title: Semisynthetic preparation of amentoflavone: A negative modulator at GABA(A) receptors.
abstract: Amentoflavone is found in a number of plants with medicinal properties, including Ginkgo biloba and Hypericum perforatum (St. John's Wort). We have developed a rapid and economic semi-synthetic preparation of amentoflavone from biflavones isolated from autumnal Ginkgo biloba leaves. Several studies have shown that amentoflavone binds to benzodiazepine receptors. Using two electrode voltage-clamp methodology, amentoflavone has been shown to be a negative modulator of GABA at GABA(A) alpha(1)beta(2)gamma(2L) receptors expressed in Xenopus laevis oocytes This action appears to be independent of the flumazenil-sensitive benzodiazepine modulatory sites on the GABA(A) receptor.
authors.affiliation: Faculty of Pharmacy, University of Sydney, 2006, Sydney, NSW, Australia. janeh@pharm.usyd.edu.au
authors.forename: Jane R
authors.initials: JR
authors.lastname: Hanrahan
authors.forename: Mary
authors.initials: M
authors.lastname: Chebib
authors.forename: Neil L M
authors.initials: NL
authors.lastname: Davucheron
authors.forename: Belinda J
authors.initials: BJ
authors.lastname: Hall
authors.forename: Graham A R
authors.initials: GA
authors.lastname: Johnston
mesh_terms: D000818:Animals; D044946:Biflavonoids / Q000138:chemical synthesis* / Q000494:pharmacology; D003975:Diazepam / Q000494:pharmacology; D035264:Flowers / Q000737:chemistry; D005442:Flumazenil / Q000494:pharmacology; D018756:GABA Antagonists / Q000138:chemical synthesis* / Q000494:pharmacology; D018757:GABA Modulators / Q000494:pharmacology; D020441:Ginkgo biloba / Q000737:chemistry; D006801:Humans; D020902:Hypericum / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D009865:Oocytes / Q000378:metabolism; D018408:Patch-Clamp Techniques; D018515:Plant Leaves / Q000737:chemistry; D011963:Receptors, GABA-A / Q000187:drug effects*; D011994:Recombinant Proteins / Q000187:drug effects; D014982:Xenopus laevis
chemical_list: D044946:Biflavonoids; D018756:GABA Antagonists; D018757:GABA Modulators; D011963:Receptors, GABA-A; D011994:Recombinant Proteins; D005442:Flumazenil; C011164:amentoflavone; D003975:Diazepam