New degradation product of des-Gly10-NH2-LH-RH-ethylamide (fertirelin) in aqueous solution.
A new degradation product was found in an ampule preparation of des-Gly10-NH2-LH-RH-ethylamide (fertirelin) stored at room temperatures. The same product, produced at a higher temperature, was identified to be a diastereomeric mixture of cyclo(His-Trp) by proton nuclear magnetic resonance spectroscopy, mass spectrometry, and comparison with authentic samples. Preferred conformations regarding substituents on the diketopiperazine ring of cyclo(His-Trp) were calculated using coupling constants between vicinal protons.
Okada
J
J
Animal Health Research Laboratories, Takeda Chemical Industries, Ltd., Osaka, Japan.
Seo
T
T
Kasahara
F
F
Takeda
K
K
Kondo
S
S
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013058:Mass Spectrometry; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D012996:Solutions
D012996:Solutions; D007987:Gonadotropin-Releasing Hormone; C009936:fertirelin