Isolation And Structural Elucidation Of Two Kinds Of Bioactive Plant Polysaccharides

With the development of science and technology, polysaccharides are not only considered as support tissues and energy sources, but also another kind of important information molecules besides the nucleic acid. Furthermore, polysaccharides are key factors in signal identification on cells surface, antigen-antibody reaction, transfer and feelings of information. Therefore, the bioactive polysaccharides have increasingly received attention.This dissertation was consisted of two parts as follows:Part â… :Polysaccharides extracted by water from flowers of Chrysanthemum morifolium were studied.1) The flower was extracted with hot water to obtain the crude polysaccharide CMP. After ethanol precipitation, deproteinization and decolorization, following isolated with DEAE Sepharose Fast-Flow anion exchange column and Sephadex G-100gel column chromatography, pure polysaccharide P2was obtained. On the basis of infrared spectra (IR), completely acid hydrolysis, partially acid hydrolysis, methylation analysis (GC-MS), and nuclear magnetic resonance (NMR) experiments, P2is an arabinogalactan containing arabinose, galactose and glucose in a molar ratio of1:1.28:0.06. The core structure features include a backbone chain consisted ofâ†'6)-β-D-Ga1p-(1â†'andâ†'3,6)-β-D-Galp-(1â†'residues. Side chains which composed of Glcp and Araf residues were at position O-3.2) The immunological activity of crude polysaccharide CMP and pure polysaccharide P2was carried out. CMP showed little effects for splenocytes and thymocytes proliferation. While P2showed good immunological activity as it significantly enhanced splenocytes proliferation in relatively low25and50ug/mL doses. However, P2showed little effects for thymocytes proliferation, indicating it may have two modes of action.Part â…¡:Polysaccharides extracted by water from the tube of Alisma orientalis were studied. With hot water extraction of the tube of Alisma orientalis,30%,60%and90%alcohol solution were used to precipitate polysaccharides, respectively. Then the polysaccharides were decolorized and isolated with DEAE Sepharose Fast Flow anion exchange column and Sephadex G-100gel column chromatography to obtain ZX-1and ZX-2. On the basis of infrared spectra (IR), completely acid hydrolysis, partially acid hydrolysis, methylation analysis(GC-MS), and nuclear magnetic resonance (NMR) experiments, ZX-1is solely composed of glucose, and its main chain is composed ofâ†'4)-α-D-Glcp-(1â†',â†'3,4)-a-D-Glcp-(1â†'andâ†'4,6)-a-D-Glcp-(1â†'residues. Side chain containsâ†'6)-α-D-Glcp-(1â†'and a-D-Glcp-(1â†'residues. ZX-2consists of glucose (94.2%, w/w) and galactose (5.8%, w/w). Its main chain is composed ofâ†'4)-α-D-Glcp-(1â†',â†'3,4)-a-D-Glcp-(1â†'andâ†'4,6)-a-D-Glcp-(1â†'residues. Side chain containsâ†'6)-a-D-Glcp-(1â†', α-D-Glcp-(1â†'andâ†'6)-β-D-Galp-(1â†'residues, etc.In addition, this research made a brief summary of the status and progress of polysaccharide researches and the facing challenges.