33033-71-5

Upstream product

• 21691-50-9 Ala-OtBu 
• 4816-89-1 Cbz-Phe-OCH₂CONH₂ 
• 3086-21-3 Z-Phe-O-Pcp 
• 13404-22-3 tert-butyl L-alaninate hydrochloride 
• 14470-30-5 N^α-benzyloxycarbonyl-L-phenylalanine anhydride 
• 60379-01-3 N-(benzyloxycarbonyl)-L-phenylalanine benzyl ester 
• 1161-13-3 N-Cbz-L-Phe 
• 35909-92-3 N-carbobenzoxy-L-phenylalanine methyl ester 
• 2578-84-9 N-benzyloxycarbonyl-L-phenylalanine p-nitrophenyl ester 

Downstream Products

• 481054-29-9 N-acetylglycyl-L-leucyl-3-chloro-L-alanyl-L-phenylalanyl-L-alanine tert-butyl ester 
• 481054-30-2 N-acetylglycyl-L-leucyl-3-chloro-L-alanyl-L-phenylalanyl-L-alanine 
• 481054-28-8 N-(benzyloxycarbonyl)-3-chloro-L-alanyl-L-phenylalanyl-L-alanine tert-butyl ester 
• 80870-40-2 H-Phe-Ala-OtBu 
• 98694-99-6 H-Phe-Ala-O-t-Bu*CH₃COOH 

Relevant academic research and scientific papers

Stereocontrolled [11C]Alkylation of N-Terminal Glycine Schiff Bases To Obtain Dipeptides

The use of various quaternary ammonium salts as chiral phase-transfer catalysts allowed effective and stereoselective radiochemical [11C]alkylation to obtain functionalized dipeptides. We herein report a broadly applicable procedure for the asymmetric [11C]alkylation of dipeptides to give labeled N-terminal peptides by using different [11C]alkyl halides. Contended stereoselectivities of the reactions were observed by using 11C-labeled alkyl halides, [11C]methyl iodide and [11C]benzyl iodide, and diastereomeric ratios with different specialized catalysts of 95:5 and 90:10 were achieved, respectively. Accordingly, the straightforward synthesis of enantioenriched compounds should play a vital role in peptide-based radiopharmaceutical development and positron emission tomography imaging.

Dehydroalanine-based inhibition of a peptide epimerase from spider venom.

Ribosomally produced peptides that contain D-amino acids have been isolated from a number of vertebrate and invertebrate sources. In each case, the D-amino acids are introduced by a posttranslational modification of a parent peptide containing only amino acids of the L-configuration. The only known enzyme to catalyze such a reaction is the peptide epimerase (also known as peptide isomerase) from the venom of the funnel web spider, Agelenopsis aperta. This enzyme interconverts two 48-amino-acid-long peptide toxins that differ only by the stereochemistry at a single serine residue. In this paper we report the synthesis and testing of two pentapeptide analogues that contain modified amino acids at the site normally occupied by the substrate serine residue. When the L-chloroalanine-containing peptide 3 was incubated with the epimerase it was converted into the dehydroalanine-containing peptide 4 via an elimination of HCl. The dehydroalanine peptide 4 was independently synthesized and found to act as a potent inhibitor of the epimerase (IC50 = 0.5 microM). These results support a direct deprotonation/reprotonation mechanism in which a carbanionic intermediate is formed. The observed inhibition by 4 can be attributed to the sp(2)-hybridization of the alpha-carbon in the dehydroalanine unit that mimics the planar geometry of the anionic intermediate.

Cross-linked crystals of subtilisin: Versatile catalyst for organic synthesis

Cross-linked enzyme crystals (CLECs) of subtilisin exhibit excellent activity in aqueous and various organic solvents. This catalyst is more stable than the native enzyme in both aqueous and mixed aqueous/organic solutions. Subtilisin-CLEC was shown to be a versatile catalyst. It was used for the syntheses of peptides and peptidomimetics, mild hydrolysis of amino acid and peptide amides, enantio- and regioselective reactions, and transesterifications.

Lithium-salt effects in peptide synthesis. Part I: Conditions for the use of lithium-salts in coupling reactions

The influence of Li-salts on the course of peptide-coupling reactions was investigated. As a model for segment couplings, Ac-Phe-OH was coupled to HCl . H-Ala-OMe using the mixed anhydride, DCCl, DCCl/HOBt, BOPCastro and TBTU-Knorr methods. As a model for

On the Use of Carboxamidomethyl Esters in the Protease-Catalyzed Peptide Synthesis

Carboxyamidomethyl esters (CAM esters) of Z-and Boc-protected alanine and phenylalanine were prepared in order to investigate their usefulness as substrates for α-chymotrypsin- and papain-catalyzed hydrolysis and peptide synthesis reactions.The easy removal of the CAM-C-protecting group under mild conditions and dependent on the enzyme specificity was demonstrated.Examples are given for the protease-catalyzed synthesis of various peptide derivatives using CAM esters as C- and N-components in aqueous-organic media.Comparatively short reaction times were observed. - Key words: Carboxyamidomethyl ester as C-protecting group; Enzymatic deprotection; Peptide synthesis; α-Chymotrypsin- and Papain-catalyzed peptide bond formation