A new stereoselective synthesis of 2-subsdtituted 1,3-bis(trimethylsilyl)propene derivatives and their conversion to cyclopentane and cyclohexane derivatives

Ester $\text{2}$ on treatment with sodium salt of sulfone or sulfoxide afforded 2-substituted 1,3-bis(trimethylsily)propene $\text{3}$ in good yield, from which cyclopentane and cyclohexane derivatives bearing a trimethylsilyl group in the molecules were synthesized.     

Reaction of 1-alkylthioisoquinolinium salts with active methylene compounds

2-Alkyl-1-alkylthioisoquinolinium salts were readily prepared from 2-alkyl-1(2H)-isoquinolones via 2-alkyl1(2H)-thioisoquinolones in two steps. Under mild conditions, the reaction of 2-alkyl-1-alkylthioisoquinolinium salts with active methylene compounds in the presence of sodium hydride afforded 2-alkyl-1-(substituted methylene)iso-quinolines in good yields. Pyrrolo[2,1-a]isoquinolines were synthesized by the cyclization of 2-benzyl-1-(substituted methylene)isoquinolines using acetic anhydride.     

Liquid chromatographic-mass spectrometric analysis for screening of patients with cystinuria, and identification of cystine stone.

Analyses of amino acids in the urine of a normal human and of patients with heterozygous and homozygous cystinuria have been carried out, using liquid chromatography-mass spectrometry with an atmospheric pressure ionization interface system. A kidney cystine stone was also analysed by this system. Very intense quasi-molecular ions ([M + H]+) of standard cystine, arginine, lysine and ornithine were observed on mass chromatograms as base peaks. Mass chromatograms of the urine samples from a normal human and from patients with heterozygous and homozygous cystinuria were easily distinguishable. The retention times in the mass chromatogram and mass spectrum of kidney stone cystine was almost the same as that of authentic cystine.     

Cellulose Synthesized by Acetobacter Xylinum in the Presence of Acetyl Glucomannan

Acetobacter xylinum was cultured in Hestrin-Schramm medium (control medium) and Hestrin-Schramm medium containing acetyl glucomannan (mannan medium). Loose bundles of the cellulose microfibrils are formed in the mannan medium in contrast to the normal ribbons being produced in the control medium. Rapid-freeze and substitution method followed by metal-shadowing revealed the droplet-like structures around the microfibril synthesized in the mannan medium. The cellulose synthesized in the mannan medium was stained heavily by the periodic acid-thiocarbohydrazide-silver proteinate (PATAg) method, while the cellulose synthesized in the control medium was not stained. X-ray diffractometry and FT-IR spectroscopy indicated that the addition of mannan induced a change in the crystal structure from the algal-bacterial type to the cotton-ramie type. Thus the presence of acetyl glucomannan in the medium prevents the assembly of cellulose microfibrils and changes the crystal structure of cellulose.     

Synthesis of spirodienones by intramolecular ipso-cyclization of N-methoxy-(4-halogenophenyl)amides using [hydroxy(tosyloxy)iodo]benzene in trifluoroethanol

Spirodienones bearing the 1-azaspiro[4.5]decane ring system have been synthesized from N-methoxy-(4-halogenophenyl)amides by the intramolecular ipso attack of a nitrenium ion generated with [hydroxy(tosyloxy)iodo]benzene in trifluoroethanol.     

POLARIZED TIME-RESOLVED FLUORESCENCE SPECTRA OF PHYCOBILISOMES ISOLATED FROM Tolypothrix tenuis EMBEDDED IN POLY(VINYL ALCOHOL) FILM

–Time-resolved fluorescence spectra in the ps time range were measured on phycobilisome (PBS) embedded in poly(vinyl alcohol) films. The cyanobacterium Tolypothrix tenuis was used as a source of PBS because the pigment composition and the structure of the PBS are well defined. Isotropic PBS in the unstretched film and PBS uniaxially oriented in the stretched film were investigated. Diameters of PBS hemidiscs were oriented parallel to the film-stretching direction. The time-resolved fluorescence spectra of the unstretched sample and of the two polarized components in the stretched samples showed several differences in the rise and decay. The delay time, estimated from the time span between the maximum laser pulse and maximal intensity of the phycocyanin and allophycocyanin fluorescence, was much longer than that reported in the aqueous media. This suggests occurrence of a higher thermal deactivation of PBS in polymer film than in aqueous media. The excitation energy transfer from excited phycocrythrin to allophycocyanin was more efficient in the unstretched than in the stretched samples, and it was greater in the parallel polarized component of the stretched sample than in the perpendicular component. The present results are in agreement with a previous suggestion which states that there are two independent pathways of excitation energy transfer in PBS and that there is more than one final emitter of fluorescence. The molecules taking part in various pathways of energy transfer differ in their orientation within PBS.     

Rapid method based on reversed-phase high-performance liquid chromatography for purification of human myelin basic protein and its thrombic and endoproteinase Lys-C peptides.

Reversed-phase high-performance liquid chromatography was applied to isolate myelin basic protein from human brain, followed by separation of proteolytic peptides thereof on the same chromatographic system. Brain tissue was delipidated under conditions that keep copurifying proteases inactive. The crude brain protein fraction was applied directly to a C4 column. The homogeneous protein obtained in this way was digested with thrombin and endoproteinase Lys-C in order to produce short defined myelin basic protein peptides. The purified peptides were used to determine the antigen fine specificity of myelin basic protein recognizing T lymphocyte lines isolated from multiple sclerosis patients.     

Simultaneous application of two or more supported liquid-phase organometallic catalysts: heterogeneous multifunctional reaction systems

Using the form of supported liquid-phase catalysts, two or more homogeneous catalysts can simultaneously be used with retaining their own activities and taking the advantage of catalyst-product separation and catalyst recycling.     

Copper-catalyzed allylation of carbonyl derivatives using allyl(2-pyridyl)silanes

[reaction: see text] We have developed an efficient copper-catalyzed allylation of carbonyl derivatives using allyl(2-pyridyl)silanes, in which the strong directing effect of the 2-pyridyl group was observed. A useful synthesis and allylation of substituted allyl(2-pyridyl)silanes is also described.