Regioselective synthesis of α- and α'-sulfur-containing ethyl esters of dehydrodesthiobiotin

Conclusions The ethyl esters of- and'-oxodehydrodesthiobiotin when reacted with thioacetic acid in the presence of BF₃ etherate respectively give the ethyl esters of-thiooxo- and, -diacetytmercaptodehydrodesthiobiotin.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 954–956, April, 1978.     

Thermal decomposition of phosphorylated hemimercaptals

Conclusions The reaction of diphenylchlorophosphine with ,,-trichloro--hydroxyethyl ethyl sulfide in the presence of triethylamine leads to the formation of -ethylthio-,,-trichloroethyl diphenylphosphonite. The reaction of diphenylchlorophosphine with dimethyl -hydroxy--propylthiophosphonate in the presence of triethylamine gives -propylthio--dimethylphosphonoethyl diphenylphosphonite. The phosphorylated hemimercaptals obtained are thermally unstable and decompose to S-alkyl diphenylthiophosphonites and the corresponding carbonyl compounds.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2619–2621, November, 1985.     

A further study of the substrate specificity in the reduction of 20-oxosteroids with a culture ofActinomyces roseochromogenus

Conclusions A culture ofActinomyces roseochromogenus ATCC 3347 reduces 17-hydroxy- and 16, 17-epoxy-20-oxopregnenes to the corresponding 20-alcohols, but is incapable of reducing 17-acetoxy-, 17-methyl-, and 16-methylprogesterones or 17-unsubstituted 20-oxopregnenes. The results obtained show that the presence of the side chain in a conformation favorable for the formation of 20-alcohols in the reduction of 20-oxosteroids with complex metal hydrides is in itself insufficient for the reduction of the 20-oxosteroids by a culture ofActinomyces roseochromogenus, which also reduces the 20-oxo group of 17-pregnenes.Khimiya Prirodnykh Soedinenii, Vol. 6, No. 1, pp. 38–47, 1970     

Complex polarizability as used to analyze dielectric relaxation measurements

The effect of representing dielectric properties in terms of the complex polarizability ^c = – i is examined. Loss curves ( and tan ) are shifted towards higher frequencies, revealing the existence of new relaxations and allowing the clarifications of ones already known. We have calculated the shift ratios (at maximum or tan )/ (at maximum or tan ) from the more conventional empirical equations representing the dielectric behavior. Some examples are given.     

Ru(III)-catalyzed oxidation of acetanilide, o-chloroacetanilide, p-chloroacetanilide and p-methylacetanilide by sodium perioda'te at pH 4

The order with respect to [Ru(III)] and [substrate] is unity in each while zero order with respect to [IO ₄ ^– ] has been observed. Variation of solvent composition has no pronounced effect on the rate. A plausible mechanism is suggested.

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[Ru(III)] [] , [IO ₄ ^– ] . . .

     

Ultrasonic extraction followed by sulfuric acid silica gel cleanup for the determination of α-hexachlorocyclohexane enantiomers in biota samples

Interest in the analysis of -hexachlorocyclohexane (-HCH) enantiomers as an alternative or complementary approach to elucidating isomer ratios of /-HCH has grown in recent years because it can provide useful information to evaluate the influence of different degradation and transformation processes. In this paper, a simple and rapid method for the determination of -HCH enantiomers in biota samples is described. The method developed consists of ultrasonic extraction, sulfuric acid silica gel cleanup, solid-phase extraction (SPE) column fractionation, and final determination with chiral high-resolution gas chromatography. Ultrasonic extraction greatly shortens the extraction process time, and the sulfuric acid silica gel and SPE cleanup perfectly remove lipids and other interference compounds in the lipid-rich samples. The method is found to be simple, less time-consuming, and easy to operate, thus providing a useful alternative method to assess the enantioselective breakdown of -HCH in biota system.     

13C NMR spectra of acetylated methyl glycosides of monosaccharides

Summary A comparative discussion of the signals in the¹³C NMR spectra of acetylated methyl - and -D-xylopyranosides, - and -D-glucopyranosides, - and -D-galactopyranosides, - and -L-arabinopyranosides, - and -L-fucopyranosides, and - and -L-rhamnopyranosides and of the corresponding free glycosides has shown a similarity of the effects of substitution at C₅ with a longer-range nature of these effects in the case of the acetylated glycosides.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center of the Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 6–8, January–February, 1979.     

Etude thermocinetique des phenomenes de dissolution par calorimetrie Calvet a haute temperature dissolution d'alumines dans la cryolithe

Although the thermal curves given by a Calvet calorimeter can be considered representative of the thermogenesis of slow phenomena, this is not the case for the brief thermal effects of dissolution, for example, which need typically no more than twenty minutes. At high temperatures, a numerical method of deconvolution of the recorded signal was applied in order to obtain the proper thermogenesis of the phenomenon. The time constants of the calorimeter were determined from thermal effects due to the dropping into the bath of small quantities of silver and platinum. The method was applied to the dissolution of a-alumina and industrial aluminas in cryolithic baths at 1290 K. The different kinds of alumina could be classified according to their time of dissolution. The dependence of the alumina concentration of the bath on the dissolution rate was also investigated.

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Zusammenfassung Die mittels eines Calvet-Kalorimeters erhaltenen thermischen Kurven sind zwar repräsentativ für langsame Phänomene der Thermogenese, nicht jedoch für kurzzeitige thermische Effekte wie z. B. ein Inlösunggehen, das im allgemeinen nicht mehr als 20 Minuten dauert. In solchen Fällen wurde für hohe Temperaturen eine numerische Methode zur Zerlegung des registrierten Signals angewandt, um die reine Thermogenese der Phänomens zu erhalten. Zeitkonstanten des Kalorimeters wurden aus den thermischen Effekten bestimmt, die beim Einwerfen kleiner Silber- und Platinmengen in das Bad auftraten. Die Methode wurde zur Untersuchung der Auflösung von -Aluminiumoxid und industriellen Aluminiumoxidproben in Kryolithbädern bei 1290 K herangezogen. Die verschiedenen Aluminiumoxidarten konnten nach der zur Auflösung notwendigen Zeit klassifiziert werden. Die Abhängigkeit der Auflösungsgeschwindigkeit von der Aluminiumoxidkonzentration des Bades wurde ebenfalls untersucht.

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, , . , , , , . , . , . - 1290 K. . .

     

Study of the rotational isomerism about the C-O bond in six-membered secondary-tertiary diols

We have determined the spectroscopic characteristics, the dipole moments, and the Kerr constants of the stereoisomers of the secondary-tertiary diols of the cyclohexane and bicyclo [4.1.0]pentane series: 3,4-dihydroxy-3-carane (I), 3,4-dihydroxy-3-methylnorcarane (II), 3,4-dihydroxy-3-methylnorcarane (III), 4, 5-dihydroxy-3-methylcyclohexene (IV), 3,4-dihydroxy-3-carane (V), 3,4-dihydroxy-3-methylnorcarane (VI), 3, 4-dihydroxy-3-carane (VII), and 3,4-dihydroxy-4-methyl-3-carane (VIII). It was found that the cis diols are more polar than their trans isomers. It was shown by electrical and electrooptical methods that rotamers with a gauche orientation with respect to the tertiary C-O are stable relative to those containing the diol at the ordinary C-C bond of the ring.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 619–625, March, 1991.     

Extraction of Polonium from Aqueous α-Hydroxyisobutyric Acid Solutions Using Dioctyl Sulphide, Cyanex 272, Cyanex 301 or Cyanex 302 in Toluene

A study of the extraction of polonium from aqueous solutions containing -hydroxyisobutyric acid (-HIBA) was performed with four different extractants, di-n-octyl sulphide (DOS), Cyanex 272, Cyanex 301 and Cyanex 302, dissolved in toluene. The extracted complex for DOS at low -HIBA concentrations is most likely PoO(-HIB)₂·2DOS, while at higher -HIBA concentrations there seems to be a solvating effect implicating an extracted complex of the type PoO(-HIB)₂(-HIBA)₂·2DOS. For the extraction of polonium with Cyanex 272 the results are inconclusive. The extracted complex is either PoOA₂ or PoO(-HIB)₂·2HA. For extraction with Cyanex 301 or Cyanex 302 the major extracted species does not contain any -HIBA molecules. The neutral species in both cases is PoOA₂, extracted at low extractant concentrations, while at higher extractant concentrations a complex of the type PoOA₂·xHA is extracted. The extraction of polonium increases in the order Cyanex 272 < DOS < Cyanex 302 < Cyanex 301.     

Steroids of the spirostan and furostan series from plants of the genus Allium. XXI. Structure of alliospiroside a and alliofuroside a from Allium cepa

Two new steroid glycosides have been isolated from the generative organs (pericarps and peduncles) ofAllium cepa L.: alliospiroside A and alliofuroside A. According to chemical transformations and spectral characteristics, alliospiroside A has the structure of (25S)-spirost-5-ene-1,3-diol 1-O-[O--L-rhamnopyranosyl-(1 2)--L-arabinopyranoside]. The structure of (25S)-furost-5-ene-1,3,22,26-tetraol 20-O--D-glucopyranoside 1-O-[O--L-rhamnopyranosyl-(1 2)--L-arabinopyranoside] has been established for alliofuroside A.Institute of the Chemistry of Plant Substances of the Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 188–196, March–April, 1986.     

GC-MS characterization and quantification of sterols and cholesterol oxidation products

Summary A GC-MS method has been studied for characterization and quantification of phytosterols, cholesterol and cholesterol oxidation products. Baseline separations have been achieved between cholesterol, cholesterol 5-6-epoxide, 5-cholestene-3-ol-7one (7-keto-cholesterol), cholestene-3-5-6-triol, 5-cholestene-3-25-diol (25-hydroxycholesterol), 5-cholestene-3-20-diol (20-hydroxycholesterol), 5-cholestene-3-7-diol (7-hydroxycholesterol) and 5-cholestene-3-19-diol (19-hydroxycholesterol) as well as between -cholestane, cholesterol, stigmasterol, campesterol and -sitosterol. Excellent linearity of response has been obtained permitting reliable quantification. The characterization of each derivatized sterol has been performed by mass-spectrometry. The results confirm the utility of combined gas chromatography-mass spectrometry in the analysis and characterization of sterols and cholesterol oxidation products.     

Alpha-counting with a solid scintillator

Alpha-counting with a commercial solid scintillator, LumaCap, in a liquid scintillation analyzer, has been studied. It has been found that LumaCap produces much more fluorescence than normal cocktail does, upon the reaction of -particles. Pulse height and pulse shape analysis have been applied for - and -discrimination successfully. This solid scintillator provides a useful means for -counting in normal liquid scintillation instruments.     

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.     

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.     

<Superscript>1</Superscript>H and <Superscript>13</Superscript>C NMR spectra of some drimanic sesquiterpenoids

One- and two-dimensional homo- and heteronuclear correlation proton, carbon, proton—proton, and proton—carbon NMR spectra of fifteen drimanic sesquiterpenoids: 11,12-dibromodrima-5,8-dien-7-one, drim-8-en-7-one, 11-hydroxydrim-8-en-7-one, 11,12-dihydroxydrim-8-en-7-one, 11-hydroxy-11,12-epoxydrim-8-en-7-one, 11-hydroxy-11,12-epoxydrim-8-en-7-one, 8,9-epoxydriman-7-one, 8,9-epoxydriman-7-ol, 11,12-diacetoxydrim-8-en-7-ol, drimane-7,8,11-triol, 7,8-isopropylidenedioxydriman-11-al, 9, 11-dihydroxydrim-7-en-6-one, drimane-7,8,9-triol, drimane-7,8,11-triol, and drim-8-ene-7,11,12-triol were studied. The proton and carbon chemical shifts were assigned.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2589–2594, December, 2004.     

Détermination spectrophotométrique de l'analgène au moyen de chlorure de fer(III) et d'α,α'-dipyridyle

Résumé On a élaboré une méthode spectrophotométrique de détermination de l'analgène au moyen de chlorure de fer-III et de l',-dipyridyle. En milieu alcalin, l'analgène réduit le fer-III en fer-II. L',-dipyridyle forme avec le fer-II un composé complexe rouge vif. La densité optique de la solution analysée est proportionnelle à la concentration de l'analgène. On effectue les mesures à 520 nm. Dans l'analyse de 18 substances pharmaceutiques, la détermination de l'analgène fut gêne par le phénylbutazon (le rapport étant supérieur à 1 1) et par le pyramidon.

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Spectrophotometric determination of Analgene by means of iron(III) chloride and ,'-dipyridyl

Summary A spectrophotometric method of determining Analgene by means of iron(III) chloride and, dipyridyl has been worked out. The analgene (in alkaline medium) reduces the Fe(III) to Fe(II). The,-dipyridyl produces a bright red complex compound with Fe(II). The optical density of the solution being analyzed is proportional to the concentration of the analgene. The measurement is made at 520 nm. In 18 pharmaceutical preparations, the determination of the analgene was impaired by phenylbutazone (ratio above 1 1) and by pyramidon.

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Zusammenfassung Eine spektrophotometrische Methode zur Bestimmung von Anaigen [1-Phenyl-2,3-dimethyl-4-(N-methyl-N-methansulfonsäure)-5-pyrazolon] mit Hilfe von Eisen(III)-chlorid und,-Dipyridyl wurde ausgearbeitet. In alkalischem Milieu reduziert Anaigen das Eisen zur zweiwertigen Stufe; dieses bildet dann mit,-Dipyridyl einen lebhaft rot gefärbten Komplex. Die Farbintensität ist der Konzentration proportional. Sie wird bei 520 nm gemessen. Unter 18 geprüften pharmazeutischen Substanzen wird die Reaktion von überschüssigem Phenylbutazon sowie von Pyramidon gestört.

     

Excess enthalpies of aqueous solutions of small peptides at 25°C

Heats of dilution of aqueous solutions of the following di-and tripeptides were determined at 25°C over a wide concentration range: -alanyl-glycine, -alanyl--alanine, DL--alanyl-glycine, glycyl-DL--alanine, L--alanyl-L-alanine, DL--alanyl-DL--alanine, DL--alanyl-DL-valine, DL--alanyl--alanine, glycyl--aminobutyric acid, glycyl-L-leucine and DL--alanyl-glycylglycine. The excess enthalpies H^ex and partial molar relative enthalpies L₂ were calculated and enthalpy coefficients of intermolecular interaction were analysed using the additivity principle of Savage and Wood. The concentration dependence of the enthalpic characteristics of peptide-peptide interactions is discussed based on of their hydrophobicity and hydrophilicity. The three-stage model of peptide association is described using enthalpic coefficients of intermolecular interactions.