Many natural-occurring peptides and peptide-ketide hybrids exhibit specific biological activities and chemical reactivities upon binding with certain metal ions. In this review we summarize the background and discuss our research on metal binding, structures, and oxidative reactivities of three peptides, the bacterial antibiotic bacitracin, the Alzheimer's disease-related β-amyloid, and the salivary antimicrobial histatin.

A novel procedure for solid-phase organic synthesis of 1,3-disubstituted uracils using a cyclization-cleavage strategy from Wang-acrylate resin, amines and isocyanates. An acrylate ester resin is reacted in turn with PhSeBr and primary amines in one-pot to afford N-substituted α-phenylseleno-β-aminoesters followed by treatment with isocyanates to form α-phenylseleno-β-ureidoester resin. Following oxidation-elimination with excess of 30% hydrogen peroxide and intramolecular cyclization cleavage of the Wang resin using potassium ethoxide as a base to furnish 1,3-disubstituted uracils in good yields and high purities.

Methoxyl silica gel was prepared readily prepared by the treatment of silica chloride with methanol. By using methoxyl silica gel as a dehydrating agent, carboxylic acids reacted with methanol in the presence of a protonic acid such as 12-phosphotungstic acid afforded the corresponding methyl esters in excellent yields.

The adsorption behavior of metal cations on gold nanoparticles was investigated by isothermal titration microcalorimetry (ITC). The binding enthalpy of metal ions on gold nanopartilces depends on the nature and concentration of added cations, and the binding process is enthalpically driven. Furthermore, the above results were verified by transmission electron microscopy (TEM), and UV-vis absorption spectroscopy.

We developed a simple way to realize the tangent-sphere model for constructing physical models of arbitrary fullerenes based on beads commonly used in the ornaments and decorative arts. Using suitably chosen weaving strategy, the beaded model can be made to be a faithful bond representation of the corresponding fullerene.

The silver nanoprisms were the dominant products of shape conversion reaction of spherical silver nanoparticles under the irradiation of a sodium lamp (max λ = 589 nm, 0.66 W/cm2) at 60°C. Some decahedral silver nanoparticles, about 10% of the final irradiation products, were observed in the synthesis (with a sodium lamp) at 15 C o . The decahedral silver nanoparticles with a fairly narrow size distribution were obtained by irradiating the spherical nanoparticle colloids with the blue LEDs (450 max = λ nm, 3.5 mW/cm2) at 2°for about 48 hours.

The reaction of sodium 4,4′-dibromobenzilmonoximate(DBBONa) with Fe(NO3)3.9H2O and Ni(NO3)2.6H2O in methanol gave [Fe(DBBO)3] as yellow and Na[Ni(DBBO)3] as brown complexes, respectively.

The enthalpies of dissolution for 3,4,5-triamino-1,2,4-triazole dinitramide in N-methyl pyrrolidone(NMP) were measured by means of a RD496-2000 Calvet microcalorimeter at four different temperatures under atmospheric pressure, and the corresponding kinetic equations describing the four dissolution processes were obtained. The values of activation energy E and pre-exponential factor A for the dissolution process were obtained as 14.13 kJṁmol-1 and 5.34×10-2 s-1.

Monodispersed particles of NiC2O4 were prepared by the precipitation method under optimized reaction conditions. It was noted that besides other experimental parameters, isoelectric point of NiC2O4 played a major role in the particles' build up. On control heating at 340 °C, the NiC2O4 particles converted into NiO particles while preserving their particles' integrity to a maximum extent.

Linear calibration plot for the related substance method was obtained over the calibration ranges tested, i.e. LOQ to 0.30% (n=3) for impurities. The correlation coefficient obtained was greater than 0.998. Plotted a graph of the area versus the actual concentration to determine the correlation coefficients, slopes and Y-intercepts of the calibration curve. The above result shows that an excellent correlation existed between the peak area and the concentration of imp-A, imp-B, imp-C and imp-D.

The scanning electron micrograph (SEM) image shows that the particle size of the matter of CTMAC+ṁI-formed by CTMAC+ and I- is about 0.15∼0.25 μm. This proves that Cetyltrimethyl ammonium chloride cation (CTMAC+) reacted with I- to form the microcrystalline matter (Ms-M) of (CTMAC+ṁI-).

1-(2-pyridylazo)-2-naphtol (PAN) is a usual chromogenic agent which can combine with a wide range of different metals. Its capability to combine with trace copper ions in aqueous solutions has been investigated in direct introduction of miscellaneous complex (DIMC) and modification of disk surface (MDS) methods.

Electropherogram for (a) 200 μM chlorogenic acid, (b) 400 μM sinapic acid, (c) 200 μM ferulic acid, (d) 200 μM caffeic acid, (e) 200 μM p-coumaric acid, (f) 200 μM vanillic acid, (g) 200 μM protocatechuic acid and (h) 400 μM gentisic acid. Conditions: separation voltage at +2.0 kV; electrokinetic injection for 5 s (at +2.0 kV); working potential, +0.9 V (vs. Ag/AgCl) at 50 μm Pt wire electrode; running buffer of 25 mM phosphate buffer (pH 7.5).

In this work, we report on the preparation of a solid-state of zinc with diclofenac. Calculations based on the mass loss up to the final temperature are in agreement with the formation of ZnO as the final residue (calc.= 88.59%; TG = 87.99%). The kinetic parameters to the dehydration, thermal decomposition and transition phase were evaluated from the DSC curves.

The sol-gel technique was used to construct copper hexacyanoferrate (CuHCNF) modified composite ceramic carbon electrodes (CCEs). CuHCNF film has been deposited on the surface of CCE by a simple electroless dipping into a potassium hexacyanoferrate solution method. The electrochemical properties and stability of the modified electrode were investigated by cyclic voltammetry. The modified electrode was used for electrocatalytic determination of sulfite in hard sugar sample.

The synthesis of (±)-curcuphenol 1, (±)-curcudiol 2, (±)-curcuhydroquinone 3 had been achieved in which the Johnson-Claisen rearrangement was used as key step.

This study investigates the antioxidant properties of the leaves of Koelreuteria henryi L. using a microarray reader and HPLC. The antioxidant, 1,3,4,5,-tetra-O-galloylquinic acid (1), was first isolated from this plant and estimated using LC-MS/MS and NMR methods. The scavenger activity of (1) was then determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and xanthine oxidase (XOD) assays, producing an IC50 of 7.1 μM and 6.7 μM, respectively.

The effective utilization of waste rice husk requires detailed studies on the kinetics and mechanism of their thermal and chemical treatment. The present work is a comparative study on the thermo-chemical and kinetic characteristics of thermal degradation of raw and treated with NaOH rice husk. The optimal conditions for extraction of SiO2 from rice husk in the form of Na2SiO3 were determined using thermal analysis (TA), scanning electron microscope (SEM) and elemental analysis. The experiments were carried out under conditions of non-isothermal heating in air and nitrogen atmosphere. Using different kinetic models, the values of the effective kinetic parameters, characterizing the destruction process were determined.

In the course of phytochemical investigations of Senecio species scattered in northeast China, a new farnesene derivative, 7R*,10S*-epoxy-3E,5E-farnesadien-1,2,11-triol, was isolated from the aerial parts of Senecio cannabifolius.