A study of the alkaloids of Kirghiz opium

Chemistry of Natural Compounds - Morphine, codeine, narcotine, thebaine, papaverine, protopine, xanthaline, prophyroxine, bases with mp 267 and 263°C,l-canadine, and cryptopine have been...     

Effect of diisocyanate nature on the properties of cyclolinear polyureas containing azacrown ether groups

New cyclolinear polyureas based on a crown-containing diamine—1,10-diaza-18-crown-6—and organic diisocyanates of different natures (aliphatic, aromatic, and alicyclic compounds) and an oligomeric diisocyanate have been synthesized. It has been found that, unlike most polyureas, azacrown-containing polymers are soluble in a wide variety of organic solvents. The calorimetric and mechanical properties of these polymers in dry and equilibrium-swollen states have been studied. It has been shown that the basic characteristics of these cyclolinear systems can be tailored by varying the nature of the diisocyanate used.     

4-Azidocinnoline—Cinnoline-4-amine Pair as a New Fluorogenic and Fluorochromic Environment-Sensitive Probe

A new type of fluorogenic and fluorochromic probe based on the reduction of weakly fluorescent 4-azido-6-(4-cyanophenyl)cinnoline to the corresponding fluorescent cinnoline-4-amine was developed. We found that the fluorescence of 6-(4-cyanophenyl)cinnoline-4-amine is strongly affected by the nature of the solvent. The fluorogenic effect for the amine was detected in polar solvents with the strongest fluorescence increase in water. The environment-sensitive fluorogenic properties of cinnoline-4-amine in water were explained as a combination of two types of fluorescence mechanisms: aggregation-induced emission (AIE) and excited state intermolecular proton transfer (ESPT). The suitability of an azide–amine pair as a fluorogenic probe was tested using a HepG2 hepatic cancer cell line with detection by fluorescent microscopy, flow cytometry, and HPLC analysis of cells lysates. The results obtained confirm the possibility of the transformation of the azide to amine in cells and the potential applicability of the discovered fluorogenic and fluorochromic probe for different analytical and biological applications in aqueous medium.     

Focusing of high power ultrasound beams and limiting values of shock wave parameters

In this work, the influence of nonlinear and diffraction effects on amplification factors of focused ultrasound systems is investigated. The limiting values of acoustic field parameters obtained by focusing of high power ultrasound are studied. The Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation was used for the numerical modeling. Solutions for the nonlinear acoustic field were obtained at output levels corresponding to both pre- and post-shock formation conditions in the focal area of the beam in a weakly dissipative medium. Numerical solutions were compared with experimental data as well as with known analytic predictions.