Document Report Card

ID: ALA1129738

Journal: J Med Chem

Title: 3-Aryl-1,2-diacetamidopropane derivatives as novel and potent NK-1 receptor antagonists.

Authors: Hipskind PA, Howbert JJ, Bruns RF, Cho SS, Crowell TA, Foreman MM, Gehlert DR, Iyengar S, Johnson KW, Krushinski JH, Li DL, Lobb KL, Mason NR, Muehl BS, Nixon JA, Phebus LA, Regoli D, Simmons RM, Threlkeld PG, Waters DC, Gitter BD.

Abstract: Early structure-activity studies on racemic tryptophan ester and amide NK-1 antagonists 5-7 led to the discovery that the potency of the series could be markedly increased by moving the carbonyl function in these molecules to an off-chain position as in the 3-aryl-1,2-diacetamidopropane 9. Further medicinal chemistry incorporating this change resulted in the discovery of a novel series of highly potent aryl amino acid derived NK-1 antagonists of the R stereoisomeric series (IC50's = 100 pM to > 5 microM). Compounds in this series were shown to be competitive antagonists using an in vitro NK-1 smooth muscle assay, and this data correlated well with observed human NK-1 binding affinities. Two of these agents, (R)-25 and (R)-32, blocked intrathecal NK-1 agonist-driven [Ac-[Arg6,Sar9,Met(O2)11]- substance P 6-11 (Ac-Sar9)] nociceptive behavior in mice. Both compounds potently blocked the neurogenic dural inflammation following trigeminal ganglion stimulation in the guinea pig after intravenous administration. Further, upon oral administration in this model, (R)-32 was observed to be very potent (ID50 = 91 ng/kg) and have a long duration of action (> 8 h at 1 micrograms/kg). Compound (R)-32, designated LY303870, is currently under clinical development as an NK-1 antagonist with a long duration of action.

CiteXplore: 8576917

DOI: 10.1021/jm950616c