Adamska, Anna published the artcileSynthesis of linear and cyclic opioid-based peptide analogs containing multiple N-methylated amino acid residues, Formula: C25H23NO4, the publication is Journal of Peptide Science (2015), 21(11), 807-810, database is CAplus and MEDLINE.
A series of six novel opioid peptide analogs containing one to three N-methylamino acid residues, and six cyclic counterparts of these peptides were prepared by the solid-phase method. Introduction of two consecutive N-methylated amino acids, as well as cyclization of such conformationally constrained sequences, turned out to be challenging. The use of a recently reported triazine-based coupling reagent, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium toluene-4-sulfonate, enabled the synthesis and cyclization of the designed analogs in acceptable yields and with a lesser amount of byproducts than observed with the standard coupling reagents such as TBTU or HATU. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.
Journal of Peptide Science published new progress about 77128-73-5. 77128-73-5 belongs to ethers-buliding-blocks, auxiliary class Inhibitor, name is (S)-2-((((9H-Fluoren-9-yl)methoxy)carbonyl)(methyl)amino)-3-phenylpropanoic acid, and the molecular formula is C25H23NO4, Formula: C25H23NO4.
Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem