title: Non-enzymatic reaction of glycosyl oxazoline with peptides.
abstract: Recently, a number of chemoenzymatic strategies have been explored for achieving preparation of homogeneous glycopeptides and glycoproteins, especially by using endoglycanases and glycosyl oxazolines. However, concomitant occurrence of non-enzymatic reactions has been reported, but no further characterization of the byproducts was conducted. In this work, we made an attempt to identify the side product by using model substrates. Analysis of the product allowed us to propose that the oxazoline ring was attacked by the amino group of lysine, leading to the formation of disubstituted acetamidine.
authors.affiliation: Synthetic Cellular Chemistry Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; Science and Technology Agency (JST), ERATO Ito Glycotrilogy Project, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. Electronic address: wangning@jiangnan.edu.cn.
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.affiliation: Science and Technology Agency (JST), ERATO Ito Glycotrilogy Project, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Seko
authors.affiliation: Science and Technology Agency (JST), ERATO Ito Glycotrilogy Project, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Shusaku
authors.initials: S
authors.lastname: Daikoku
authors.affiliation: Science and Technology Agency (JST), ERATO Ito Glycotrilogy Project, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Kanie
authors.affiliation: Science and Technology Agency (JST), ERATO Ito Glycotrilogy Project, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Takeda
authors.affiliation: Synthetic Cellular Chemistry Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; Science and Technology Agency (JST), ERATO Ito Glycotrilogy Project, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. Electronic address: yukito@riken.jp.
authors.forename: Yukishige
authors.initials: Y
authors.lastname: Ito
mesh_terms: D000578:Amidines / Q000737:chemistry*; D006020:Glycopeptides / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry*; D006031:Glycosylation; D009682:Magnetic Resonance Spectroscopy; D010080:Oxazoles / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000578:Amidines; D006020:Glycopeptides; D006023:Glycoproteins; D010080:Oxazoles; C023731:acetamidine
keywords: Acetamidine; Chemical ligation; Lysine; Oxazoline