Mar. Drugs 2007, 5(3), 71-84; doi:10.3390/md503071
Article

Cytoskyrins and Cytosporones Produced by Cytospora sp. CR200: Taxonomy, Fermentation and Biological Activities

1 Natural Products Research, Chemical and Screening Sciences, Wyeth Research, Pearl River, NY 10965, USA 2 Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
* Author to whom correspondence should be addressed.
Received: 22 June 2007; Accepted: 8 July 2007 / Published: 19 July 2007
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Abstract: In screening endophytic fungi from Costa Rica for bioactivity, fungal culture CR200, isolated from a buttonwood tree, was found to contain compounds that initiate DNA damage in a test strain of E. coli (Biochemical Induction Assay, BIA) and inhibit growth of Gram-positive bacteria, including antibiotic-resistant strains. Two new bisanthraquinones (cytoskyrins A and B) and five new related octaketides (cytosporones A-E) were isolated from fermentation broths of this fungus. Cytoskyrin A exhibited potent in-vitro antibacterial (MICs against Gram-positive bacteria, 0.03 - 0.25 μg/mL) and DNA-damaging activities (10 ng/spot), whereas cytoskyrin B was inactive in these assays. Among the cytosporones, only D and E exhibited Gram-positive activity, but they were inactive in the BIA. Mechanistically, cytoskyrin A specifically inhibited DNA synthesis in E. coli imp at its MIC; however, it also moderately inhibited protein synthesis at 2x its MIC. Cytoskyrin A exhibited poor cytotoxicity against tumor cell lines (IC50 > 5 μg/mL) compared to known antitumor agents. The nuclear ribosomal internal transcribed spacer region of CR200 was found to share highest similarity (94-96%) with Cytospora spp. Micro- and macroscopic morphological observations of the conidia and conidiomata, respectively, also suggested this fungus to be a Cytospora sp.
Keywords: Cytospora sp. CR200; cytoskyrins; cytosporones; antimicrobial; cytotoxic

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MDPI and ACS Style

Singh, M.P.; Janso, J.E.; Brady, S.F. Cytoskyrins and Cytosporones Produced by Cytospora sp. CR200: Taxonomy, Fermentation and Biological Activities. Mar. Drugs 2007, 5, 71-84.

AMA Style

Singh MP, Janso JE, Brady SF. Cytoskyrins and Cytosporones Produced by Cytospora sp. CR200: Taxonomy, Fermentation and Biological Activities. Marine Drugs. 2007; 5(3):71-84.

Chicago/Turabian Style

Singh, Maya P.; Janso, Jeffrey E.; Brady, Sean F. 2007. "Cytoskyrins and Cytosporones Produced by Cytospora sp. CR200: Taxonomy, Fermentation and Biological Activities." Mar. Drugs 5, no. 3: 71-84.

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