventional overnight digestion. This approach typically exploits the unique microwave properties to facilitate the digestion of proteins into their peptides within minutes. Conventional digestion is carried out at 37°C while microwave-assisted digestion requires much higher and sometimes inconsistent temperatures. Thus, this study aims to investigate whether the faster reaction rate is due to the microwave quantum effect or the thermal effect. Quantitative mass spectrometry was used to conduct kinetic analysis of tryptic digestion for several proteins by microwave and conventional heating. The percentages of digestion products relative to internal standards showed no significant difference between microwave and conventional heating conditions at the same digestion temperature. The optimum temperature for tryptic digestion was determined to be 50°C. Furthermore, this study compares the digestion completeness indicators of several proteins under microwave and conventional heating. Again, the values obtained from microwave and conventional heating were similar given identical temperatures. The overall results prove that a nonthermal effect does not exist in microwave-assisted tryptic digestion. Therefore, conventional heating at high temperatures (50°C) can be also used to accelerate digestion reactions.

Synthesis of mono, bis-2-(2-arylideneaminophenyl) indole azomethines as potential antimicrobial agents.

A series of mono and bis 2-2-(arylidineaminophenyl)indole azomethines have been synthesized by a condensation reaction of 2-(2-amino phenyl) indole with various mono and diketones R-CO-R(l) /R-CO-X-CO-R(l) (1:1/2:1 ratio) in ethanol media. The synthesized azomethines were characterized via IR, (1)H-NMR, (13)C-NMR, MS and elemental analysis. The antimicrobial activity of these compounds against different bacteria and fungi was also evaluated.

Advances in mass spectrometry for the identification of pathogens.

Mass spectrometry (MS) has become an important technique to identify microbial biomarkers. The rapid and accurate MS identification of microorganisms without any extensive pretreatment of samples is now possible. This review summarizes MS methods that are currently utilized in microbial analyses. Affinity methods are effective to clean, enrich, and investigate microorganisms from complex matrices. Functionalized magnetic nanoparticles might concentrate traces of target microorganisms from sample solutions. Therefore, nanoparticle-based techniques have a favorable detection limit. MS coupled with various chromatographic techniques, such as liquid chromatography and capillary electrophoresis, reduces the complexity of microbial biomarkers and yields reliable results. The direct analysis of whole pathogenic microbial cells with matrix-assisted laser desorption/ionization MS without sample separation reveals specific biomarkers for taxonomy, and has the advantages of simplicity, rapidity, and high-throughput measurements. The MS detection of polymerase chain reaction (PCR)-amplified microbial nucleic acids provides an alternative to biomarker analysis. This review will conclude with some current applications of MS in the identification of pathogens.

Binuclear cobalt(II), nickel(II), copper(II) and palladium(II) complexes of a new Schiff-base as ligand: synthesis, structural characterization, and antibacterial activity.

A binucleating new Schiff-base ligand with a phenylene spacer, afforded by the condensation of glycyl-glycine and o-phthalaldehyde has been served as an octadentate N4O4 ligand in designing some binuclear complexes of cobalt(II), nickel(II), copper(II), and palladium(II). The binding manner of the ligand to the metal and the composition and geometry of the metal complexes were examined by elemental analysis, conductivity measurements, magnetic moments, IR, ¹H, ¹³C NMR, ESR and electronic spectroscopies, and TGA measurements. There are two different coordination/chelation environments present around two metal centers of each binuclear complex. The composition of the complexes in the coordination sphere was found to be [M2(L)(H(2)O)4] (where M=Co(II) and Ni(II)) and [M2(L)] (where M=Cu(II) and Pd(II)). In the case of Cu(II) complexes, ESR spectra provided further information to confirm the binuclear structure and the presence of magnetic interactions. All the above metal complexes have shown moderate to good antibacterial activity against Gram-positive and Gram-negative bacteria.

Identification of pathogens by mass spectrometry.

BACKGROUND: Mass spectrometry (MS) is a suitable technology for microorganism identification and characterization. CONTENT: This review summarizes the MS-based methods currently used for the analyses of pathogens. Direct analysis of whole pathogenic microbial cells using MS without sample fractionation reveals specific biomarkers for taxonomy and provides rapid and high-throughput capabilities. MS coupled with various chromatography- and affinity-based techniques simplifies the complexity of the signals of the microbial biomarkers and provides more accurate results. Affinity-based methods, including those employing nanotechnology, can be used to concentrate traces of target microorganisms from sample solutions and, thereby, improve detection limits. Approaches combining amplification of nucleic acid targets from pathogens with MS-based detection are alternatives to biomarker analyses. Many data analysis methods, including multivariate analysis and bioinformatics approaches, have been developed for microbial identification. The review concludes with some current clinical applications of MS in the identification and typing of infectious microorganisms, as well as some perspectives. SUMMARY: Advances in instrumentation (separation and mass analysis), ionization techniques, and biological methodologies will all enhance the capabilities of MS for the analysis of pathogens.

Digestion completeness of microwave-assisted and conventional trypsin-catalyzed reactions.

Microwave-assisted proteolytic digestion often yields misscleaved peptides, attributed to incomplete hydrolysis reactions between enzymes and substrates. The number of missed cleavages is an important parameter in proteome database searching. This study investigates how various factors affect digestion processes. Optimum conditions for microwave-assisted digestion (50 mM Tris buffer, 30 min at 60 degrees C, and enzyme to protein molar ratio of 1:5) were determined. The digestion products obtained from eight standard proteins were characterized based on matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Experimental results indicate that the digestion temperature, reaction time, enzyme to substrate ratio, and digestion buffer affect the number of misscleaved peptides and incomplete digestion percentages. Although all protein molecules in a sample could be digested into peptides within a few minutes under microwave irradiation, longer reaction times or methods to maximize the enzyme activity should be considered if digestion completeness is a major concern.

Concentration and in situ detection of peptides using liquid matrix-assisted laser desorption ionization matrixes.

A ternary component system composed of alpha-cyano-4-hydroxycinnamic acid/3-aminoquinoline/quinoline (CHCA/3-AQ/Q; at a weight ratio of 1:4:4) was used as an extraction solvent as well as a liquid matrix for matrix-assisted laser desorption ionization (MALDI) mass spectrometry analysis. Peptides in aqueous solutions were extracted, concentrated, and prepared for MALDI analysis in one step. Extracting peptides in aqueous solutions was analogous to dispersive liquid-liquid microextraction and completed in less than 2 min because CHCA/3-AQ/Q was dispersed rapidly into the aqueous phase by ultrasonication during extraction. The detection limit for peptides in aqueous solutions was as low as 1.25 nM for angiotensin I. Protein digests obtained from conventional MALDI analysis and the proposed method were compared with respect to sequence coverage. The new approach was applied to sample cleanup, preconcentration, and in situ analysis of protein digests in signal suppressing agents such as Tris buffer and urea.

6-substituted indolo[1,2-c]quinazolines as new antimicrobial agents.

A series of 2-o-arylidineaminophenylindoles and their cyclic derivatives (indolo[1,2-c]quinazolines) were synthesized. The reactions occurred under relatively mild conditions and afforded the desired product in good yields. Molecular structures of the synthesized compounds were confirmed by IR, (1)H-NMR,( 13)C-NMR, MS spectra, and elemental analyses. Furthermore, all the final products were screened for in-vitro antibacterial activity against three Gram-positive and three Gram-negative bacteria and also tested for their inhibitory action against three strains of fungi. Compound IIc showed potent activity against all the bacterial (except S. typhimurium) and fungal strains. Especially, compounds IIi and IIj which have isoquinolyl and pyridyl substituents displayed potent antibacterial as well as antifungal activities compared to those of the respective standard drugs Ampicillin and Ketoconazole.

Ru(II) complexes of N4 and N2O2 macrocyclic Schiff base ligands: their antibacterial and antifungal studies.

Reactions of [RuCl2(DMSO)4] with some of the biologically active macrocyclic Schiff base ligands containing N4 and N2O2 donor group yielded a number of stable complexes, effecting complete displacement of DMSO groups from the complex. The interaction of tetradentate ligand with [RuCl2(DMSO)4] gave neutral complexes of the type [RuCl2(L)] [where L=tetradentate macrocyclic ligand]. These complexes were characterized by elemental, IR, 1H, 13C NMR, mass, electronic, thermal, molar conductance and magnetic susceptibility measurements. An octahedral geometry has been proposed for all complexes. All the macrocycles and macrocyclic Ru(II) complexes along with existing antibacterial drugs were screened for antibacterial activity against Gram +ve (Bacillus subtilis, Staphylococcus aureus) and Gram -ve (Escherichia coli, Klebsiella pneumonia) bacteria. All these compounds were found to be more active when compared to streptomycin and ampicillin. The representative macrocyclic Schiff bases and their complexes were also tested in vitro to evaluate their activity against fungi, namely, Aspergillus flavus and Fusarium species.

Ru(III)-catalyzed oxidation of pyridoxine and albuterol in pharmaceuticals.

Ru(III) complexes with coordinated amide were synthesized and characterized by elemental, IR, mass, electronic, ESR spectral analysis, magnetic and conductance measurements and octahedral structures have been proposed. These complexes were used as catalysts for the oxidation of pyridoxine and albuterol in pharmaceuticals in presence of hydrogen peroxide. The role of co-oxidant and the effect of reaction time on the yields of oxidation products which were spectrophotometrically determined by condensing them with sulfanilic acid in acid medium were investigated. Structures of the oxidation products were established with the help of IR and NMR spectral analysis.