title: Caldoramide, a Modified Pentapeptide from the Marine Cyanobacterium Caldora penicillata.
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.
authors.affiliation: Smithsonian Marine Station at Ft. Pierce , 701 Seaway Drive, Ft. Pierce, Florida 34949, United States.
authors.forename: Sarath P
authors.initials: SP
authors.lastname: Gunasekera
authors.forename: Lorelie
authors.initials: L
authors.lastname: Imperial
authors.affiliation: Smithsonian Marine Station at Ft. Pierce , 701 Seaway Drive, Ft. Pierce, Florida 34949, United States.
authors.forename: Christiana
authors.initials: C
authors.lastname: Garst
authors.forename: Ranjala
authors.initials: R
authors.lastname: Ratnayake
authors.forename: Long H
authors.initials: LH
authors.lastname: Dang
authors.affiliation: Smithsonian Marine Station at Ft. Pierce , 701 Seaway Drive, Ft. Pierce, Florida 34949, United States.
authors.forename: Valerie J
authors.initials: VJ
authors.lastname: Paul
authors.forename: Hendrik
authors.initials: H
authors.lastname: Luesch
mesh_terms: D051792:Basic Helix-Loop-Helix Proteins; D000458:Cyanobacteria / Q000737:chemistry*; D005431:Florida; D045325:HCT116 Cells; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D015394:Molecular Structure; D009842:Oligopeptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009842:Oligopeptides; C556090:belamide A; C000618454:caldoramide