10.1021/acs.jnatprod.6b00203.s001 Sarath P. Gunasekera Sarath P. Gunasekera Lorelie Imperial Lorelie Imperial Christiana Garst Christiana Garst Ranjala Ratnayake Ranjala Ratnayake Long H. Dang Long H. Dang Valerie J. Paul Valerie J. Paul Hendrik Luesch Hendrik Luesch Caldoramide, a Modified Pentapeptide from the Marine Cyanobacterium <i>Caldora penicillata</i> American Chemical Society 2016 Marine Cyanobacterium Caldora penicillata HCT 116 colorectal cancer cells marine cyanobacterium Caldora penicillata Caldoramide dolastatin HIF caldoramide oncogenic KRAS LCMS 2016-07-05 16:50:15 Journal contribution https://acs.figshare.com/articles/journal_contribution/Caldoramide_a_Modified_Pentapeptide_from_the_Marine_Cyanobacterium_i_Caldora_penicillata_i_/3471329 The isolation, structure determination, and biological activities of a new linear pentapeptide, caldoramide (<b>5</b>), from the marine cyanobacterium <i>Caldora penicillata</i> from Florida are described. Caldoramide (<b>5</b>) has structural similarities to belamide A (<b>4</b>), dolastatin 10 (<b>1</b>), and dolastatin 15 (<b>2</b>). 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 (<b>5</b>) showed differential cytotoxicity for cells containing both oncogenic KRAS and HIF over the corresponding knockout cells. LCMS dereplication indicated the presence of caldoramide (<b>5</b>) in a subset of <i>C. penicillata</i> samples.