title: Venturia inaequalis-inhibiting Diels-Alder adducts from Morus root bark.
abstract: In organic apple orcharding there is a continuous need for natural fungicides effective against Venturia inaequalis (Cooke) Winter, the causal agent of apple scab. In this study an in vitro assay is presented for determining the germination inhibitory potential of extracts and pure compounds. From a screening of plant extracts, the methanol extract of Morus root bark revealed distinct V. inaequalis inhibiting qualities, which were subjected to a bioguided fractionation. Among the isolated metabolites [moracins M (1), O/P (2), kuwanon L (3), and sanggenons D (4), B (5), G (6), O (7), E (8), and C (9)] all the Diels-Alder adducts (3-9) showed an antifungal activity with IC50 values between 10 and 123 microM. The in vitro activity of the most active fraction (A5, IC50 39.0 +/- 4.2 microg/mL) was evaluated in vivo, confirming a distinct antifungal activity against V. inaequalis for the tested natural material.
authors.affiliation: Institute of Pharmacy/Pharmacognosy , Innrain 52c, and Institute of Organic Chemistry, Innrain 52a, Center for Molecular Biosciences Innsbruck, Leopold Franzens-Universität, A-6020 Innsbruck, Austria. Judith.Rollinger@uibk.ac.at
authors.forename: Judith M
authors.initials: JM
authors.lastname: Rollinger
authors.forename: Renate
authors.initials: R
authors.lastname: Spitaler
authors.forename: Magdalena
authors.initials: M
authors.lastname: Menz
authors.forename: Klaus
authors.initials: K
authors.lastname: Marschall
authors.forename: Roland
authors.initials: R
authors.lastname: Zelger
authors.forename: Ernst P
authors.initials: EP
authors.lastname: Ellmerer
authors.forename: Peter
authors.initials: P
authors.lastname: Schneider
authors.forename: Hermann
authors.initials: H
authors.lastname: Stuppner
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D001203:Ascomycota / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid; D015394:Molecular Structure; D031625:Morus / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry*; D018517:Plant Roots / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry
chemical_list: D000935:Antifungal Agents