title: Fractionation of bamboo hemicelluloses by graded saturated ammonium sulphate.
abstract: The hemicelluloses were isolated with 10% KOH at 25°C from dewaxed and delignified bamboo powder. The alkali-soluble hemicelluloses from Sinocalamus affinis were fractionated by ammonium sulphate precipitation method. The bamboo alkali-soluble hemicelluloses yielded seven hemicellulosic fractions obtained at 0, 5, 15, 25, 40, 55, and 70% saturation with ammonium sulphate. It was found that the more branched hemicelluloses were precipitated at higher ammonium sulphate concentrations (55 and 70%), the more linear hemicelluloses were precipitated at lower ammonium sulphate concentrations (0, 5, 15, 25, and 40%). The molecular weights of hemicellulosic fractions become lower from 35,270 (H0) to 18,680 (H70)gmol(-1) with the increasing concentrations of saturated ammonium sulphate from 0 to 70%. Based on the FT-IR, (1)H, (13)C and 2D HSQC NMR studies, the alkali-soluble hemicelluloses were 4-O-methyl-glucuronoarabinoxylans composed of the (1→4)-linked β-d-xylopyranosyl backbone with branches at O-3 of α-L-arabinofuranosyl or at O-2 of 4-O-methyl-α-d-glucuronic acid.
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Guan
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors.forename: Xian-Ming
authors.initials: XM
authors.lastname: Qi
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China. Electronic address: fengpeng@bjfu.edu.cn.
authors.forename: Feng
authors.initials: F
authors.lastname: Peng
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China.
authors.forename: Chun-Li
authors.initials: CL
authors.lastname: Yao
authors.affiliation: Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University, Beijing 100083, China. Electronic address: rcsun3@bjfu.edu.cn.
authors.forename: Run-Cang
authors.initials: RC
authors.lastname: Sun
mesh_terms: D000645:Ammonium Sulfate / Q000737:chemistry*; D031723:Bambusa / Q000737:chemistry*; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D005591:Chemical Fractionation / Q000379:methods*; D020723:Glucuronic Acid / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D011134:Polysaccharides / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D011134:Polysaccharides; C007916:hemicellulose; D020723:Glucuronic Acid; D000645:Ammonium Sulfate
keywords: Hemicelluloses; Saturated ammonium sulphate; Sinocalamus affinis