bluuebunny/crossref_metadata_2025_split huggingface dataset:
Struktur und Mechanismus bei Fragmentierungsreaktionen 1. Teil. Die stereoisomeren 10‐Chlor‐decahydro‐isochinoline. Fragmentierungsreaktionen, 23. Mitteilung
Authors: Geisel M. , Grob C. A. , Wohl R. A. 
Published: December 2004

Abstractcis‐10‐Chloro‐N‐methyl‐decahydro‐isoquinoline (5) and its trans‐isomer 6 undergo heterolytic fragmentation in 80% ethanol by different mechanisms. As predictable on stereo‐chemical grounds the cis‐isomer 5 reacts by the accelerated synchronous mechanism, the trans‐isomer 6, however, by the two‐step carbonium ion mechanism. Synchronous fragmentation therefore dominates over the two‐step process even when the latter would lead to a relatively stable tertiary carbonium ion. In both cases the more highly substituted and thermochemically more stable olefinic fragment 8 is formed.
Rapid Instrumental Nuclear Activation Analysis of Rocks, Cements and Meteorites
Authors: Wyttenbach A. 
Published: December 2004

AbstractThe experimental set‐up and the method for γ‐spectrum analysis as used in the activation analysis of rocks, cements and meteorites by reactor neutrons are discussed. Rapid nondestructive simultareous determination of several elements is possible. Fractional percent reproducibility is possible for Al, Na and Mn; the determination of Ca, Mg and V in the samples studied us influenced by the Al‐ and Mn‐content, but reproducibility approaches 1% in favorable cases. Accuracy is generally within the limits set by the reproducibility. The minimum weight of the sample is small (10–40 mg), but the grain‐size must be below 150 mesh; in the case of meteorites, a grain‐size effect has been demonstrated. Representative results for several standard rocks and cements, for 7 L‐chondrites, 2 hyperstene achondrites and separate mineral phases of the Elenovka chondrite are given.
Dosage de traces d'hafnium dans l'aluminium par activation neutronique
Authors: Balsenc L. , Haerdi W. 
Published: December 2004

AbstractThree methods are proposed for the assay of traces of hafnium in aluminium metal by neutron activation analysis. In the first method, the isotope 179mHf (T = 19 s), produced is counted after anionic resin exchange‐separation in sulfuric acid medium. The two other methods, which are non‐destructive, are based on the formation of 180mHf (T = 5,5 h) and 179mHf (T = 19 s). The latter method comprises an instrumental separation.
Inhaltstoffe der Wurzeln von Margaretta rosea Oliv. Glykoside und Aglykone, 323. Mitteilung
Authors: Sierp D. , Stöcklin W. , Reichstein T. 
Published: December 2004

AbstractThe roots of Margaretta rosea Oliv., subsp. rosea Bullock contain cardenolides mixed with Kedde negative ester glycosides. 6 Cardenolides were identified by paper chromatography (PC) and thin layer chromatography (TLC). Three of them were free aglycones (uzarigenin (1), corotoxigenin (3) and coroglaucigenin (5), the other three their corresponding 6‐deoxy‐β‐D‐allo‐pyranosides (ascleposide (2), gofruside (4) and frugoside (6). Only two cardenolides (1 and 5) were isolated in crystalline form. The behaviour of the more polar portion of the glycoside mixture shows that D‐gluco derivatives of at least 5 of the 6 cardenolides mentioned were also present.The Kedde. negative glycosides were a complicated mixture containing mainly 2,6‐dideoxysugars linked to esterified polyhydroxy‐pregnanes. After mild acid hydrolysis cymarose, oleandrose and digitoxose could be identified by PC and TLC. From the crude aglycone portion only one cristalline genin (M) could be isolated. This was still a mixture, but its main component according to the mass spectrum was a monobenzoyl derivative C28H38O7. ‐ A small amount of cristalline O‐acetyl‐β‐amyrin was isolated from the least polar components.
Katalysierte Nitrilreduktionen mit Natriumborhydrid
Authors: Egli Robert A. 
Published: December 2004

AbstractThe reduction of benzonitrile with sodium borohydride in aqueous methanol in the presence of Raney nickel as a catalyst provides high yields of benzylamine as compared with the known low yields in the absence of Raney nickel. An explanation is proposed. Butyronitrile gives similar good yields of n‐butylamine.
Synthese der isomeren 3, 4‐Dimethyl‐4‐phenyl‐3, 4‐dihydro‐carbostyrile
Authors: Schmutz J. , Künzle F. 
Published: December 2004

AbstractCyclisation of 2‐methyl‐3‐phenyl‐but‐3‐en‐anilide (III) with polyphosphoric acid gave cis‐3, 4‐dimethyl‐4‐phenyl‐3, 4‐dihydro‐carbostyril (VII) in 61% yield together with a small amount of 2, 3‐dimethylindenone (VIII), whereas with AlCl3 a phenyl group was split off to give 3, 4‐dimethylcarbostyril (VI). The anilide III isomerises to cis‐ and trans‐2, 3‐dimethyl‐cinnam‐anilide (IV resp. V) under basic conditions.The anilides IV and V gave only small yields of the dihydrocarbostyril VII with polyphosphoric acid. Chlorination of VII in position 3 using PCl5 yielded IX which, on splitting out HCl, gave 3‐methylene‐4‐methyl‐4‐phenyl‐3, 4‐dihydro‐carbostyril (X). X was converted to trans‐3, 4‐dimethyl‐4‐phenyl‐3, 4‐dihydro‐carbostyril (XI) by catalytic hydrogenation.
Séparation des terres rares par chromatographie sur échangeurs d'ions II. Séparation et analyse de la paire europium‐gadolinium [1]
Authors: Brunisholz G. , Roulet R. 
Published: December 2004

AbstractA displacement chromatography technique is described for the separation of europium and light rare earths using the eluent ethylene‐diaminetetraacetate buffered by ammonium acetate giving a determined pH in the separation columns. This method gives concentrations up to 20 g of pure rare earth oxides per liter of eluate. A chromatographic method of analysis of europium in presence of other rare earths is also described.
Thermisches Verhalten von o‐Dipropenylbenzol, Beispiel einer aromatischen [1,7]‐sigmatropischen H‐Verschiebung. Vorläufige Mitteilung
Authors: Heimgartner[1] H. , Hansen H.‐J. , Schmid H. 
Published: December 2004

Abstractcis, cis‐, cis, trans‐ and trans, trans‐o‐Dipropenylbenzene (cis, cis‐, cis, trans‐ and trans, trans‐1) were prepared. At 225° cis, cis‐1 isomerises to give cis, trans‐1 and vice versa. The isomerisation follows 1. order kinetics. At equilibrium 89% cis, trans‐ and 11% cis, cis‐1 are present. It is shown by deuterium labelling that the isomerisation is due to aromatic [1, 7 a] sigmatropic H‐shifts. trans, trans‐1 rearranges at 225° to yield 2, 3‐dimethyl‐1, 2‐dihydronaphthalene (3). This can be visualized by disrotatory ring closure of trans, trans‐1 followed by an aromatic [1, 5 s] H‐shift. When cis, cis‐ or cis, trans‐1 are heated for 153 hrs at 225° a small amount (3%) of 1‐ethyl‐1,2‐dihydronaphthalene (5) is formed.
Utilisation d'ylides du phosphore non stabilisés en chimie des sucres. V. Sucres ramifiés dérivés du méthyl α‐D‐lyxo‐hexopyrannosul‐4‐oside. Communication préliminaire
Authors: Tronchet J. M. J. , Chalet J. M. 
Published: December 2004

AbstractCis and trans‐methyl‐4‐deoxy‐2, 3‐O‐isopropylidene‐6‐O‐methyl‐4‐methylthio‐methylene‐α‐D‐lyxo‐hexopyra‐nosides are prepared by a Wittig reaction. Methods are described for the determination of the configuration of the geometrical isomers whose Raney‐Nickel reduction leads to derivatives of 4‐deoxy‐4‐methyl‐hexoses of the D‐manno and D‐talo series.
Die Synthese des corticotrop hochaktiven [1‐D‐Serin, 17, 18‐dilysin]‐β‐corticotropin‐(1‐18)‐octadecapeptidamids
Authors: Riniker B. , Rittel W. 
Published: December 2004

AbstractA synthesis is described of [1‐D‐serine, 17, 18‐dilysine]‐β‐corticotropin‐(1–18)‐octadecapeptide amide (I), a short chain ACTH analogue which has been found to possess in animals and also in man high and prolonged corticotropic activity. Synthesis was carried out by the fragment condensation approach involving, in the last build‐up step, coupling of the protected sequences 1–10 and 11–18. From the protected octadecapeptide derivative 1–18 the free peptide was obtained in high yield by acidolysis.
Structure et synthèse de la damascénone (triméthyl‐2,6,6‐trans‐crotonoyl‐1‐cyclohexadiène‐1,3), constituant odorant de l'essence de rose bulgare (rosa damascena Mill.
Authors: Demole E. , Enggist P. , Säuberli U. , Stoll M. , Sz. Kováts E. 
Published: December 2004

AbstractDamascenoneDORICENONE (trade mark applied for by Firmenich & Cie, Geneva).
an odoriferous ketone isolated in minute amounts from Bulgarian rose oil (Rosa damascena Mill.) is shown to be trans‐2,6,6‐trimethyl‐1‐crotonoyl‐cyclohexa‐1, 3‐diene (I). A synthesis starting from beta;‐cyclocitral is described for this conspicuous constituent of rose oil, which displays a powerful fragrance. The synthesis of four related, more saturated ketones, damasconesDORINONE (trade mark applied for by Firmenich & Cie, Geneva).
, is also described.
Komplexe mit makrocyclischen Liganden I. Mechanismus der Komplexbildung zwischen Ni2+ und 1,4,8,11‐Tetraazacyclotetradecan
Authors: Kaden T. H. 
Published: December 2004

AbstractThe kinetics of the formation of the NiII‐complex with 1,4,8,11‐tetraazacyclotetradecan (Cyclam) are studied by spectrophotometric and potentiostatic methods. The reaction of Ni2+ with the cyclic ligand is about 30000 times slower than with the open chain triethylenetetraamine (Trien). Therefore the rate determining step with Cyclam can not be the dissociation of the first coordinated water molecule, as it is usually in complexation reactions, but it must be the formation of the second coordinative bond. This is considered to be due to the more rigid structure of Cyclam in comparison with Trien.
Zur Abscheidung von Antimon und Wismut auf Goldelektroden
Authors: Schmidt E. , Gygax H. R. , Cramer Y. 
Published: December 2004

AbstractThe electrodeposition of Sb and Bi on gold electrodes from HCl solutions was studied using a voltammetric thin layer technique. The metal deposition is preceded by the formation of cation adsorption monolayers. Alloy formation could not be observed.
Die Photoelektron‐Spektren von CH3CHtCHCH3, CH3NtCHCH3, CH3NtNCH3, ein Beitrag zur Frage nach der Wechselwirkung zwischen den einsamen Elektronenpaaren der trans‐konfigurierten Azogruppe [1]
Authors: Haselbach E. , Heilbronner E. 
Published: December 2004

AbstractA correlation of the photoelectron spectra of trans‐2‐butene, trans‐acetaldehydemethylimin and trans‐azomethane shows that the split Δ = ε (ag(n))−ε (bu(n)) between the lone pair orbitals ag(n) and bu(n) of trans‐azomethane amounts to 3.3 ± 0.2 eV. Molecular orbital calculations by the MINDO/1 procedure indicate that ag(n) lies above bu(n). In agreement with the experimental results the π‐orbital au(π) is predicted to fall into the interval between ag(n) and bu(n).
Isolierung und Struktur der Antibiotica Phomin und 5‐Dehydrophomin
Authors: Rothweiler W. , Tamm Ch. 
Published: December 2004

AbstractFrom cultures of a Phoma species (strain S 298) (Fungi imperfecti) two new antibiotics, phomine (1) and 5‐dehydrophomine (4) have been isolated. Phomine and 5‐dehydrophomine represent a novel type of macrolide antibiotics, the large lactone ring being fused to a highly substituted octahydro‐isoindole system. Both show cytostatic activity.
Die Stereospezifität der Alkoholdehydrogenase
Authors: Bally C. , Leuthardt F. 
Published: December 2004

AbstractThe glyceraldehyde formed by oxidation of glycerol through alcohol dehydrogenase (E.C. 1.1.1.1) from horse liver has been condensed with phosphodihydroxyacetone using either rabbit muscle or liver aldolase. The single product was identified after silylation by gas chromatography as L‐sorbose‐1‐phosphate. No D‐fructose‐1‐phosphate was detected. Apparently liver alcohol dehydrogenase oxidizes glycerol stereospecifically to L‐(−)‐glyceraldehyde. Thus, the earlier conclusions of Hadorn et al. from chromatography of the borate complexes on Dowex 1 have been confirmed. The same stereospecific behavior was found for both isoenzymes III and IV.With Bis‐(trimethylsilyl)‐trifluoroacetamide L‐sorbose‐1‐phosphate and D‐fructose‐1‐phosphate are persilylated. Two trimethylsilyl groups are bound to the phosphate group. These bonds are not cleaved during gas chromatography.
Recherches dans la série des cyclitols XXXVIII Etudes conformationnelles de dérivés cyclopenténiques disubstitués‐3, 5
Authors: Cocu F. G. , Wolczunowicz G. , Bors L. , Posternak Th. 
Published: December 2004

AbstractCyclopentenones substituted in position 4, and 3, 5‐cis or ‐trans disubstituted cyclopentenes have been studied by NMR. and by IR. spectroscopy. Cyclopentenone derivatives and cyclopentene derivatives adopt a quasi‐coplanar and an envelope conformation, respectively. The preferential orientation of the substituents has been established according to their nature and to the solvents by correlation to the vicinal and the long‐range coupling constants.
Synthese der 2‐Thio‐D‐glucose und einiger 3‐Thio‐D‐altrose‐Derivate
Authors: Hardegger E. , Schüep W. 
Published: December 2004

AbstractDie Umsetzung von Natriumbenzylmercaptid mit 1, 6‐2, 3‐Dianhydro‐β‐D‐mannopyranose (IV) führte vorwiegend unter diäquatorialer Öffnung des 2, 3‐Epoxidringes zur 1, 6‐Anhydro‐3‐desoxy‐3‐benzylthio‐β‐D‐altropyranose (XV) und unter diaxialer Öffnung desselben Ringes zur 1, 6‐Anhydro‐2‐desoxy‐2‐benzylthio‐β‐D‐glucopyranose (V). Von den beiden Thio‐Derivaten V und XV wurden mehrere z. T. bekannte Umwandlungsprodukte hergestellt, die in Kombination mit physikalischen Messungen die eindeutige Strukturaufklärung der erwähnten Verbindungen ermöglichten und erstmals zur Synthese der krist. als β‐Pyranose formulierten 2‐Thio‐D‐glucose (XIV) führten.
Die Tautomeriegleichgewichte von Dihydrochinoxalinen
Authors: Schellenberg M. 
Published: December 2004

AbstractThe primary product of the two step reduction of 2‐phenylquinoxaline is the 1,4‐dihydrocompound which undergoes a tautomeric rearrangement to the thermodynamically more stable 1,2‐dihydro‐3‐phenylquinoxaline. The 1,4‐dihydro compound is an extremely reactive reducing agent whereas the 1,2‐dihydro form is almost inert against oxidizing agents. Both dihydro forms are in a kinetically hindered equilibrium. The rearrangement requires a transfer of a proton from a nitrogen to a carbon atom and is therefore relatively slow even at pH 0.The 1,2‐dihydro compound cannot take part in redox reactions directly. If this compound is oxidized, the rate determining step is always the reversed tautomeric rearrangement.The effect of the kinetics of the tautomeric rearrangement on the polarographic behavior of the 2‐phenylquinoxaline system is discussed.
Über die Reaktion von Schwefel mit Aminen und Formaldehyd. Eine neue Methode zur Herstellung von Thioformamiden und Dithiocarbamaten
Authors: Maier Ludwig 
Published: December 2004

AbstractThe reaction of sulfur with primary or secondary amines and formaldehyde has been studied. A simple one step process for the preparation of thioformamides (RR′NCHS; R  H, R′  CH3, C2H5; R  R′  CH3, C2H5; R+R′  (CH2), (CH2), C2H4OC2H) and the amine salts of N, N‐dialkyl‐dithiocarbamic acids (R2NCS2 · H2NR2, R  CH3, C2H5, C4H9; R2  (CH2), (CH2), C2H4OC2H) is reported. In addition, the isolation of diethylamidosulfoxylic acid, (C2H5)2NSOH · 1/2 H2O, the first derivative of a new class of compounds, is described. The physical properties and the 1H‐NMR. spectra of the above mentioned compounds are given.
L'action de l'ammoniac sur l'hydroxyde de cobalt(II) et la stabilité des complexes en milieu aqueux
Authors: Gübeli A. O. , Hébert J. , Taillon R. , Côté P. A. 
Published: December 2004

AbstractFrom the solubility of precipitated Co(OH)2 (s) determined radiometrically as a function of pH and ammonia content of the heterogeneous systems, the formation constants have been obtained for the following mononuclear hydroxo‐, ammine‐ and mixed hydroxo‐ammine‐complexes: Co(OH)2, Co(OH)3−, Co(NH3)22+, Co(NH3)32+, Co(NH3)42+ and Co(OH)2 (NH3)2. The solubility of cobalt(II) hydroxide has also been calculated. The medium was 1M NaClO4 and the temperature 25° C.
Stereochemistry of the σ‐Complex Intermediate in Sterically Hindered Electrophilic Aromatic Substitutions. (20th communication on diazo coupling reactions)
Authors: Snyckers F. , Zollinger H. 
Published: December 2004

AbstractThe kinetics of the diazo coupling reactions of diazotized sulfanilic acid with 9 derivatives of 2‐naphthol, each containing a substituent in the 8‐position, have been measured. The reactions proceed by general base catalysis. The rate constants (k1) for the formation of the steady‐state intermediate in the presence of varying concentrations of a base (pyridine) have been evaluated from rate measurements. Similarly the ratios k2/k1 (where k2 is the rate constant for proton transfer from the steady‐state intermediate to the base, and k−1 is the rate constant for the dissociation of the intermediate) have been determined. The dependence of logk1 on σ+m and of the ratio k2/k−1 on a steric parameter Rf (defined in this paper) is interpreted as evidence for the steady‐state intermediate existing as a benzodienone σ‐complex with the sp3‐bound hydrogen in a pseudo‐equatorial position and the electrophile pseudo‐axial. A sterically caused destabilisation of the intermediate can be excluded. The steric influence on the ratio k2/k−1 is therefore due to the steric influence on k2 only. Diazo coupling of 8‐(2′‐pyridyl)‐2‐naphthol is subject to intramolecular base catalysis, as demonstrated by kinetic hydrogen isotope effects.
Herstellung der 1‐Thio‐D‐chinovose
Authors: Schüep W. , Hardegger E. 
Published: December 2004

AbstractAus β‐Pentaacetyl‐D‐glucose wurde unter Variation und methodischer Verbesserung der Reaktionsbedingungen über die bekannten Zwischenprodukte II, III, IIIa die eben‐falls bekannte α‐Acetobro n‐D‐chinovose (IV) hergestellt. Der Übergang in die 1‐Thio‐D‐chinovose‐Reihe, V, Va, VI bis VIc, erfolgte in durchwegs sehr guten Ausbeuten aus der Acetohalogenose IV mit Kalium‐äthylxanthogenat und Folgeraktionen, bzw. mit Kaliumthioacetat. Die krist., wenig beständige 1‐Thio‐D‐chinovose wurde als β‐Pyranose VIa formuliert.
Thermal Interconversion of Phenylcarbene and Tropylidene. Preliminary communication
Authors: Wentrup C. , Wilczek K. 
Published: December 2004

AbstractPhenylcarbene and tropylidene interconvert in the gas‐phase, as evidenced by the formation of stilbene and heptafulvalene (5) from both at 300°. Heptafulvalene itself rearranges to stilbene and anthracene above 500°. Phenylcarbene, but not tropylidene, undergoes ring contraction to fulvenallene (9) at 900°. Formation of fluorene from diphenylcarbene involves a complete ring expansion to 2‐phenyltropylidene (14), and subsequent ring contraction to 2‐biphenylylcarbene (15).
Utilisation d'ylides du phosphore non stabilisés en chimie des sucres VI. Sucres ramifiés dérivés des di‐O‐isopropylidène‐1,2:5,6‐α‐D‐ribo‐et‐α‐D‐xylo‐hexofurannosul‐3‐oses
Authors: Tronchet J. M. J. , Bourgeois J. M. 
Published: December 2004

AbstractThe cis and trans isomers of 3‐deoxy‐1,2:5,6‐di‐O‐isopropylidene‐3‐C‐methylthiomethylene‐α‐D‐xylo‐ and ‐α‐D‐ribo‐hexofuranoses have been prepared by treatment of 1,2:5,6‐di‐O‐isopropylidene‐α‐D‐xylo‐ and ‐α‐D‐ribo‐hexofuran‐3‐uloses with methylthiomethylene‐triphenylphosphorane. Configurations are assigned by NMR. A new type of 4J is described. Hydrogenation‐desulfurization of the methylthiovinylic sugars affords 3‐deoxy‐3‐methyl sugars of the D‐allo, D‐gulo, and D‐galacto series. Derivatives of 3‐deoxy‐3‐methyl‐D‐lyxose and 3‐deoxy‐3‐methyl‐D‐ribose are prepared by chain‐shortening of derivatives of the corresponding 3‐deoxy‐3‐methyl‐hexoses.
Zur Stereochemie der thermischen Fragmentierung von Hydrazonderivaten substituierter N‐Amino‐aziridine. Vorläufige Mitteilung
Authors: Müller Robert K. , Felix Dorothee , Schreiber J. , Eschenmoser A. 
Published: December 2004

AbstractThe thermally induced fragmentations of the hydrazones derived from phenylglyoxal and the diastereomeric 2,3‐diphenyl‐1‐amino‐aziridines and 2,3‐dimethyl‐1‐amino‐aziridines proceed with high stereospecificity.
études sur les composés organométalliques, VIII. Synthése du tétrabenzyltitane
Authors: Jacot‐Guillarmod André , Tabacchi Raffaele , Porret Jacques 
Published: December 2004

AbstractTetrabenzyltitane is prepared by reaction of TiCl4 on dibenzylmagnesium in pentane or hexane at – 20° in the presence of a small amount of ether.
Pyramidal Inversion in Cyclic Sulfonium Salts
Authors: Garbesi A. , Corsi N. , Fava A. 
Published: December 2004

Abstract5‐ and 6‐membered cyclic sulfonium salts carrying methyl substituents on the ring have been synthetized and partially resolved. These salts undergo thermal stereomutation at rates which are 103 times lower than that of non‐cyclic sulfonium cations. Very stringent evidence is presented that racemisation or, where the case may be, epimerisation takes place by pyramidal inversion of the sulfur atom.
Cardenolide aus dem chinesischen Krötengift Ch'an Su. Über Krötengifte, 35. Mitteilung
Authors: Höriger Niklaus , Linde Horst H. A. , Meyer Kuno 
Published: December 2004

AbstractFrom the toad venom Ch'an Su the cardenolides I, III and V have been isolated. It is the first time that cardenolides and bufadienolides are detected simultaneously in a biological material.
Recherches dans la série des cyclitols XXXIX RMN. de protons d'hydroxyles de cyclopentane‐ et de cyclopentène‐polyols
Authors: Cocu F. G. , Wolczunowicz G. , Bors L. , Posternak Th. 
Published: December 2004

AbstractSeveral mono‐, di‐, and tri‐hydroxy derivatives of cyclopentane and cyclopentene have been studied by NMR. spectroscopy. The chemical shifts and the coupling constants of the OH groups have been correlated with their position, with their configuration and, in some cases, with their conformation.
Bilirubinkonjugate der menschlichen Galle: Ausscheidung als Acylglykoside von Aldobiouron‐, Pseudoaldobiouron‐ und Hexuronosylhexuronsäuren
Authors: Kuenzle Clive C. , Rüttner Jacques R. , Eugster Conrad Hans 
Published: December 2004

AbstractDie Bilirubinderivate der menschlichen Galle wurden in Form ihrer Phenylazoverbindungen isoliert und durch mehrfache Verteilungschromatographie mit umgekehrten Phasen in 8 Fraktionen aufgetrennt (Azopigmente A1, A2 und B1 bis B6). Der Hauptanteil des Bilirubins erscheint in der Galle nicht wie bisher angenommen als Glucuronid, sondern als Acylglykoside von Aldobiouron‐, Pseudoaldobiouron‐ und Hexuronosylhexuronsäuren. Für die Hauptkomponenten schlagen wir die folgenden vorläufigen Strukturen vor (acyl = Acylrest des Aglykons):

Acyl‐(6‐O‐hexopyranosyluronsäure‐hexosid)
Acyl‐(4‐O‐hexofuranosyluronsäure‐glucosid)
Acyl‐(4‐O‐β‐D‐glucofuranosyluronsäure‐glucosid)
Acyl‐(4‐O‐(α‐D‐glucofuranosyl)‐β‐D‐glucosiduronsäure)
Acyl‐(4‐O‐(3‐C‐hydroxymethyl‐ribofuranosyluronsäure)‐β‐D‐glucosiduronsäure)
.
Chemical Structure Studies of Cow ϰ‐Casein: Study of the soluble tryptic peptides
Authors: Jollès Jacqueline , Alais Charles , Jollès Pierre 
Published: December 2004

AbstractThe sequences of 13 tryptic peptides of cow ϰA‐casein (accounting for about one half of the amino acid residues present in the protein) were established. The rennin sensitive linkage could be located in a large fragment (36 residues). ϰ‐casein consists of a hydrophilic part (ϰ‐caseino‐glycopeptide) and of a hydrophobic moiety (para‐ϰ‐casein); in this latter, however, several quite hydrophilic sequences were characterized. Another feature of the ϰ‐casein structure is the frequent duplication or triplication of certain amino acids (Pro‐Pro; Phe‐Phe; Gln‐Gln‐Gln‐Asn‐Glu‐Glu‐Glu; Pro‐Pro‐Lys‐Lys‐Asn‐Gln‐; etc. …).