Exserohilum rostratum

OH r H CO2H HO H Marine fungi -Exserohilum rostratum Rostratin A - disuifide containing diketopiperazine with cytotoxicity against human coion carcinoma 232... 

Four new cytotoxic disulfides, rostratins A-D 57-60, were isolated from the broth of the marine-derived fungus Exserohilum rostratum (Drechsler), a fungal strain found associated with a marine cyanobacterial mat. These compounds showed in vitro cytotoxicity against human colon carcinoma (HCT-116) with IC50 values of 8.5, 1.9, 0.76, and 16.5 pg mL, respectively. 

Exserohilum rostratum (Dreschsl.) Leonard et Suggs Spartina altemiflora ... 

Exserohilon (603) can be found in Exserohilum rostratum together with rostratins A-D (398) (Fig. 10.5 (404)). These mycotoxins exhibit in vitro cytotoxicity against the HCT-166 human colon cancer cell line (405). 

Tan RX, Jensen PR, Williams PG, Fenical W (2004) Isolation and Structure Assignments of Rostratins A-D, Cytotoxic Disulfides Produced by the Marine-Derived Fungus Exserohilum rostratum. J Nat Prod 67 1374... 

The Ascomycete Exserohilum rostratum (strain CNK-630) and the Deuteromycete Zygosporium masonii (strain CNK-458), from cyanobacterial carpets collected on the Hawaiian islands of Lanao and Maui, respectively, both yield rostratins A-D, which are cyclic disulfides related to diketopiperazine and presenting structural analogies with gliotoxin (vide supra). Rostratins A-D are cytotoxic to the cell line HCT-116 (colon cancer) with IC50 values respectively of 8.5, 1.9, 0.76, and 16.5 pgml (Tan et al, 2004). 

Tan, R.X., Jensen, P.R., Williams, P.G., and Fenical, W. (2004) Isolation and structure assignments of rostratins A-D, cytotoxic disulfides produced by the marine-derived fungus Exserohilum rostratum. J. Nat. Prod., 67, 1374-1382. 

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