The Study Of Derivative Methods And Absorption Of Maltodextrin

Objective:Saccharide, an important kind of organic compounds, widely distributes in nature. Plenty of evidences show that polysaccharide plays important biological effects including adjustment of immunity, development of inflammation and progression of cancer. However,the complex structures of pharmacokinetics in new drug research. At present, several saccharide-drugs have been on sale. However, whether saccharide can be absorbed in gastrointestinal is still unclear. The aim of this study is to detect the absorption characteristics of oligosaccharides by adding UV absorptive or fluorescent groups to oligosaccharide, and to provide a technical method for the research of saccharide pharmacokinetics. Methods:1. To establish a quantitative detected method for oligosaccharides pharmacokinetics. Maltodextrin were derivatizated by three kinds of ultraviolet derivatization reagents: 1-phenly-3-methyl-5-pyrazolone (PMP), 3-amino-9-ethylcarbazole (AEC), para-amino benzooic acid ethyl ester (ABEE). UV derivatives were analyzed by Laser desorption ionization mass spectrometry (ESI-MS). At the same time, maltodextrin labeled by fluorescein isothiocyanate (FITC). The fluorescence intensity was detected by fluorescence spectrophotometer.2. To establish a method to detect the quantity of derivative oligosaccharides in the intestinel tract perfusion model and Caco-2 monolayer model by HPLC. The best one from the three ultraviolet derivants was selected, which has the highest marked rate, stability and repeatability.3. To observe the absorption character of maltodextrin derivants using the intestinal tract perfusion model and Caco-2 monolayer model.Results:1. We obtained four maltodextran derivatization labeled with PMP, AEC, ABEE and FITC. ESI-MS assay showed that PMP, AEC and ABEE can mark each molecular of oligosaccharide at the ratio of 2:1, 1:1 and 1:1, respectively. FITC-maltodextran showed high sensitivity, but it was just a qualitative detection but not quantitative detection. The fluorescence spectrophotometer cannot be distinguished different degrees of polymerization of oligosaccharides.2. The best one for HPLC assay was PMP- maltodextrin. The other two maltodextrin derivatives were difficult in separating by HPLC.3. The intestinal perfusion experiments showed that monosaccharide, disaccharide and trisaccharide can be detected in the blood after perfusing 1mg·mL-1 PM for 30 min. Caco-2 cell monolayer absorption experiments showed that six kinds of sachharide were detected transferring through the epithelial cell layer, they are monosaccharide, disaccharide, trisaccharide, tetrasaccharide, pentasaccharide, hexasaccharide. But the mechanisms need further study.Conclusion:1. Maltodextrin was successfully derivated quantitavely by PMP, AEC, and ABEE. The reaction ratios of derivatization reagents to oligosaccharides were 2:1 or 1:1. It provides a way for the pharmacokinetic study of oligosaccharide.2. Three kinds of oligosaccharides in blood were absorpted in prototype used by intestinal perfusion model in rat. Disaccharide content in outflow liquid was fluctuated elevated, while contents of oligosaccharide in other degree of polymerization were decreased. Six different degrees of polymerization of oligosaccharides derectely crossed the Caco-2 monolayer cell, namely, monosaccharide, disaccharide, trisaccharide, tetrasaccharide, pentasaccharide and hexasaccharide.