Study On The Active Constituents And Structural Modifications Of ?-glucosidase In Mulberry Leaves

Folium Mori, the leaf of Morus alba. L, is a very important Chinese traditional medicine recorded in the ChP. It has many activities such as lowering blood sugars, antihypertensive, antibiosis and antiviaral. The author has investingated its active part, chemical constitutes, semi-synthesis derivatives, and their inhibitory activity of?-glucosidase.The experiments to screen the inhibitory activity toward?-glucosidase in vitro among the alkaloids part, flavonoids part and their mixture indicated that the alkaloids part produced a marked effect through the mechanism of inhibiting?-glucosidase. The flavonoids part did not have inhibitory activity but can play as a weak antagon toward the alkaloids part.In this thesis, the chemical constituents of the Alkaloid part from Morus Alba. L were studied, 4 compounds were isolated with ion exchange chromatography, CM sephadex C 25, preparative TLC etc. On the basis of analysis of NMR, MS data and measuring of physicochemical characters, their chemical structures were elucidated as 1-deoxynojirimycin(?), Fagomine(?), 1, 4-deoxy- 1, 4-imino- D-arabinitol (?), 1-aragine acetate(?).11 DNJ derivatives were semi-synthesized by applying the synthetic route consisted of DNJ and series of alkylogen for the first time. On the basis of analysis of NMR, MS data and measuring of physicochemical characters, their chemical structures were elucidated as 1, 2-bis-[ (2R, 3R, 4R, 5S) 2-hydroxymethyl -3, 4, 5, -trihydroxylpiperidine-1-yl]-ethane, (1), 1, 3-bis-[ (2R, 3R, 4R, 5S) 2-hydroxymethyl -3, 4, 5, -trihydroxylpiperidine -1-yl] -propane, (2), 6-[ (2R, 3R, 4R, 5S) 2-hydroxy methyl -3, 4, 5, -trihydroxylpiperidine-1-yl]-1-hexanol, (3), 1, 6-bis-[ (2R, 3R, 4R, 5S) 2-hydroxymethyl- 3, 4, 5, -trihydroxylpiperidine -1-yl]-hexane, (4), 1, 7-bis- [(2R, 3R, 4R, 5S) 2-hydroxymethyl -3, 4, 5, -trihydroxylpiperidine -1-yl] -heptane, (5), 1, 8-bis-[ (2R, 3R, 4R, 5S) 2- hydroxym- ethyl-3, 4, 5, -trihydroxylpiperidine -1-yl] -octane, (6), 1, 9-bis-[ (2R, 3R, 4R, 5S) 2-hydroxy- methyl -3, 4, 5, -trihydroxylpiperidine -1-yl]-nonane, (7), 1, 10-bis- [ (2R, 3R, 4R, 5S) 2-hydroxy- methyl-3, 4, 5, -trihydroxyl- piperidine-1-yl] -decane, (8), 1, 11-bis-[ (2R, 3R, 4R, 5S) 2-hydroxy- methyl-3, 4, 5, -trihydroxylpiperidine -1 -yl]-undecane, (9), 12-[ (2R, 3R, 4R, 5S) 2-hydroxy- methyl-3, 4, 5, -trihydroxylpiperidine-1-yl]-1-lauryl alcohol, (10), 1, 12-bis -[ (2R, 3R, 4R, 5S) 2-hydroxymethyl-3, 4, 5, -trihydroxylpiperidine -1-yl]-dodecane, (11). Of all these compounds, compounds 2, 3, 5, 7, 9, 10, 11 are new compounds.9 semi-synthesized DNJ derivatives were studied for their inhibitory activity of?-glucosidase and?-amylase.