Crystal solvates and polymorphs of N-(3-methylthio-1,2,4-thiadiazol-5-yl-aminocarbonylmethyl)cytisine

A polymorphs, crystallohydrate and crystallosolvates of N-(3-methylthio-1,2,4-thiadiazol-5-yl-aminocarbonylmethyl)cytisine, C₁₆H₁₉N₅O₂S₂, with chloroform, methanol, benzene have been obtained and crystal structures have been determined by the method of single crystal X-ray diffraction. In the investigated crystals N-(3-methylthio-1,2,4-thiadiazol-5-yl-aminocarbonylmethyl)cytisine have taken four types of conformation due to intra-molecular rotations around N–C and C–C bonds. So free rotations in the molecule assisted in formation a different crystallosolvates and polymorphs depending on nature of solvents. The thermal decomposition of the hydrate and methanol solvated crystals was studied by means of a TG-DSC.     

Transfer measurements for the Ti+Ni systems at near barrier energies

Large enhancements have been observed in the sub-barrier fusion cross sections for Ti+Ni systems in our previous studies. Coupled channel calculations incorporating couplings to 2⁺ and 3⁻ states failed to explain these enhancements completely. A possibilty of transfer channels contributing to the residual enhancements had been suggested. In order to investigate the role of relevant transfer channels, measurements of one- and two-nucleon transfer were carried out for ^46,48Ti+⁶¹Ni systems. The present paper gives the results of these studies.     

Components of cottonplant leaves, their functional role and biological activity

This review generalizes information on the composition of the components of cottonplant leaves: hydrocarbons, organic, amino, and hydroxy acids, alcohols, triterpenes, phenolic compounds, carotenoids, sugars, pectin substances, polyisoprenoids, diols, tocopherols, sterol esters, and others. Their role in the growth and development of the plant and their biological properties are discussed.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 773–788, November–December, 1997.     

X-ray structural investigation of tricyclic 2,3-tetra and 2,3-pentamethylene-3,4-dihydroquinazol 4-ones and their derivatives

The fine structures of the alkaloid 2, 3-tetramethylene-3, 4-dihydroquinazol-4-one and its synthetic analogs 2, 3pentamethylene-3, 4-dihydro- and -1, 2, 3, 4-tetmhydroquinazol-4-ones and the complex of 2, 3 pentamethylene3, 4-dihydroquinazol-4-one with succininide in a ratio of 2:1 have been studied by the x-ray structural method. By an analysis of the lengths of the valence bonds, including those given in the literature, the degree of delocalization of the -electron system of the N1=C2 double bond and the role of the C=O bond in the overall conjugation have been evaluated.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 410–420, May–June, 1995. Original article submitted June 20, 1994.     

Novel α-methyl(benzyl)deoxyvasicinones

A method was developed to prepare -methyl(benzyl)deoxyvasicinones by alkylation of -hydroxy- methylidenedeoxyvasicinone. It has been shown that the reaction proceeds anomalously through a deformylation step.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 407–409, September–October, 2004.     

Synthesis of bicyclic analogues of deoxyvasicinone

6-Methyl-2,3-tri-, -tetra-, and -pentamethylene-3,4-dihydropyrimidin-4-ones and 6-phenyl-2,3-tri-3,4-dihydropyrimidin-4-one (bicyclic analogues of deoxyvasicinone) have been synthesized by the condensation of ethyl esters of -aminocrotonic and -aminocinnamic acids with lactams. It has been shown that the occurrence of the reaction and yields of the products of the condensation of ethyl -aminocrotonate with lactams depend both on the number of methylene groups in the lactams and also on the reaction conditions. With an increase in the number of methylene groups of the lactams the yields of condensation products decrease.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. A. Navoi Samarkand State University. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 394–396, May–June, 1991.