New polyhydroxysteroids from the far-eastern starfish Henricia sp.

From the far-eastern starfishHenricia sp. we have isolated and characterized the new polyhydroxysteroid (24S)-5-cholestane-3,4,6,8,15,24-hexaol and three new glycosides: (24S)-5-cholestane-3,4,6,8,15,24-hexaol 3-O-(2,4-di-O-methyl--D-xylopyranoside) (henricioside H₁), 24-methyl-5-cholesta-4,22E-diene-3,6,8,15,16,26-hexaol 3-O-(2,3-di-O-methyl--D-xylopyranoside) (henricioside H₂), and the 22,23-dihydro derivative of henricioside H₂ (henricioside H₃).Pacific Ocean Institute of Bioorganic Chemistry, Far-Eastern Scientific Center, Russian Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 249–253, March–April, 1993.     

Design criteria for molecular mimics of fragments of the β-turn. 1. Cα atom analysis

Peptides represent an extensive class of biologically active molecules. They may be used as leads in the development of novel therapeutic agents provided the pharmacophoric information present within them can be translated into non-peptide analogs that lack the peptide backbone and are stable to proteolysis. This is the rationale for peptidomimetic drug design. Frequently, the -turn has been implicated as a conformation important for biological recognition of peptides. Empirical evidence from known peptidomimetics, coupled with a theoretical model of peptide binding and the observation that glycine and proline residues are common within the -turn, has suggested the design of molecules to mimic placement of between two and four of the side-chains. The moderate number of different -turn conformations, combined with the combinatoric nature of side-chain selection complicates the procedure. In this paper, cluster analysis has been used to classify the arrangement of C_{_} atoms about the various fragments of the -turn. Recombination of the observed patterns provides a general model for the -turn which may be used as an effective screen for potential peptidomimetic scaffolds in chemical databases.     

Structural Studies on Host + Guest Recognition Sensory Systems

Rhodamine B-ethylenediamine--cyclodextrins (RhB--CDen) and rhodamine B--cyclodextrins (RhB--CD) can form inclusive complexes with many guest molecules, a reaction which can be used as a nucleic acid probe. In this paper, the most stable conformations of RhB--CDen and RhB--CD have been determined by fluorescence experiments and analyzed by molecular modeling simulation. The interaction between RhB--CDen and two guest molecules, 1-borneol and cyclohexanol, has also been investigated. The results showed that RhB--CDen has a stronger interaction with 1-borneol than with cyclohexanol. Borneol could push the three aromatic-rings of rhodamine B out of the CD cavity, while the cyclohexanol could not. The interactive sites of host and guest are also presented.     

Triterpene glycosides from Pulsatilla chinensis

Four triterpene glycosides were isolated from the roots of Pulsatilla chinensis (Bunge) Regel (Ranunculaceae). Two new glycosides, chinensiosides A (1a) and B (2), were identified as 3-O-[-L-rhamnopyranosyl-(12)--L-arabinopyranosyl]-28-O-[-L-rhamnopyranosyl-(14)--D-glucopyranosyl-(16)--D-glucopyranosyl]-3,23-dihydroxylup-20(29)-en-28-oic acid and 3-O-{-L-rhamnopyranosyl-(12)-[-D-glucopyranosyl-(14)]--L-arabinopyranosyl}-28-O-[-L-rhamnopyranosyl-(14)--D-glucopyranosyl-(16)--D-glucopyranosyl]-3,23-dihydroxylup-20(29)-en-28-oic acid. The other two glycosides were identified as previously known hederasaponin C (3) from Hedera helix and glycoside III (4) from Pulsatilla cernua.     

Structure of psolusoside a — The main triterpene glycoside from the holothurianPsolus fabricii

The structure of psolusoside A — the main component of the glycosidic fraction from the holothurianPsolus fabricii Duben et Koren — has been determined as 3-0-[0-(3-0-methyl-6-0-sulfato--D-glucopyranosyl)-(1 3)-0-(6-0-sulfato--D-glucopyranosyl)-(1 4)-0--D-quinovopyranosyl-(1 2)--D-xylopyranosyloxy]holosta-9(11),25-dien-16-one.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 212–217, March–April, 1985.     

Conformational Heterogeneity of a Tripeptide in the Solid State and in Solution: Characterization of a γ-Turn Containing Incipient Hairpin in Solution

A terminally blocked tripeptide Boc--Ala-Aib--Ala-OMe 1 with noncoded amino acids forms a novel type of hairpin structure containing a -turn instead of a conventional -turn in the central loop region in solution. This new type structural motif was characterized by NMR and restraint molecular dynamics simulation study. In the solid state peptide 1 adopts an extended backbone conformation and self-assembles to form supramolecular -sheet.     

Structures of some lilioglycosides from the bulbs ofLilium regale

Six steroid glycosides, which gave been called lilioglycosides B, C, E, F, H, and I have been isolated from fresh bulbs ofLilium regale Wills. The structure of each compound has been determined by methods of physicochemical analysis. This is the first time that lilioglycosides B, C, H, and I, have been described; they are, respectively: (25S)-spirost-5-ene-3,27-diol3-O--D-glucopyranoside; (25R)-spirost-5-ene-3,27-diol3-O--D-glucopyranoside27-(3-hydroxy-3-methylglutarate); (25S)-spirost-5-ene-3,27-diol3-O-{[O--L-rhamnopyranosyl-(12)],[O--D-glucopyranosyl-(13)]--D-glucopyranoside}; and (25S)-spirost-5-ene-3,27-diol 3-O-{[O--L-rhamnopyranosyl-(12)],[O--D-glucopyranosyl-(13)]-O--D-glucopyranoside} 27-[(S)-3-hydroxy-3-methylglutarate].Institute of Genetics, Academy of Sciences of the Republic of Moldava, 2002, Kishinev, ul. Padurilor, 20. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 841–847, November–December, 1997.     

Steroid saponins and sapogenins ofAllium. XVII. The structure of karatavioside C

A new furostanol glycoside — karatavioside C (I) has been isolated from a methanolic extract of the inflorescences ofAllium karataviense Rgl. (family Liliaceae). By the complete acid hydrolysis, enzymatic hydrolysis, methylation, and reduction of compound (I), and also by the reduction of yuccagenin (II), the structure of the glycoside (I) has been established as 25(R)-furost-5-ene-2, 3, 22, 26-tetrao] 26-0--D-glucopyranoside 3-0-{[0--D-glucopyranosyl-(12)][0--D-xylopyranoside-(13)]-0--D-glucopyranosyl-(14)--D-galactopyranoside.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 355–359, May–June, 1980.     

Synthesis and Characterization of Silica Gels Functionalized with Monochlorotriazinyl β-Cyclodextrin and their Sorption Capacities towards Organic Compounds

Different supports, containing a new derivative of-cyclodextrin – monochlorotriazinyl-cyclodextrin (-CDMCT) – used forthe reduction of pollutants in waste water, have beenprepared. They are based on silica gel, initially eithercoated with polyethyleneimine (PEI) or grafted with3-aminopropyltrimethoxysilane, functionalized in asecond step with -CDMCT. In order to obtainsorbents with high -cyclodextrin content andmaximum accessibility of the -CD cavity, thefuntionalization was studied while varying experimentalconditions. Thermogravimetry, Raman spectroscopy,specific surface area and pore size distribution were usedfor the characterization of supports. Sorption experimentsshow that these sorbents have sorption capacities towardssome organic pollutants. The mechanism of sorption is bothphysical adsorption in the polymer network (for supportsobtained by coating) and/or the formation of an inclusioncomplex between -CDMCT and guest molecules.     

Triterpene glycosides of Pulsatilla dahurica structures of glycosides A,B, C,and D

The isolation of four triterpene glycosides from the roots of the dahurian anemonePulsatilla dahurica (Fisch. ex DC) Spreng, is described together with their identification, on the basis of chemical transformations, spectral characteristics, and literature analogies, as hederagenin 3-O--L-arabinoside, hederagenin 3-O-[O--D-glucopyranosyl-(12)--L-arabinopyranoside], hederagenin 3-O--L-arabinopyranoside 28-O-[O--L-rhamnopyranosyl-(14)--D-glucopyranosyl-(16)--D-glucopyranoside], and hederagenin 3-O-[O--D-glucopyranosyl-(14)--L-arabinopyranoside] 28-O-[O--L-rhamnopyranosyl-(14)--D-glucopyranosyl-(16)--D-glucopyranoside].Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, Nos. 3,4, pp. 349–356, May–August, 1992.     

Über Heterocyclen, 15. Mitt.

Zusammenfassung Bei der Umsetzung von Vinylphenylketonen mit Harnstoffen oder Thioharnstoffen entstehen 2-Oxo- bzw. 2-Thionotetrahydropyrimidine und 2-Oxo- bzw. 2-Thiono-5-(-benzoyläthyl)-6-phenyltetrahydropyrimidine; -Benzoyläthyldimethylamin und analoge Basen geben mit Thioharnstoffen nur 5--Benzoyläthylderivate. 2-Oxo- und 2-Thiono-6-phenyltetrahydropyrimidine sind in der Kernstelle 5 alkylierbar brw. aminoalkylierbar.

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Vinyl phenyl ketones react with ureas or thioureas to 2-oxo-or 2-thionotetrahydropyrimidines and 2-oxo- or 2-thiono-5-(-benzoylethyl)-6-phenyltetrahydropyrimidines; -benzoylethyldimethylamines and analogous compounds give with thiocarbamides 5--benzoylethyl derivates. 2-oxo- and 2-thiono-6-phenyltetrahydropyrimidines react with 1-phenyl-2-propene-1-ones, -benzoylethylamines resp. formaldehyde and amines to 5-alkyl products.

     

Triterpene glycosides ofAstragalus and their genins. XV. Cyclosiversiosides B and D fromAstragalus basineri

Two new glycosides have been isolated from the roots of the plantAstragalus basineri Trautv. — cyclosiversiosides B and D. It has been shown that cyclosiversioside B is cyclosiversigenin 3-O-(2,3-di-O-acetyl--D-xylopyranoside)-6-O--D-glucopyranoside. Cyclosiversioside D is cyclosiversigenin 3-O-(2-O-acetyl--D-xylopyranoside)-6-O--D-glucopyranoside.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 188–191, March–April, 1984.     

Triterpene glycosides ofHedera taurica XVI. Structures of glycosides St-A, St-B1, St-B2, St-C, St-D1, St-D2, St-E, St-F1, and St-F2 from the stems of Crimean ivy

From the stems of Crimean ivyHedera taurica Carr. (fam. Araliaceae) we have isolated previously known glycosides of oleanolic acid — the 3-O-[O--L-rhamnopyranosyl-(12)--L-arabinopyranoside], the 3-O--D-glucopyranuronoside, and the 3-O-[O--D-galactopyranosyl-(12)--D-glucopyranuronoside]; known glycosides of hederagenin — the 3-O--L-arabinopyranoside, the 3--D-glucopyranoside, the 3-O-[O--D-glucopyranosyl-(12)-O--L-arabinopyranoside], and the 3-O--D-glucopyranuronoside; and also the new triterpene glycoside St-D₂, hederagenin 3-O-[O--L-rhamnopyranosyl-(12)--D-glucopyranoside].Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 411–416, May–June, 1997.     

Some Pharmaceutical Properties of a New Branched Cyclodextrin, 6-O-α-(4-O- α-D-Glucuronyl)-D-glucosylβ-cyclodextrin

Some physicochemical and biological properties of a new branched cyclodextrin, 6-O--(4-O--d-glucuronyl)-d-glucosyl--cyclodextrin GUG--CyD) were investigated. Further, theinteraction of GUG--CyD with several drugs was studied by the solubility and spectroscopic methods, and compared with those of parent -CyD and 6-O--maltosyl--CyD(₂--CyD).The hemolytic activity of GUG--CyD on rabbit erythrocytes was lower than those of -CyD and ₂--CyD. GUG--CyD and ₂--CyD showed negligible cytotoxicity on Caco-2 cells up to at least 0.1 M. The inclusion ability of GUG--CyD to neutral and acidic drugs was comparable to or slightly smaller than those of -CyD and ₂--CyD, probably because of a steric hindrance of the branched sugar. On the other hand, GUG--CyD showed greater affinity for the basic drugs, compared with -CyD and ₂--CyD, owing to the electrostatic interaction of its carboxylate anion with positive charge of basic drugs. Thus GUG--CyD may be useful as a safe solubilizing agent particularly for basic drugs.     

Effect of acid-base properties of oxide catalysts in the oxidative dehydrodimerization of olefins

The dependence of the activity of tin-containing oxide catalysts on their basicity and acidity has been examined. The rate of oxidative dehydrodimerization of olefins is shown to be determined by the mobility of allyl compounds depending on the catalyst acid properties.

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Steroids of the furostan and spirostan series from Nolina microcarpa II. structures of nolinospiroside D and nolinofurosides D, E, and F

Proofs are given of the structures of two new glycosides of the furostan series isolated from the leaves of the plantNolina microscarpa S. Wats. (family Dracaenaceae). Nolinofuroside D is (25S)-furost-5-ene-1,3,22,26-tetraol 1-O--D-galactopyranoside 26-O--D-glucopyranoside (I), and nolinofuroside F is (25S)-furost-5-ene-1,3,22,26-tetraol 1-O--D-fucopyranoside 26-O--D-glucopyranoside 3-O--L-rhamnopyranoside (VII). The latter was characterized as its 22-O-methyl ether (VIII). Nolinofuroside E (IV) has the structure of (25S)-furost-5-ene-1,3,22,26-tetraol 26-O--glucopyranoside 1-O-[O--L-rhamnopyranosyl-(12)--D-fucopyranoside], which followed from the structure of the fermentation product (VI). The products of the fermentation of the above-named compounds were present in the plant in only trace amounts. Only one of them — nolinospiroside D (III) — has not been described previously. This monoside of the spirostan series is (25S)-spirost-5-ene-1,3-diol 1-O--D-galactopyranoside.M. V. Frunze Simferopol' State University. Institute of Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 678–686, September–October, 1991.     

Polyhydroxysteroids from the Far-Eastern starfishCtenodiscus crispatus

Four new polyhydroxysteroids, 5-cholesta-3,5,6,15,16,25,26-heptaol, 24-ethyl-5-cholesta-3,5,6,15,28,29-heptaol-29-sulfate, (22E)-24-methyl-5-cholest-22-ene-3,5,6,15,25,26-hexaol-26-sulfate, 24-propyl-5-cholesta-3,5,6,8,15,28,29-heptaol, and the known 5-cholesta-3,5,6,15,16,26-hexaol, have been isolated from the starfishCtenodiscus crispatus.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1821–1825, October, 1994.     

Gitoxigenin glycosides

Summary Three cardiac glycosides have been synthesized from gitoxigenin and D-glucose: gitoxigenin 3-O--D-glucopyranoside, gitoxigenin 16 -O- -D-glucopyranoside, and gitoxigenin 3, 16-di-O- -D-glucoside. The first glycoside, obtained with a yield of 49% on the weight of the initial aglycone, possesses a fairly high biological activity (0.25 mg/kg), while the other two, formed in a yield of about 0.3%, do not possess the action on the heart that is specific for the cardenolides.Khar'kov Chemical and Pharmaceutical Scientific-Research Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 45–49, January, 1971.     

Isoflavones of the roots of Lupinus luteus

Conclusions For the first time in the isoflavone series, a compound which has the structure of 5,7-dihydroxy-3,4-methylenedioxyisoflavone (3,4-methylenedioxyorobol) and two of its glucosides — 3,4-methylenedioxyorobol 7-O--D-glucoside and 3,4-methylenedioxyorobol 7-O--D-glucosylglucoside — and also a genistein C-monoglucoside, have been described. The isoflavones were isolated from the roots ofLupinus luteus L. by preparative chromatography on paper and on columns of polyamide. In addition, the previously known genistein, genistein 7-O--D-glucoside (genistin), and genistein 7-O--D-glucosylglucoside have been obtained.V. F. Kuprevich Institute of Experimental Botany, Academy of Sciences of the Belorussian SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 162–166, March–April, 1974.     

Über die Darstellung von 3β, 16α-und 3β, 16β-Diacetoxy-5α-pregnan-20-on

Zusammenfassung Die Synthese von 3, 16-Diacetoxy-5 -pregnan-20-on (VI) aus 3-Acetoxy-5 -pregn-16-en-20-on und eine verbesserte Darstellung von 3, 16-Diacetoxy-5 -pregnan-20-on (III) aus 3-Acetoxy-pregna-5, 16-dien-20-on werden beschrieben.