title: 3-Aryl-1,2-diacetamidopropane derivatives as novel and potent NK-1 receptor antagonists.
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.
authors.affiliation: Central Nervous System Research, Lilly Research Laboratories, A Division of Eli Lilly and Company, Lilly Corporate Center, Indianapolis, Indiana 46285, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Hipskind
authors.forename: J J
authors.initials: JJ
authors.lastname: Howbert
authors.forename: R F
authors.initials: RF
authors.lastname: Bruns
authors.forename: S S
authors.initials: SS
authors.lastname: Cho
authors.forename: T A
authors.initials: TA
authors.lastname: Crowell
authors.forename: M M
authors.initials: MM
authors.lastname: Foreman
authors.forename: D R
authors.initials: DR
authors.lastname: Gehlert
authors.forename: S
authors.initials: S
authors.lastname: Iyengar
authors.forename: K W
authors.initials: KW
authors.lastname: Johnson
authors.forename: J H
authors.initials: JH
authors.lastname: Krushinski
authors.forename: D L
authors.initials: DL
authors.lastname: Li
authors.forename: K L
authors.initials: KL
authors.lastname: Lobb
authors.forename: N R
authors.initials: NR
authors.lastname: Mason
authors.forename: B S
authors.initials: BS
authors.lastname: Muehl
authors.forename: J A
authors.initials: JA
authors.lastname: Nixon
authors.forename: L A
authors.initials: LA
authors.lastname: Phebus
authors.forename: D
authors.initials: D
authors.lastname: Regoli
authors.forename: R M
authors.initials: RM
authors.lastname: Simmons
authors.forename: P G
authors.initials: PG
authors.lastname: Threlkeld
authors.forename: D C
authors.initials: DC
authors.lastname: Waters
authors.forename: B D
authors.initials: BD
authors.lastname: Gitter
mesh_terms: D000577:Amides / Q000737:chemistry / Q000494:pharmacology*; D000700:Analgesics / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D004558:Electric Stimulation; D004952:Esters / Q000737:chemistry / Q000494:pharmacology*; D006168:Guinea Pigs; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D064729:Neurokinin-1 Receptor Antagonists; D051381:Rats; D013045:Species Specificity; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D000577:Amides; D000700:Analgesics; D004952:Esters; D064729:Neurokinin-1 Receptor Antagonists