Components ofHaplophyllum obtusifolium

Skimmianine, folimine, benzamide, and new alkaloid haplotusine (mp 118–119°C, C₁₁H₁₁NO₃, M⁺ 205) have been isolated from the epigeal part ofHaplophyllum obtusifolium Ledeb. growing in the environs of Kora-Koly, Turkmen SSR. By the analysis of spectral characteristics it has been established that haplotusine has the structure of 1,4-dimethoxy-2-quinolone.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 635–636, September–October, 1984.     

Search for and study of curaremimetic drugs among the diterpene alkaloids

A number of diterpene alkaloids (DAs) and their derivatives have been investigated for curaremimetic activity. Their structure-activity relationships and the mechanisms of their action have been studied. Structural fragments of the DAs that are responsible for curaremimetic properties have been revealed. Among the compounds studied, nudicauline and lycaconitine are superior to the curaremimetic drugs melliktin and condelphine.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. 6, pp. 841–848, November-December, 1995. Original article submitted April 10, 1995.     

Septerine and septefine — new alkaloids ofAconitum septentrionale

From the roots of Aconitum septentrionale Koelle we have isolated the new nor- and bisnorditerpenoid alkaloids septerine (1) and septefine (2), each containing a N-methylanthraniloyl fragment. Their structures have been established from IR-, mass-, and PMR-spectral results. Structure (1) for septerine has been confirmed by the formation of lycoctonine on its hydrolysis.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. 2, pp. 225–228, March–April, 1996. Original article submitted December 25, 1995.     

Thermoelasticity of segmented polyurethanes

Various diphenylmethane diisocyanate-containing polyurethanes whose soft blocks differ in polarity and crystallizability have been investigated using deformation and scanning calorimetry to ascertain the contribution of different types of intermolecular interaction to elasticity of polyurethane elastomers. The phase composition of polyurethanes being investigated and its dependence on mechanical action have been analyzed on the basis of scanning calorimetry data. By measuring the mechanical work and thermal effect during extension (λ=1–3.5) deformation dependences of internal energy changes and the ratio of energy and entropy changes have been determined as well as energy contributions have been calculated. The data obtained for different temperatures demonstrate that a decrease in the fraction of energy changes is largely due to hard block structurization in the course of re-building the network of hydrogen bonds during deformation.