title: Bi-, tri-, and polycyclic acylphloroglucinols from Hypericum empetrifolium.
abstract: The ¹H NMR-guided fractionation of a petroleum ether extract of Hypericum empetrifolium led to the isolation of four new bicyclic (1-4), four known bicyclic (5-8), three new tricyclic (9-11), and three new polycyclic acylphloroglucinols (12/13 and 14) possessing a monoterpenoid citran moiety. Compounds 12/13 were isolated as a mixture of two inseparable structural isomers. The compounds showed in vitro antiproliferative activity against human microvascular endothelial cells (HMEC-1) with IC₅₀ values in the range 9.2 ± 2.0 to 29.6 ± 3.5 μM.
authors.affiliation: Pharmaceutical Biology,  Universität Regensburg , Universitätsstraße 31, D-93053 Regensburg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schmidt
authors.forename: Guido
authors.initials: G
authors.lastname: Jürgenliemk
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Schmidt
authors.forename: Helen
authors.initials: H
authors.lastname: Skaltsa
authors.forename: Jörg
authors.initials: J
authors.lastname: Heilmann
mesh_terms: D042783:Endothelial Cells / Q000187:drug effects; D006115:Greece; D006801:Humans; D020902:Hypericum / Q000737:chemistry*; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010696:Phloroglucinol / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D010696:Phloroglucinol