Scytalidamides A and B, new cytotoxic cyclic heptapeptides from a marine fungus of the genus Scytalidium.
Two new cyclic heptapeptides have been isolated from the culture broth of a marine fungus, Scytalidium sp., collected from the Bahamas. The planar structures of scytalidamides A (1) and B (2) were assigned on the basis of 1D and 2D NMR spectroscopic techniques, while the absolute configuration of the amino acid residues in both molecules was determined by application of the advanced Marfey's method. The absolute stereochemistry of the uncommon 3-methylproline moiety in scytalidamide B (2) was confirmed by isolation and CD measurements, as well as application of the advanced Marfey's method. Scytalidamides A (1) and B (2) showed moderate in vitro cytotoxicity toward HCT-116 human colon adenocarcinoma with IC(50) values of 2.7 and 11.0 microM, respectively.
Tan
Lik Tong
LT
Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California-San Diego, La Jolla, CA 92093-0204, USA.
Cheng
Xing C
XC
Jensen
Paul R
PR
Fenical
William
W
D000970:Antineoplastic Agents / Q000737:chemistry* / Q000302:isolation & purification; D045744:Cell Line, Tumor; D002942:Circular Dichroism; D004354:Drug Screening Assays, Antitumor; D005658:Fungi / Q000737:chemistry*; D006801:Humans; D008386:Marine Biology; D019906:Nuclear Magnetic Resonance, Biomolecular; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D013237:Stereoisomerism
D000970:Antineoplastic Agents; D010456:Peptides, Cyclic; C482958:Scytalidamide A; C482959:scytalidamide B