title: Invariom structure refinement, electrostatic potential and toxicity of 4-O-methylalpinumisoflavone, O,O-dimethylalpinumisoflavone and 5-O-methyl-4-O-(3-methylbut-2-en-1-yl)alpinumisoflavone.
abstract: The accurate X-ray single-crystal structures of the isoflavone compounds 4-O-methylalpinumisoflavone, O,O-dimethylalpinumisoflavone and 5-O-methyl-4-O-(3-methylbut-2-en-1-yl)alpinumisoflavone {alpinumisoflavone = 5-hydroxy-7-(4-hydroxyphenyl)-2,2-dimethyl-2H,6H-benzo[1,2-b:5,4-b']dipyran-6-one} from data sets measured at cryogenic temperature have been obtained from invariom modelling using theoretically predicted Hansen and Coppens multipole-model form factors, which describe the aspherical electron density distribution. Molecular dipole moments and electrostatic potentials obtained from invariom modelling are discussed and compared with results from ab initio theoretical calculations. All three studied compounds are solvent extracts of root bark or seed powder of Millettia thonningii (leguminosae), a plant molluscicide and cercaricide used in Franco West Africa as medication against various diseases. The compounds' toxicities to brine shrimp have been determined and their different potencies tentatively related to conformation differences, intramolecular contacts, dipole moments and electrostatic potential features.
authors.affiliation: Department of Chemistry, University of Ghana, LG 56 Legon, Accra, Ghana. kadabohs@ug.edu.gh
authors.forename: Robert
authors.initials: R
authors.lastname: Kingsford-Adaboh
authors.forename: Birger
authors.initials: B
authors.lastname: Dittrich
authors.forename: Christian B
authors.initials: CB
authors.lastname: Hübschle
authors.forename: Winfred S K
authors.initials: WS
authors.lastname: Gbewonyo
authors.forename: Hideki
authors.initials: H
authors.lastname: Okamoto
authors.forename: Masaro
authors.initials: M
authors.lastname: Kimura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ishida
mesh_terms: D000818:Animals; D001156:Artemia / Q000187:drug effects; D018360:Crystallography, X-Ray; D007529:Isoflavones / Q000737:chemistry* / Q000633:toxicity*; D033641:Millettia / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry / Q000633:toxicity; D055672:Static Electricity
chemical_list: D007529:Isoflavones; D010936:Plant Extracts; C000154:alpinumisoflavone