title: Cyclotheonamides E2 and E3, new potent serine protease inhibitors from the marine sponge of the genus Theonella.
abstract: Two new potent serine protease inhibitors, cyclotheonamides E2 (3) and E3 (4), have been isolated from a marine sponge of the genus Theonella. Their structures were determined by interpretation of spectral data and chemical degradation studies. They are closely related to the previously reported cyclotheonamide E, from which they differ in the N-acyl group of the alanyl side chain. Cyclotheonamides E, E2, and E3 were more active against thrombin than against trypsin.
authors.affiliation: Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Nakao
authors.forename: N
authors.initials: N
authors.lastname: Oku
authors.forename: S
authors.initials: S
authors.lastname: Matsunaga
authors.forename: N
authors.initials: N
authors.lastname: Fusetani
mesh_terms: D000818:Animals; D010456:Peptides, Cyclic / Q000302:isolation & purification* / Q000494:pharmacology; D011161:Porifera / Q000737:chemistry*; D015842:Serine Proteinase Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D013917:Thrombin / Q000037:antagonists & inhibitors*; D014361:Trypsin Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D010456:Peptides, Cyclic; D015842:Serine Proteinase Inhibitors; D014361:Trypsin Inhibitors; C112727:cyclotheonamide E2; C112728:cyclotheonamide E3; D013917:Thrombin