title: Kulokekahilide-1, a cytotoxic depsipeptide from the cephalaspidean mollusk Philinopsis speciosa.
abstract: The cytotoxic depsipeptide kulokekahilide-1, which contains two unusual amino acids, 4-phenylvaline and 3-amino-2-methylhexanoic acid, was isolated from the cephalaspidean mollusk Philinopsis speciosa. Structure elucidation of kulokekahilide-1 was carried out by spectroscopic analysis and chemical degradation. The absolute stereochemistry was determined by Marfey analysis for amino acids and chiral HPLC analysis for hydroxy acids. All four stereoisomers of 4-phenylvaline and 3-amino-2-methylhexanoic acid, which were necessary for Marfey analysis, were synthesized by use of the Heck reaction and Evans's method, respectively. Kulokekahilide-1 showed cytotoxicity against P388 murine leukemia cells with an IC(50) value of 2.1 microg/mL.
authors.affiliation: Department of Chemistry, University of Hawaii at Manoa, 2545 The Mall, Honolulu, Hawaii 96822-2275, USA.
authors.forename: Junji
authors.initials: J
authors.lastname: Kimura
authors.forename: Yuuki
authors.initials: Y
authors.lastname: Takada
authors.forename: Tomoko
authors.initials: T
authors.lastname: Inayoshi
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nakao
authors.forename: Gilles
authors.initials: G
authors.lastname: Goetz
authors.forename: Wesley Y
authors.initials: WY
authors.lastname: Yoshida
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Scheuer
mesh_terms: D000595:Amino Acid Sequence; D000614:Aminocaproates; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002208:Caproates / Q000138:chemical synthesis / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D047630:Depsipeptides; D004354:Drug Screening Assays, Antitumor; D006254:Hawaii; D020128:Inhibitory Concentration 50; D007941:Leukemia P388; D051379:Mice; D008815:Mice, Inbred Strains; D008968:Molecular Conformation; D015394:Molecular Structure; D008974:Mollusca / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D013237:Stereoisomerism; D014633:Valine / Q000031:analogs & derivatives / Q000138:chemical synthesis
chemical_list: C456483:3-amino-2-methylhexanoic acid; C456482:4-phenylvaline; D000614:Aminocaproates; D000970:Antineoplastic Agents; D002208:Caproates; D047630:Depsipeptides; D010456:Peptides, Cyclic; C108201:dolastatin 16; C456481:kulokekahilide-1; D014633:Valine