503073-40-3Relevant academic research and scientific papers
Phosphinic Dehydrodipeptides: Diversification of the P1′ Residue with the Morita–Baylis–Hillman Acetates and Inhibition of Alanyl Aminopeptidases
Talma, Micha?
, p. 2109 - 2117 (2020/01/11)
Activated allyl acetates (the Morita–Baylis–Hillman acetates) were confirmed as convenient electrophilic precursors of the P1′ fragment of phosphinic dehydrodipeptides, and then, their selected saturated analogs were obtained in the subsequent reduction. This approach is particularly appropriate for structurally complex side chains and thus is an alternative to the addition of α-substituted acrylates with aminoalkylphosphinic acids. While phosphinic dehydrodipeptides were found to be good inhibitors of two mammalian alanyl metalloaminopeptidases, the saturated compounds showed higher activities than their structurally constrained counterparts. Docking calculations and molecular modeling showed that conformational freedom allowed for the favorable binding of distinct stereoisomers of phosphinates, while the presence of the double bond was more restrictive.
Structure-activity relationships of GHRP-6 azapeptide ligands of the CD36 Scavenger Receptor by solid-phase submonomer azapeptide synthesis
Sabatino, David,Proulx, Caroline,Pohankova, Petra,Ong, Huy,Lubell, William D.
, p. 12493 - 12506 (2011/10/09)
The cluster of differentiation 36 (CD36) class B scavenger receptor binds a variety of biologically endogenous ligands in addition to synthetic peptides (i.e., growth hormone-releasing peptides, GHRPs), which modulate biological function related to anti-angiogenic and anti-atherosclerotic activities. Affinity labeling had previously shown that GHRP-6 analogues such as hexarelin, [2-Me-W2]GHRP-6 (1), bind to the lysine-rich domain of the CD36 receptor. Moreover, the azapeptide analogue [aza-F4]GHRP-6, 2, exhibited a characteristic β-turn conformation as described by CD and NMR spectroscopy and a slightly higher CD36 binding affinity relative to hexarelin (1.34 and 2.37 μM, respectively), suggesting receptor binding was mediated by the conformation and the aromatic residues of these peptide sequences. Ligand-receptor binding interactions were thus explored using azapeptides to examine influences of side-chain diversity and backbone conformation. In particular, considering that aromatic cation interactions may contribute to binding affinity, we have explored the potential of introducing salt bridges to furnish GHRP-6 azapeptide ligands of the CD36 receptor. Fifteen aza-glutamic acid analogues related to 2 were prepared by submonomer solid-phase synthesis. The azapeptide side chains were installed by novel approaches featuring alkylation of resin-bound semicarbazone with Michael acceptors and activated allylic acetates in the presence of phosphazene base (BTPP). Moreover, certain Michael adducts underwent intramolecular cyclization during semicarbazone deprotection, leading to novel pyrrazoline and aza-pyroglutamate N-terminal residues. Structural studies indicated that contingent on sequence the [aza-Glu]GHRP-6 analogues exhibited CD spectra characteristic of random coil, polyproline type II and β-turn secondary structures in aqueous media. In covalent competition binding studies with the GHRP-6 prototype hexarelin bearing a radiotracer, certain [aza-Glu]GHRP-6 azapeptides retained relatively high (2-27 μM) affinity for the CD36 scavenger receptor.
The Baylis-Hillman chemistry in aqueous media: Elucidation of mechanism for synthesis of ether side-product leads to an efficient approach to C-O bond formation
Patra,Roy,Joshi,Roy,Batra,Bhaduri
, p. 663 - 670 (2007/10/03)
The formation of an ether from the Baylis-Hillman (BH) adduct during the BH reaction of 5-isoxazolecarboxaldehydes is a common phenomenon if the reaction is allowed to proceed for longer periods. The amount of formation of such ethers depends on the acryl
