14317-83-0

Upstream product

• 2304-96-3 N-benzyloxycarbonyl-L-asparagine 
• 7517-19-3 methyl (L)-leucinate hydrochloride 
• 2666-93-5 (S)-Leu-OMe 
• 3256-57-3 N-benzyloxycarbonyl-L-asparagine p-nitrophenyl ester 

Downstream Products

• 87136-46-7 N^α-Benzyloxycarbonyl-N^ε-tert-butyloxycarbonyl-L-lysylglycyl-L-asparaginyl-L-leucine Lithium Salt 
• 87136-45-6 N^α-Benzyloxycarbonyl-N^ε-tert-butyloxycarbonyl-L-lysylglycyl-L-asparaginyl-L-leucine Methyl Ester 

Relevant academic research and scientific papers

Transesterification and other conversion reactions of acid derivatives, using an amidine base

A process employs amidine or amidine base and a metal compound in the presence of an alcohol or water to transesterify, or saponify esters or amides. Since the process employs relatively mild conditions, it is especially suitable for the production of optically active substances and biomolecules, e.g. peptides, amino acids and nucleic acids which are sensitive to elevated temperatures, extreme pH values and/or long reaction times since these compounds are easily racemised or denatured. The conditions additionally find use in solid phase systems. When amino acid or peptide esters are saponified, the splitting is brought about with lithium hydroxide alone under mild conditions. The use of an amidine base, more particularly DBU or DBN, in combination with the metal salt additionally accelerates the reaction so strongly that even sensitive acid derivatives can be reacted under mild conditions. The amidine based system lends itself to the manufacture of complex esters, gentle splitting of peptides from the carrier, gentle saponification of amides or esters.

Synthetic Studies on Sequences of Vitamin K Dependent Proteins. Gla-Arg-Gla Sequences

The synthesis of peptides containing the Gla-Arg-Gla sequence is reported.Nuclear magnetic resonance studies suggest that intramolecular salt bridge interactions occur between the guanidino group of arginine and the γ-carboxyglutamic acid.

Process for the manufacture of cystine-containing peptides

The invention concerns an improved process for the manufacture of cystine-containing peptides from cysteine-containing aminoacid sequences whose mercapto groups are protected by trityl groups, wherein the S-trityl cysteine-containing sequences are directly oxidized with iodine to yield the cystine disulfide bond.

Chlorosulfite, a Versatile and Mild Condensation Reagent for the Synthesis of Peptides

The title compound 5, which can be easily obtained from hexamethylphosphoric triamide (1) and thionyl chloride by catalysis of dimethylformamide, is succesfully applied as a mild condensation reagent for the synthesis of peptides.

N-acyl and desamino human calcitonin and analogs thereof

The new hypocalcaemically active peptides of formula I and corresponding compounds in which one or more of the asparagine and glutamic acid radicals are replaced by the aspartic acid or glutamic acid radical and/or the aspartic acid radical is replaced by the asparagine radical, their dimers, especially those in which 2 identical peptide sequences (1-32 and 1'-32') are joined in an anti-parallel arrangement via the cysteine radicals 1,7' and 7,1' by means of a disulfide bond, and derivatives are useful as hypocalcaemic agents and are prepared by splitting off groups protecting at least one amino or one carboxyl group or oxidizing the corresponding sulfides to the disulfides or condensing together adequate peptides.

Hypocalcaemic peptides and processes for their manufacture

Synthetic hypocalcaemic dotriacontapeptide of the formula H-Cys-Ser-Asn-Leu-Ser--Thr-Cys-Val-Leu-Ser-Ala-Tyr-Try-Arg-Asn-Leu-Asn-Asn-Phe-His-Arg-Phe-Ser-Gly-Met-Gly-Phe-Gly-Pro-Glu-Thr-Pro-OH I and analogues and derivatives, salts and complexes thereof and process for their manufacture.