1.Macromolecular crowding agents-assisted imprinted polymers for analysis of Glycocholic acid in human plasma and urine.
Li QF1, Zhan YM1, Zhong YG1, Zhang B1, Ge CQ1. Biomed Chromatogr. 2016 Apr 8. doi: 10.1002/bmc.3737. [Epub ahead of print]
Glycocholic acid (GCA) is a new identification of biomarker for hepatocellular carcinoma (HCC) patients. In this study, a method based on macromolecular crowding strategy has been applied for preparation of molecularly imprinted polymer (MIP), which possesses high adsorption capacity for GCA. Polymethyl methacrylate (PMMA) was used as macromolecular crowding agent, N-(3-aminopropyl)-methacrylamide hydrochloride (APMA · HCl) as functional monomer, ethylene dimethacrylate (EDMA) as cross-linker. The morphology and binding characteristics of MIP were assessed by scanning electron microscopy and absorption experiments. The MIP was used as an adsorbent material to separate GCA, and the molecularly imprinted solid-phase extraction (MISPE) was carefully optimized. The MISPE combined with high performance liquid chromatography (HPLC) analysis was successfully used to determine the GCA in plasma and urine samples. When spiked levels ranged from 0.
2.Development of quantitative immunochromatographic kit and visual screening immunoassay strip for cadmium.
Arai H1, Nakamura K2, Yoshida Y2, Tawarada K3. Anal Bioanal Chem. 2016 Apr 2. [Epub ahead of print]
Cadmium is a highly toxic heavy metal for humans. In 2006, the Codex Alimentarius Commission set the international standard value of Cd contained in polished rice at 0.4 mg kg-1, thus requiring the monitoring of Cd in food. We developed two types of Cd immunochromatographic kit by using anti-(Cd-EDTA) antibody. One is the quantitative Cd immunochromatographic device which can precisely measure Cd concentrations. The other is the Cd screening strip that enables visible evaluation of Cd exceeding 0.003 mg L-1. Compared with conventional instrumental analysis methods, the immunoassay kits provide rapid, simple, and inexpensive on-site methods. For these kits, we also developed an efficient pretreatment method that can be easily administrated on-site. In this method, brown rice samples are coarsely crushed by a hand-held grinder then mixed with an enzyme solution, and Cd is extracted with HCl. The extracted solution is then purified by a newly developed Cd-selective ion exchange column.
3.Quasi-Classical Trajectory Study of Atom-Diatomic Molecule Collisions in Symmetric Hyperspherical Coordinates: The F + HCl Reaction as a Test Case.
Freixas-Lemus VM1, Martínez-Mesa A1, Uranga-Piña L1. J Phys Chem A. 2016 Apr 7;120(13):2059-69. doi: 10.1021/acs.jpca.5b11525. Epub 2016 Mar 29.
We investigate the reactive dynamics of the triatomic system F + HCl → HF + Cl for total angular momentum equal zero and for different low-lying rovibrational states of the diatomic molecule. For each of the initial vibrational quantum numbers, the time evolution of the atom-diatom collision process is investigated for a wide range of impact angles and collision energies. To this purpose, the Quasi-Classical Trajectories (QCT) method was implemented in a hyperspherical configuration space. The Hamilton equations of motion are solved numerically in an intermediate effective Cartesian space to exploit the relative simplicity of this intermediate representation. Interatomic interactions are described by a London-Eyring-Polanyi-Sato potential energy surface, specifically developed for the title reaction, and the results of the QCT simulations are discussed in terms of the time-evolution of the hyperangles. The analysis of the collision dynamics using symmetric hyperspherical coordinates provides, in addition to the description in terms of a natural reaction coordinate (the hyperradius), a more striking representation of the exchange dynamics, in terms of the time-dependent probability distribution along the kinematic rotation hyperangle, and a precise distinction between direct and indirect mechanisms of the reaction.
4.Improving the yield of (+)-terrein from the salt-tolerant Aspergillus terreus PT06-2.
Zhao C1, Guo L1, Wang L2, Zhu G1, Zhu W3. World J Microbiol Biotechnol. 2016 May;32(5):77. doi: 10.1007/s11274-016-2029-0. Epub 2016 Apr 2.
(+)-Terrein has a potential application for drug discovery. To improve the yield of (+)-terrein, two-level Plackett-Burman design and response surface methodology methods were used to optimize the condition of a salt-tolerant fungus, Aspergillus terreus PT06-2. As a result, the yield of (+)-terrein reached 8.20 ± 0.072 g/L in a 500-mL flask containing 150 mL optimal medium consisted of 13.1 % NaCl, 3.6 % starch, 2 % sodium glutamate, 0.05 % KCl, 3 % inoculum size, adjusting initial pH value to 5 with 10 % HCl and shaking for 18 days at 28 °C and 180 rpm. The production of (+)-terrein was 47.0 % higher than the highest production reported in shake flasks. The advantages of this optimization are uses of single carbon source and nitrogen source and easy separation and purification by recrystallization. The result exhibited the potential and advantages of A. terreus PT06-2 in industrial production of (+)-terrein by fermentation.
