Terpenoid coumarins ofFerula kokanica

From an alcoholic extract of the roots ofFerula kokanica Rgl. et Schmalh., collected in the region of the village of Oman-kutan (Samarkand Province), have been isolated polyanthinin, mogoltadone, gummosin, kellerin, feshurin, and umbelliferone, and two new coumarins: deacetylkellerin, C₂₄H₃₂O₅, M⁺ 400, mp 134–136°C, [α] _D ²² +52° (c 0.1, ethanol), and kokanidin, C₂₆H₃₄O₆, M⁺ 442, mp 189–191°C, [α] _D ¹⁸ ?30° (c 1.0; ethanol). The structure of deacetylkellerin has been established on the basis of the results of a study of UV, IR, PMR, and mass spectra. The structure and configuration of kokanidin have been established on the basis of spectral characteristics and also conversion into conferol acetate and feshurin.     

QSPR Modeling of Complex Stability by Correlation Weighing of the Topological and Chemical Invariants of Molecular Graphs

The concept of modeling of the complex stability based on optimization of the correlation weights of the nearest neighborhood codes (NNC), the hydrogen bond index (HBI), and the cyclicity code (CC) is described. The NNC is a local topochemical invariant of a vertex of the molecular graph whose numerical value is a function of the total number and the composition of vertices adjacent to the given vertex. The HBI is a global chemical invariant of the molecular graph calculated from the number of oxygen and nitrogen atoms. The CC is a global topological invariant of the graph equal to the number of rings present in the ligand structure. The statistical characteristics of the best model of the stability constants of the complexes are as follows: n = 75, r = 0.9738, s = 0.457, F = 1337 (training sample); n = 75, r = 0.9795, s = 0.461, F = 1724 (test sample).     

IR spectroscopic study of the interaction between trimethylgallium and arsine in the liquid phase

The formation of a donor-acceptor complex Me₃Ga · AsH₃ in a solution in liquid krypton at 130 K and in a binary liquid solution of those substances at 263 K was established by IR spectroscopy. In the latter case, Me₃Ga and AsH₃ react at an appreciable rate to form an amorphous product of composition Me_3-x ,GaAsH_3-x .Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2259–2262, September, 1996.     

Aggregation and photoisomerization of amphiphilic crown-ether styryl dye in monolayers at the interface

The molecules oftrans-isomer of styryl dye1a, containing the benzo-18-crown-6 moiety and the methoxybenzothiazole residue with theN-octadecyl substituent, were shown to form stable, highly ordered monolayers at the water/air interface. Increasing the surface pressure of the monolayer results in the formation of the H-aggregated molecules of compound1a. The H-aggregates tend to dissociate to the monomerictrans-form, when the monolayer forms in the Langmuir-Blodgett film (LB film). The light irradiation of the LB films leads to the partially reversibletrans-cis-photoisomerization of compound1a, whose efficiency is much lower than that observed in an acetonitrile solution of1a. The aggregation of cis-1a isomers in the LB film is suggested to hamper the reversecis-trans-isomerization. The aggregation oftrans-1a molecules in the LB films does not occur in air, but, after dipping in an aqueous solution, molecules of the LB film slowly form J-aggregates. A model of the structural organization oftrans-1a molecules in the LB films was proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2490–2496, October, 1996.     

Alkaloids ofPetilium raddeana. III. Structure of petisidinine

From a mixture of bases from the epigeal part and the bulbs ofPetilium raddeana (Rgl.) Vved. ex Pazij, a new base petisidinine has been isolated with mp 290–292°C (decomp.), composition C₂₇H₃₉NO₃ (I). On the basis of the physicochemical properties of the alkaloid and a correlation with petisine, the structure and configuration of petisidinine have been established as those of 3-hydroxy-20-(5-hydroxy-3-methylpyridin-6-yl)-5-pregnan-6-one.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Trashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 747–749, November–December, 1983.