title: Focused library development of 2-phenylacrylamides as broad spectrum cytotoxic agents.
abstract: With our lead compound (E)-3-(4-chlorophenyl)-2-(1H-pyrrole-2-carbonyl)acrylonitrile (1) inducing 50% growth inhibition of 11 cancer cell lines at 27-61 μM, potency enhancements were rapidly established through the synthesis of a series of focused compound libraries. Six highly focused libraries (46 compounds in total) were synthesised. Each library allowed the identification of a new lead compound, viz Library A identified (E)-3-(pentafluorophenyl)-2-(1H-pyrrole-2-carbonyl)acrylonitrile (11) and (E)-3-(1H-indol-3-yl)-2-(1H-pyrrole-2-carbonyl)acrylonitrile (13) as inhibitors with improved cytotoxicity. Synthesis of discrete libraries of amidoacrylamide analogues (Ar-CC(CN)-Ar✠Ar-CC(CN)-C(O)NH)-Ar) resulted in a series of analogues significantly more potent that the lead, 1. Three furan three analogues: (E)-3-(5-chlorofuran-2-yl)-2-cyano-N-(4-methoxybenzyl)acrylamide (33), (E)-3-(5-bromofuran-2-yl)-2-cyano-N-(4-methoxybenzyl)acrylamide (34) and (E)-2-cyano-3-(furan-3-yl)-N-(4-methoxybenzyl)acrylamide (37) returned broad spectrum growth inhibition (GI(50) values of 5-16 μM). Replacement of the furan moiety with simple aromatics gave an additional three analogues: (E)-2-cyano-N-(4-methoxybenzyl)-3-phenylacrylamide (39), (E)-3-(4-chlorophenyl)-2-cyano-N-(4-methoxybenzyl)acrylamide (41) and (E)-2-cyano-N-(4-methoxyphenyl)-3-(naphthalen-1-yl)acrylamide (45) with GI(50) values of 7-24 μM. The final library retained the aromatic substituents but introduced a 3,4-dichlorbenzylamine moiety to afford the 1-naphthyl substituted 52, which was the most potent broad spectrum cytotoxic analogue produced here in with an average GI(50)=8.6 μM. This represents a fivefold potency enhancement relative to 1 and a new cytotoxic scaffold suitable for further development.
authors.affiliation: Centre for Chemical Biology, Chemistry, The University of Newcastle, University Drive, Callaghan, NSW 2308, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: Tarleton
authors.forename: Lauren
authors.initials: L
authors.lastname: Dyson
authors.forename: Jayne
authors.initials: J
authors.lastname: Gilbert
authors.forename: Jennette A
authors.initials: JA
authors.lastname: Sakoff
authors.forename: Adam
authors.initials: A
authors.lastname: McCluskey
mesh_terms: D000178:Acrylamides / Q000737:chemistry* / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003603:Cytotoxins / Q000737:chemistry / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D009369:Neoplasms / Q000188:drug therapy; D013329:Structure-Activity Relationship
chemical_list: D000178:Acrylamides; D000970:Antineoplastic Agents; D003603:Cytotoxins