60058-91-5

Upstream product

• 7536-58-5 BOC-L-aspartic acid 4-benzyl ester 
• 65864-22-4 (S)-2-amino-3-phenylpropionamide hydrochloride 
• 5241-58-7 L-Phenylalanine amide 
• 26048-69-1 (S)-2-tert-Butoxycarbonylamino-succinic acid 4-benzyl ester 1-(4-nitro-phenyl) ester 
• 60058-69-7 (tert-butyloxycarbonyl)-β-benzyl-L-aspartyl-L-phenylalanine amide 
• 76-05-1 trifluoroacetic acid 

Downstream Products

• 97530-02-4 (tert-butyloxycarbonyl)-L-leucyl-β-benzyl-L-aspartyl-L-phenylalanine amide 
• 83443-88-3 Boc-Met(O)-Asp(OBzl)-Phe-NH₂ 
• 129594-08-7 Z-Orn(Boc)-Asp(OBzl)-Phe-NH₂ 
• 118333-46-3 Z-β-homo-D-Leu-Asp(OBzl)-Phe-NH2 
• 107327-02-6 C₅₇H₆₈N₁₀O₁₃ 
• 97530-09-1 (tert-butyloxycarbonyl)-L-tryptophyl-L-leucyl-ψ(CH2-NH)-β-benzyl-L-aspartyl-L-phenylalanine amide 
• 65864-24-6 Boc-Nle-Asp(OBzl)-Phe-NH₂ 
• 118247-71-5 Z-β-homo-Leu-Asp(OBzl)-Phe-NH2 

Relevant academic research and scientific papers

CCK-B agonist or antagonist activities of structurally hindered and peptidase-resistant Boc-CCK4 derivatives

Replacement of Met31 by (N-Me)Nle in CCK8 or CCK4 has been shown to improve the affinity and selectivity for CCK-B receptors. In order to obtain molecules with enhanced bioavailability, two novel series of protected tetrapeptides of the general formula Boc-Trp30-X-Asp-Y33 have been developed. Introduction of (N-Me)Nle and the bulky, aromatic naphthylalaninamide (Nal-NH2) in positions X and Y, respectively, does not greatly modify the affinity for guinea pig brain CCK-B receptors. In contrast, incorporation of hindering N-methyl amino acids such as (N-Me)Phe, (N-Me)Phg, or (N-Me)Chg, but not their non-methylated counterparts, in position X induced a large decrease in affinity for the CCK-B binding sites. Among the various peptides synthesized, Boc-[(N-Me)Nle31,1Nal- NH233]CCK4 (2) (K(I) = 2.8 nM), Boc-[Phg31,1Nal-NH233]CCK4 (15) (K(I) = 14 nM), and Boc-[Phg31,1Nal-N(CH3)233]CCK4 (17) (K(I) = 39 nM) displayed good affinities for brain CCK-B receptors and had good selectivity ratios. These pseudopeptides, in which the presence of unnatural and hydrophobic residues is expected to improve their penetration of the central nervous system, were shown to be very resistant to brain peptidases. Interestingly, whereas compounds 2 and 15 proved to be full agonists for rat hippocampal CCK-B receptors when measured in an electrophysiological assay, compound 17 behaved as a potent antagonist in the same test and displayed a good affinity in rat brain K(I)(CCK-B) = 51 nM as compared to the Merck antagonist L365,260, K(I)(CCK-B) = 12 nM. This illustrates a simple means to obtain CCK-B antagonists and suggests that the free, CONH2 group plays a critical role in the recognition of the agonist state of brain CCK-B receptors.

Aspartate Racemization in Synthetic Peptides. Part 2. Tendency to Racemization of Aminosuccinyl Residue

Aminosuccinyl (Asu) peptides, containing a strained ring system, are very vulnerable to epimerization and, during their formation, even as transients, in the presence of nucleophilic and nonnucleophilic bases, partial epimerization occurs.In the presence

Synthesis of gastrin antagonists, analogues of the C-terminal tetrapeptide of gastrin, by introduction of a β-homo residue

A series of analogues of Boc-Trp-Leu-Asp-Phe-NH2, a potent gastrin agonist, were synthesized by introducing a β-homo residue in the sequence. These compounds were tested in vivo on acid secretion, in the anesthetized rat, and for their ability

Synthesis and biological activities of some pseudo-peptide analogues of tetragastrin: The importance of the peptide backbone

Pseudo-peptide analogues of the C-terminal tetrapeptide of gastrin, in which a peptide bond has been replaced by a CH2-NH bond, i.e. (tert-butyloxycarbonyl)-L-tryptophyl-Ψ(CH2-NH)-L-leucyl-L-aspartyl-L-phenylalanine amide (8), (tert-