title: Preparation and antioxidant activity of xanthan oligosaccharides derivatives with similar substituting degrees.
abstract: Maleoyl xanthan oligosaccharides (XGOSMAs) and phthaloyl xanthan oligosaccharides (XGOSPAs) were prepared by reacting xanthan oligosaccharides with maleic anhydride and phthalic anhydride, respectively. The substituting degrees (DSs) of XGOSMAs and XGOSPAs were determined by a neutralization reaction. XGOAMA-1 (DS=0.30), XGOSPA (DS=0.31), XGOSMA-2 (DS=0.62) and XGOSPA-2 (DS=0.60) were selected for structural characterization and antioxidant activity evaluation. Their structural changes were confirmed by Fourier transform infrared spectra (FT-IR), and their molecular weights were determined with a gel permeation chromatography method (GPC). The pyruvate acid and reducing sugar contents were determined by ultraviolet spectrophotometry and the dinitrosalicylic acid method. The antioxidant activity was evaluated by the scavenging of the superoxide anion radical (O2(-)), hydroxyl radical (OH), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and determination of reducing power. The results indicated that XGOSPA exhibited higher antioxidant activity than XGOSMA with similar substituting degrees in all the above mentioned antioxidant evaluation systems, which may be related to the fact that phthaloyl group has a stronger electron-withdrawing effect than the maleoyl group.
authors.affiliation: College of Food Science & Technology, Shanghai Ocean University, Shanghai 201306, PR China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Xiong
authors.affiliation: College of Food Science & Technology, Shanghai Ocean University, Shanghai 201306, PR China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: College of Food Science & Technology, Shanghai Ocean University, Shanghai 201306, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xie
authors.affiliation: College of Food Science & Technology, Shanghai Ocean University, Shanghai 201306, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xue
authors.affiliation: College of Food Science & Technology, Shanghai Ocean University, Shanghai 201306, PR China. Electronic address: taosun@shou.edu.cn.
authors.forename: Tao
authors.initials: T
authors.lastname: Sun
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000737:chemistry; D017665:Hydroxyl Radical / Q000737:chemistry; D008970:Molecular Weight; D009844:Oligosaccharides / Q000737:chemistry*; D010851:Picrates / Q000737:chemistry; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013481:Superoxides / Q000737:chemistry
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D009844:Oligosaccharides; D010851:Picrates; D011135:Polysaccharides, Bacterial; D013481:Superoxides; D017665:Hydroxyl Radical; C004931:1,1-diphenyl-2-picrylhydrazyl; C002563:xanthan gum
keywords: Antioxidant activity; Maleoyl; Phthaloyl; Substituting degree; Xanthan oligosaccharides