13257-67-5Relevant articles and documents
Regioselectivity in the Catalytic Hydrogenolysis of 1-Amino-1-cyclopropanecarboxylic Acid and Its Methyl Ester
Isogai, Koji,Sakai, Jun-ichi,Yamauchi, Keiji,Watanabe, Katsuya
, p. 2839 - 2842 (1986)
The title compounds were hydrogenolyzed over Pd-C.The ring-bond cleavage in the hydrogenolysis of the acid in water or methanol occurred at both the C1-C2 bond and the C2-C3 bond in nearly equal proportion, whereas the C1-C2 bond was cleaved mainly in the presence of ammonia and the C2-C3 bond was cleaved mainly in acetic acid.Selective hydrogenolysis of the C1-C2 bond of ester occurred in hexane or methanol, whereas the C2-C3 bond was hydrogenolyzed mainly in acetic acid.The role of the amino group is discussed.
Structural characterization of folded pentapeptides containing centrally positioned β(R)Val, γ(R)Val and γ(S)Val residues
Dinesh, Bhimareddy,Basuroy, Krishnayan,Shamala, Narayanaswamy,Balaram, Padmanabhan
, p. 4374 - 4380 (2012)
A cylindrical pore of ～7.5 diameter containing a one-dimensional water wire, within the confines of a hydrophobic channel lined with the valine side chain, has been observed in crystals of the peptide Boc-d-Pro-Aib-Val-Aib-Val- OMe (1) (Raghavender et al., 2009, 2010). The synthesis and structural characterization in crystals of three backbone homologated analogues Boc-d-Pro-Aib-β3(R)Val-Aib-Val-OMe (2), Boc-d-Pro-Aib- γ4(R)Val-Aib-Val-OMe (3), Boc-d-Pro-Aib-γ4(S) Val-Aib-Val-OMe (4) are described. Crystal structures of peptides 2, 3 and 4 reveal close-packed arrangements in which no pore was formed. In peptides 2 and 3 the N-terminus d-Pro-Aib segment adopted conformations closely related to Type II′ β-turns, while residues 2-4 form one turn of an αβ right-handed C11 helix in 2 and an αγ C12 helix in 3. In peptide 4, a continuous left-handed helical structure was observed with the d-Pro-Aib segment forming a Type III′ β-turn, followed by one turn of a left-handed αγ C12 helix.
Tetrazole as a Replacement of the Electrophilic Group in Characteristic Prolyl Oligopeptidase Inhibitors
Kilpel?inen, Tommi P.,Tyni, Jonna K.,Lahtela-Kakkonen, Maija K.,Etel?inen, Tony S.,My?h?nen, Timo T.,Wallén, Erik A. A.
supporting information, p. 1635 - 1640 (2019/12/02)
4-Phenylbutanoyl-aminoacyl-2(S)-tetrazolylpyrrolidines were studied as prolyl oligopeptidase inhibitors. The compounds were more potent than expected from the assumption that the tetrazole would also here be a bioisostere of the carboxylic acid group and the corresponding carboxylic acids are at their best only weak inhibitors. The aminoacyl groups l-prolyl and l-alanyl gave potent inhibitors with IC50 values of 12 and 129 nM, respectively. This was in line with typical prolyl oligopeptidase inhibitors; however, we did observe a difference with N-methyl-l-alanyl, which gave potent inhibitors in typical prolyl oligopeptidase inhibitors but not in our novel compound series. Furthermore, all studied 4-phenylbutanoyl-aminoacyl-2(S)-tetrazolylpyrrolidines decreased α-synuclein dimerization at the concentration of 10 μM, also when they were only weak inhibitors of the proteolytic activity of the enzyme with an IC50 value of 205 μM. Molecular docking studies revealed that the compounds are likely to bind differently to the enzyme compared to typical prolyl oligopeptidase inhibitors represented in this study by 4-phenylbutanoyl-aminoacyl-2(S)-cyanopyrrolidines.
Synthesis of peptides employing protected-amino acid halides mediated by commercial anion exchange resin
Bhaskara Redddy,Kumari, Y. Bharathi,Ananda, Kuppanna
, p. 225 - 229 (2013/12/04)
Coupling of protected-amino acid halides (chloride, fluoride) mediated by commercial anion exchange resin for the solution phase synthesis of peptides is described. The reaction was carried out in an organic medium, circumventing the use of an organic base or an inorganic base. The coupling is fast, clean and racemization free. The anion exchange resin functions as a solid-phase basic scavenger, soaking up the HCl produced and allowing the amine to react. The method is extended for the coupling of sterically hindered α,α,- dialkylamino acids. Graphical Abstract: [Figure not available: see fulltext.]
