title: Effects of lipid constituents on membrane-permeabilizing activity of amphidinols.
abstract: Amphidinols (AMs) are a new class of polyhydroxyl polyene compounds with potent antifungal activity. Membrane-permeabilizing activities of AM2, AM3, and AM6 were examined using fluorescent-dye leakage experiments with various phosphatidylcholines (PCs) and sterols. All the AMs tested showed the potent activity to cholesterol-containing liposomes. In the absence of the sterol, AM2, AM3, and AM6 had no membrane-permeabilizing activities to membranes of saturated PC. In liposomes consisting of unsaturated PC, AM2, which possesses an additional ether ring in a polyhydroxyl chain, showed membrane-permeabilizing activities with a moderate efficacy, while AM3 or AM6 did not. The potentiation by sterols was prominent even at 0.5% (wt/wt) and structure-dependent, which ruled out the possibility that alteration of the membrane physical properties induced by sterol was chiefly responsible for this sterol effect. The finding that their activity was not affected by membrane thickness implies that AMs permeabilized membrane by a different mechanism from that of polyene macrolide antibiotics.
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka University, 1-16 Machikaneyama, Toyonaka, Osaka 560-0043, Japan.
authors.forename: Nagy
authors.initials: N
authors.lastname: Morsy
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Houdai
authors.forename: Keiichi
authors.initials: K
authors.lastname: Konoki
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Matsumori
authors.forename: Tohru
authors.initials: T
authors.lastname: Oishi
authors.forename: Michio
authors.initials: M
authors.lastname: Murata
mesh_terms: D000475:Alkenes / Q000494:pharmacology*; D000935:Antifungal Agents; D002463:Cell Membrane Permeability / Q000187:drug effects*; D005233:Fatty Alcohols / Q000494:pharmacology; D008055:Lipids / Q000494:pharmacology*; D008081:Liposomes; D010713:Phosphatidylcholines; D011090:Polyenes / Q000494:pharmacology; D011714:Pyrans / Q000494:pharmacology*; D013261:Sterols / Q000494:pharmacology; D000095722:Amphidinols
chemical_list: D000475:Alkenes; D000935:Antifungal Agents; D005233:Fatty Alcohols; D008055:Lipids; D008081:Liposomes; D010713:Phosphatidylcholines; D011090:Polyenes; D011714:Pyrans; D013261:Sterols; C523181:amphidinol 2; D000095722:Amphidinols; C438973:amphidinol 3