This study was done to investigate the effects of five screw configurations (config.) on rice grain extrudates. Five different screw configurations, in which the angles (45°, 90°, and 135°) and number of kneading screws were different, were used in extruding rice. The pressure and specific mechanical energy (SME) increased (5,748.76 kPa and 52.80 kJ/kg, respectively) as the angle and number of kneading screws increased. As shown in Config. 5, the angle of two kneading screws increased to 135° from 45°. The expansion ratio (ER) and water solubility index (WSI) increased as shear increased. In Config. 5, the ER increased to 3.06 and the WSI increased 16.2 times, unlike the control item. The results can be applied in producing processed rice, such as rice expansion snack and cereal for breakfast, and solubilizing functional dietary fiber in water.

The marine alginate lyase from Streptomyces sp. ALG-5, which specifically degrades poly-G block of alginate, was functionally expressed as a His-tagged form with an Escherichia coli expression system. The recombinant alginate lyase expressed with pColdI at 15 °C exhibited the highest alginate-degrading activity. The recombinant alginate lyase was efficiently immobilized onto two types of magnetic nanoparticles, superparamagnetic iron oxide nanoparticle, and hybrid magnetic silica nanoparticle, based on the affinity between His-tag and Ni(2+) that displayed on the surfaces of nanoparticles. An alginate oligosaccharide mixture consisting of dimer and trimer was prepared by the immobilized alginate lyase. The immobilized enzymes were re-used repeatedly more than 10 times after magnetic separation.

Touch, Pauson, engage: To explain the unique superior reactivity and stereoselectivity of O-tethered enynes in asymmetric Pauson–Khand type reaction (APKR) than their congeners, the internal-chelation to metal of oxygen atom of the substrate in the transition state was proposed. This proposition was well supported by APKR with several different substrates. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

A cationic rhodium(I)/2,2'-bis[bis(3,5-di-tert-butyl-4-methoxyphenyl)phosphino]-6.6'-dimeth- oxy-1.1'-biphenyl (DTBM-MeO-BIPHEP) catalyst was highly efficient for the asymmetric catalytic Pauson-Khand reaction, especially for those substrates containing aryl group-substituted alkynes. The formation of the products that were derived from a beta-hydride eliminated intermediate 5 was completely suppressed over a wide range of substrates. This reaction was a serious process competing reaction with the migratory CO insertion that led to the Pauson-Khand reaction product and often substantially ruined the chemical yield of the Pauson Khand reaction. The advantages of this system were clearly demonstrated for previously troublesome substrates, N-tosyl- (lb) and malonate-tethered 1,6-enynes (1c). that exhibited a higher enantioselectivity without a loss in the chemical yields The obvious beneficial effects were attributed to the synergic effect of various factors, such as the electron density of the phosphorus of the ligand, the dihedral angles of the atropisomeric ligand, and the substitution on the phosphine aryl rings which play a crucial role in the stereochemical outcome of Rh-catalyzed Pauson-Khand react ion.

A marine bacterium was isolated from seaweeds for its ability to degrade alginate. Analysis of 16S ribosomal DNA sequence and chemotaxonomic characterizations revealed that the strain belongs to Streptomyces. The alginate lyase gene of Streptomyces sp. ALG-5 was cloned by using PCR with the specific primer designed from homologous nucleotide sequences. The consensus sequences of N-terminal YXRSELREM and C-terminal YFKAGXYXQ were conserved in the ALG-5 alginate lyase gene. The recombinant alginate lyase was purified by using Ni-Sepharose affinity chromatography. The alginate lyase appears to be poly-guluronate lyase degrading poly-G block preferentially than poly-M block. The degraded products were determined to be di-, tri-, tetra- and pentasaccharides by using BioGel P-2 gel filtration chromatography and ionization mass spectroscopy method.

An unusual crystallization affording an apparently pseudoachiral crystal from single enantiomers 1a and 1b was observed. In cases of enantiopure molecules such as 1a and 1b with structural flexibility, the tendency toward a centrosymmetric arrangement was so overwhelming that apparently achiral crystals were formed even by homochiral compounds via the formation of a pseudo-centrosymmetric asymmetric unit accompanying structural adjustment. In addition, these crystals of 1a constitute as a counter-example of Wallach’s rule.

A kinetic resolution of 1-arylallyl propargyl ethers by enantioselective Pauson-Khand-type reaction catalysts was successfully carried out. While cationic rhodium(I) with a BINAP-based ligand having an electron-deficient phosphine is the choice for the slow reacting substrates, neutral iridium(I) with a BINAP-based ligand possessing an electron-rich phosphine provided excellent results for the more reactive substrates.

Asymmetric desymmetrization of the diallyl acetals of alkynal (1) by an enantioselective Pauson-Khand-type reaction catalyst was studied. The corresponding 5-oxabicyclo[3.3.0]octenones (2) were obtained as a mixture of diastereomers (2a and 2b), which were hydrolyzed to afford a single enantiomer (3), in high yields (up to 88%) as well as excellent enantioselectivities (up to 97%).

An efficient asymmetric PKR mediated by Rh(I) catalyst at ambient temperature was developed. The reaction utilizing a Rh(I) catalyst bearing a (R)-3,5-diMeC4H4-BINAP ligand at 18-20 degrees C under a reduced partial pressure of CO (0.1 atm) provided PKR products in high chemical yield as well as high enantioselectivity.

This study is conducted to prepare high quality raw materials for food processing by processing different parts of Tartary buckwheat in different methods. Fine structure and water solubility were compared among different materials processed in different ways. Young sprouts(9 days-old), whole grains , and matured stems of Tartary buckwheat were used in this experiment. The materials were dried in a far infrared drier at 60 "(; to less than 8% in water content(Wb)' Three kinds of raw materials were processed in three kinds of methods: hyperfinely grinded powder, roasted powder, and extruded powder. Fine structure of each raw material processed differently was observed by Field Emission Scanning Electron Microscope(S4300, HITACHI, Japan). Water' Solubility Index (WSI) was measured by centrifuging mixture of milled powder Ig and water 20 ml in 1452Orpm(2000 x g) speed for 10min and by calculating percent ratio of the supernatant to weight of powder tested. In sprout-derived and stem-derived powder, extruded one was finest; 13.677 ImI in sprout and 18.2121m1 in stem. Fine structure of seed-derived powder was spherical type in hyperfinely grinded powder but blocky type in roasted powder, which seems to be attributed to gelatinization of starch by heat during the roasting. Extruded powder showed a blocky type structure of which surface are enclosed with a number of small crystal structures due to starch gelatinization. Water solubility of sprout-derived powder was respectively 15.74%, 16.17%, and 23.70% in hyperfinely grinded powder, roasted powder, and extruded powder obtained from sprouts, seeds, and stems of Tartary buckwheat.

The electronic and steric effects of chiral biaryl diphosphine ligands on the Rh(I)-catalyzed asymmetric Pauson-Khand type reaction were examined. We demonstrated that enantioselectivity and reaction yield were influenced by the electronic density on phosphorus, the dihedral angle of ligands and the electronic density of the alkyne substrate. Ligands bearing a narrower dihedral angle than Binap, such as Synphos (L4) and Difluorphos (L5), were of the reaction, compared to Binap-type ligands. Ligands having a deshielded phosphine, such as p-CF3-Binap (L3) and Difluorphos (L5) provided better enantioselectivity than Binap, with reduced formation of side products, especially with electron-poor alkyne substrates.

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(1 − x )SiO 2 -( x )ZrO 2 ( x = 0.1, 0.2) composite fiber mats were prepared by electrospinning their sol-gel precursors of zirconium acetate and tetraethyl orthosilicate (TEOS) without using a polymer binder. The electrospun composite fibers were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR) and mercury porosimetry. The composite fibers having a tetragonal crystalline ZrO 2 were obtained by calcining the electrospun composite fibers at high temperatures. The results show that the structure and crystallization of ZrO 2 in the composite fibers can be controlled by sintering temperature, while the porosity and morphology of the fiber mats did not depend on the sintering temperature.

(1 - x)SiO2-(x)ZrO2 (x = 0.1, 0.2) composite fiber mats were prepared by electrospinning their sol-gel precursors of zirconium acetate and tetraethyl orthosilicate (TEOS) without using a polymer binder. The electrospun composite fibers were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR) and mercury porosimetry. The composite fibers having a tetragonal crystalline ZrO2 were obtained by calcining the electrospun composite fibers at high temperatures. The results show that the structure and crystallization of ZrO2 in the composite fibers can be controlled by sinterincy temperature, while the porosity and morphology of the fiber mats did not depend on the sintering temperature.