bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diffusion von Azulen in Kunststoffolien
Authors: van Tets A. , Günthard Hs. H. 
Published: December 2004

AbstractThe kinetics of diffusion of azulene and azulene‐d2−(1,3) from the vapor phase into thin slabs (28–250 μ thickness) of copolyn, teflon und polyethylene has been studied photometrically at temperatures between 25° and 40°C. The diffusion process was found to be accompanied by a decay reaction of azulene. Values are given for the diffusion constant, the decay rate constant and the saturation concentration in copolyn and polyethylene, as well as thermodynamical standard data for the solution process of azulene in all the plastic materials mentioned. The order‐disorder properties of the solutions are briefly discussed.
Komplexone XXXV. Die Metallkomplexe der Triund der Tetramethylendiamin‐NN′‐tetraessigsäure
Authors: L'Eplattenier F. , Anderegg G. 
Published: December 2004

AbstractThe stability constants of the complexes formed by different metal ions with ligands of the type (−OOCCH2)2N(CH2)nN(CH2COO−), with n = 3 and 4, have been determined. In the case of trimethylenediamine‐NNN′N′‐tetraacetate, complex formation has been investigated using 5 different methods. The results from all these methods are coincident.
Zum Mechanismus der Metallionen‐Katalysierten Hydrolyse von Adenosintriphosphat (ATP) II. Reaktionsverlauf in H218O
Authors: Moll H. , Schneider P. W. , Brintzinger H. 
Published: December 2004

AbstractIn the hydrolytic cleavage of the terminal POP bond of adenosine triphosphate, which is catalyzed by Cu2+ at pH 5–6, l8O from the aqueous reaction medium enters the terminal phosphate group. The electropositive character of thc leaving group is the rate‐determining factor in this reaction.
Isolierung und Synthese des Ergostins, eines neuen Mutterkorn‐Alkaloids. 62. Mitteilung über Mutterkornalkaloide
Authors: Schlientz W. , Brunner R. , Stadler P. A. , Frey A. J. , Ott H. , Hofmann A. 
Published: December 2004

AbstractA new alkaloid C34H37O5N5, only a very small quantity of which (0.5 to 1%)is present as an accompanying alkaloid of ergotamine, was found in ergot obtained from a variety of sources. The new ergot alkaloid, which was named ergostine, structurally falls midway between ergotamine and ergocristine. It differs from these two alkaloids only in the α‐hydroxy‐α‐amino acid radical, in as far as ergostine contains the α‐hydroxy‐α‐amino butyric acid radical.
Fluoreszierende Stoffe auf Roten Waldameisen der Gattung Formica (Inc. Hym.). 2. Mitteilung. Isolierung einer Riboflavin‐Formicapterin‐Verbindung
Authors: Schmidt G. H. , Viscontini M. 
Published: December 2004

AbstractAus Arbeiterinnen der Art Formica rufa L. wurde ein hellgrün fluoreszierender Stoff isoliert, der nach ammoniakalischer Behandlung Riboflavin und Formicapterin als fluoreszierende Substanzen erkennen liess. Die vorliegende Riboflavin‐Formicapterin‐Verbindung wurde durch UV.‐Spektren und Rf‐Werte charakterisiert.
Anwendung der Thermodynamik der irreversiblen Prozesse auf die Theorie von Dampfmembranen‐Osmometern
Authors: Milićević B. 
Published: December 2004

AbstractThe non equilibrium thermodynamics of vapor‐membrane osmometers based on a simple theoretical model are discussed. The equations for mass and heat transport are given for three types of vapor‐membrane osmometers, of which two are known as “the method of bithermal equilibration after STOKES[4]” and as “the thermoelectric method after HILL[6] and BALDES[7]”. From the nonequilibrium thermodynamic theory the suggestion for the construction of a new type of vapor‐membrane osmometer is also given.
Synthèses de nouvelles phényl‐1‐triazoline‐1,2,4‐ones‐5 substituées en 3 et 4. 2e communication
Authors: Gold‐Aubert Ph. , Melkonian D. , Toribio L. 
Published: December 2004

AbstractWe describe the synthesis and the properties of new 3 and 4 substituted 1‐phenyl‐1, 2, 4‐triazoline‐5‐ones. The aminated alkyl stems fixed in position 4 strongly increase the analgesic and anti‐inflammatory properties of these substances.
Über Pterinchemie. 9., vorläufige Mitteilung. Beitrag zur Kenntnis der Reoxydation von hydrierten Pterinen
Authors: Viscontini M. , Bobst A. 
Published: December 2004

AbstractMit dem Ziel, die Reoxydation von hydrierten Pterinen zu studieren, wurden 8 neue Körper dieser Stoffklasse synthetisiert. Alle erwiesen sich gegen Luftsauer‐stoff als sehr empfindlich.
Über die Isolierung von (+)‐Pronuciferin und (−)‐Anonain aus den Keimlingen von Nelumbo nucifera GAERTN. 2. Mitteilung über natürliche und synthetische Isochinolinderivate
Authors: Bernauer Karl 
Published: December 2004

AbstractFirst isolation of the isoquinolinedienone alkaloid Pronuciferine (I), and of the noraporphine alkaloid Anonaine (V), besides the aporphines Nuciferine (11), Roemerine (III), and 5‐Methoxy‐6‐hydroxy‐aporphine (IV), from cotyledons of Nelumbo nucifera GAERTN. (Asiatic Lotus) is described.
Konstitution und Reaktionen des (+)‐Pronuciferins 3. Mitteilung über natürliche und synthetische Isochinolinderivate
Authors: Bernauer Karl 
Published: December 2004

AbstractConstitution and reactions of the isoquinoline‐dienone alkaloid (+)‐pronuciferine are described. The latter include reduction with complex hydrides, transformation into (−)‐nuciferine, catalytic hydrogenation, and dienone‐phenol‐rearrangement to (−) ‐3‐hydroxy‐5,6‐dimethoxy‐aporphine.
Nucleophile Ringöffnung und Fragmentierung von 1‐Aza‐bicyclo[2.2.0]hexan Fragmentierungs‐Reaktionen, 11. Mitteilung
Authors: Grob C. A. , Krasnobajew V. 
Published: December 2004

Abstract1‐Aza‐bicyclo[2.2.0]hexane (1) is formed in a unimolecular reaction from 2‐(2‐bromoethyl)‐azetidine (13) in aqueous or alcoholic medium. Thermal instability and high reactivity have, however, so far precluded its isolation. Hydrochloric acid, aqueous sodium hydroxide and ethanolic sodium ethoxide convert the bicyclic amine 1 into 4‐chloro‐, 4‐hydroxy‐ and 4‐ethoxy‐piperidine, (14), (15) and (16), respectively. Upon heating in solution to ca. 80° it undergoes fragmentation to N‐methylene‐3‐butenyl‐amine (17). This unusual reactivity is ascribed to strain and to concomitant weakening of the N‐C4 bond in the bicyclic amine 1.
4,5‐Dihalogen‐O‐acetylindoxyle
Authors: Kambli Ed. 
Published: December 2004

AbstractIn the synthesis of 4‐chloro‐5‐bromo‐O‐acetyl indoxyl, an important substance used in locating esterase activity, difficulties arose from the formation of isomeric intermediate products. Selection of different starting compounds not only facilitates the syntheses of this dihalogeno O‐acetyl indoxyl, but also enables the production of new o‐acetyl indoxyls of equal applicability.
Étude du comportement et de l'électrolyse de solutions d'oxyde de Germanium dans des fluorures fondus
Authors: Monnier R. , Tissot P. 
Published: December 2004

AbstractPure Ge is obtained in good yield by electrolysis of GeO2 solutions in appropriate mixtures of fluorides wich melt at a temperature to 900°C. The suggested mechanism of the electrolysis consists in the dissociation of GeO2 in Ge4+ and O2− and the direct discharge of these ions at the electrodes.
Umwandlung von Krötengiften (Bufadienoliden) durch Mikroorganismen. II. 12β‐Hydroxyresibufogenin. 12. Mitteilung über Reaktionen mit Mikroorganismen
Authors: Schüpbach M. , Tamm Ch. 
Published: December 2004

AbstractIncubation of resibufogenin (1) with cultures of Fusarium lini (BOLLEY) yielded the unknown 12β‐hydroxyresibufogenin (4). The structure of 4 was proved by the degradation of its diacetyl derivative 5 to methyl 3β,12β‐diacetoxy‐l4β, 15β‐epoxy‐5β, 14β, 17αH‐etianate (9) which was identical with the degradation product obtained from 14β,15β‐epoxy‐14‐anhydro‐digoxigenin diacetate (7). The latter was prepared from di‐O‐acetyl digoxigenin (8). Incubation of 14β, 15β‐epoxy‐14‐anhydro‐digitoxigenin (2) with F. lini led to the 12β‐hydroxy derivative 6, its diacetate being identical with 7. LiAlH4‐reduction of both the epoxyester 9 and the hydroxyester 12 derived from digoxigenin gave the same tetrol 10.
Metallmethylate und deren Bildungsgleichgewichte
Authors: Gut Rudolf 
Published: December 2004

AbstractA pH‐scale has been defined for absolute methanol as solvent and the ionic product of methanol was evaluated (20°, μ = 1.0, N(CH3)4Cl or LiC1). The formation of methoxide complexes has been studied by titration of methanolic solutions of BCl3, AlCl3, GaCl3, InCl3, PCl3, TiCl4, ZrCl4, ThCl4, GeCl4, ZnCl2, TaCl5, NbCl5, NbOCl3, WOCl4 with lithiummethylate.
Die Glykoside von Streblus asper LOUR. 3. Mitteilung. Untersuchung der stark wasserlöslichen Anteile Glykoside und Aglykone, 260. Mitteilung
Authors: Manzetti A. R. , Reichstein T. 
Published: December 2004

AbstractThe highly polar cardenolide glycosides from the root bark of Streblus asper contain components which are attacked by snail glycosidases and thereby transformed into chloroform‐soluble monoglycosides. The remaining water‐soluble (chloroform‐insoluble) portion is a mixture of highly polar glycosides of mono‐ or disaccharides. 21 cardenolides could be detected in this material by paper chromatography. Of these 4 could be isolated in crystals and 8 other ones in amorphous form, giving only one spot each in paper chromatograms. One of these glycosides, Strophallosid (J), has recently been obtained from seeds of Antiaris toxicaria. The 11 other cardenolides are most probably new compounds. The main component is the crystalline glucostrebloside (M), which is not attacked by strophanthobiase although it contains terminal D‐glucose.
Die Glykoside von Streblus asper LOUR. 4. Mitteilung. Strukturbestimmung einiger stark wasserlöslicher Glykoside Glykoside und Aglykone, 261. Mitteilung
Authors: Manzetti A. R. , Reichstein T. 
Published: December 2004

AbstractTentative structures are derived for eight water‐soluble cardenolide glycosides from the root bark of Streblus asper LOUR. They are mainly based on identification by paper and thin layer chromatography of the products obtained after acid hydrolysis in micro scale, using both ‘KILIANI’ and ‘MANNICH’ conditions. In derivatives containing D‐glucose as β‐D‐glucopyranosidic end group this sugar could be split off by prolonged treatment with snail enzyme. In a few cases it was possible to perform hydrolysis in preparative scale and to show that the isolated sugar component belonged to the D‐series. Strophalloside (J) could be reduced to strophanolloside (K) with NaBH4.
Synthetische Analoge des Hypertensins. VI. α‐L‐Asp(NH2)1‐aza‐α′‐homo‐Tyr4‐Val5‐Hypertensin II und β‐L‐Asp1‐aza‐α′‐homo‐Tyr4‐Val5‐Hypertensin II
Authors: Riniker B. , Schwyzer R. 
Published: December 2004

AbstractThe use of the CURTIUS azide method for the synthesis of peptides is known to produce urea derivatives as side‐products due to partial rearrangement of the azide to an isocyanate. As model compounds for this type of reaction the two urea analogues of Val5‐hypertensin II mentioned in the title have been synthesised.
Optische Spaltung des 5‐Hydroxy‐DL‐Tryptophans
Authors: Rinderknecht Heinrich 
Published: December 2004

AbstractA novel method for the resolution of 5‐hydroxy‐DL‐tryptophan is described. Successive treatment of N‐Benzyloxycarbonyl‐5‐benzyloxy‐DL‐tryptophan with the stereoisomeric bases quinidine and quinine precipitates directly the corresponding salts of the L‐ and D‐antipodes.
Sur les esters activés I. Aminolyse des dérivés de oximes et amidoximes
Authors: Buyle R. 
Published: December 2004

AbstractO‐Acylamidoximes and acyloximes can be considered as activated esters which are useful acylating agents. A number of activated esters are compared in their action on benzylamine. Their acylating power is directly related to the acidity of the OH group of the leaving species (alcohol or oxime respectively).
Absolute Konfiguration von Terpinenol‐(4)
Authors: Ohloff G. , Uhde G. 
Published: December 2004

AbstractZur Aufklärung der absoluten Konfiguration von Terpinenol‐(4) wurde (−)‐Terpinenol‐(4) über das (+)‐Carvomenthol mit dem (−)‐Limonen verbunden. Das (−)‐Terpinenol‐(4) besitzt daher die (4R)‐Konfiguration. Für das (+)‐Terpinenol‐(4) wurde auf indirektem Wege die (4S)‐Konfiguration ermittelt.
Die synchrone Fragmentierung von γ‐Amino‐cycloalkylhalogeniden. 2. Teil. Solvolysen von 4‐Bromchinuclidin. Fragmentierungs‐Reaktionen, 12. Mitteilung
Authors: Brenneisen P. , Grob C. A. , Jackson R. A. , Ohta M. 
Published: December 2004

AbstractThe fragmentation of 4‐bromo‐quinuclidine (7) to N,4‐bis‐methylene‐piperidinium bromide (8) has been studied in six solvents. In 80% ethanol and in 70% dioxane 4‐bromo‐quinuclidine reacts 5.5 · 104 times as fast as the homomorphous compound 1‐bromo‐bicyclo[2.2.2]octane (9). The nitrogen atom therefore participates in the rate determining step.
Über die Struktur von Verrucarin A. Verrucarine und Roridine, 5. Mitteilung
Authors: Gutzwiller J. , Tamm Ch. 
Published: December 2004

AbstractThe antibiotic verrucarine A (C27H34O9) yields on base catalysed hydrolysis three products: (1) the sesquiterpene alcohol verrucarol (C15H22O4) (12), (2) cis, trans‐muconic acid (C6H6O4) (7), and (3) verrucarinolactone (C6H10O3) (9). The latter is the δ‐lactone of the hitherto unknown trans‐α, δ‐dihydroxy‐β‐methyl‐valeric acid (verrucarinic acid (16)). The absolute configuration of verrucarinolactone results from its degradation to (R)‐(+)‐methylsuccinic acid (21). Verrucarinolactone is a new natural isomer of mevalolactone.
Schwingungsspektrum von Cyclododecan und Cyclododecan‐d2 zwischen 4000 und 50 cm−1. Normalkoordinatenanalyse von zwei Cyclododecanmodellen
Authors: Fuhrer H. , Günthard Hs. H. 
Published: December 2004

AbstractThe infrared, far infrared and RAMAN spectra of cyclododecane and the infrared and far infrared spectra of cyclododecane‐(1,1)‐d2 with D2 symmetry have been measured. For the light isotopic modification a numerical normal coordinate analysis has been carried out, using the 35‐constants potential for paraffins given by SCHACHTSCHNEIDER, and an automatic computer program for the calculation of the G‐matrix, the normal frequencies and the normal vectors.
Alkaloide aus Schizozygia caffaeoides (BOJ.) BAILL. II. Die Struktur des Schizozygins
Authors: Renner U. , Fritz H. 
Published: December 2004

AbstractFrom chemical degradation experiments and spectroscopical data structure I is deduced for schizozygine, the major alkaloid of Schizozygia caffaeoides (BOJ.) BAILL. The given relative configuration is suggested by experiments indicating a strain‐free ring system.
Einfluss der Porenstruktur auf die Gasdiffusion in porösen Körpern
Authors: Richarz W. , Alder H. P. , Guyer A. 
Published: December 2004

AbstractEs wurde an zylindrischen Probekörpern, hergestellt aus nichtporösen pulverigen Materialien unterschiedlicher Härte, die spezifische Permeabilität gemessen und mit der Porosität in Beziehung gebracht.
Circulardichroitische Messungen an gesättigten und α,β‐ungesättigten Cyclopropyl‐ketonen
Authors: Schaffner K. , Snatzke G. 
Published: December 2004

AbstractThe circular dichroism (CD) of saturated and α,β‐unsaturated ketones containing three‐membered rings has been measured and correlated with the configurations and conformations of these compounds.
Réarrangement thermique des oxo‐2‐oxathiadiazoles‐1,2,3,5 en dioxo‐1,1‐benzothiadiazines‐1,2,4
Authors: Eloy F. 
Published: December 2004

Abstract2‐Oxo‐1,2,3,5‐oxathiadiazoles containing an aromatic substituent in the 3‐position and an aliphatic substituent in the 4‐position rearrange on heating into 1,1‐dioxo‐1,2,4‐benzothiadiazines. The mechanism of the transposition is discussed.
Die HAMMETT'sche Substituentenkonstanten für m‐ und p‐ständige Phenylazogruppen
Authors: Syz M. , Zollinger Hch. 
Published: December 2004

Abstract1. HAMMETT's σ‐values for the phenylazo group in meta and para position have been determined from the acid‐base equilibrium constants of the respective phenols, anilines and benzoic acids.
De la chimie des ptérines. 11e communication. Sur une nouvelle synthèse de ptérines 7,8‐dihydrogénées et sur l'obtention inattendue de l'hydroxyméthyl‐6‐ptérine isomériquement pure
Authors: Viscontini M. , Nasini G. 
Published: December 2004

AbstractPar action de l'hydrate d'hydrazine et du diméthylformamide sur la tétrahydroptérine (II) on obtient l'hydrazone de la formyl‐6‐dihydro‐7,8‐ptérine (III), qu'on oxyde ensuite facilement en hydrazone de la formyl‐6‐ptérine (IV). Un traitement acide transforme par oxydo‐réduction cette hydrazone en hydroxyméthyl‐6‐ptérine (V) isomériquement pure.
Spektren und Basizität der reinen trans‐Konfigurationen von substituierten 4‐Dimethylaminostilbenen
Authors: Syz M. , Zollinger Hch. 
Published: December 2004

Abstract(1) It has been found that under normal light conditions solutions of trans‐4‐dimethylaminostilbene and a series of its derivatives contain appreciable percentages of the respective cis‐isomers; this occurs even if direct sunlight is excluded.
Zur Methylierung von 1‐Phenyl‐5‐sulfanilamido‐pyrazol
Authors: Eichenberger K. , Zürcher R. F. , Rossi A. , Wilhelm M. , Schmidt P. 
Published: December 2004

AbstractBy methylation of 1‐phenyl‐5‐sulfanilamido‐pyrazole in alkaline medium N1‐Methyl‐1‐phenyl‐5‐sulfanilamido‐pyrazole has been isolated, the structure of which is proved by an unambiguous synthesis.
NMR.‐Spektren von Zwischenprodukten elektrophiler aromatischer Substitutionen und Elektronen‐Donator‐Acceptor‐Komplexen
Authors: Koch W. , Zollinger Hch. 
Published: December 2004

Abstract(1) The structure of the intermediates (σ‐complexes) in two bromination reactions have been studied by proton magnetic resonance spectroscopy. The structures correspond to those earlier described in the bromination of 2‐naphthol‐6,8‐disulphonic acid [1].
Etudes sur les matières végétales volatiles CXCVI. Sur la déshydratation du linalol et la préparation de β‐myrcène et de trans‐β‐ocimène
Authors: Naves Yves‐René , Bondavalli Francesco 
Published: December 2004

AbstractThe linalol treated by iodine at 140–150°C loses water and yields a mixture of β‐myrcene (45%) and trans‐β‐ocimene (16%).
Über die Bindung der Wassermolekel in den Verbindungen MeIISO4, 1 H2O und MeIISeO4, 1 H2O: I. Strukturuntersuchungen. (MeII = Mg, Ni, Cu, Co, Fe, Zn, Mn)
Authors: Oswald H. R. 
Published: December 2004

AbstractThe monohydrates of the sulphates of bivalent Mg, Ni, Cu, Co, Fe, Zn, Mn and some of the corresponding selenates have been prepared and the unit cell dimensions tabulated. All except the copper compounds have the monoclinic MgSO4·1H2O (Kieserite) structure. CuSO4·1H2O and CuSeO4·1H2O have a very similar triclinic crystal structure. The lattice parameters of CoSO4·1H2O have been determined by a least square refinement with 73 powder X‐ray reflections, and the interatomic distances and angles are given. It is shown that these monohydrates are not to be formulated as salts MeH2SO5 of a «meso sulfuric acid».
Recherches sur la formation et la transformation des esters LVII. Acides ou chlorures d'acides de PIII et alcools α‐acétyléniques: estérification sans ou avec réarrangement
Authors: Cherbuliez E. , Jaccard S. , Prince R. , Rabinowitz J. 
Published: December 2004

AbstractWhen α‐acetylenic alcohols are reacted with acid chlorides of trivalent phosphorus in the presence of a tertiary base, the intermediate trivalent esters rearrange to pentavalent phosphorus derivatives, with formation of a new PC bond. Generally, the C3 group fixed on the phosphors has an allenic structure: ; in some cases this group tautomerizes to the corresponding acetylenic derivative: .
Die Struktur des Alstonia‐Alkaloides Villalstonin Vorläufige Mitteilung
Authors: Hesse M. , Hürzeler H. , Gemenden C. W. , Joshi B. S. , Taylor W. I. , Schmid H. 
Published: December 2004

AbstractDas Alstonia‐Alkaloid Villalstonin liefert bei der Isomerisierung mit Trifluoressigsäure Villamin, welches thermisch in Pleiocarpamin(1) und Macrolin übergeht. Auf Grund chemischer Reaktionen, spektroskopischer Analysen und Vergleiche wurde für Macrolin die Struktur 13 abgeleitet. Daraus folgt für Villamin die Formel 10 und schliesslich 2 für Villalstonin.
Decahydrochinolole, 1. Teil. Synthese und Konfiguration der epimeren 1‐Methyl‐4‐hydroxy‐trans‐decahydrochinoline
Authors: Grob C. A. , Lutz H. J. 
Published: December 2004

AbstractThe epimeric 4α‐ and 4β‐hydroxy‐1‐methyl‐trans‐decahydroquinolines, 1a and 2a respectively, have been synthesized from 1‐acetylcyclohexene, and their configurations and conformations determined by chemical and NMR.‐spectral methods.
Decahydrochinolole. 2. Teil. Synthese und Konfiguration von 1‐Methyl‐5‐hydroxy‐decahydrochinolinen
Authors: Grob C. A. , Kiefer H. R. 
Published: December 2004

AbstractThree stereoisomers of 5‐hydroxy‐1‐methyl‐decahydroquinoline, namely the 5α‐cis, the 5α‐trans, and 5β‐trans froms, 1a,2a and 3a respectively, have been synthesized from cyclohexane‐1,3‐dione. Configurations and conformations are assigned on the basis of chemical, IR.‐and NMR.‐spectral properties.
Der oxydative Abbau von Verrucarin A, ein weiterer Strukturbeweis. Verrucarine und Roridine, 7. Mitteilung
Authors: Zürcher W. , Gutzwiller J. , Tamm Ch. 
Published: December 2004

AbstractThe structure of verrucarin A (1) has been confirmed by a stepwise oxidative degradation of mono‐O‐acetyl‐β‐epoxy‐verrucarin (6).
Über 9β, 10α‐Steroide 1. Mitteilung. Herstellung und Eigenschaften von 6‐Halogen‐9β, 10α‐androstan‐Derivaten
Authors: Els H. , Englert G. , Müller M. , Fürst A. 
Published: December 2004

Abstract(1) The synthesis of Δ4‐,Δ1,4‐,Δ4,6‐, and Δ1,4,6‐3‐keto‐6‐halogen(F, Cl, Br)derivatives of the 9β,10α‐androstane series is described.
Organische Phosphorverbindungen XVIII. Eine neue Methode zur Knüpfung von PCP‐Bindungen (Darstellung von Di‐, Tri‐ und Tetra‐tertiären‐Phosphinen)
Authors: Maier Ludwig 
Published: December 2004

AbstractTertiary phosphines containing dialkylaminomethylgroups condense readily at elevated temperature (∼ 160°) with compounds containing a PH bond, with the formation of PCP bonds according to the general equation:
equation image
.
Die Sterine und Bufadienolide der Haut von Bufo formosus BOULENGER. Über Krötengifte, 31. Mitteilung
Authors: Iseli E. , Kotake M. , Weiss Ek. , Reichstein T. 
Published: December 2004

AbstractIn the skin of the Japanese toad Bufo formosus BOULENGER three sterols and 19 bufadienolides have been traced by thin layer and paper chromatography. Combining different preparative chromatographic methods a complete qualitative separation could be achieved. From 490 animals the following amounts of the 3 sterols and 16 crystalline bufadienolides were obtained (amounts in mgs): cholesterol (ca. 20000; only a fraction was purified), 7α‐hydroxy‐cholesterol (1.5, identification tentative), 7β‐hydroxy‐cholesterol (8.5), cinobufagin (40), bufalone (8.5), bufotalone (12), bufalin (353), 3‐epi‐bufalin (32), cinobufotalin (54), marinobufagin (45), bufotalin (1357), bufotalinin (13), telocinobufagin (42), desacetyl‐cinobufagin (18), desacetyl‐bufotalin (76), arenobufagin (143), hellebrigenin = bufotalidin (25), desacetyl‐cinobufotalin (18), gamabufotalin (2136). The following three were obtained in amorphous from: resibufogenin (74, identified as crystalline O‐acetyl‐derivative), argentinogenin (14) and U5 (7, not identified).
Die Konstitution von Tanghinin Glykoside und Aglykone, 268. Mitteilung
Authors: Flury E. , Weiss Ek. , Reichstein T. 
Published: December 2004

AbstractDegradation of tanghinigenin 9 yields the known methyl 3‐oxo‐7,8β‐epoxy‐14β‐hydroxy‐5β‐etianate 13. This ester, after bromination followed by dehydrobromination with concomitant opening of the oxirane ring, gave methyl 3‐oxo‐8β, 14β‐dihydroxy‐etia‐4,6‐dienate 18. This same compound was obtained from scillirosidin, whose structure has already been established, following an unequivocal route. The dienone 18 from tanghinigenin gave after hydrogenation the two saturated methyl 3‐oxo‐8β, 14β,‐dihydroxy‐etianates 21 and 22, isomeric in the 5‐position. Both these compounds were products of degradation reactions carried out on scillirosidin. Together with earlier results these transformations establish the structure of tanghinigenin as 3β, 14β‐dihydroxy‐7, 8β‐epoxy‐Δ20(22)‐cardenolide 9.