title: Arthrinins A-D: novel diterpenoids and further constituents from the sponge derived fungus Arthrinium sp.
abstract: Bioassay-guided fractionation of a methanolic extract of the fungus Arthrinium sp., isolated from the Mediterranean sponge Geodia cydonium, afforded 10 natural products including five new diterpenoids, arthrinins A-D (1-4) and myrocin D (5). In addition, five known compounds were obtained, which included myrocin A (6), norlichexanthone (7), anomalin A (8), decarboxycitrinone (9) and 2,5-dimethyl-7-hydroxychromone (10). The structures of all isolated compounds were unambiguously elucidated based on extensive 1D and 2D NMR and HR-MS analyzes. The absolute configuration of arthrinins A-D (1-4) was established by the convenient Mosher method performed in NMR tubes and by interpretation of the ROESY spectra. Antiproliferative activity of the isolated compounds was assessed in vitro against four different tumor cell lines, including mouse lymphoma (L5178Y), human chronic myelogenous leukemia (K562), human ovarian cancer (A2780) and cisplatin-resistant ovarian cancer cells (A2780CisR), using the MTT assay. Norlichexanthone (7) and anomalin A (8) exhibited the strongest activities with IC₅₀ values ranging from 0.40 to 74.0 μM depending on the cell line investigated. This was paralleled by the inhibitory activity of both compounds against 16 cancer related protein kinases including aurora-B, PIM1, and VEGF-R2. In vitro IC₅₀ values of 7 and 8 against these three protein kinases ranged from 0.3 to 11.7 μM. Further investigation of the potential antitumoral activity of compounds 5-8 was performed in an in vitro angiogenesis assay against human umbilical vascular endothelial cells (HUVEC) sprouting induced by vascular endothelial growth factor A (VEGF-A). Anomalin A (8), myrocin D (5) and myrocin A (6) inhibited VEGF-A dependent endothelial cell sprouting with IC₅₀ values of 1.8, 2.6 and 3.7 μM, respectively, whereas norlichexanthone (7) was inactive.
authors: Institut für Pharmazeutische Biologie und Biotechnologie, Heinrich-Heine-Universität, Geb. 26.23, Universitätsstrasse 1, D-40225 Düsseldorf, Germany.
authors: Sherif S
authors: SS
authors: Ebada
authors: Barbara
authors: B
authors: Schulz
authors: Victor
authors: V
authors: Wray
authors: Frank
authors: F
authors: Totzke
authors: Michael H G
authors: MH
authors: Kubbutat
authors: Werner E G
authors: WE
authors: Müller
authors: Alexandra
authors: A
authors: Hamacher
authors: Matthias U
authors: MU
authors: Kassack
authors: Wenhan
authors: W
authors: Lin
authors: Peter
authors: P
authors: Proksch
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D001203:Ascomycota / Q000737:chemistry*; D045744:Cell Line, Tumor; D004224:Diterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D051379:Mice; D009369:Neoplasms / Q000188:drug therapy*; D009389:Neovascularization, Pathologic / Q000188:drug therapy; D011161:Porifera / Q000382:microbiology; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D004224:Diterpenes; D047428:Protein Kinase Inhibitors; D042461:Vascular Endothelial Growth Factor A; D011494:Protein Kinases