2-arylfuro [2,3-b] quinoxalines

2-Arylfuro[2,3-b]quinoxalines were obtained by cyclization of 2-phenacyl-3-quinoxalones in the presence of polyphosphoric acid or a mixture of phosphorus oxychloride and phosphorus pentachloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 259–260, February, 1973.     

Structural investigation of the lipopolysaccharide ofYersinia pseudotuberculosis of type IB

Summary Using the chromato-mass spectrometry of the methylated sugars formed in the hydrolysis of the fully methylated lipopolysaccharide fromYersinia pseudotuberculosis of type IB the nature of the glycosidic bonds between the monosaccharide residues has been established. The hapten formed in the partial hydrolysis of the lipopolysaccharide has also been studied by methylation. The results obtained have confirmed the results of an investigation of the methylated lipopolysaccharide; they have enabled an idea to be put forward of the composition of the repeating unit of the O-specific side chains of the lipopolysaccharide.Pacific-Ocean Institute of Bioorganic Chemistry of the Far-Eastern Scientific Center of the Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 563–570, September–October, 1975.     

Synthesis and Properties of First Bis(fluoreno)crownophanes

Alkylation of 2,7-dihydroxy-9H-fluoren-9-one with 2-(2-chloroethoxy)ethanol, 2-[2-(2-chloroethoxy)-ethoxy]ethanol, and 2-{2-[2-(2-chloroethoxy)ethoxy]ethoxy}ethanol in dimethylformamide in the presence of potassium carbonate gave 78–80% of the corresponding diols which were treated with p-toluenesulfonyl chloride in a dioxanechloroform mixture in the presence of triethylamine at 0– 5°C (30 h). The resulting bis(p-toluene-sulfonates) were brought into condensation with 2,7-dihydroxy-9H-fluoren-9-one in a very dilute solution in dimethylformamide containing anhydrous potassium carbonate at 80–85°C. Appropriate treatment of the reaction mixture, followed by chromatographic purification afforded 53–27% of the first representatives of a new class of cyclophanes, bis(oxofluoreno)crownophanes. Raising the temperature to 95–105°C resulted in an appreciable decrease of the product yield. The yield of the target products did not increase on replacement of potassium carbonate by cesium carbonate.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 144–149.Original Russian Text Copyright © 2005 by Lyapunov, Kirichenko, Kulygina, Luk’yanenko.     

Photoreduction of benzophenone by dimethylaminoethyl methyacrylate in solutions

The photoreduction of benzophenone by dimethylaminoethyl methacrylate was investigated under the conditions of stationary and pulsed irradiation. With stationary irradiation of this system in benzene an intermediate photoproduct is formed, and its destruction is described by a kinetic equation of second order. By irradiation under pulsed conditions it is possible to detect the formation of the ketyl radicals of benzophenone, the yield and destruction of which depend substantially on the nature of the medium. The relationship between the destruction constant and the concentration of the aminomethacrylate and butyl methacrylate was examined and explained; the constant increases with decrease in the aminomethacrylate concentration and with increase in the butyl methacrylate concentration. The mechanism of the photoreduction of aromatic carbonyl compounds by aminomethacrylates is described.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 26, No. 1, 56–62, January–February, 1990.     

Electrophoretic and amino acid compositions of the proteins of maize lines differing in the anthocyan coloration of the seeds

The electrophoretic and amino acid compositions of the proteins of lines of maize differing in the anthocyan coloration of their seeds have been investigated. The molecular masses of the quantitatively main components ranged from 11 to 42 kDa for the albumins and from 15 to 81 kDa for the globulins. Differences between the lines were observed in the levels of components with molecular masses of from 11 to 31 kDa. The amino acid compositions of the zeins of the lines studied were characterized by high levels of leucine, glutamic acid, aspartic acid, alanine and serine, and those of the other groups of proteins by high levels of arginine, glutamic acid, and glycine.Institute of Genetics, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 64 22 30. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 871–873, November–December, 1997.     

Liquid chromatography of cardiac glycosides

Summary LC was used for the separation of several cardiac glycosides with water-alcohol eluents on a silanised silica column. The influence of temperature and composition of the eluent on the retention time, the retention volumes of the glycosides, the selectivity and the capacity factor of the column were studied. Higher temperature and a higher ethanol content in the eluent reduce the retention time, the selectivity and the capacity factor but the efficiency of the column increases. The best separation of six glycosides studied was obtained at 50°C, the ethanol content in the eluent being about 30%.     

Mass spectrometry of π-complexes of transition metals : XII. Ferrocenyl and cymantrenyl derivatives of chalcones

The main processes of the electron-impact induced fragmentation of the ferrocenyl and cymantrenyl analogues of chalcones RCOCH=CHR′ (R, R′ = C₅H₄FeC₅H₅, C₅H₄Mn(CO)₃, or aryl) involve a cleavage of the metalligand bond. A “chalcone” mode of fragmentation is weakly pronounced, due to the fact that the positive charge is localized preferably on the metal atom.     

Acid-base properties of 1-acyl-5-hydroxypyrazolidines in a hydrogen bond

In solutions, 1-acyl-5-hydroxypyrazolidines form only intermolecular hydrogen bonds in which the proton acceptor is the oxygen atom of the hydroxyl group. These compounds are similar to phenols with respect to the acidity in a hydrogen bond.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 936–939, July, 1989.     

Application of high-performance liquid chromatography of some antibiotics in clinical microbiology

During recent years high-performance liquid chromatography has become an excellent tool for the determination of antibiotics in biological fluids. Compared with biological assays, the major benefits of this method are specificity and rapidity. In particular, the determination of biologically inactive metabolites emphasizes that this technique plays an outstanding role for the analysis of antibiotics. This paper describes how the method can be used in the analysis of several antibiotics and demonstrates the efficacy of this method for clinical microbiology. Methods for the determination in biological fluids of acylaminopenicillins (azlocillin, mezlocillin, piperacillin and aspoxicillin), quinolones (ciprofloxacine, norfloxacine and ofloxacine), a penem (imipenem) and a cephalosporin (cefixime) are summarized. Furthermore, their application to in vitro studies and their trial in clinical studies are described.     

Reaction of 2,3,3-trimethyl-3H-indole hydrochloride with methacrylic and crotonic amides

Reaction of 2,3,3-trimethyl-and 2,3,3,5-tetramethyl-3H-indole hydrochlorides with methacrylic and crotonic amides gives 3- and 4-methyl-1,2,3,4,10,10a-hexahydropyrimido[1,2-a]indol-2-ones. With perchloric acid these are converted to 1-carbamoylpropyl-3H-indolium perchlorates. The syntheses of 10a-(4-dimethylaminostyryl)- and 10a-[(4-dimethylaminophenyl)butadienyl]-3,10,10-trimethylpyrimido[1,2-a]indol-2-ones have been studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 625–627, May, 1990.