157974-05-5

Upstream product

• 7732-18-5 water 
• 4530-37-4 N-t-butyloxycarbonylglycyl-L-phenylalanine 
• 543-27-1 isobutyl chloroformate 
• 4530-20-5 BOC-glycine 
• 1393121-84-0 Boc-Gly-N-MePhe-OMe 
• 7524-50-7 methyl (2S)-2-amino-3-phenylpropanoate hydrochloride 
• 106624-70-8 methyl (2S)-2-[[2-(t-butoxycarbonylamino)acetyl]amino]-3-phenylpropanoate 
• 37553-64-3 (S)-methyl 2-((tert-butoxycarbonyl)(methyl)amino)-3-phenylpropanoate 
• 19460-86-7 (N-methyl)-L-phenylalanine methyl ester hydrochloride 
• 17193-30-5 (S)-(+)-α-methylamino-β-phenylpropionamide 

Relevant academic research and scientific papers

Study of intramolecular aminolysis in peptides containing N-alkylamino acids at position 2

Many peptides and proteins, containing Nα-alkylamino acids (including proline) at the second position, are prone to intramolecular aminolysis (IA) with elimination of N-terminal dipeptide sequence as 2,5-diketopiperazines (DKP). We synthesized a series of short peptides, containing N-alkylamino acids at position 2, and studied their stability in the presence of acetic acid and amines. The presence of side chains in the second and the third amino acid residues and alkylation at Nα of the third amino acid residue slowed down IA. Nα-Alkyl residue in the first amino acid residue impeded IA only in peptides, containing three or more residues. Side chains of the first amino acids did not affect significantly the cleavage rates. Acetic acid promoted IA more strongly than aqueous ammonia, while tertiary amines were less effective. Peptides with methionine-S-oxide residues were more labile than the unoxidized analogs, suggesting intramolecular assistance of the S-oxide group in aminolysis. Surprisingly, intermediate compounds of the formula Boc-Met-MeXaa-Sar-NHR underwent rapid cleavage (endopeptolysis) upon attempted acidolytic deprotection.

Novel Asp32-replacement tetrapeptide analogues as potent and selective CCK-A agonists

A series of novel CCK tetrapeptide analogues of the general formula Boc- Trp-Lys(Tac)-N(R)-(CH2)(n)CON(R')Phe-NH2 (Tac = o-tolylaminocarbonyl), where R,R' = H or Me and n = 1-5, have been synthesized and tested. These analogues, which lack an acidic residue at the penultimate position, demonstrated surprisingly high CCK-A receptor affinity and selectivity. The effect of N-methylation pattern on CCK-A receptor affinity showed consistent trends for analogues in which n = 1, 2, or 3, with the di-N-methylated analogues having the highest affinity in each case. However, none of these analogues had full agonist activity, as measured by percent maximal PI hydrolysis. Two conformationally constrained analogues also demonstrated high CCK-A receptor affinity and selectivity, as well as nearly maximal agonist activity. In addition, one of these conformationally-constrained analogues demonstrated anorectic activity in rats.

Enkaphalin derivatives

Novel analgesic and antipsychotic agents having the formula STR1 wherein Q is STR2 in which R1 is hydrogen, hydroxy or halogen and R4 is hydrogen or, R1 and R4 are both hydroxy; Z is hydrogen or straight chain lower alkyl having from 1 to 4 carbon atoms and X is methylene, carbonyl, hydroxymethylene, thio, sulfinyl or sulfonyl, or Z and X, taken together, are methylidenyl, with the proviso that when X is sulfonyl or sulfinyl, Z is other than hydrogen; R5 is hydrogen or halogen, and R2 is H, a straight or branched lower alkyl group having from 1 to 4 carbon atoms, the group STR3 or the group STR4 wherein R3 is hydroxy, amino, alkylamino or dialkylamino wherein the alkyl moiety is straight or branched and has from 1 to 4 carbon atoms, diastereomers, enantiomers and pharmaceutically acceptable salts thereof.