Deamino-oxytocin

Time-resolved fluorescence and proton NMR studies of tyrosyl residues in oxytocin and small peptides: correlation of NMR-determined conformations of tyrosyl residues and fluorescence decay kinetics

“…One oxytocin analogue, desaminodicarbaoxytocin, also displayed in Figure 1, has the disulfide bridge replaced with an ethylene bridge and lacks the N-terminal amino group (Jost & Rudinger, 1967). The second analogue, desaminooxytocin (not shown), lacks the N-terminal amino group (Ferrier et al, 1965). Of these three peptides, only oxytocin has been extensively characterized in aqueous solution by NMR (Glickson et al, 1972;Richard-Brewster et al, 1973;Bradbury et al, 1974;Hruby, 1974;Glickson, 1975;Wyssbrod et al, 1977).…”

Synthesis of deaminooxytocin by the solid phase method

“…The O-benzyl-L-tyrosine and S-benzyl-3mercaptopropionic acid residues were incorporated onto the Boc-lisoleucyllglutaminy 1 -lasparaginyl -S-benzyl-L-cysteinyl-L-prolyl-L-leucylglycyl nitrated resin utilizing steps 1-12 of the reaction cycle previously described and using a 15-ml portion of the appropriate solvent for each washing. Solutions of 1.98 mmol of the protected amino acid in 12 ml of methylene chloride and of 1.98 mmol of , '-cyclohexylcarbodiimide in 3 ml of methylene chloride were used in steps 9 and 10, respectively. The coupling reactions were allowed to proceed overnight.…”

Stability Enhancing N-Terminal PEGylation of Oxytocin Exploiting Different Polymer Architectures and Conjugation Approaches

“…This led to an increase in the stability of aqueous solutions of the peptide highlighting the potential of applying PEGylation as a method for reducing degradation of this therapeutic. Moreover, previous modifications at the N -terminal amine where the free amino group is lacking from the structure of the peptide (desamino-oxytocin) have shown high levels of uterine contractility proving potentially more potent than the native peptide as an oxytocic drug. − A further oxytocin analogue that has proved fairly successful is carbetocin (1-deamino-1-monocarba-[2- O -methyltyrosine]-oxytocin), which also has changes to the amino groups, along with other structural modifications. This octapeptide oxytocin alternative has been approved for human and veterinary use in several countries and provides effective uterotonic activity while maintaining a higher stability than the native peptide. , Amino targeting chemistry is site selective for oxytocin as the only amine group present on the peptide structure is that at the N -terminus, leading to the possibility of only one site of polymer attachment.…”