A complex of Erbium perchloric acid coordinated with l-aspartic acid and imidazole, Er2(Asp)2(Im)8(ClO4)6·10H2O was synthesized for the first time. It was characterized by IR and elements analysis. The heat capacity and thermodynamic properties of the complex were studied with an adiabatic calorimeter (AC) from 80 to 390 K and differential scanning calorimetry (DSC) from 100 to 300 K. Glass transition and phase transition were discovered at 220.45 and 246.15 K, respectively. The glass transition was interpreted as a freezing-in phenomenon of the reorientational motion of ClO4− ions and the phase transition was attributed to the orientational order/disorder process of ClO4− ions. The thermodynamic functions [HT − H298.15] and [ST − S298.15] were derived in the temperature range from 80 to 390 K with temperature interval of 5 K. Thermal decomposition behavior of the complex in nitrogen atmosphere was studied by thermogravimetric (TG) analysis and differential scanning calorimetry (DSC).
Authors:W. Zhou, X. Y. Zhang, Y. P. Lv, X. D. Liu, C. Xu, and G. L. Duan
Radix Isatidis has widely useful activities including anti-virus, anti-bacterial. Tryptanthrin, indigo, and indirubin are active ingredients in R. Isatidis. Response surface methodology (RSM)-optimized infrared-assisted extraction (IRAE) was developed and combined with HPLC for simultaneous determination of tryptanthrin, indigo, and indirubin from R. Isatidis. IRAE were investigated through extraction yields of the three components and optimized by RSM. The optimum conditions were as follows: infrared power of 129 W, solid/liquid ratio of 1:40 g/mL, and irradiation time of 22.5 min. IRAE conditions obtained by RSM were not only accurate, but also had practical value reflecting the expected optimization. Subsequently, this novel IRAE method was evaluated by extraction yield of the components of R. Isatidis samples from different regions. Compared with common extraction methods including maceration extraction (ME), reflux extraction (RE), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE), IRAE showed higher yield with advantages of no limitation of solvent selection, low cost, convenience under optimum extraction conditions. These results suggested the potential of RSM-optimized IRAE for extraction and analysis of the water-/fat-soluble compositions of Chinese herbal medicine. A simple chromatographic separation for simultaneous determination of tryptanthrin, indigo, and indirubin from Chinese herbal medicine R. Isatidis was performed on a C18 column (Diamonsil 150 mm × 4.6 mm i.d., 5 μm) with a mobile phase isocratic consisting of methanol and water at a flow-rate of 0.8 mL min−1. The retention times of tryptanthrin, indigo, and indirubin were 15.4, 31.9, and 58.6 min, respectively. The linear equations were obtained as follows: y = −3094.5744 + 21208.792x for tryptanthrin (R = 0.9998, 0.9–18.0 μg mL−1), y = 4730.0448 + 30180.567x for indigo (R = 0.9997, 0.5–10.0 μg mL−1) and y = −6582.9045 + 67069.312x for indirubin (R = 0.9997, 0.4–8.0 μg mL−1). The result showed that RSM-optimized IRAE was a simple, efficient pretreatment method for the analysis of complex matrix.
Authors:X.-C. Lv, Z.-C. Tan, Z.-A. Li, Y.-S. Li, J. Xing, Q. Shi, and L.-X. Sun
The (R)-BINOL-menthyl dicarbonates,
one of the most important compounds in catalytic asymmetric synthesis, was
synthesized by a convenient method. The molar heat capacities Cp,m
of the compound were measured over the temperature range from 80 to 378 K
with a small sample automated adiabatic calorimeter. Thermodynamic functions
[HT–H298.15] and [ST–S298.15] were derived in the
above temperature range with a temperature interval of 5 K. The thermal stability
of the substance was investigated by differential scanning calorimeter (DSC)
and a thermogravimetric (TG) technique.
Authors:C. Han, Z. Yu, S. Feng, D. Lv, X. Yan, G. Chen, X. Li, W. Ma, and Y. Yan
Separation and analysis of water-soluble proteins (WSP) are important in understanding wheat grain proteome fundamentals. However, due to their high degree of heterogeneity and complexity in the compositions, separating WSP is generally difficult and relevant methodologies are not efficiently developed yet. Capillary electrophoresis (CE) is one of the analytical methods currently used for protein separation and characterization. In the present study, a CE method is established for rapidly separating and characterizing WSP of wheat grains. The established method was tested in various applications including wheat variety and germplasm identification as well as protein synthesis and accumulation studies during different grain development stages subject to genotypic and environmental variations. As results, the characteristic CE patterns of a range of bread wheat cultivars and related species were readily identified. The synthesis and accumulation patterns of wheat WSP during developing grains as well as their stabilities in different environments were also investigated. The technical advancements present in this article appear to be useful for wheat cultivar and germplasm identification as well as genetics and breeding research.
Two lines, L-19-613 and L-19-626, were produced from the common wheat cultivar Longmai 19 (L-19) by six consecutive backcrosses using biochemical marker-assisted selection. L-19 (Glu-D1a, Glu-A3c/Gli-A1?; Gli-A1? is a gene coding for unnamed gliadin) and L-19-613 (Glu-D1d, Glu-A3c/Gli-A1?) formed a set of near-isogenic lines (NILs) for HMW-GS, while L-19-613 and L-19-626 (Glu-D1d, Glu-A3e/Gli-A1m) constituted another set of NILs for the LMW-GS/gliadins. The three L-19 NILs were grown in the wheat breeding nursery in 2007 and 2008. The field experiments were designed using the three-column contrast arrangement method with four replicates. The three lines were ranked as follows for measurements of gluten strength, which was determined by the gluten index, Zeleny sedimentation, the stability and breakdown time of the farinogram, the maximum resistance and area of the extensogram, and the P andWvalues of the alveogram: L-19-613 > L-19-626 > L-19. The parameters listed above were significantly different between lines at the 0.05 or 0.01 level. The Glu-D1 and Glu-A3/Gli-A1 loci had additive effects on the gluten index, Zeleny sedimentation, stability, breakdown time, maximum resistance, area, P and W values. Although genetic variation at the Glu-A3/Gli-A1 locus had a great influence on wheat quality, the genetic difference between Glu-D1d and Glu-D1a at the Glu-D1 locus was much larger than that of Glu-A3c/Gli-A1? and Glu-A3e/Gli-A1m at the Glu-A3/Gli-A1 locus. Glu-D1d had negative effects on the extensibility and the L value compared with Glu-D1a. In contrast, Glu-A3c/Gli-A1? had a positive effect on these traits compared with Glu-A3e/Gli-A1m.