Caldoramide, a Modified Pentapeptide from the Marine Cyanobacterium Caldora penicillata

  • J Nat Prod. 2016 Jul 22;79(7):1867-71. doi: 10.1021/acs.jnatprod.6b00203.
Sarath P Gunasekera  1 ,  Lorelie Imperial ,  Christiana Garst  1 ,  Ranjala Ratnayake ,  Long H Dang ,  Valerie J Paul  1 ,  Hendrik Luesch
Affiliations
  • 1. Smithsonian Marine Station at Ft. Pierce , 701 Seaway Drive, Ft. Pierce, Florida 34949, United States.
PMID: 27380142 DOI: 10.1021/acs.jnatprod.6b00203
Abstract

The isolation, structure determination, and biological activities of a new linear pentapeptide, caldoramide (5), from the marine cyanobacterium Caldora penicillata from Florida are described. Caldoramide (5) has structural similarities to belamide A (4), dolastatin 10 (1), and dolastatin 15 (2). We profiled caldoramide against parental HCT116 colorectal Cancer cells and isogenic cells lacking oncogenic KRAS or hypoxia-inducible factors 1α (HIF-1α) and 2α (HIF-2α). Caldoramide (5) showed differential cytotoxicity for cells containing both oncogenic KRAS and HIF over the corresponding knockout cells. LCMS dereplication indicated the presence of caldoramide (5) in a subset of C. penicillata samples.