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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 112 (1981), S. 1313-1323 
    ISSN: 1434-4475
    Keywords: Crosslinking mechanism ; N-Alkyl-1,4-dihydropyridines ; N,N′-Alkyl-1,5-diiminopentanes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The interaction of glutaraldehyde with model aliphatic amines was studied in order to understand the crosslinking reaction of glutaraldehyde with proteins. The reaction in organic solvents gave N-alkyl-1,4-dihydropyridines and N,N′-dialkyl-1,5-diiminopentanes. The isolated products are new or were previously described by us for the first time1. Hydration of the reaction products led to stable N-alkylpiperidines and N,N′-dialkyl-1,5-diaminopentanes. In aqueous solution the reaction depends on thepH: at apH above 7, N-alkyl-1,4-dihydropyridines and at apH below 7, polymers were obtained. For the crosslinking reaction of proteins with glutaraldehyde the following mechanism is proposed: Monomeric glutaraldehyde reacts with the protein to give intermediate N-alkyl-2,6-dihydroxypiperidines. Intramolecular dehydration leads to the corresponding N-alkyl-1,4-dihydropyridines. Condensation of the cyclic monohydrate of glutaraldehyde and N-alkyl-2,6-dihydroxypiperidines gives linear polymeric crosslinks containing α-oxo-N-alkylpiperidine units.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Durch ein spezielles Reduktionsverfahren mit LiAlH4 wurden aus Glycyl-L-phenylalanyl-L-phenylalanin 1-Amino-3.6-diaza-4.7-dibenzyl-octanol-(8) (II), aus Glycyl-L-phenylalanyl-L-phenylalanyl-L-tyrosin 1-Amino-3.6.9-triaza-4.7-dibenzyl-10-[p-hydroxy-benzyl]-undecanol-(11)-kalium (III) und aus Carbobenzoxy-glycyl-L-phenylalanyl-L-phenylalanin 1-Methylamino-3.6-diaza-4.7-dibenzyl-octanol-(8) (I) dargestellt. Die Polyamine wurden als Oxalate isoliert und analysiert.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Das in der Phenylalaninkette des Insulins enthaltene Pentapeptid L-seryl-L-histidyl-leucyl-L-valyl-L-glutaminsäure erhielten wir durch gliedweisen Aufbau vom Carboxylende her. Ferner wurden L-Valyl-L-glutaminsäure und L-Leucyl-L-valyl-L-glutaminsäure aus den entsprechenden geschützten Derivaten dargestellt.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 731 (1970), S. 91-100 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Peptides, LXXIV1). Synthesis of the Insulin Sequence (B 1-16)2 as a Symmetrical Disulfide2)In order to synthesize insulin by a method avoiding the problems of sulfur protecting groups, the protected bishexadecapeptide (B 1-16)2, [Z-Phe-Val-Asn-Gln-His-Leu-Cys(-)-Gly-Ser(But)-His-Leu-Val-Glu-(OBut)-Ala-Leu-Tyr(But)-OMe]2 (15), is synthesized by an azide coupling of the disulfide (B 1-8)2 (8) with an excess of the octapeptide derivative B 9-16 (13). 8 is obtained by a stepwise procedure using [Z-Cys(-)-ONp]2.
    Notes: Für eine neue Insulin-Synthese wird unter Umgehung des Schwefelschutzgruppen-Problems das geschützte Bis-hexadecapeptid (B 1-16)2, [Z-Phe-Val-Asn-Gln-His-Leu-Cys(-)-Gly-Ser(But)-His-Leu-Val-Glu(OBut)-Ala-Leu-Tyr(But)-OMe]2 (15), durch Azidkupplung des Disulfids der Sequenz (B 1-8)2 (8) mit überschüssigem Octapeptid-Derivat B 9-16 (13) hergestellt. 8 wird durch stufenweise Kettenverlängerung unter Verwendung von [Z-Cys(-)-ONp]2 erhalten.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 740 (1970), S. 1-17 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Peptides, LXXIX1).Merrifield-Synthesis of Symmetrical Cystine Peptides2)The problem of sulfur protection in peptide chemistry can be circumvented by synthesis of symmetrical cystine peptides. Such peptides are available by the Merrifield method as follows: Coupling of excess bis-tert.-butyloxycarbonyl-cystine or of the corresponding bis-2,4,5-trichlorophenyl ester with an aminoacyl resin leads to the formation of resin-bound symmetrical and mixed disulfides. After reduction with a large excess of thiophenol, the unreacted cystinehalves are washed out. The disulfide bridges are regenerated by subsequent oxidation with air in the presence of iron(III)-sulfate in dimethyl sulfoxide/methylene chloride, or with a small excess of di-α-pyridyldisulfide to form the desired resin bound symmetrical cystine peptide. However, an elongation of this peptide without side reactions is only possible, if the cystine residue is separated from the binding site on the resin by more than one amino acid residue.
    Notes: Das Problem der Schwefel-Schutzgruppen in der Peptidchemie kann durch die Synthese symmetrischer Cystinpeptide umgangen werden. Diese lassen sich auch nach der Merrifield-Methode gewinnen: Bei der Kupplung von überschüssigem Bis-tert.-butyloxycarbonyl-cystin oder dessen Bis-2.4.5-trichlor-phenylester mit einem Aminoacyl-Harz entsteht ein Gemisch von Träger-gebundenen symmetrischen und gemischten Disulfiden. Nach Reduktion mit einem großen Überschuß Thiophenol werden die nicht-umgesetzten Cystin-Hälften ausgewaschen und bei der anschließenden Oxydation mit Luft in Gegenwart von Eisen(III)-sulfat in Dimethylsulfoxid/Methylenchlorid oder mit einem geringen Überschuß Di-α-pyridyldisulfid die Disulfid-Brücken unter Bildung des gewünschten Harz-gebundenen symmetrischen Cystinpeptids regeneriert. Eine Verlängerung dieses Peptids gelingt ohne Nebenreaktionen nur dann, wenn das Cystin durch mehr als eine Aminosäure von der Bindungsstelle am Harz getrennt ist.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Synthesis of Monomeric, Cyclic Cystine-peptide Derivatives, I. - The Synthesis of the Sequence A 6-9 of Sheep Insulin as Cyclocystine DerivativeThe synthesis of the sequence A 6-9 of sheep insulin in the protected form: Boc-Cys-Cys-Ala-Gly-OBut (5) is reported. The chemical reactivity of the monomeric, cyclic cystine-containing peptide with common reagents in peptide chemistry (boron tri-fluoride/glacial acetic acid, triethylamine and hydrazine hydrate) is evaluated.
    Notes: Es wird die Synthese der Sequenz A 6-9 des Schafinsulins in der geschützten Form Boc-Cys-Cys-Ala-Gly-OBut (5) sowie das Verhalten dieses monomeren cyclischen Cystinpeptidderivates gegenüber den in der Peptidchemie gebräuchlichen Reagenzien Bortrifluorid/Eisessig, Triäthylamin und Hydrazinhydrat beschrieben.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1975 (1975), S. 1092-1106 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Peptides 981). - Synthesis of the A-chain of Sheep Insulin with S-Tetrahydropyranyl Protecting GroupsTeh synthesis of a fully protected A-chain of sheep insulin is described. Teh acid labile protecting groups used were: tert. butyl substitution for teh carboxylic and hydroxy functions, tetrahydropyranyl for the thiol function, and the 2-(p-biphenylyl)isopropyloxycarbonyl group for amine protection. Total deblocking was achieved with thiocyanogen in a mixture of acetic acid and trifluoroacetic acid. After purification in the tetra S-sulfonate form, the A-chain was combined with native B-chain to yield crystallizable sheep insulin.
    Notes: Die A-Kette des Schafinsulins wurde in vollständig geschützter Form synthetisiert. Dabei wurden ausschließlich besonders säurelabile Schutzgruppen verwandt, und zwar für die Carboxyl- und Hydroxyfunktionen solche vom tert.-Butyltyp, für die Thiolgruppen der Cysteinreste die Tetrahydropyranylgruppe und als Aminoschutz die 2-(p-Biphenylylisopropyloxycarbonylgruppe. Die vollständige Deblockierung der Peptidkette erfolgt mit Dirhodan in Essigsäure/Trifluoressigsaure. Nach Reinigung über das Tetra-S-sulfonat wurde das Peptid mit nativer B-Kette zu halbsynthetischem, kristallisierbarem Schafinsulin umgesetzt.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Peptides, 99. Monomeric Cyclic Cystine Peptide Derivatives, III. - Synthesis of Sheep Insulin A-chain Sequences A2 - 21 and A1 - 21 as Monomeric Cyclic Dicystine Peptide DerivativesThe synthesis of the sheep-insulin A-chain sequences A1 - 21 and A2 - 21 as monomeric cyclic dicystine peptide derivatives is described. Fully protected A-chain derivatives have previously eluded purification owing to their insolubility in organic solvents. This difficulty was overcome by the use of the intrachain cystine bridges A6 - 7 and A11 - 20, miking the derivatives 13 and 15 fully soluble in dimethylformamide. The protecting groups of these derivatives 13 and 15 are quantitatively removed using trifluoracetic acid and 2-mercapto- ethanol.
    Notes: Die Synthese der Sequenzen A2 - 21 (13) und A1 - 21 (15) der Schafinsulin-A-Kette als monomere cyclische Dicystinpeptidderivate wird beschrieben. Die intrachenaren Cystinbrücken A6 - 7 und A 11  - 20 vermitteln die Löslichkeit dieser Derivate in Dimethylformamid und ermöglichen erstmalig die Reindarstellung vollgeschützter Insulin-A-Kettenderivate. Die während der Synthese eingesetzten Schutzgruppen lassen sich mittels Trifluoressigsäure und 2-Mercaptoäthanol quantitativ entfernen.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 618 (1958), S. 158-166 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Entsprechend der früher3) beschriebenen Synthese cyclischer Oligomerer der ε-Aminocapronsäure wurden das Hepta-, Okta- und Nonamere (n = 7, 8, 9) [NH(CH2)5CO]n dargestellt. Die Synthese gelang mit der Azid-Methode aus Carbobenzoxy-oligo-ε-aminocapronsäure-hydrazid.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Das in der Phenylalaninkette des Insulins vorkommende Pentapeptid l-Alanyl-l-leucyl-l-tyrosyl-l-leucyl-l-valin wurde aus Carbobenzoxy-l-alanyl-l-leucin und l-Tyrosyl-l-leucyl-l-valin synthetisiert und sein säurehydrolytischer und enzymatischer Abbau untersucht.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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