title: Cyclic peptides. XXVI. Synthesis of AM-toxin II analogs by cyclization through ester bond formation.
abstract: In order to explore the route for the preparation of cyclodepsipeptide by cyclization through an ester bond formation, two analogs of AM-toxin II, cyclotetradepsipeptide, were synthesized. As a preliminary experiment, synthesis of [L-Phe3, L-Ser(Bzl)4]-AM-toxin II, containing L-Phe and L-Ser(Bzl) in place of L-App (2-amino-5-phenyl-pentanoic acid) and delta Ala (alpha, beta-dehydroalanine), respectively, was attempted. Cyclization of H-L-Hmb-L-Phe-L-Ser(Bzl)-L-Ala-OH in CH2Cl2 at 10 mM concentration using water-soluble carbodiimide (EDC) and 4-dimethylaminopyridine (DMAP) successfully gave a cyclic monomer in 16% yield. Cyclization of H-L-Hmb-L-App-L-Ser(Bzl)-L-Ala-OH under the same conditions also afforded a cyclic monomer, [L-Ser(Bzl)4]AM-toxin II, in 19% yield. Analytical parameters of these cyclic monomers obtained were identical to those of the authentic samples obtained by cyclization through a peptide bond formation.
authors: Department of Chemistry, Faculty of Liberal Arts, Nagasaki University, Japan.
authors: K
authors: K
authors: Ueda
authors: M
authors: M
authors: Waki
authors: N
authors: N
authors: Izumiya
mesh_terms: D007202:Indicators and Reagents; D009183:Mycotoxins / Q000138:chemical synthesis*; D009904:Optical Rotation; D010456:Peptides, Cyclic / Q000138:chemical synthesis*; D013055:Spectrophotometry, Infrared; D013329:Structure-Activity Relationship
chemical_list: D007202:Indicators and Reagents; D009183:Mycotoxins; D010456:Peptides, Cyclic; C021614:AM toxin II