Synthesis ofS-(Carboxymethyl)-d-cysteine by 3-chloro-d-alanine chloride-lyase ofPseudomonas putida CR 1-1

S-(Carboxymethyl)-d-cysteine, which is an important component of semisynthetic cephalosporin, MT-141, was enzymatically synthesized.S-(Ethoxy-carbonyl-methyl)-d-cystein was synthesized from 3-chloro-d-alanine and ethyl thioglycolate by the β-replacement reaction of 3-chloro-d-alanine chloride-lyase fromPseudomonas putida CR 1-1 and subsequently hydrolyzed by alkali. The synthesizedS-(carboxymethyl)-d-cysteine was isolated from a large scale reaction mixture and identified physicochemically. The reaction conditions for the synthesis ofS-(ethoxycarbonylmethyl)-d-cysteine were optimized using resting cells ofP. putida CR 1-1.     

Turpinionosides A-E: megastigmane glucosides from leaves of Turpinia ternata Nakai

From leaves of Turpenia ternata (Staphylaceae), one megastigmane and seven of its glucosides (1-8) were isolated. Megastigmane and two of the glucosides were found to be known compounds, namely, 3S,5R,6R,9S-tetrahydroxymegastigmane (1), corchoionoside C (2), and icariside B4 (3). The structures of compounds 4-8 (turpinionosides A-E, respectively) were elucidated by means of spectroscopic analyses, and then their absolute structures were determined by the modified Mosher's method to be (3S,5R,6S,9S)-3,6,9-trihydroxymegastigman-7-ene 3-O- and 9-O-beta-D-glucopyranosides (4, 5, respectively), (1S,3S,5R,6S,9R)-3,9,12-trihydroxymegastigmane 3-O-beta-D-glucopyranoside (6), (3S,4R,9R)-3,4,6-trihydroxymegastigman-5-ene 3-O-beta-D-glucopyranoside (7), and (2S,9R)-2,9-dihydroxymegastigman-5-en-4-one 2-O-beta-D-glucopyranoside (8).     

Heat capacity measurement of cubic lithium tungsten bronzes from 200 to 800°K

Heat capacities of three cubic lithium tungsten bronze samples (Li_xWO₃) with x values of 0.363, 0.437, and 0.478 were measured from 200 to 800°K. Heat capacities per gram-atom at the same temperature of Li_0.363WO₃ and Li_0.437WO₃ were equal within experimental error and also equal to those of Na_0.485WO₃, Na_0.698WO₃, and Na_0.794WO₃, regardless of the difference of the composition. λ-type heat capacity anomalies were observed around 330, 460, and 590°K in Li_0.363WO₃ and around 330 and 460°K in Li_0.437WO₃ and Li_0.478WO₃, showing the existence of second-order phase transitions. The entropy increments of the transitions were obtained as 1.36, 0.45, and 1.68 J mole^?1 K^?1 for Li_0.363WO₃, 1.09 and 0.59 J mole^?1 K^?1 for Li_0.437WO₃, and 1.42 and 0.50 J mole^?1 K^?1 for Li_0.478WO₃.     

Preparation and Stereochemistry of Dioxatetraazaperhydroanthracenes and -perylenes from the Reaction of 2-Hydrazinoethanols with Aldehydes and Glutaraldehyde

Hydrazinoethanols 1 were reacted with aldehydes 2 and 6 and glutaraldehyde (14) in aqueous solution to give dioxatetraazaperhydroanthracenes 3, 7, 12, and 13 and -perylenes 15 in yields of 19-88 and 42-72%, respectively. Compounds 3, 7, 12, and 15 were deduced by (13)C-NMR spectra to have two C(2) symmetry axes, while compound 12 was shown to have a symmetry axis by X-ray crystallography. The most favorable stereoisomers were consistent with predictions obtained by the semiempirical molecular orbital method AM1. The structure of compound 15 was confirmed by X-ray crystallography.     

Generation of protonic acid sites originating from molecular hydrogen over H-ZSM-5

Infrared studies of adsorbed pyridine and OH groups on H-ZSM-5 zeolite demonstrate that protonic acid sites are generated on the surfaces by exposure to molecular hydrogen above 373 K. By evacuation of gas phase hydrogen, the protonic acid sites are eliminated.

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, H-ZSM-5 373 . .

     

Host-guest sensory system of sodium anthranilate-modifiedβ-cyclodextrin: Molecular recognition properties

Sodium anthranilate-modified-cyclodextrin (1) has been prepared as a sensor for detecting organic compounds including terpenoids and steroids.1 shows a pure monomer fluorescence whose intensity is increased or decreased upon addition of the guest species examined. In this system, the sodium anthranilate moiety acts either as a spacer, which enables the cyclodextrin to form a 11 guest complex by narrowing the-cyclodextrin cavity or acts as a hydrophobic cap.1 shows a higher sensitivity for terpenoids than for steroids, but has a higher selective molecular recognition ablity for steroids than for terpenoids.     

Synthesis and binding behaviors of monomethyl cucurbit[6]uril

By reacting 3a-methylglycoluril and glycoluril with paraformaldehyde, monomethyl cucurbit[6]uril was synthesized in 14% yield. The new host molecule forms stable inclusion complexes with diamine and hexylaminocarbazole derivatives.     

Numerical methods for the eigenvalue determination of second-order ordinary differential equations

An accurate method for the numerical solution of the eigenvalue problem of second-order ordinary differential equation using the shooting method is presented. The method has three steps. Firstly initial values for the eigenvalue and eigenfunction at both ends are obtained by using the discretized matrix eigenvalue method. Secondly the initial-value problem is solved using new, highly accurate formulas of the linear multistep method. Thirdly the eigenvalue is properly corrected at the matching point. The efficiency of the proposed methods is demonstrated by their applications to bound states for the one-dimensional harmonic oscillator, anharmonic oscillators, the Morse potential, and the modified Pöschl–Teller potential in quantum mechanics.     

Green polynomials at roots of unity and Springer modules for the symmetric groups

We consider the Green polynomials at roots of unity. We obtain a recursive formula for the Green polynomials at roots of unity whose orders do not exceed some positive integer. The formula is described in a combinatorial manner. The coefficients of the recursive formula are realized by the cardinality of a set of permutations. The formula gives an interpretation of a combinatorial property on a family of graded modules for the symmetric group in terms of representation theory.     

Magnetic susceptibility measurements of solutions by surface nanodisplacement detection.

A new principle to measure the magnetic susceptibility of a solution was proposed; it utilized the displacement of solution surface caused by the magnetic force applied to the solution. The interfacial displacement was measured with the sensitivity of 5 nm from a change of the interference fringes, so called Newton Ring, generated from the solution surface and an upper surface of a small plano-convex lens on the bottom wall of a cell. The surface displacement measurement was carried out in a homemade cell attached by one or two small Nd-Fe-B magnets. The performance of this method was investigated by the measurements of magnetic susceptibility of manganese(II) chloride solution and some lanthanide(III) solutions. An excellent linear relationship between the magnetic susceptibility and the interfacial displacement was observed for each solution system. Then, it was demonstrated that this relationship could be used for the determination of the magnetic susceptibility of solutions or the concentration of a solute by using the manganese(II) solution as a standard solution.