Arthrinins A–D: Novel diterpenoids and further constituents from the sponge derived fungus Arthrinium sp

• Published in: Bioorganic & medicinal chemistry Vol. 19; no. 15; pp. 4644 - 4651
• Main Authors: Ebada, Sherif S., Schulz, Barbara, Wray, Victor, Totzke, Frank, Kubbutat, Michael H.G., Müller, Werner E.G., Hamacher, Alexandra, Kassack, Matthias U., Lin, Wenhan, Proksch, Peter
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01.08.2011; Elsevier
• Subjects: angiogenesis; animal ovaries; Animals; Antineoplastic Agents - chemistry; Antineoplastic Agents - isolation & purification; Antineoplastic Agents - pharmacology; Antiproliferative; Arthrinium; Ascomycota - chemistry; Biological and medical sciences; Cell Line, Tumor; chemistry; Cytotoxicity; Diterpenes - chemistry; Diterpenes - isolation & purification; Diterpenes - pharmacology; Diterpenoid; diterpenoids; endothelial cells; fractionation; fungi; General pharmacology; Geodia cydonium; Humans; inhibitory concentration 50; leukemia; lymphoma; Medical sciences; Mice; Neoplasms - drug therapy; Neovascularization, Pathologic - drug therapy; nuclear magnetic resonance spectroscopy; ovarian neoplasms; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Porifera - microbiology; Protein kinase inhibition; Protein Kinase Inhibitors - chemistry; Protein Kinase Inhibitors - isolation & purification; Protein Kinase Inhibitors - pharmacology; protein kinases; Protein Kinases - metabolism; vascular endothelial growth factor A; Vascular Endothelial Growth Factor A - metabolism; Mediterranean Sea; Antiproliferative; Cytotoxicity; Diterpenoid; Protein kinase inhibition; Arthrinium; Antineoplastic agent; Terpenoid; Enzyme; Transferases; Non-specific serine/threonine protein kinase; Enzyme inhibitor; Lactone; Fungi; Marine environment; Signal transduction; Porifera; Diterpene; Isolation; Sponge; Fungi Imperfecti; Invertebrata; Structural analysis
• ISSN: 0968-0896; 1464-3391
• DOI: 10.1016/j.bmc.2011.06.013

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 IC 50 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 IC 50 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 IC 50 values of 1.8, 2.6 and 3.7 μM, respectively, whereas norlichexanthone ( 7) was inactive.