title: Nazumazoles D-F, Cyclic Pentapeptides That Inhibit Chymotrypsin, from the Marine Sponge Theonella swinhoei.
abstract: Nazumazoles D-F (1-3) were isolated from the marine sponge Theonella swinhoei. The compounds gave extremely broad peaks by reversed-phase HPLC using an ODS column. HPLC using a gel permeation column was instrumental for the separation of the three compounds. Their planar structures were determined by interpretation of NMR data to be cyclic pentapeptides. Nazumazoles D-F contained one residue each of α-keto-l-norvaline (l-Knv) {or α-keto-d-leucine (l-Kle)}, l-alanyloxazole (l-Aox), d-Abu (or d-Ser), N-α-CHO-β-l-Dpr, and cis-4-methyl-l-proline. The absolute configuration of each amino acid residue was determined by Marfey's method in combination with conversion of the α-keto-β-amino acid to the α-amino acid by oxidation. Nazumazoles D-F are not cytotoxic against P388 cells at 50 μM, but inhibit chymotrypsin.
authors.affiliation: Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Fukuhara
authors.affiliation: Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Takada
authors.affiliation: Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Okada
authors.affiliation: Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Matsunaga
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D008386:Marine Biology; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification*; D047232:Theonella / Q000737:chemistry*
chemical_list: D010456:Peptides, Cyclic; C000618971:nazumazole D