Phytoecdysteroids of plants of the genus Melandrium I. Polypodin B 22-acetate from Melandrium turkestanicum

Known ecdysteroids — ecdysterone, ecdysterone 22-acetate, polypodin B, integristerone A, and sileneosides A and D — and a new phytoecdysteroid — polypodin B 22-acetate — have been found in the epigeal parts of the plantMelandrium turkestanicum (Rg1.) Vved. (family Caryophyllaceae).Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 480–483, July–August, 1990.     

Phytoecdysteroids of plants of the genus Silene. XVII. Ecdysterone 22,25-di-O-benzoate from Silene scabrifolia

The new phytoecdysteroid ecdysterone 22,25-di-O-benzoate (IV) has been isolated from the epigeal organs ofSilene scabrifolia Kom. The alkaline hydrolysis of (IV) gave ecdysterone 25-O-benzoate and ecdysterone (I). Details of the IR, UV, mass, PMR, and¹³C NMR spectra of compound (IV) are given.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 363–366, May–June, 1990.     

Isolation of ecdysterone from the roots ofRhaponticum carthamoides

The solubility of ecdysterone in individual solvents and mixtures has been studied. A method has been developed for isolating ecdysterone from the roots ofRhaponticum carthamoides. Extraction from the raw material was carried out with methanol. The catty oils and tanning and resinous substances were eliminated from the concentrated and water-diluted extract by treatment with chloroform. The combined ecdysteroids were extracted from the purified aqueous solution with chloroform-isopropanol (1:1). They were freed from pigments by chromatography on alumina (Brockmann activity grade II) with elution by methanol-chloroform (1:2). The product was recrystallized from methanol-ethyl acetate (1:9), giving 0.05% (on the weight of the raw material) of ecdysterone.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirornykh Soedinenii, No. 4, pp. 528–529, July–August, 1980.     

Isolation of ecdysterone

The kinetics of the extraction of ecdysterone from the roots with rhizomes ofRhaponticum carthamoides has been studied. The results of investigations on the selection of the optimum solvent for extracting ecdysterone from the raw material, for the process of sorption purification, and for the recrystallization of the ecdysterone are given.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 601–605, September–October, 1983.     

Phytoecdysteroids of plants of the genusSilene

Ecdysteroids produced by plants of the genusSilene are considered. The discussion covers 17 species of plants, from which 45 ecdysteroids have been isolated. It has been shown that ecdysterone is the most characteristic representative of the biosynthesis of ecdysteroids in theSilene series.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 627–635, September–October, 1993.     

Dissociation processes and factors causing the stabilization of complexes in solutions

The factors causing the thermodynamic and kinetic stability of complexes of metal ions in various media have been discussed. It has been shown in the case of the protolytic dissociation reactions of the porphyrin, tetraazaporphyrin, and phthalocyanine complexes of magnesium, zinc, and copper that the decisive role in the kinetic stabilization of these compounds is played by the rigid structure and the extensive system of conjugation in the macrocyclic ligand.The material was presented at the 17th Chugaev Conference on the Chemistry of Complex Compounds, Minsk, 1990.Ivanovo Chemical-Engineering Institute. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 27, No. 3, pp. 270–278, May–June, 1991. Original article submitted February 25, 1991.     

Phytoecdysones of Serratula III. Mass spectrometric study of the acetates and acetonides of ecdysterone and viticosterone e

Summary Features of the fragmentation of the side chain of the acetates and acetonides of ecdysterone and of viticosterone E have been studied. It has been shown that the presence of an oxygen-containing function at C₂₅ in these compounds imparts to the spectra certain distinguishing features which have analytical value.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 155–158, March–April, 1975.     

High-performance liquid chromatography of the phytoecdysteroids ofMelandrium nutans

With the aid of high-performance liquid chromatography, six phytoecdysteroids have been detected in the butanolic fraction of extractive substances from the epigeal part ofMelandrium nutans L. Preparative separation has yielded ecdysterone and polypodine B.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Institute of Physiologically Active Substances, Academy of Sciences of the USSR, Chernogolovka. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 322–324, May–June, 1984.     

Phytoecdysteroids of plants of the genus Silene. IX. Ecdysterone 22-O-benzoate from Silene scabrifolia

An ecdysteroid which has proved to be ecdysterone 22-O-benzoate has been isolated from the epigeal organs ofSilene scabrifolia Kom.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 77–80, January–February, 1986.     

Ecdysteroids of a culture of tissues and cells ofAjuga turkestanica

The possibility has been studied of obtaining ecdysteroids — ecdysterone and turkesterone — with the aid of a culture of the tissues and cells of the plantAjuga turkestanica. Conditions have been selected under which the yield of ecdysteroids in the culture of tissues and cells is comparable with amounts of the same substances in the organs of the whole plant.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 51–52, January–February, 1990.     

Phytoecdysteroids of plants of the genus Silene. XIV. Ecdysterone 20-O-benzoate from Silene tatarica

A new ecdysteroid, which has proved to be ecdysterone 20-O-benzoate, has been isolated from the whole plantSilene tatatica (L.) Pers.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 850–852, November–December, 1987.     

Isolation of ecdysterone from the inflorescences ofRhaponticum integrifolium

A method has been developed for isolating ecdysterone from the inflorescences ofRh. integrifolium. The yield is 0.15% on the weight of the raw material.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 667–668, September–October, 1979.     

Polysaccharides ofPolygonatum. VI. A study of the structure of a glucomannan fromPolygonatum sewerzowii by13C NMR spectroscopy,electron microscopy,and x-radiography

A phytoecdysteroid, sileneoside D, has been isolated from the roots ofSilene brahuica Boiss. and it has been shown to be ecdysterone 3-O--D-galactopyranoside.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 741–744, November–December, 1984.     

Chromato-spectrophotometric method of determining ecdysterone in plant raw material

Summary A chromato-spectrophotometric method is proposed for determining ecdysterone in the epigeal part of the roots ofRhaponticwn orientate andRh, integrifotium, the limit of detection of ecdysterone being 60 jig.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 737–740, November-December, 1978. Original article submitted June 30, 1978.     

Crown Ether Catalysis in the Synthesis of Xanthates

Xanthates (0,S-dialkyl dithiocarbonates) received much attention in connection with technological¹ and synthetic applications². Pyrolytic elimination of xanthates, called the Chugaev reaction, has been widely used as a method of dehydrating alcohols without rearrangement of carbon skeleton³.     

Phytoecdysones ofSerratula xeranthemoides

Summary Ecdysterone and integristerone A have been isolated from the inflorescences ofSerratula xeranthemoides.The amount of these phytoecdysones in the flower heads increases as the plant ripens, reaching a maximum for ecdysterone in the full-flowering phase and for integristerone A at the end of the flowering phase and the beginning of fruit formation.A. V. Palladin Institute of Biochemistry, Academy of Sciences of the Ukrainian SSR, Kiev. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 171–174, March–April, 1979.     

A new entry to Amaryllidaceae alkaloids from carbohydrates: total synthesis of (+)-vittatine

The stereoselective and chiral synthesis of the Amaryllidaceae alkaloid, (+)-vittatine 1, is described; the quaternary carbon in 1 was generated by Claisen rearrangement of a cyclohexenol derived from D-glucose by way of a Ferrier's carbocyclisation reaction and a hexahydroindole skeleton was effectively constructed by intramolecular aminomercuration-demercuration, followed by Chugaev reaction.     

Nonempirical calculations of potential-energy surfaces for nucleophilic addition of H− and F− to an acetylene molecule

The minimal energy paths for the nucleophilic addition of a hydride ion (H^–) and a fluoride ion (F^–) to a molecule of acetylene (A) have been calculated with the use of 3–21++G and 3–21+G double basis sets in the framework of the Hartree-Fock-Roothaan method. The values of the total energies of the reactants, transition states, and products have been refined by means of calculations with more complete basis sets [6–31++G// 3–21++G and 6–31++G*//3–21++G for reaction (1); 6–31+G*//3–21+G and 6–31++G**//3–21+G for reaction (2)] and by taking into account the correlation energy for reaction (1) in the framework of the SCEP/6–31++*//3–21++G method. It has been established that the activation energy of reaction (2) is 15.94 kJ/mole lower than that for reaction (1), that reaction (1) is exothermic, and that the enthalpy change accompanying reaction (2) is close to zero. The character of the distribution of the electron density along the minimal energy paths of both reactions has been analyzed, and the differences appearing as a result of the replacement of the soft nucleophile H^– by the harder nucleophile F^– have been ascertained. The results of the calculations have been compared with the results available in the literature for reaction (1).Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 149–155, March–April, 1989.     

Phytoecdysteroids of plants of the genus Silene. XVIII. 2-Deoxyecdysterone 20,22-monoacetonide from Silene brahuica

In addition to the known 2-deoxy--ecdysone, 2-deoxyecdysterone, 2-deoxy--ecdysone-22-O-acetate, ecdysterone, integristerone A, and sileneoside A, B, and C, the new ecdysteroid 2-deoxyecdysterone 20,20-monoacetonide has been isolated from the roots of the plantSilene brahuica Boiss.Institute of Chemistry of Plant Substances Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 241–244, March–April, 1991.