title: Controlled acetylation of water-soluble glucomannan from Bletilla striata.
abstract: Glucomannans from Bletilla striata (bletillan) were used as excipient for controlled deliveries of drugs, genes and tissue engineering. In the present study, a controlled acetylation method was developed to improve water solubility of bletillan 70 (BT) firstly, by reacting with acetic anhydride (AA) in N,N-dimethylformamide solvent. The preparation parameters, such as reaction temperature, reaction time and molar ratio of BT/AA, were optimized based on degrees of acetyl group in addition. IR and (1)H NMR spectra were applied to elucidate the reaction process and substitution pattern, which indicated that the acetylation took place at C-6 and C-2 of the hexose units in a ratio of 2:1, with DS up to 0.83. Relative viscosity analysis revealed that the resulted products had improved water solubilities. This novel method is simple, economic and easily controlled.
authors.affiliation: College of Pharmaceutical Science, Soochow University, Suzhou 215123, China.
authors.forename: Jiang-yun
authors.initials: JY
authors.lastname: Liu
authors.forename: Hu-cheng
authors.initials: HC
authors.lastname: Wang
authors.forename: Yin
authors.initials: Y
authors.lastname: Yin
authors.forename: Nan
authors.initials: N
authors.lastname: Li
authors.forename: Pei-lie
authors.initials: PL
authors.lastname: Cai
authors.forename: Shi-lin
authors.initials: SL
authors.lastname: Yang
mesh_terms: D000107:Acetylation; D009682:Magnetic Resonance Spectroscopy; D008351:Mannans / Q000737:chemistry*; D029595:Orchidaceae; D035281:Plant Tubers; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water / Q000737:chemistry
chemical_list: D008351:Mannans; D014867:Water; C022901:(1-6)-alpha-glucomannan