Stepwise Synthesis of Fullerene Cyclopentadienide R(5)C(60)(-) and Indenide R(3)C(60)(-). An Approach to Fully Unsymmetrically Substituted Derivatives

Fullerene cyclopentadienide (PhCH(2))(2)Ph(3)C(60)(-) and indenide (PhCH(2))(2)PhC(60)(-), each bearing two different organic groups, were efficiently synthesized through regioselective reactions of 1,4-(PhCH(2))(2)C(60) with an organocopper reagent (PhMgBr/CuBr.SMe(2)) or a Grignard reagent (PhMgBr) followed by deprotonation with KO(t)()Bu.     

Preparation of substituted benzoyltrimethylsilanes by the palladium-catalyzed silylation of substituted benzoyl chlorides with hexamethyldisilane

A direct preparative route to benzoyltrimethylsilane has been found by the reaction of benzoyl chloride with hexamethyldisilane in the presence of a specified palladium(II) complex as catalyst.     

Comparative pharmacokinetics of 67Ga among the different routes of injection

The pharmacokinetic study of 67Ga-citrate (67Ga) following intravenous (i.v.), subcutaneous (s.c.) and intraperitoneal (i.p.) injection was performed in anesthetized rats using the repeated blood sampling method by cannulation technique into the external jugular vein. The disappearance of 67Ga from the blood following i.v. and s.c. injection was best fit a three-exponential equation. There was no significant difference between the areas under the curves following i.v. and s.c. injection of 67Ga. In the case of i.p. injection, the disappearance of 67Ga from the blood was described by a two-exponential equation. However, the maximum blood radioactivity was very low, and the disappearance rate of 67Ga from the blood was extremely slow compared to the other routes of injection. The conclusion from these results was that s.c. injection was as suitable as i.v. injection, but i.p. injection was not appropriate for the distribution study of 67Ga such as scintigraphy or autoradiography. However, i.p. route may be available for a special experiment which needs the long-time retention of 67Ga in the blood.     

Selective flow-injection determination of methanol in the presence of ethanol based on a multi-enzyme system with chemiluminescence detection

A highly selective flow-injection system was developed for the determination of methanol. The system consisted of three immobilized enzymes with luminol chemiluminescence detection. First, methanol was oxidized in the presence of alcohol oxidase to yield formaldehyde and hydrogen peroxide. The hydrogen peroxide produced was then destroyed by catalase. The formaldehyde formed in the first stage was further oxidized by NAD⁺-formaldehyde dehydrogenase. The NADH formed was oxidized by 1-methoxy-5-methylphenazinium methylsulphate (1-MPMS), and finally the reduced 1-MPMS was spontaneously oxidized and hydrogen peroxide was produced. The concentration of the hydrogen peroxide produced, which was proportional to the initial concentration of methanol, was determined by luminol chemiluminescence. The determination range was from 0.1 to 100 mg l⁻¹ and the response time was less than 2 min per sample with a relative standard deviation of less than 3%. The system showed good selectivity for methanol; the response was ca. 50 times higher than for ethanol.     

1,3,8,10-Tetrahydro-2,9-diazadibenzo[cd,lm]perylenes: synthesis of reduced perylene bisimide analogues

A unique family of 1,3,8,10-tetrahydro-2,9-diazadibenzo[cd,lm]perylenes (THDAP) was prepared through a new synthetic strategy. Completion of the synthesis was achieved in several steps from commercially available perylene-3,4,9,10-tetracarboxylic dianhydride via reactions between 3,4,9,10-tetra(chloromethyl)perylene and primary amines. The successful use of a variety of primary amines in the reactions indicated that the synthetic approach provides a rich opportunity to produce new functionalized perylene derivatives.     

General and practical catalytic enantioselective Strecker reaction of ketoimines: significant improvement through catalyst tuning by protic additives

Significant improvement in enantioselectivity and catalyst activity was achieved for the catalytic enantioselective Strecker reaction. Using a catalyst (1-2.5 mol %) prepared from Gd(OⁱPr)₃ and d-glucose derived ligand 1, and in the presence of 2,6-dimethylphenol as an additive, high enantioselectivity was obtained from a wide range of ketoimines, including heteroaromatic and cyclic ketoimines. The new method was applied to an efficient catalytic asymmetric synthesis of sorbinil, a therapeutic agent for diabetic complications.     

Organotrichlorogermane synthesis by the reaction of elemental germanium, tetrachlorogermane and organic chloride via dichlorogermylene intermediate

Organotrichlorogermanes were synthesized by the reaction of elemental germanium, tetrachlorogermane and organic chlorides, methyl, propyl, isopropyl and allyl chlorides. Dichlorogermylene formed by the reaction of elemental germanium with tetrachlorogermane was the reaction intermediate, which was inserted into the carbon-chlorine bond of the organic chloride to give organotrichlorogermane. When isopropyl or allyl chloride was used as an organic chloride, organotrichlorogermane was formed also in the absence of tetrachlorogermane. These chlorides were converted to hydrogen chloride, which subsequently reacted with elemental germanium to give the dichlorogermylene intermediate. The reaction of elemental germanium, tetrachlorogermane and organic chlorides provides a simple and easy method for synthesizing organotrichlorogermanes, and all the raw materials are easily available.     

Substoichiometric isotope-dilution determination of sulphur after conversion to methylene blue and ion-pair extraction with dodecyl sulphate

The proposed substoichiometric determination of sulphur includes two key steps: conversion of sulphur to methylene blue and ion-pair extraction of methylene blue into chloroform with a substoichiometric amount of dodecyl sulphate. The method, combined with isotope dilution is applied to the determination of total sulphur in NBS SRM Citrus Leaves and in a seaweed sample (Laminaria religiosa Miyabe). The mean values obtained were 0.401±0.008% S (RSD 2%; n=9; certified value 0.407±0.009%) for the SRM, and 0.756±0.012% S (RSD 1.6%; n=5) for the seaweed. A sample of 0.5–1 g containing ca. 100 μg of sulphur can be analysed.     

Abnormal protein spots revealed by two-dimensional electrophoresis in mycoplasma-infected human fibroblasts

Six new protein spots were detected by two-dimensional electrophoresis in cultured human fibroblasts infected with mycoplasma. No changes were observed in other protein spots present in normal and pathological cells. After treatment with an antimycoplasma drug for a week, the new spots disappeared and the cells became negative for mycoplasma stain.