title: Stylissamides E and F, cyclic heptapeptides from the caribbean sponge Stylissa caribica.
abstract: In addition to the four known stylissamides, A (1), B (2), C, and D, two new cyclic heptapeptides, stylissamides E (3) and F (4), were isolated from the Caribbean sponge Stylissa caribica. The structures of 3 and 4 were elucidated from a combination of mass spectrometric and NMR spectroscopic data as cyclo-(cis-Pro(1)-Tyr(2)-trans-Pro(3)-Ala(4)-Ile(5)-Gln(6)-Ile(7)) for stylissamide E (3) and cyclo-(trans-Pro(1)-cis-Pro(2)-Phe(3)-Asp(4)-trans-Pro(5)-Arg(6)-Phe(7)) for stylissamide F (4).
authors.affiliation: Alfred-Wegener-Institut für Polar- und Meeresforschung in der Helmholtz-Gemeinschaft, Am Handelshafen 12, 27570 Bremerhaven, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Cychon
authors.forename: Matthias
authors.initials: M
authors.lastname: Köck
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017691:Caribbean Region; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification*; D011161:Porifera / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D010456:Peptides, Cyclic; C549728:stylissamide E; C549727:stylissamide F