title: Potential cancer chemopreventive in vitro activities of monomeric xanthone derivatives from the marine algicolous fungus Monodictys putredinis.
abstract: Investigation of the fungal strain Monodictys putredinis isolated from the inner tissue of a marine green alga led to the isolation of four new monomeric xanthones and a benzophenone. All structures were elucidated by extensive spectroscopic measurements. The relative configuration of compound 1 was determined by X-ray crystal structure analysis, while for 2 and 3 configurations were confirmed by NOE experiments. Absolute configurations for compounds 1-3 were deduced by comparing experimental circular dichroism spectroscopic data with those calculated employing quantum-chemical time-dependent density functional theory (TDDFT). The compounds were examined for their cancer chemopreventive potential. Xanthone 2 was shown to inhibit cytochrome P450 1A activity with an IC50 value of 3.0 microM. Compounds 2 and 3 displayed moderate activity as inducers of NAD(P)H:quinone reductase (QR) in cultured mouse Hepa 1c1c7 cells, with CD values (concentration required to double the specific activity of QR) of 12.0 and 12.8 microM, respectively. Compound 3 showed weak inhibition of aromatase activity.
authors.affiliation: Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, D-53115 Bonn, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Krick
authors.forename: Stefan
authors.initials: S
authors.lastname: Kehraus
authors.forename: Clarissa
authors.initials: C
authors.lastname: Gerhäuser
authors.forename: Karin
authors.initials: K
authors.lastname: Klimo
authors.forename: Martin
authors.initials: M
authors.lastname: Nieger
authors.forename: Armin
authors.initials: A
authors.lastname: Maier
authors.forename: Heinz-Herbert
authors.initials: HH
authors.lastname: Fiebig
authors.forename: Iuliana
authors.initials: I
authors.lastname: Atodiresei
authors.forename: Gerhard
authors.initials: G
authors.lastname: Raabe
authors.forename: Jörg
authors.initials: J
authors.lastname: Fleischhauer
authors.forename: Gabriele M
authors.initials: GM
authors.lastname: König
mesh_terms: D016588:Anticarcinogenic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D047072:Aromatase Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D001203:Ascomycota / Q000737:chemistry*; D018360:Crystallography, X-Ray; D020128:Inhibitory Concentration 50; D008386:Marine Biology; D008968:Molecular Conformation; D015394:Molecular Structure; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000096:biosynthesis; D044004:Xanthones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D016588:Anticarcinogenic Agents; D047072:Aromatase Inhibitors; D044004:Xanthones; D016660:NAD(P)H Dehydrogenase (Quinone)