title: Callyaerins A-F and H, new cytotoxic cyclic peptides from the Indonesian marine sponge Callyspongia aerizusa.
abstract: Bioassay guided fractionation of the EtOAc fraction of the sponge Callyspongia aerizusa yielded seven new cytotoxic cyclic peptides callyaerins A-F (1-6) and H (8). Their structures were determined using extensive 1D (1H, 13C and DEPT) and 2D (COSY, HMQC, HMBC, TOCSY, and ROESY) NMR and mass spectral (ESI and HRESI-TOF) data. All compounds were cyclic peptides containing ring systems of 5-9 amino acids and side chains of 2-5 amino acids in length. An unusual (Z)-2,3-diaminoacrylic acid unit provided the template for ring closure and afforded the linkage to the peptidic side chain which was always initiated with a proline moiety. All peptides contained three or more proline residues and the remaining residues were predominantly hydrophobic residues with all amino acids present in the l form. Callyaerins A-F (1-6) and H (8) showed biological activity in antibacterial assays and in various cytotoxicity assays employing different tumour cell-lines (L5178Y, HeLa, and PC12). Callyaerins E (5) and H (8) exhibited strong activity against the L5178Y cell line with ED50 values of 0.39 and 0.48 microM, respectively. On the other hand, callyaerin A (1) showed strong inhibitory properties towards C. albicans.
authors.affiliation: Institut für Pharmazeutische Biologie und Biotechnologie, Heinrich-Heine-Universität, Geb. 26.23, Universitätsstrasse 1, D-40225 Düsseldorf, Germany.
authors.forename: Sabrin R M
authors.initials: SR
authors.lastname: Ibrahim
authors.forename: Cho Cho
authors.initials: CC
authors.lastname: Min
authors.forename: Franka
authors.initials: F
authors.lastname: Teuscher
authors.forename: Rainer
authors.initials: R
authors.lastname: Ebel
authors.forename: Christel
authors.initials: C
authors.lastname: Kakoschke
authors.forename: Wenhan
authors.initials: W
authors.lastname: Lin
authors.forename: Victor
authors.initials: V
authors.lastname: Wray
authors.forename: RuAngelie
authors.initials: R
authors.lastname: Edrada-Ebel
authors.forename: Peter
authors.initials: P
authors.lastname: Proksch
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D001424:Bacterial Infections / Q000188:drug therapy; D047128:Callyspongia / Q000737:chemistry*; D002176:Candida albicans / Q000187:drug effects; D002177:Candidiasis / Q000188:drug therapy; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D015394:Molecular Structure; D009369:Neoplasms / Q000188:drug therapy; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D000970:Antineoplastic Agents; D010456:Peptides, Cyclic