title: Inhibitory effects of xanthones on platelet activating factor receptor binding in vitro.
abstract: Nine naturally occurring xanthones were investigated for their platelet activating factor (PAF) receptor binding inhibitory effects using rabbit platelets. 2-(3-methylbut-2-enyl)-1,3,5-trihydoxyxanthone, macluraxanthone, 1,3,5-trihydroxy-6,6'-dimethylpyrano(2',3':6,7)-4-(1,1-dimethylprop-2-enyl)xanthone, 6-deoxyjacareubin and 2-(3-methylbut-2-enyl)-1,3,5,6-terahydroxyxanthone showed strong inhibition with IC50 values of 4.8, 11.0, 21.0, 29.0 and 44.0 microM, respectively. The prenyl group at C-2, the dimethylprop-2-enyl group at C-4 and the hydroxyl group at C-5 are all beneficial to the binding of xanthones to the PAF receptor. The results revealed that xanthones can represent a new class of natural PAF receptor antagonists.
authors: Department of Pharmacy, Faculty of Allied Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300, Kuala Lumpur, Malaysia. ibj@medic.ukm.my
authors: I
authors: I
authors: Jantan
authors: J
authors: J
authors: Juriyati
authors: N A
authors: NA
authors: Warif
mesh_terms: D000818:Animals; D010980:Platelet Membrane Glycoproteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011485:Protein Binding; D011817:Rabbits; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D014966:Xanthenes / Q000737:chemistry / Q000494:pharmacology*; D044004:Xanthones
chemical_list: D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D014966:Xanthenes; D044004:Xanthones; C039351:platelet activating factor receptor; C009689:xanthone