Catechins and proanthocyanidins ofAlhagi sparsifolia. I

Ten individual compounds have been isolated from the epigeal part ofAlhagi sparsifolia Shap. in various stages of vegetative growth. Their structures have been established by a study of PMR spectra, physicochemical properties, and the products of chemical transformations: (–)-epicatechin, (–)-epigallocatechin, (–)-epigallocatechin gallate, (+)-catechin, (+)-gallocatechin, proanthocyanidin B-2, (–)-epigallocatechin-(4–8)-(–)-epicatechin, epigallocatechin gallate-(4–8)-(–)-epicatechin, proanthocyanidin B-1, and (–)-epicatechin-(4–8)-gallocatechin.The materials of this paper were presented at the Second International Symposium on the Chemistry of Natural Compounds (SCNC, Eskiehir, Turkey, October 22–24, 1996).Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 232–237, March–April, 1997.     

New liquid crystal derivatives of thiazole

2-(4-Alkoxybenzylidenamino)-4-(4-nitrophenoxy)thiazoles, which possess monotropic mesomorphism of the nematic type over the range 68–160°C, have been synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 546–548, April, 1996.     

Proanthocyanidins ofZiziphus jujuba

The catechin and proanthocyanidin compositions of the leaves and bark ofZiziphus jujuba have been studied over the vegetation periods. This has led to the isolation of 16 compounds, including 8 monomeric catechins — (–)-epiafzelechin, (–)-epicatechin, (–)-epigallocatechin, (–)-epicatechin gallate, (–)-epigal-locatechin gallate, (+)-catechin, (+)-catechin gallate, and (+)-gallocatechin; 4 dimeric proanthocyanidins — (–)-epiafzelechin-(4-8)-(–)-epicatechin, proanthocyanidin B-2, (–)-epicatechin-(4-8)-(–)-epigallocatechin, and (–)-epiafzelechin-(4-8)-(–)-epigallocatechin; and 4 oligomeric proanthocyanidins consisting of epiafzelechin, epigallocatechin, catechin, and epicatechin with different degrees of polymerization. Their structures have been established by a study of PMR and¹³C NMR spectra and the products of chemical transformation.The materials of this paper were presented at the Second International Symposium on the Chemistry of Natural Compounds (SCNC, Eskiehir, Turkey, October 22–24, 1996).Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 221–231, March–April, 1997.     

Purification and characteristics of the endo-1,4-β--glucanase formed by the hybrid fungusTrichoderma harzianum-G-1

An endo-1, 4--glucanase consisting of a low-molecular-mass enzyme with a molecular mass of 19,862 Da has been isolated for the culture liquid of the hybrid fungusTrichoderma harzianum-G-1.Institute of Microbiology of the Academy of Sciences, Republic of Uzbekistan, Tashkent, fax (3712) 41 71 29. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 908–911, November–December, 1996. Original article submitted September 11, 1996.     

Electronic absorption spectra of rhenium(VII) compounds: The effect of the coordination number

Changes in electronic absorption spectra in the following series: MeRe(L₂)O₃ McReO3 ReO4– ReO₆5–, have been studied in terms of the qualitative MO scheme.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1563–1566, June, 1996.     

Isolation of hispidin from a walnut-tree fungus and its antioxidant activity

An -styrylpyrone derivative — hispidin — has been isolated from a walnut-tree fungus. Its antioxidant activity has been studied inin vitro andin vivo experiments on animals of different ages.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. 1, pp. 34–37, January–February, 1996. Original article submitted November 3, 1995.     

Chemistry of natural compounds and bioorganic chemistry Synthesis of (±)-furodizinin and (±)-furodizin

The racemic forms of natural Omnoterpenoids, (±)-furodizinin and (±)-furodizin, were synthesized by cationic cyclization of the or -furylmethyl derivatives of linalool, geraniol and nerol.A. M. Moiseenkov (1936–1992), an outstanding Russian organic chemist, would have been sixty on July 6, 1996, He contributed significantly to the chemistry of terpenoids. The scientific heritage of A, M. Moiseenkov is rich and diversified. This work is devoted to the walizWon of one of his ideas. For the preliminary communication see Ref. 1.DeceasedTranslated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1842–1847, July, 1996.     

Proanthocyanidins ofPolygonum coriarium III. Structures of proanthocyanidins T1 and T2

The roots ofPolygonum coriarum have yielded two oligomeric proanthocyanidins, T1 and T2, and their structures have been established: 3-O-galloyl-7-O-[O-(6-O-galloyl)--D-glucopyranosyl]-(–)-epigallocatechin-(4-8)-(–)-epicatechin-(4-8)-(–)-epicatechin-(4-8)-(–)-epigallocatechin 3-O-gallate (T1) and (–)-epicatechin-(4-8)-[3-O-galloyl-(–)-epigallocatechin]-(4-8)-(–)-epicatechin-(4-8)-(+)-catechin (T2).The material of this paper were presented at the IInd International Symposium on the Chemistry of Natural Compounds (SCNC, Eskisehir, Turkey, October 22–24, 1996).Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 588–593, July–August, 1977.     

Study of the catechins and proanthocyanidins ofQuercus robur

More than 20 compounds have been isolated from the bark ofQuercus robur. Monomers: (–)-epicatechin, (–)-epicatechin gallate, (+)-catechin, (+)-catechin gallate, (+)-gallocatechin, (–)-epigallocatechin, and (–)-epigallocatechin gallate; dimeric proanthocyanidins: (+)-catechin-(4-8)-(+)-catechin, 3-O-galloyl-(+)-catechin-(4-8)-3-O-galloyl-(+)-catechin, 3-O-galloyl-(+)-gallocatechin-(4-8)-(+)-gallocatechin, (–)-epicatechin-(4-8)-3-O-galloyl-(–)-epigallocatechin gallate, 3-O-galloyl-(–)-epicatechin-(4-8)-3-O-galloyl-(–)-epigallocatechin, 3-O-galloyl-(–)-epigallocatechin-(4-8)-(+)-catechin; and oligomeric proanthocyanidins: D14-D19.Materials presented at the IInd International Symposium on the Chemistry of Natural Compounds (SCNC, Eskiehir, Turkey, October, 22–24, 1996).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. 819–833, November–December, 1997.     

Influence of temperature on quenching of fluorescence in compounds of the coumarin series

A study has been made of the influence of temperature on the quantum yield of fluorescence of 3,4-benzocoumarin in ethanol or n-hexane, in the temperature interval 77–300 K. A mechanism of fluorescence quenching is proposed, consisting of thermal activation of intercombination conversion between neighboring energy levels that differ in orbital nature.Poltava Branch, Academy of Sciences of Engineering Cybernetics of the Ukraine, 3 Koval' Street, Poltava 314601, Ukraine. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 32, No. 4, pp. 247–250, July–August, 1996. Original article submitted September 26, 1995.     

Features of the synthesis of proteins in the digestive organs of animals under the action of some toxic chemicals

The influence on protein synthesis of toxic chemicals in the digestive organs on single and repeated administration has been studied. It has been shown that the actions of Harvade F25, -sum, and T-86 on protein synthesis are different. Toxic chemicals change the levels not only of ribosomal but also of nuclear protein synthesis.The materials of this paper were presented at the Second International Symposium on the Chemistry of Natural Compounds (SCNC, Eskiehir, Turkey, October 22–24, 1996).Tashkent Pediatric Medical Institute. A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 162 70 71. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 205–208, March–April, 1998.     

Unsaponifiable substances of the lipids of the leaves ofHibiscus sp

The unsaponifiable substances of the lipids of the leaves ofHibiscus sp. have been studied. The compositions have been found of seven classes of compounds: hydrocarbons, carotenoids, tocopherols, isoprenols, triterpenols, and phytosterols and their esters.The materials of the paper were presented at the IInd International Symposium on the Chemistry of Natural Compounds (SCNC, Turkey, Eskiehir, October 22–24, 1996).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, Vol. 33, No. 1, pp. 49–51, January–February, 1997.     

Carbohydrate compositions of preparations of fungal origin

The fractional composition of the polysaccharides formed by some local strains of basidial fungi (Panus tigrinus, Pleurotus ostreatus, Fomes formentarius, andPhanarechaeta chrysosporium) in a submerged medium on various plant wastes (spent cottonseed pulp and cottonplant stems) has been investigated. Water-soluble polysaccharides, pectin substances, and hemicelluloses have been isolated from the products synthesized by the fungi, and their qualitative and quantitative monosaccharide compositions have been determined.Materials presented at the Second International Symposium of the Chemistry of Natural Compounds (SCNC, Eskiehir, Turkey, October 22–24, 1996).Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 352–357, May–June, 1977.     

Change of intensity of a1Δg → X3Σ g − transition in oxygen molecule upon interaction with H2, N2, and CS2

The semiempirical MINDO/3 CI method has been used to calculate collision complexes of the oxygen molecule with certain diamagnetic molecules, simulating the effect of solvents in increasing the intensity of the a¹_g X³ _g ^– transition in the oxygen molecule.Cherkassy Engineering Technology Institute, 460 Shevchenko Street, Cherkassy 257006, Ukraine. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 32, No. 3, pp. 143–146, May–June, 1996. Original article submitted July 12, 1995.     

Molecular structure of mixed adsorption layers surfactant—polymer at a liquid—liquid interface

Isotherms of the binding of dodecyl sulfate anions (DDS^–)and Na⁺ counterions during their coadsorption with a nonionic polymer. proxanol (PR). at the interface of dodecane-water emulsions have been measured by conductometry and Na-selective potentiometry. The adsorption of DDS^– and PR is concurrent. The affinity constant of PR to the interface determined by the Langmuir model decreases as the concentration of PR increases, and the surface concentration of DDS^– tends to a nonzero limiting value at high concentrations of PR. The surface (_o) and electrokinetic () potentials at the interface have been determined at various polymer concentrations by the spin probe and electrophoresis methods. The average dielectric permeability and density of polymer segments in We adsorption layer have been determined by ESR. The lower boundary of the hydrodynamic thickness of the polymer adsorption layer at the interface has been estimated from the dependences of _o and on the ionic strength.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1653–1661, July, 1996.     

Triterpene glycosides ofAstragalus and their genins LIII. Chemical transformation of cycloartanes III. Modification of ackendoside D

The 17E- and 17Z- isomers of 3-[O--L-arabinopyranosyl-(12)-ß-D-xylophranosyloxy]-6-(-D-xylopy-ranosyloxy)-25-norcycloart-17-en-16-on-24-oic acid have been synthesized in four stages from askendoside D.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. 4, pp. 565–567, July–August, 1996. Original article submitted January 15, 1996.     

Polysaccharides of saponin-bearing plants VIII. Structural investigation of a glucogalactan from the roots ofAllochrusa gypsophiloides

It has been established that the glucogalactan is a branched polysaccharide, that its main chain consists of -16-bound galactopyranose residues, C-2 atoms of the galactopyranose residues serve as the branching points, and the reducing ends are both galactopyranose and glucopyranose residues.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. 4, pp. 530–533, July–August, 1996. Original article submitted January 9, 1995.     

Synthesis of porphyrins with reactive groups on phenyl rings. 8. Azo dyes on tetraphenylporphyrins

Porphynns having covalently attached residues of azo dyes on the periphery of the molecule have been synthesized by the diazotization of tetraaminophenylporphynns and subsequent azo coupling of the diazonium salts with phenol, and with - and -naphthols. The possibility of - electron interaction of the two chromophoric systems has been studied.Ivanovo State Institute of Chemical Technology, Ivanovo Center, 153460.Translated from Khimiya Geterotsklicheskikh Soedinenii, No. 8, pp. 1045–1049, August, 1996. Original article submitted July 2, 1996.     

Formation of the pyrroline-N-oxide ring by the reaction of isonitrosoketones with enamines and some conversions of the pyrroline-N-oxides obtained

Compounds containing the pyrroline-N-oxide ring are obtained when isonitrosoketones — 2,6-dihydroxyiminocyclohexanone and -isonitrosoacetophenone — react with enamines. The compounds obtained behave as synthetic equivalents of 1,4-dicarbonyl compounds when undergoing reaction with amines, hydrazine, and hydroxylatnine.Novosibirsk Institute of Organic Chemistry, Siberian Section of the Russian Academy of Sciences (SO RAN) Novosibirsk, 630090. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1055–1061, August, 1996. Original article submitted February 28, 1996.     

Synthesis of 2,4-disubstituted pyrimido[4,5-b]-indoles,pyrano[4′,3′:4,5]pyrrolo[2,3-d]pyrimidines and some conversions of pyrimido[4,5-d]indoles

Methods have been developed for the production of 2,4-disubstituted 5,6,7,8-tetrahydro-9H-pyrimido[4,5-b]indoles and pyrano[43:4,5]pyrrolo[2,3-d]pyrimidines. Heterocyclization reactions were carried out on 4-hydrazinopyrimido[4,5-b]indoles.A. L. Mndzhoyan Institute of Fine Organic Chemistry, National Academy of Sciences of the Republic of Armenia, Erevan, 375014. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10. pp. 1413–1416, October, 1996. Original article submitted June 21, 1996.