Hydroxy acids of the seed oils of five plants of the family Asteraceae

A comparative study has been made of the fatty hydroxy acids and epoxy acids of the seed oils ofArtemisia absinthium, Arctium tomentosum, Onopordum acanthium, Onopardum olgae, andCousinia severzovii by GLC, TLC, and IR and mass spectroscopy. It has been shown that the hydroxy acids present in largest amount are the products of the metabolism of 9-hydroperoxyoctadecadienoyl; the epoxy acids are represented mainly by 9,10-epoxy-cis-octadeca-12-enoic acid.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 30–34.     

A five-coordinate complex of copper chloride with 2-amino-5-ethyl-1,3,4-thiadiazole

A complex of Cu(II) chloride with 2-amino-5-ethyl-1,3,4-thiadiazole (AET) was prepared, and its structure was studied by IR spectroscopy and single crystal X-ray diffraction. The complex has the composition CuCl₂(AET)₄. The coordination sphere of the copper atom includes four molecules of the heterocyclic ligand coordinated via N atoms of thiadiazole rings and one of Cl^? anions; the second Cl^? anion is in the outer sphere.     

Pyrroloindoles. 16. Some electrophilic substitution reactions of 2,7-dicarbethoxy-1H,6H-pyrrolo[2,3-e]indoles

Electrophilic substitutions of 2,7-dicarbethoy-1H,6H-pyrrolo[2,3-e]indole (Friedel-Crafts acylation, nitration, bromination) take place both at position 3 of the indole ring and at positions 5 and 8 in the benzene ring.For communication 15 see [1].Iv. Dzhavakhishvili State University, Tbilisi 380028. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1197–1201, September, 1994. Original article submitted July 5, 1994.     

Glycosylation of cyclosieversiosides A and H

Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan. Tashkent Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 621–622, July–August, 1993.     

Reaction of 5-haloanthra[1,9-cd]-6-isoxazolones with aziridine

The reaction of 5-haloanthra[1,9-cd]-6-isoxazolones with aziridine gave 5-aziri-dinoanthra[1,9-cd]-6-isoxazolones. The latter, upon reaction with acids, undergo cleavage of the aziridine ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 885–888, July, 1984.     

TPD study of catalyst surface acidity

Acidity of catalyst surfaces of different nature such as -Al₂O₃, natural zeolite-clinoptilolite, and synthetic zeolite zeokar by adsorption of ammonia over a wide temperature range has been studied. Ammonia is adsorbed on the catalysts with different strengths, as evidenced by the presence of different types of acid sites.

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(-Al₂O₃, - , () . , , .

     

Extraction of uranium(VI) with non-plasticized and TBP-plasticized polyurethane foam sorbents loaded with dibenzoylmethane

Studies have shown that plots of the log of the distribution ratio versus pH for the distribution of uranium(VI) between non-plasticized and TBP-plasticized dibenzoylmethane-loaded polyurethane foams and dilute aqueous uranium(VI) solutions have a limiting slope of 0.6 at equilibrium pH values 4 and reach a maximum distribution constant at about pH 6.0. The results indicate that the extracted complex is a simple chelate, UO₂Me₂, where HMe denotes dibenzoylmethane. Plasticization of the foam with TBP has been found to significantly enhance the rate of extraction.     

Spectral and quantum-chemical study of some heteroanalogs of 1,4-bis(5-phenyl-2-azolyl)benzenes

The effect of structural changes in the molecules of thiophene and furan analogs of 1,4-bis(5-phenyl-2-azolyl)benzenes on their electronic spectra was studied by the MO LCAO method within the -electron approximation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 817–821, June, 1991.     

Enhancement of the solubilities of polycyclic aromatic hydrocarbons by weak hydrogen bonds with water

Summary The thermodynamics of mobile order is applied to predict the aqueous solubility of liquid and solid aliphatic and polycyclic aromatic hydrocarbons. The solubility values are mainly determined by the magnitude of the hydrophobic effect. However, contrary to the solubilities of the alkanes, the solubilities of polycyclic aromatic hydrocarbons in water predicted in absence of solute-solvent hydrogen (H) bonds are systematically too low. This shows the contribution of weak specific interactions between the OH groups and the electrons of the aromatic substances. According to the theory, these interactions are characterized by a stability bility constant K_o which can be derived from solubility data. At 25°C, this constant amounts to 80 cm³/mol, the order of magnitude of which can be explained by the competition of these intermolecular bonds with the rather weak self-association bonds in the secondary chains of water.