Hemorrhagic action of the venoms of Central Asian snakes

Collective characteristics of the venoms belonging to various taxons of Central Asian snakes, demonstrating levels of toxicity and efficiency of hemorrhagic action, together with proteolytic, esterase, and phospholipase activities, have been obtained. A comparative analysis of the collective characteristics (“portraits”) of the venoms and their changes on degradative treatment has shown that the hemorrhagic action of the venoms of viperine and crotalid snakes is connected with metalloproteins. In contrast to the venoms of the elapids (cobras) the toxicity of the venoms of the viperine and crotalid snakes exhibits a dependence on the hemmorhagic effect and the activity of the metalloproteins causing it.     

Mannich reaction in the series of 7-hydroxy-3-phenoxychromones and their derivatives

The Mannich condensation of amino acids with 3-phenoxychromones and polyhydroxy-α-phenoxyacetophenones has given a series of 8-carboxyalkylaminomethylchromones and 3-carboxymethylaminomethyl-2,4-dihydroxy-α-phenoxyacetophenones. Some features of the course of the Mannich reaction as a function of the structures of the chromones and acetophenones have been studied. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 475–481, July–August, 1998.     

Bimetallic Alkoxides of Barium and Zirconium: Preparation of BaZrO3 Powder

Complex formation in solutions of barium and zirconium alkoxides in ROH (R=i-Pr, Et) was studied. A number of bimetallic complexes were isolated, and their structure and properties were studied. The sol-gel method yields a single-phase BaZrO₃ powder only wheni-PrOH solutions of the alkoxides are used. In this case, the oxocomplex, BaZrO(OPr-i)₄.(1–2)i-PrOH, is the precursor of the mixed oxide.     

Conversion of 2-amino-5-R-phenyl-1,3,4-oxadiazoles into 3-R-phenyl-5-alkoxy-1,2,4-triazoles

2-Amino-5-R-phenyl-1,3,4-oxadiazoles have been shown to isomerize in alcoholic potassium hydroxide solution to 3-R-phenyl-5-alkoxy-1,2,4-triazoles. The dissociative ionization of 3-R-phenyl-5-alkoxy-1,2,4-triazoles and 3-R-phenyl-1,2,4-triazolin-5-ones has been examined. The mass spectra of the oxadiazoles have been compared with those of the triazoles.Translated from Khimiya Geterotslklicheskikh Soedinenii, No. 11, pp. 1553–1556, November, 1986.     

Synthesis of 1,4-dihydropyridines having an N-alkylpyridinium substituent at the 4-position and their affinity towards liposomal membranes

There has been synthesized a series of 1,4-dihydropyridines having an N-alkylpyridinium substituent at position 4 with a varying length of hydrocarbon chain. Their affinity to model (liposomal) membranes has been studied. It was found that this affinity increased with lengthening of the hydrocarbon chain on the Npyridinium substituent at the 4-position of the 1,4-dihydropyridine ring. However, lengthening of the hydrocarbon chain in the 3,5-ester groups of the 1, 4-dihydropyridine ring led to a decrease in the binding to the liposome when a 4-(N-hexadecylpyridinium) substituent was present.Latvian Institute of Organic Synthesis, Riga LV-1006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1112–1117, August, 1995. Original article submitted June 6, 1995.     

Purification of 3-ethoxycarbonylquinuclidine and its conversion to 3-quinuclidinecarboxylic acid and 3-quinuclidinylmethanol

3-Ethoxycarbonylquinuclidine obtained by the Grob method is a mixture of 3-ethoxycarbonyl-1-azabicylo-[2.2.2]- and, according to ¹³C NMR data, 5-ethoxycarbonyl-5-azatricyclo[3.2.1.0^2,7]octanes (1621). 3-Ethoxy-carbonylquinuclidine was purified by recrystallization of the hydrochloride, hydrolyzed by water to 3-quinuclidinecarboxylic acid, and reduced by LiAlH₄ to 3-quinuclidinylmethanol.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, 1509–1512, November, 1992.     

Synthesis of 2-methyl-3,5,6-trichloro-4-pyridyl vinyl sulfone and its reactions with nucleophilic reagents

The reaction of excess primary aliphatic amines and mercaptans with 2-methyl-3,5,6-trichloro-4-pyridyl vinyl sulfone gives products of addition to the double bond.     

Ion Mobility,Phase Transitions,and Ion Conductivity in Alkali Metal Tetrafluoroantimonates(III) MSbF4 (M = Na,K, Rb,Cs)

The internal mobility of fluoride ions and electrophysical characteristics of alkali metal tetrafluoroantimonates(III) (M = Na, K, Rb, and Cs) are studied by ¹⁹F NMR and impedance spectroscopies. The types of ion motions in the anionic sublattice of these compounds are determined in the 180-510 K temperature range. The superionic conductivity of the MSbF₄ compounds is established above 480 K ( 2.9 × 10^-2 to 1.3 × 10^-4 S/cm).     

Hydrolysis of bis(chloromethyl)phosphonic acid p-nitroanilide in aqueous micellar surfactant solutions

The hydrolysis of bis(chloromethyl)phosphonic acid p-nitroanilide has been studied in the pH range 6.86–13.0 and the effects of ionic surfactant micelles on this process have also been examined. The nature of the micellar effects of cetyltrimethylammonium bromide (CTAB) and sodium dodecylsulfate (SDS) on this reaction lead us to conclude that both the neutral and anionic forms of the substrate are reactive, and that in the range of pH > pK_a hydrolysis of the ionic form of the anilide predominates, while at pH < pK_a the reaction of the neutral form is predominant. The binding constants for both the neutral and anionic forms of bis(chloromethyl)phosphonic acid p-nitroanilide in micellar CTAB and SDS solutions have been determined using a kinetic method, as well as by measuring the changes in the acid-base properties of the substrate resulting from the influence of micelles.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1718–1722, August, 1990.     

Catalytic properties of initial and thermosteamed faujasites in n-hexane aromatization

Regularities in n-hexane conversion on decationized Y zeolites under cracking and aromatization conditions have been studied. Possible formation of lower olefins and benzenes in parallel reactions following different mechanisms at low conversion degrees is suggested. The effect of thermosteam treatment on the activity and selectivity of Y zeolites in n-hexane conversion has been examined.

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