title: Structure-activity relationship studies of hemicholinium (HC-3) congeners.
abstract: In a continuing investigation of structural requirements for hemicholinium-like activity (inhibition of neuromuscular transmission due to inhibition of uptake of choline into nerve terminals), some additional molecular modifications of hemicholinium ("HC-3"; structure 1) were made. The target compounds were prepared by standard one- or two-step sequences. Noncyclic acetal moieties in general permitted retention of pharmacological activity, as did concomitant replacement of the central biphenyl "spacer" by other bulky cyclic groupings and replacement of the oxazinium rings by piperidine or 4-methylpiperidine. However, these modifications generally produced compounds of a lower potency. Replacement of the biphenyl moiety of HC-3 with polyakylene chains permitted retention of a considerable degree of activity. In these target compounds, the two quaternary nitrogens can exist the same distance apart (approximately 14 A) as in the hemicholinium molecule. The ditertiary amino congener of a pharmacologically active bis-quaternary oxazinium compound was almost completely inactive. To date, only one tertiary amine has been found which displays a significant degree of hemicholinium-like activity.
authors.affiliation: Division of Medicinal and Natural Products Chemistry, College of Pharmacy, University of Iowa, Iowa City 52242.
authors.forename: J G
authors.initials: JG
authors.lastname: Cannon
authors.forename: T M
authors.initials: TM
authors.lastname: Lee
authors.forename: Y
authors.initials: Y
authors.lastname: Chang
authors.forename: A M
authors.initials: AM
authors.lastname: Nyanda
authors.forename: B
authors.initials: B
authors.lastname: Bhattacharyya
authors.forename: J R
authors.initials: JR
authors.lastname: Flynn
authors.forename: T
authors.initials: T
authors.lastname: Chatterjee
authors.forename: R K
authors.initials: RK
authors.lastname: Bhatnagar
authors.forename: J P
authors.initials: JP
authors.lastname: Long
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002794:Choline / Q000378:metabolism; D006426:Hemicholinium 3 / Q000031:analogs & derivatives* / Q000494:pharmacology*; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009469:Neuromuscular Junction / Q000187:drug effects; D011817:Rabbits; D051381:Rats; D013055:Spectrophotometry, Infrared; D013329:Structure-Activity Relationship; D009435:Synaptic Transmission / Q000187:drug effects; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism
chemical_list: D006426:Hemicholinium 3; D002794:Choline