The Establishment Of Sample Pretreatment And Analysis Methods For Monosaccharides And Glycopeptides

Sugars are one of three kinds of main substances in organisms. They mainly include monosaccharides, oligosaccharides, polysaccharides and glycoconjugates (i.e. glycopeptides, glycolipids, glycoproteins). They play important roles in the process of biological organisms. Saccharides (such as glucose, starch and glycogen) serve as the energy substances. Polysaccharides and glycoconjugates which make up with polysaccharides and protein or lipid, feature in the immune system and endocrine system, fertilization, brain development, pathogenesis and blood clotting. But the matrix of sugars is complex, therefore, it is necessary to establish the sample pretreatment and analysis methods.In Chapter1, the sample pretreatment and detection method of monosaccharides and glycopeptides are overviewed. It summaries the sample pretreatment of monosaccharides, such as the cleanup, liquid-liquid, liquid-solid and molecule imprinting method and the detection method of monosaccharides, for example, high performance thin layer chromatography, high performance liquid chromatography, gas chromatography and capillary electrophoresis. The sample pretreatment of glycopeptides is discussed, i.e. lectin affinity, hydrophilic interaction chromatography, borate affinity, hydrazine chemistry and TiO2affinity. The development of mass spectrometry is conducted in the chapter. At last, the research thought is proposed.In Chapter2, the method combined microwave assisted extraction, solid phase extraction and high performance liquid chromatography was established for the detection of monosaccharides in plants. The extraction solvent, extraction temperature and time were optimized and the confocal images of the untreated tobacco leaves and microwave assisted extraction treated tobacco leaves were took. The results indicated the rupture of leaves under microwave irradiation was complete. The conditions of solid phase extraction and the separation of liquid chromatography were investigated. In the end, the linear correlation coefficient of each target was greater than0.9990, the recovery was greater than85%. The experimental results indicate the monosaccharides in plants can be extracted and detected quickly and efficiently by the method.In Chapter3, a new type of boric acid functioned carbon nanotubes was synthesized for enriching glycopeptides in pancreatic enzyme digest of glycoprotein. Acid treated single-walled carbon nanotubes were reacted with3-aminophenylboronic acid, thus boronic acid was bonded to carbon nanotubes with covalent bonds. The materials were characterized by infrared spectroscopy and X-ray photoelectron spectroscopy analysis, the results showed that the modification was successful. The material was mixed with pancreatic enzyme digest of horse radish peroxidase. After centrifugation, washing and elution, the desalination and enrichment of glycopeptides were completed, taking advantage of the molecular intercept ablitiy of ultrafiltration tube. The enriched glycopeptides were analyzed by MALDI-TOF and the data was anlyzed by GlycoMod Tool. The experimental results show that the method can successfully desalt and enrich glycopeptides simultaneously.