Synthesis and DNA Binding Properties of γ-Carbolinium Derivatives and Benzologues
摘要:
The 5H-pyrido[4,3-b]indole, 11H-indolo[3,2-c]quinoline, 5H-benzo[f]pyrido[4,3-b]indole, and 13H-benz[5,6]indolo[3,2-c]quinoline heteroaromatic nuclei have been synthesized by the Graebe-Ullmann method by classical heating or under microwave irradiation. These tri-, tetra-, and pentacyclic compounds were transformed into the corresponding cationic derivatives by N-alkylation, and the DNA-binding properties of the resulting cationic systems were examined using UV-vis spectroscopy, viscometric determinations, and molecular modeling techniques. The tetracyclic cations were transformed into his-salts by means of a diethyl bispiperidine rigid chain and a more flexible polyamide linker, but the low solubility of these bis-salts made the study of their bisintercalating properties difficult.
One-pot Graebe-Ullmann synthesis of γ-carbolines under microwave irradiation
作者:Andrés Molina、Juan J. Vaquero、José L. García-Navio、Julio Alvarez-Builla
DOI:10.1016/s0040-4039(00)77653-2
日期:1993.4
One-pot efficient and simple synthesis of γ-carboline derivatives by the Graebe-Ullmann method was conducted in a commercial microwave oven in a few minutes at a low energy level and using erlenmeyer as adequate reaction vessels. Yields are similar to those obtained by conventional heating.
NONAQUEOUS ELECTROLYTE AND NONAQUEOUS SECONDARY BATTERY
申请人:Asahi Kasei Kabushiki Kaisha
公开号:EP3279997A1
公开(公告)日:2018-02-07
The purpose of the present invention is to provide a nonaqueous electrolyte that contains acetonitrile having an excellent balance between viscosity and the dielectric constant and a fluorine-containing inorganic lithium salt, wherein the generation of complex cations comprising a transition metal and acetonitrile is suppressed, excellent load characteristics are exhibited, and increases in internal resistance upon repeated charge/discharge cycles are suppressed; a further purpose of the present invention is to provide a nonaqueous secondary battery. The present invention relates to a nonaqueous electrolyte which contains: a nonaqueous solvent comprising acetonitrile; a fluorine-containing inorganic lithium salt; and a specific nitrogenous cyclic compound typified by benzotriazole.
Nonaqueous electrolyte and nonaqueous secondary battery
申请人:Asahi Kasei Kabushiki Kaisha
公开号:US10756394B2
公开(公告)日:2020-08-25
The purpose of the present invention is to provide a nonaqueous electrolyte that contains acetonitrile having an excellent balance between viscosity and the dielectric constant and a fluorine-containing inorganic lithium salt, wherein the generation of complex cations comprising a transition metal and acetonitrile is suppressed, excellent load characteristics are exhibited, and increases in internal resistance upon repeated charge/discharge cycles are suppressed; a further purpose of the present invention is to provide a nonaqueous secondary battery. The present invention relates to a nonaqueous electrolyte which contains: a nonaqueous solvent comprising acetonitrile; a fluorine-containing inorganic lithium salt; and a specific nitrogenous cyclic compound typified by benzotriazole.
Fluorescence Studies with Tryptophan Analogs: Excited State Interactions Involving the Side Chain Amino Group
作者:Maurice R. Eftink、Jiwei Jia、Dana Hu、Camillo A. Ghiron
DOI:10.1021/j100015a064
日期:1995.4
The fluorescence of a large set of tryptophan analogues, including several that are conformationally constrained, was studied. The constrained analogues include tetrahydrocarboline-3-carboxylic acid and 3-amino-3-carboxytetrahydrocarbazole. Steady state and time-resolved fluorescence measurements were made as a function of pH. The fluorescence quantum yields of the constrained analogues are higher than those for the unconstrained counterparts. The emission intensity of the constrained analogues, as well as 4-methyltryptophan, decreases with deprotonation of the side chain alpha-ammonium group; this is in contrast to the increase in fluorescence of tryptophan with deprotonation of this group. These results are consistent with the existence of excited state proton transfer to carbon 4 of the indole ring as a quenching mechanism, which is sterically prohibited in the constrained analogues and 4-methyltryptophan. From quantum yield and lifetime data (most decays are nonexponential), the effective rate constant for nonradiative depopulation of the excited state was calculated. For tryptophan analogues having two side chain functional groups, there is a synergistic effect; the presence of two side chain groups causes more quenching than expected from the sum of the individual contributions. For analogues having ana-ammonium group, this synergism appears to be correlated with an induced change in the pK(alpha) of this group. Deprotonation of this cl-ammonium group also causes a red shift in the emission of these compounds; this appears to be due to electrostatic repulsion between the alpha-NH3+ group and the excited indole dipole.