Steroid compounds of marine sponges. VII. Preparation of derivatives of sokotrasterol and halistanol sulfates and structure-activity interrelationships among these compounds

Five new sulfated derivatives of sokotrasterol and halistanol have been obtained: 24-nor-5-cholane-2,3,6,23-tetraol 2,3,6-tri(sodium sulfate); 24-nor-5-cholane-2,3,6,23-tetraol 2,3,6-tri(sodium sulfate) 23-palmitate; 24,25-dimethyl-5-cholestane-2,3,6-triol 3-(sodium sulfate); 24,25-dimethyl-5-cholestane-2,3,6-triol 6-(sodium sulfate); and 24,25-dimethyl-5-cholestane-2,3,6-triol 2,6-di(sodium sulfate). The inhibiting and membranolytic properties of the polysulfated steroids from sponges and their derivatives have been studied. It has been shown that physiological activity in this series of compounds depends on biphilicity.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 441–445, July–August, 1986.     

Depsipeptides Communication 31. Synthesis of depsipeptides containing α-hydroxy α-amino acid residues

Summary Depsipeptides containing -hydroxy -amino acid residues as hydroxy-acid component were synthesized.Communication 11 of the series -Substituted -Amino Acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 1987–1992, November 1965     

Electrochemical oxidation of tetramethyl esters of α,α,ω,ω-alcaneteracarboxylic acids

Cyclization of esters of butane-1,1,4,4- and pentane-1,1,5,5-tetracarboxylic acids during electrolysis in methanol in the presence of Nal produces, with a yield of 95%, the esters of cyclobutane-1,1,2,2- and cyclopentane-1,1,2,2-tetracarboxylic acids. Under similar conditions, esters of the highest ,,,-alkanetetracarboxylic acids undergo iodation and hydroxymethylation due to electrical oxidation of methanol to formaldehyde. During electrolysis in methanol in the presence of NaOAc, the esters of ,,,-alkanetetracarboxylic acids undergo effective hydroxymethylation, followed by cyclization into substituted five- and six-member lactones, or tetrahydrofurans when structurally possible.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2332–2339, October, 1992.     

On the role of the functional group in determining the strength of hydrophobic interactions in aqueous solutions of α-amino acid derivatives

Calorimetric measurements were carried out at 25°C on binary aqueous solutions containing N-acetyl derivatives of the following -amino acids: glycine, alanine, valine, leucine, norleucine, aspartic acid, glutamic acid, phenylalanine, methionine, asparagine, glutamine, cysteine, histidine, serine. The N-acetyl derivative of the -amino acid proline was also studied. The results obtained have been used to calculate the pairwise enthalpic interaction coefficients and these are compared with results reported in the literature concerning free -amino acids, and their acetylamide derivatives. The coefficients largely increase passing from free amino acids to N-acetyl derivatives. The derivatives of -amino acids bearing unsubstituted alkyl chains present an increased cooperativity of hydrophobic interactions.     

Characterization and determination of someα-amino acids using optical rotatory dispersion spectroscopy

Summary The optical rotatory dispersion spectra of 16-amino acids have been recorded over wave lengths down to 200 nm. The linear relationship between the molecular rotation in 0.1N HCl and the concentration permits the rapid and simple microdetermination of various-amino acids in the range of 0.2 to 500 mg/ml with an average recovery of 98%. The data on the molecular rotation of the various acids and their relation with the nature of the substituent groups are also presented.

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Charakterisierung und Bestimmung einiger -Aminosäuren mit Hilfe der optischen Rotations-Dispersions-Spektroskopie

Zusammenfassung Die Spektren der optischen Rotations-Dispersion von 16-Aminosäuren wurden bei Wellenlängen bis herunter auf 200 nm gemessen. Das lineare Verhältnis zwischen der molekularen Rotation in 0,1N HCl und der Konzentration ermöglicht die rasche und einfache Mikrobestimmung verschiedener-Aminosäuren zwischen 0,2 und 500 mg/ml mit durchschnittlich 98% Genauigkeit. Die Daten der molekularen Rotation der verschiedenen Aminosäuren und deren Abhängigkeit von der Art der Substituenten-Gruppen wurden ebenfalls angegeben.

     

Quinazolines X. Synthesis of 6,6'-methylenebisdeoxyvasicinone and its homologs

Summary 6,6-Methylenebisdeoxyvacisinone and its homologs have been synthesized by the reaction of methylenebisanthranilic acid with lactams (-butyrolactam, -valerolactam, -caprolactam, and -chloro- and ,-dichloro--caprolactams). The condensation of anthranilic acid and its derivatives (4-nitro-, 5-bromo-, 5-iodo-, and 5-nitroanthranilic acids) with ,-dichloro--caprolactam has given seven-membered analogs of deoxyvasicinone containing two chlorine atoms in the polymethylene ring.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 544–547, July–August, 1977.     

Polyhydroxylated steroids from the starfishPatiria pectinifera

By chromatography on Polikhrom-1, silica gel, and Florisil, an ethanolic extract of the digestive organs of the starfishPatiria pectinifera has yielded the steroid polyols 5-cholestan-3,6,8,15,16,26-hexaol and 5-cholestan-3,4,6,7,8,15,16,26-octaol 6-(sodium sulfate). The structures of the compounds have been shown by spectral characteristics and chemical transformations.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 738–741, November–December, 1984.     

Charge-transfer Interaction: A Driving Force for Cyclodextrin Inclusion Complexation

PM3 calculations were performed on the complexation of -cyclodextrin (-CD) with nitrobenzene, benzoic acid, benzoate anion, 4-nitrophenol, and 4-nitrophenolate anion. The results, in agreement with the experimental observations, indicated that the complex -CD-benzoic acid was more stable than -CD-nitrobenzene, and -CD-4-nitrophenolate was more stable than -CD-4-nitrophenol. Frontier orbital analysis suggested that charge-transfer interaction led to such behaviors, and hence constituted a nontrivial driving force in the molecular recognition of -CD.     

Electroreduction of α-glucose on CNT/graphite electrode modified by Zn and Zn–Fe alloy

Electroreduction of -glucose to form sorbitol on Zn/CNTs and Zn alloy/CNTs electrodes has been investigated in this paper. Carbon nanotubes (CNTs) used in this paper are grown directly on graphite disks by chemical vapor deposition. Zn and Zn alloy are electrodeposited on the activated CNTs/graphite electrode by pulse galvanostatic method. The micrographs of Zn/CNTs and Zn alloy/CNTs electrodes are characterized by scanning electron microscopy. The results show that the current efficiency of -glucose reduction on CNTs electrodes is much better than that on flat Zn electrodes. The order of the current efficiency on different electrodes is as follows: Zn/CNT (0.58) Zn–Fe/CNT (0.57)>Zn–Ni/CNT (0.43) Zn/graphite (0.42)>Zn (0.40). It indicates that CNTs have good potential application in electrosynthesis. Additionally, effects of some operating parameters, such as pH, temperature and -glucose concentration, on the current efficiency of -glucose reduction are also discussed.     

Resolution of amino acids on optically active stationary phase by gasChromatography

Summary The various enantiomeric esters of TFA--amino acid may be separated directly by gas chromatography on optically active stationary phase. In this work we investigated the resolution of relatively volatile amino acids (alanine, -amino-n-butyric acid, valine, threonine, allo-isoleucine, isoleucine, norvaline, leucine, proline, norleucine, serine) and less volatile amino acids (cysteine, aspartic acid, methionine, phenylalanine, glutamic acid) on a glass capillary column coated with N-caproyl-L-valyl-L-valine cyclohexyl ester.     

Versuche zur Darstellung von 4- Vinyltriarylmethylradikalen

Zusammenfassung Beim Versuch zur Darstellung von 4-Vinyltriarylmethylradikalen durch Umsetzung von 4-Vinyltriarylmethylchloriden mit Metallen entstehen intermediär Radikale, die jedoch sofort in einer mesomeren Form weiterreagieren, wobei Polymere mit Chinodimethan-Strukturen entstehen. Als Modell hierfür dient das gelbe 1,4-,-Diphenylchinodimethan, das aus 4-Methyltriphenylmethylchlorid und Pyridin in Lösung erhalten werden kann; es ist nicht in fester Form isolierbar und polymerisiert sich leicht zu Poly-1,4-,-diphenylxylylen, das durch IR- und NMR-Spektren identifiziert wird.

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The attempted preparation of 4- vinyltriarylmethyl radicals

The attempted preparation of 4-vinyltriarylmethyl radicals by interaction of 4-vinyltriarylmethylchlorides with metals yielded unstable radical intermediates immediately undergoing further reaction to give polymers of a quinodimethane structuretype. 1,4-,-Diphenylquinodimethane, obtained from 4-methyltriphenylmethyl chloride and pyridine in solution, was used as a model compound. It cannot be isolated and readily polymerizes to give poly-1,4-,-diphenylxylylene identified by IR and NMR spectra.

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Mit 2 Abbildungen     

Triterpene saponins fromThalictrum minus. V. Structure of thalicoside B

The epigeal part ofThalictrum minus L. has yielded a new bidesmoside — thalicoside B — which has the structure of oleanolic acid 28-O--D-glucopyranoside 3-O-[O--L-rhamnopyranosyl-(1 2)-O--D-glucopyranosyl-(1 3)--L-arabinopyranoside].Irkutsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR; A. A. Zhdanov Irkutsk State University; and Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 670–676, September–October, 1985.     

Membrane transport of dicarboxylic and α-hydroxy carboxylic acids induced by α-amino phosphonates

New -amino phosphonates containing different alkyl and aryl substituents at the -carbon atom were synthesized in high yields by the Kabachnik—Fields and Pudovik reactions. These compounds were studied as carriers of several -hydroxy carboxylic and dicarboxylic acids through liquid impregnated membranes. These -amino phosphonates studied are capable of molecular recognition of oxalic acid among structurally similar -hydroxy carboxylic and dicarboxylic acids. The efficiency and selectivity of mass transfer of oxalic acid increase with an increase in the lipophilicity of the -amino phosphonate.     

Determination of the absolute configuration of carbohydrate components of flavonol glycosides of the chestnut

Conclusions On the basis of the rates of their acid hydrolysis, their optical activities, and their IR spectra, it has been established that the glycosides ofAesculus hippocastanum L. are (SK-1) 3--L-arabofuranosyloxy-5,7,4-trihydroxyflavone, (SK-2) 3--L-rhamnofuranosyloxy-5,7,4-trihydroxyflavone, (SK-3) 3--L-arabofuranosyloxy-5,7,3,4-tetrahydroxyflavone, and (SK-4) 3--L-rhamnofuranosyloxy-5,7,3,4-tetrahydroxyflavone.The glycoside SK-3 is identical with avicularin isolated from the leaves ofPsidium quajava [5]. The complete structures of the other three glycosides have been established for the first time.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 1, pp. 5–7, 1969     

3-Äthyl-3-phenylpiperidindion-(2,4) und 3-Äthyl-3-phenylpyrrolidindion-(2,4) aus α-Phenylacetessigester

Zusammenfassung -Äthyl--phenylacetessigester (I) wurde bromiert, der resultierende -Bromacetylphenylbuttersäureester (II) mit NaBH₄ zum Bromhydrin (III) reduziert. Umsetzung mit KCN lieferte den -Cyan--hydroxy--phenyl--äthylbuttersäureester (IV), der in Gegenwart vonRaney-Ni zu den beiden stereoisomeren 3-Äthyl-3-phenyl-4-hydroxypiperidonen-(2) (Va) und (Vb) reduziert wurde. Oxydation von (Vb) mit CrO₃ lieferte das 3-Äthyl-3-phenylpiperidindion-(2,4) (VI).     

Synthesis of α,α′-bisdialkylphosphonoisopropylnitroxyls

Conclusions Some,-bisdialkylphosphonoisopropylnitroxyl radicals were obtained by the thermolysis of dialkyl -nitrosoisopropylphosphonates and isolated in the pure state.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1867–1868, August, 1979.     

Über die Darstellung der α-Acylamidoketone aus α-Aminosäuren

Zusammenfassung Kurz- und langkettige -Aminosäuren (bis zu 18 C-Atomen) und Carbonsäureanhydride (von Säuren bis zu 18 C-Atomen) wurden in Pyridin der klassischenDakin-West-Reaktion unterworfen. Auf einfache Weise und in befriedigenden Ausbeuten wurde eine Reihe von -Acylamidoketonen (1–21) mit Kettenlängen bis zu 25 C-Atomen dargestellt. Zur Charakterisierung wurden die Ketone in 2,4-Dinitrophenylhydrazone und Oxime übergeführt.

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The classicalDakin-West reaction was applied to both short- and long-chain -amino acids (up to 18 C-atoms) and carboxylic acid anhydrides (acids containing up to 18 C-atoms). Thus, a series of -acylamido ketones (1–21) with a chain length of up to 25 C-atoms were readily prepared in satisfactory yields. For characterization the ketones were converted into their 2,4-dinitrophenylhydrazones and oximes.

     

Isomerization of (Het)arylbenzoins in Basic Media

The isomerization of the hetaryl analogs of unsymmetrical benzoins on heating in basic media is a convenient preparative method for the production of -hydroxyacyl derivatives of -excessive heterocycles. The motivating force here for the isomerization is the formation of a thermodynamically more stable product. It was established that isomerization is promoted by increase in the difference between the electron-donating characteristics of the (het)aryl residues