Synthesis Of 7-0-galloylsedoheptulose, An Immunosuppressive Compound From Cornas Offianalis

The dry fruit of Cornusofficinalis Sieb.et Zucc. is a traditional Chinese herb used for nourishing liver and kidney. A few of galloyl-sedoheptu-loses were separated by Scholar, and 7-0-galloylsedoheptulose was also separated from the fruit of Cornusofficinalis Sieb.et Zucc.in Our previously works by using Immunosuppressive detecting ways.In the preliminary pharmacology in vitro ,we found this compound showed strong Immunosuppressive effects.It could inhibit splenocyte proliferation and reduce the level of IgG in supernatant of cultured splenocytes in vitro. The compound is hard to gained for the low content and hard seperation, so the complete active estimation on the compound is difficult to go on. The synthesis of the compound were not reported in literature previously. The aim of this study was how to synthesize the compound, so it would afford ways for the synthesis of galloyl-D-sedoheptuloses and afford the compound for the complete Immunosuppressive estimation.In the study, sedoheptulosan as a beginning materialreacted with benzoyl chloride catalyzed by pyridine to get 1, 3, 4, 5-0-tetrabenzoyl sedoheptulosan( I ). I acted with Hac-(CF3C0)20-BF3. aether to get 1, 3, 4, 5-0-tetrabenzoyl-7-0-acetylsedoheptulose ( II ) . II was selectly deacetyla-ted in HCL-methnaol solution to get 1, 3, 4, 5-0-tetrabenzoyl sedoheptulose (III) . Ill reacted with tribenzyl methy chloride catalyzed by pyridine to get 1, 3, 4, 5-0-tetrabenzoyl- 7- tribenzyl methyl-O-sedoheptulose (IV ) . IV was debenzoylation in 1% potassium carbonate aquiferous methanol solution to get 7-tribenzyl methyl-O-sedoheptulose (V). V reacted with benzyl chloroformate catalyzed by DMAP to get 1, 2, 3, 4, 5-0-pentabenzyloxycarbonyl-7-tribenzyl methyl- O-sedoheptu- lose,then the later was acted with CAN in aquiferous acetonitrile solution to delete tribenzyl methyl to get 1, 2, 3, 4, 5 -0-penta-benzyloxycarbonyl sedoheptulose (VI) . VI was esterified by 3, 4, 5-tribenzyl- 0-galloyl chloride under the condition of DCC and DMAP, then the ester was hydrogenated by H2 with 10% Pd-C to get the aim product, 7-0-galloylsedoheptulose (VD) .