| Mulberry has a high nutritional value and medical health care efficacy because of its rich nutrients. Hydroxy alkaloids(polyhydroxy alkaloids, PHA) is a kind of hydrophilic alkaloids compoundsas an important one of the active ingredients of mulberry leaves,their also known as sugar analogues or the amino sugar as their structure are similar with sugar.PHA were extensive researched by scholars both at home and abroad as their function of improvement insulin sensitivity and increase glucose transporter 4 and lpha glycosidase enzymeinhibition. This topic is intended to provide theoretical basis for the comprehensive utilization of mulberry leaves from their extraction process, dynamic change rule,alpha glycosidase enzyme inhibitory activity, regulation of sugar steady state of DNJ and Fagomine.It aimed at providing theoretical basis for functional food research.The results are as follows:(1)Optimization of extraction technology for PHA.Ths subject selecting three factors affecting the extraction effect-ratio of material to liquid and extraction time and p H to optimize the mulberry DNJ, Fagomine extraction process.The best extraction technology conditions is 35.88 min, 0.06g/m L,p H5.19. The theoretical is DNJ extraction yield 0.322% and Fagomine extraction yield of 0.218%. The actual value is DNJ extraction yield 0.315% and Fagomine extraction yield of 0.21%.It show that the model has good fitting and improved the extraction rate of active ingredients.(2)PHAis affacted of mulberry varieties, harvest season, collecting parts, etc. PHA were analyzed from nine mulberry varieties, 6 month, 5 maturity harvested in mulberry leaf samples.It show that:mulberry varieties,harvest season and leaf position significantly influence on DNJ, Fagomine content.The higher average levels of DNJ and Fagomine are Morus atropurpurea Roxb“kangqing 10”, 6.02 mg/g and Morus australis Poir“zibai 4”,2.50 mg/g;The lower average levels of DNJ and Fagomine are Morus mutlicaulis P.“nongsang12”,0.87 mg/g and Morus alba Linn“yu 2”,0.31 mg/g;The DNJ is increased at first and then decreased in six month and highest in august;The higher average levels of DNJ and Fagomine aretender leaf in different maturity of mullberry leaves,and then are gradually reduced.From what has been discussed above,the content of DNJ and Fagomineare affacted of mulberry varieties, harvest season, collecting parts.Ithelp mulberry resources development and clinical application.(3)The alpha glycosidase enzyme inhibitory activity was studied of mulberry leaf aqueous extract,DNJ,polysaccharides and polyphenols.The study show that mulberry leaf aqueous extract of IC50 was 1.59 mg/m L,its contains DNJ 12.37 mu g/m L, polysaccharide was 0.69 mg/m L, polyphenol 9.43 mu g/m L.The DNJ?polysaccharides and polyphenols of IC50 are 7.48 mg/m L?38.63 ?g/m L and 20.82 ?g/m L.It can be seen that the rate of contribution of DNJ?polysaccharides and polyphenols is 70%?48% and 10%.It show that the three substances create synergies together, but The DNJ plays a major role in it.(4) This topic research the regulation of DNJ to glucose homeostasis from the change of PI3K?IR?GLUT4?AMPK?ADIPO?Akt. The results show that the selection experiment of different concentrations of DNJ can promote cell glucose absorption, presents the significant changes. With real-time quantitative PCR to test the sugar metabolism related gene. Different concentrations of DNJ can promote the expression of related factor exceptlow concentrations to PPAR? gamma and GLUT4. And in a certain concentration range, the relative expression increases with the increase of concentration and, but with concentration further increased, the expression is reduced.Tested the sugar metabolism related regulatory proteins with western-blot. Different concentrations of DNJ has promoting effect. Speculated that DNJ promoting the absorption of sugarthough IR-PI3K-AKT-GLUT4 and ADIPO-AMPK-GLUT4. |
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