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A new method for the rapid enrichment and highly sensitive determination of nickel ion has been developed by using a nanofiber-composite membrane filter, which was fabricated by stacking a nanofibrous material made of nylon 6 over a water-permeable membrane filter. The noncharged nickel-α-furil dioxime complex was adsorbed on a nanofibrous layer of the membrane filter under significantly higher flow rates than those used for conventional solid-phase extraction techniques. Highly sensitive determinations with detection limits at sub-parts per billion levels were achieved by enrichment from 50 mL of the complex solution, and the enrichment was completed within 3 min. The color that was developed on the membrane filter was successfully subjected to visual colorimetric analysis and quantitative determination by solid-phase spectrophotometry. In addition, colorimetric determination was feasible with a handheld spectrometer after elution of the colored agent with 50 μL of acetone. This combination of rapid enrichment and spectrometric measurement in a small-volume sample provides a useful analytical method suitable for on-site analysis, which requires neither expensive instruments nor high laboratory skills.

A new triple-electrode system was developed for the simultaneous determination of l-lactate and d-glucose by using track-etched microporous membrane electrodes, which enabled efficient electrolysis as electroactive substances passed through the electrode. The proposed biosensor was fabricated by alternate stacking of the electrodes and immobilized enzyme reactors along the flow direction of the sample solution. When the sample solution containing l-lactate and d-glucose flowed into the proposed biosensor, hydrogen peroxide was produced by each enzymatic reaction and detected individually by anodization at each detector-electrode positioned downstream of each enzyme reactor. The interfering substances, such as l-ascorbic acid and uric acid, were electrolyzed completely at the pre-reactor electrode that was positioned upstream of the enzyme reactors. As a result, the simultaneous detection of l-lactate and d-glucose was achieved with no other catalytic material such as peroxidase or an electron mediator in ...

The cellulose binding domain (CBD) of cellulosome-integrating protein A from Clostridium thermocellum NBRC 103400 was genetically fused to FMN-dependent NADH-azoreductase (AZR) and glucose 1-dehydrogenase (GDH) from Bacillus subtilis. The fusion enzymes, AZR-CBD and CBD-GDH, were expressed in Escherichia coli Rosetta-gami B (DE3). The enzymes were purified from cell-free extracts, and the specific activity of AZR-CBD was 15.1 U/mg and that of CBD-GDH was 22.6 U/mg. AZR-CBD and CBD-GDH bound strongly to 0.5 % swollen cellulose at approximately 95 and 98 % of the initial protein amounts, respectively. After immobilization onto the swollen cellulose, AZR-CBD and CBD-GDH retained their catalytic activity. Both enzymes bound weakly to 0.5 % microcrystalline cellulose, but the addition of a high concentration of microcrystalline cellulose (10 %) improved the binding rate of both enzymes. A reactor for flow injection analysis was filled with microcrystalline cellulose-immobilized AZR-CBD and CBD-GDH. This flow injection analysis system was successfully applied for the determination of glucose, and a linear calibration curve was observed in the range of approximately 0.16-2.5 mM glucose, with a correlation coefficient, r, of 0.998.

Farnesyl diphosphate synthase (FPPase) is an enzyme that catalyzes the condensation between one molecule of dimethylallyl diphosphate (DMAPP) and two molecules of isopentenyl diphosphate (IPP) to produce farnesyl diphosphate (FPP). FPP is an important precursor in the isoprenoid synthesis pathway. In this study, the crystal structure of FPPase from Geobacillus stearothermophilus (GsFPPase) was determined at 2.31 A resolution. The structure of GsFPPase shows a three-layered all α-helical fold and conserved functional domains similar to other prenyltransferases. We have analyzed the structural features of GsFPPase related to thermostability and compared it with those of human and avian mesophilic FPPases. "Semi-conserved" regions which appear to be possible features contributing to the thermostability of FPPase were found.

An enantioresolution of 2-methoxy-2-(1-naphtyl)propionic acid (MαNP acid) using the diastereomeric salt with chiral (R)-phenylethylamine was achieved to give enantiopure (R)-MαNP acid in 29% yield with >99% ee based on rac-MαNP acid. X-ray crystallographic analysis of diastereomeric salt revealed that (R)-MαNP acid was tightly arranged by four independent hydrogen bonds and one CH–π interaction with (R)-phenylethylamine.

We have studied the water treatment by pulsed power discharge in water droplets spray in air. Ethylene glycol was used for sample. The dependence of decomposition of ethylene glycol on initial concentration was investigated. It was found that intermediate product was generated by decomposing process of ethylene glycol. In the concentration of 50 mg/L, whole ethylene glycol was decomposed by water treatment for 4 hours. However whole intermediate product wasn't decomposed in 4 hours treatment. In the concentration of 25 mg/L, ethylene glycol and intermediate product were decomposed in treatment time at 4 hours.

An alkylation of aminals with organozinc reagents derived from allyl bromide, benzyl bromide, alpha-bromoacetate, and alpha-bromonitrile proceeded efficiently in the presence of TMSCl and diisopropylamine. This reaction system was applied to the synthesis of an antispasmodic: butaverine.

Novel racemic polyhydroquinoline derivatives were synthesized by a one-pot approach via a modified Hantzsch reaction and then by aromatization. The optical resolution was carried out by using lipase L-2 in MTBE containing one equivalent of butanol. This method allows the preparation of (+)-7 (>99% ee) and (-)-8 (99% ee) in 50% yield, respectively. The E value is up to 1175.

A novel ethyl 5-cyano-6-hydroxy-2-methyl-4-(1-naphthyl)-nicotinate is successfully synthesized and the structure is determined by XRD, GC–MS analysis, element analysis and NMR spectroscopic in detail. A reaction mechanism for the reaction is proposed.

Fatty acids containing a C18 alkyl chain such as stearic acid (C18:0 fatty acid), oleic acid (C18:1 fatty acid) and linoleic acid (C18:2 fatty acid) are common emulsifiers in skin-care products and cosmetics and are also used in skin cleansers. In this study, we prepared calcium salts (Ca salts) of the above fatty acids to determine the effect of the degree of unsaturation of the alkyl chain. Scanning electron microscopy images and X-ray diffraction patterns show that C18:0 and C18:1 fatty acid Ca salts are plate-shaped, lamellar-crystalline powder, while C18:2 fatty acid Ca salt is amorphous powder. Therefore, C18:2 fatty acid Ca salt exhibits a lower lubrication ability than do C18:0 and C18:1 fatty acid Ca salts. In addition, the bactericidal ability against Staphylococcus aureus, Staphylococcus epidermidis and Propionibacterium acnes improved with increasing degree of unsaturation. These findings suggest that Ca salts of unsaturated fatty acids have potential applications in cleansing and cosmetic products.

Palmitoleic acid is a promising bactericidal agent for cleansing products with alternative bactericidal abilities. In this study, we focus on the physical and biological activity of palmitoleic acid calcium salt (C16:1 fatty acid Ca salt) because it forms via an ion-exchange reaction between palmitoleic acid and Ca ions in tap water, and remains on the skin surface during the cleansing process. Here, we prepared C16:1 fatty acid Ca salt to investigate its crystal structure and physical and bactericidal properties. The Ca salt was a plate-shaped lamellar crystalline powder with a particle diameter of several micrometers to several tens of micrometers; it exhibited significant lubricity and alternative bactericidal activity against Staphylococcus aureus (S. aureus) and Propionibacterium acnes (P. acnes). We also examined other fatty acid Ca salts prepared from lauric acid (C12:0 fatty acid), palmitic acid (C16:0 fatty acid), and oleic acid (C18:1 fatty acid). The bactericidal activities and lubricity of the fatty acid Ca salts changed with the alkyl chain length and the degree of unsaturation. The C16:1 fatty acid Ca salt exhibited the strongest selective bactericidal ability among the four investigated fatty acid Ca salts. These findings suggest that C16:1 fatty acid and its Ca salt have potential applications in cleansing and cosmetic products.

The Calix[4]arene 1 including two alternately arranged phloroglucinols and p-tert-butylphenols was synthesized via the “3+1” coupling procedure, and its pKa values were estimated to be 3–4 and 7.5, while those of the other six phenolic hydroxyls were approximately 11. Its UV–vis spectrum at pH 11 and 1H and 13C NMR spectra in NaOD-D2O solution (pH 12.8) showed a dramatic change like those of the phloroglucinol when compared to those in acidic or neutral solution, which suggests a change in the phloroglucinol moiety to the keto-form. During the solvent extraction for alkali metal species using 1, Li+ was only extracted in the low yield of 15% at pH 11. The cyclic voltammetry study of 1 was used to compare it with the phloroglucinol and p-tert-butylphenol. The redox potential of the corresponding two phloroglucinols was observed in 1.

The new type of amperometric biosensor described herein, which was fabricated by using a track-etched microporous membrane electrode for glucose detection, comprises a prereactor electrode, a detec...

For the purpose of developing a new chiral crown ether unit as a chiral synthon, three racemic mono azabenzo-15-crown-5-ethers, i.e. (R,S)-1-(6,7,9,10,12,13,15,16-octahydro-5,8,14,17-tetraoxa-11-aza-benzocyclopentadecen-11-yl)-propan-2-ol, (R,S)-2-(6,7,9,10,12,13,15,16-octahydro-5,8,14,17-tetraoxa-11-aza-benzocyclopentadecen-11-yl)-1-phenyl-ethanol and (R , S)-1-[2-(6,7,9,10,12,13,15,16-octahydro-5,8,14,17-tetraoxa-11-aza-benzocyclopentadecen-11-ylmethyl)-phenyl]-ethanol were esterified with vinyl acetate using a lipase from Candida antarctica. The enzymatic acylation of alcohols produced monoacylated products. Two optically active azacrown ethers, (R)-propionic acid 1-methyl-2-(6,7,9,10,12,13,15,16-octahydro-5,8,14,17-tetraoxa-11-aza-benzocyclopentadecen-11-yl)-ethyl ester and (R)-acetic acid 1-[2-(6,7,9,10,12,13,15,16-octahydro-5,8,14,17-tetraoxa-11-aza-benzocyclopentadecen-11-ylmethyl)-phenyl]-ethyl ester were obtained within 48% and 36% yields, respectively and, at an enantiometric excess of over 99% in each case.

Dechlorinative coupling–dimerization reaction is studied to synthesize alkanes by using tris-triphenylphosphine ruthenium (II) in the presence of hydrogen atmosphere. Two types of halides (α-chlorodiarylmethanes 1a – d and bis(chlorophenylmethyl)-1,3-phenylene 6 ) are employed as substrates to form radical species and then dimerized to generate alkanes in high yields. To our knowledge, it is the first time that the formation of 1,1,2,2-tetraarylethanes and 1,2,9,10-tetraphenyl-di- m -xylylene over typical ruthenium-catalyzed dehalogenative coupling–dimerization conditions is reported.

A number of 1,1′-bis(benzo-1,3-dithiol-2-ylidene)ferrocene derivatives 7a–b and 12–14 based on the strong electron donating ability of 1,3-dithiole and ferrocene moieties were synthesized as new π-donors. The structure and physical properties of these compounds were characterized both by experimental techniques and spectral analysis. These new classes of donor compounds were obtained in very high yields based on modification of the Wittig–Horner reaction and the 1,3-dithiole rings were separated by conjugated spacers including aryl–ferrocenyl–aryl. The electrochemical properties of the new compounds have been studied in comparison to DB-TTF 4 analogues, and the parent ferrocene donor by cyclic voltammetry (CV), using Pt electrode as the working electrode in CH2Cl2 solutions at room temperature. Three subsequent oxidation processes are observed as three oxidation waves associated only with two reduction processes. Polycrystalline samples of 14a–b are conducting σrt 14a=0.2 S cm−1 and σrt 14b=4.8×10−4 S cm−1) respectively, while compounds 15 and 16 were found essentially as insulator (σrt

An enantioresolution of 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl oxide (BINAPO) into its enantiomers was achieved using the inclusion complex with a commerciallyavailable chiral 2,2'-dihydroxy-1,1'-binaphthyl ((R)-BINOL), giving the two enantiomers with 99% ee and 72% ee, respectively.

The reductive coupling of aromatic N,N-acetals and N,O-acetal activated by chlorotrimethylsilane proceeded smoothly in the presence of zinc to give the corresponding diamines in good yields.

We have achieved an efficient synthesis of 1,1-dimethyl-3-(trifluoromethyl)-1H-isoindole N-oxide (2) in 39% yield by seven steps from 2-bromobenzoic acid (3). This compound serves as a spin trap reagent, giving a strong and stable ESR signal of the radical adduct of 2 in the presence of i-amyloxy radical generated by UV photolysis of i-amyl nitrite.

The synthesis of 2-acetyl-6-(1-naphthyl)-pyridine oxime ligand from 2,6-dibromopyridine and 1-bromo-naphthalene is described, and the new palladium(II) complex used as a Pd(0) precatalyst in the Suzuki cross-coupling reaction was studied. The results showed that the novel naphthalene pyridine oxime complex could serve as an efficient precatalyst. J. Heterocyclic Chem., 46, 116 (2009).

Immobilized lipase (Candida Antarctica lipase, CAL) efficiently catalyzes the transesterification and amidation of the racemic ferrocenes, l-hydroxyethylferrocene, (±)-1, 1-hydroxy[3](1,1') ferrocenophane, (±)-4, 1-amonoethylferrocene, (±)-2, and 1-amono[3](1,1') ferrocenophane, (±)-5, with acyl esters, resulting in the formation of R products possessing high enantiomeric purity. When 1-hydroxyethylferrocene, (±)-1, and 1-hydroxy[3](1,1') ferrocenophane, (±)-4, was used as substrate diisopropyl ether was a suitable solvent. In the reaction conditions investigated, the use of vinyl acetate in diisopropyl ether gave the best yield of(R)-1a (49%, 99% ee) after 2h of incubation at 30°C. But, with the amino ferrocenes, I-aminoethylferrocene, (±)-2, and 1-amono[3](1,1') ferrocenophane, (±)-5, as substrate, diisopropyl ether was unsuitable as a solvent owing to the low solubility of the substrate in this solvent. Using tetrahydrofuran as a solvent, enzymatic amidation of 1-amonoethylferrocene, (±)-2, gave the best yield of (R)-2a (21%, 99% ee) after 120 h of incubation at 30°C. CAL working in organic solvent is able to efficiently carry out the resolution of ferrocenyl alcohol and amine derivatives which have similar structures, such as (±)-1 and (±)-2, (±)-4 and (±)-5 which possess central chirality. This enzyme accepted only non-bulky primary alcohols and amines as ferrocenyl substrates.

Optically active chlorohydrin analog incorporating crown ether was synthesised by enzymatic hydrolysis using Candida Antarctica lipase in high enantiomeric excess.

The fluorescence spectra of subtilisin Carlsberg (STC) and subtilisin BPN′ (STB) were measured in aqueous–organic mixed solvents over a wide range of solvent composition. The tryptophan fluorophores were used as probes of the environmental polarity, and the structural changes of the enzymes were detected as changes of the difference in the emission wavelength between the enzymes and N-acetyl-L-tryptophan ethyl ester (Δλem). It was found that Δλem was well correlated with the catalytic activity of the enzymes, as expressed by the hydrolysis rate of N-acetyl-L-tyrosine ethyl ester. For example, the characteristic dependency of the activity of STC on the solvent composition in acetonitrile–water was closely related to the change in Δλem. Similar correlations between Δλem and the catalytic activity were observed for subtilisins in aqueous 1,4-dioxane, THF, DMF, DMA, and DMSO solutions with high correlation coefficients, except for STB in water–DMF and –DMA. The results are discussed in terms of the structural...

Aromatic N,N-acetals and N,O-acetal (X), activated by TmsCl, are coupled in the presence of zinc to give mixtures of dl- and meso-diamines.

Racemic amino acid esters were optically resolved via hydrolysis in organic solvents by the catalysis of an industrial alkaline protease, “Alcalase”. The products which were composed mainly of L-amino acids were insoluble and easily separated by filtration. The activity of the enzyme and enantiomeric excess of the products were significantly dependent on the nature of solvent and the water content in the reaction media. Generally, high values of enantiomeric excess were obtained at low water contents. Many natural and unnatural amino acids were resolved by this method.

Immobilized lipase (Candida Antarctica lipase, CAL) efficiently catalyzes the transesterification and amidation of the racemic ferrocenes, l-hydroxyethylferrocene, (±)-1, 1-hydroxy[3](1,1') ferrocenophane, (±)-4, 1-amonoethylferrocene, (±)-2, and 1-amono[3](1,1') ferrocenophane, (±)-5, with acyl esters, resulting in the formation of R products possessing high enantiomeric purity. When 1-hydroxyethylferrocene, (±)-1, and 1-hydroxy[3](1,1') ferrocenophane, (±)-4, was used as substrate diisopropyl ether was a suitable solvent. In the reaction conditions investigated, the use of vinyl acetate in diisopropyl ether gave the best yield of(R)-1a (49%, 99% ee) after 2h of incubation at 30°C. But, with the amino ferrocenes, I-aminoethylferrocene, (±)-2, and 1-amono[3](1,1') ferrocenophane, (±)-5, as substrate, diisopropyl ether was unsuitable as a solvent owing to the low solubility of the substrate in this solvent. Using tetrahydrofuran as a solvent, enzymatic amidation of 1-amonoethylferrocene, (±)-2, gave the best yield of (R)-2a (21%, 99% ee) after 120 h of incubation at 30°C. CAL working in organic solvent is able to efficiently carry out the resolution of ferrocenyl alcohol and amine derivatives which have similar structures, such as (±)-1 and (±)-2, (±)-4 and (±)-5 which possess central chirality. This enzyme accepted only non-bulky primary alcohols and amines as ferrocenyl substrates.

Racemic large secondary alcohol, 4′-hydroxyethyl-benzo-15-crown-5-ether, (±)-1 was kinetically resolved in high optical yield by asymmetric transformation with Candida antarctica lipase and Pseudomonas cepacia lipase.

Racemic large secondary alcohol, 4′-hydroxyethyl-benzo-15-crown-5-ether, (±)-1 was kinetically resolved in high optical yield by asymmetric transformation with Candida antarctica lipase and Pseudomonas cepacia lipase.

The synthesis of 2-acetyl-6-(1-naphthyl)-pyridine oxime ligand from 2,6-dibromopyridine and 1-bromo-naphthalene is described, and the new palladium(II) complex used as a Pd(0) precatalyst in the Suzuki cross-coupling reaction was studied. The results showed that the novel naphthalene pyridine oxime complex could serve as an efficient precatalyst. J. Heterocyclic Chem., 46, 116 (2009).

An alkylation of aminals with organozinc reagents derived from allyl bromide, benzyl bromide, alpha-bromoacetate, and alpha-bromonitrile proceeded efficiently in the presence of TMSCl and diisopropylamine. This reaction system was applied to the synthesis of an antispasmodic: butaverine.

The fluorescence emission wavelength of alpha-chymotrypsin (CT) correlated with its enantioselectivity (E value) for the resolution of DL-tyrosine ethyl ester. The changes in the E value of the CT due to the changes in the solvent composition were closely related to its fluorescence properties (delta lambda(em)), which were most probably associated with the structural modification of the enzyme. A linear relationship was established between E value and delta lambda(em) in aqueous acetonitrile with high correlation coefficients (r = 0.94).

The target N6-ferrocene substituted NAD derivatives (ferrocene-labeled NAD, Fc-NAD) were synthesized as an electron-relay NAD cofactor. The synthesized NAD derivatives possessed some biological activities as substrates in the alcohol dehydrogenase systems. The oxidation current depended on both addition of ethanol and spacer length of Fc-NAD.

The relative and absolute configurations of the title compound, C26H28O3Se, were assigned from the known configuration of (R)-(−)-2-methoxy-2-(1-naphthyl)propionic acid used as starting material, and by examination of the Bijvoet (Friedel) pairs, using the anomalous dispersion data collected with Mo Kα radiation at low temperature. The geometry around the carbonyl group exists in the syn conformation, as reflected in torsion angles involving this group, and the stability of the structure is affected by weak bifurcated intramolecular C—H...O hydrogen bonds.