title: Adenosine-1 active ligands: cirsimarin, a flavone glycoside from Microtea debilis.
abstract: Several plants collected through different approaches were screened on distinct receptors using ligand-binding studies as bioassay. Extracts of Microtea debilis showed high activity on adenosine A1 receptors. Bioassay-guided fractionation using ligand-binding studies resulted in the isolation of an adenosine A1 active ligand, cirsimarin (cirsimaritin 4'-O-glucoside). GTP did not influence the radioligand inhibition curve of cirsimarin, indicating that this compound is acting as an antagonist at the adenosine-A1 receptors. The use of this plant against "proteinuria" in traditional medicine in Suriname (South America) may be explained by the adenosine A1 antagonistic action of cirsimarin. A series of flavonoids was tested in the same assay, but they were less active. No structure-activity relationship could be observed.
authors.affiliation: Department of Pharmaceutical Sciences, University of Antwerp, Belgium.
authors.forename: J A
authors.initials: JA
authors.lastname: Hasrat
authors.forename: L
authors.initials: L
authors.lastname: Pieters
authors.forename: M
authors.initials: M
authors.lastname: Claeys
authors.forename: A
authors.initials: A
authors.lastname: Vlietinck
authors.forename: J P
authors.initials: JP
authors.lastname: De Backer
authors.forename: G
authors.initials: G
authors.lastname: Vauquelin
mesh_terms: D000818:Animals; D047309:Flavones; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D066298:In Vitro Techniques; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry; D016548:Prosencephalon / Q000187:drug effects / Q000378:metabolism; D058915:Purinergic P1 Receptor Antagonists; D011869:Radioligand Assay; D051381:Rats; D018047:Receptors, Purinergic P1 / Q000187:drug effects*; D013056:Spectrophotometry, Ultraviolet; D013532:Suriname; D014970:Xanthines
chemical_list: D047309:Flavones; D005419:Flavonoids; D006027:Glycosides; D008024:Ligands; D010936:Plant Extracts; D058915:Purinergic P1 Receptor Antagonists; D018047:Receptors, Purinergic P1; D014970:Xanthines; C107783:cirsimarin; C051360:1,3-dipropyl-8-cyclopentylxanthine