35010-98-1

Upstream product

• 21691-53-2 L-leucine tert-butyl ester 
• 1138-80-3 N-(Benzyloxycarbonyl)glycine 
• 1212-53-9 methyl N-benzyloxycarbonylglycinate 
• 2748-02-9 L-leucine tert-butyl ester hydrochloride 
• 80682-32-2 tert-butyl leucinate hydrotosylate 

Downstream Products

• 80682-33-3 (S)-2-(2-Amino-acetylamino)-4-methyl-pentanoic acid tert-butyl ester; compound with toluene-4-sulfonic acid 

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.

Carbohydrate Protease Conjugates: Stabilized Proteases for Peptide Synthesis

The synthesis of oligopeptides using stable carbohydrate protease conjugates (CPCs) was examined in acetonitrile solvent systems.CPC was used for the preparation of peptides containing histidine, phenylalanine, tyrosine, and tryptophan in the P1 position in 60-93percent yield.The CPC was used to synthesize peptides containing both hydrophilic and hydrophobic amino acids.The P2 specificity of papain for aromatic residues was utilized for the 2 + 3 coupling of Z-Tyr-Gly-OMe to H2N-Gly-Phe-Leu-OH to generate the leucine enkephalin derivative in 79percent yield.Although papain is nonspecific for the hydrolysis of N-benzyloxycarbonyl amino acid methyl esters in aqueous solution, the rates of synthesis for these derivatives with nucleophile leucine tert-butyl ester differed by nearly 2 orders of magnitude.CPC was used to prepare the aspartame precursor Z-Asp-Phe-OMe in 90percent yield.The increased stability of CPCs prepared from periodate-modified poly(2-methacrylamido-2-deoxy-D-glucose), poly(2-methacrylamido-2-deoxy-D-galactose), and poly(5-methacrylamido-5-deoxy-D-ribose), carbohydrate materials designed to increase the aldehyde concentration in aqueous solution, suggests that the stability of CPCs is directly related to the aldehyde concentration of the carbohydrate material.Periodate oxidation of poly(2-methacrylamido-2-deoxy-D-glucose) followed by covalent attachment to α-chymotrypsin gave a CPC with catalytic activity in potassium phosphate buffer at 90 deg C for 2 h.

PEPTIDES-XXXXV. SYNTHESIS OF THE 118-129 FRAGMENT OF A LYSOZYME ANALOGUE

The synthesis of the (118-129) fragment of a Lysozyme analogue was achieved by the fragment coupling approach.The fragments were assembled using the DCCI/HONSu method and the (118-122), (123-126) and (127-129) subfragments were each built up in a stepwise

Pseudosymmetry in the structure of luteinizing hormone releasing hormone studies on a series of novel analogs

Pseudosymmetry in the LH RH structure is described. Eleven analogs of LH RH (2) have been synthesized by the fragment condensation method and the repetitive excess mixed anhydride method. Multiple subs

[8 Homoarginine]luteinizing hormone releasing hormone

The synthesis and LH releasing activity of [8 homoarginine] LH RH are described. Its biological activity is discussed in relation to that of other analogues with substitutions in position 8. Although in homoarginine the positive charge of the guanidino gr