Synthesis And Anti-inflammatory Activity Of Tetrahydroberberine Derivatives

Objectve: Based on the the previous studies, the reductive product ofberberine was found to show good anti-inflammatory potency. So three series oftetrahydroberberine derivatives were designed and synthesized to evaluate theirinhibitory potency on the production of nitric oxide （NO） in LPS-stimulatedRAW264.7cells，it was expected to obtain better anti-inflammatory compounds.Methods:（1）Synthesis of target compounds: In this thesis, berberine chloridewas used as the starting material for structural modifications in three routes. Routeone: the particial demethylation of berberine at high temperature under vacuum gaveberberrubine; tetrahydroberberrubine was obtained by the reduction of berberrubinewith sodium borohydride; then different amines reacted with triphosgene to givecorresponding carbamyl chlorides; finally, the target compounds H1-H12wereobtained by the reaction of tetrahydroberberrubine with carbamyl chlorides. Routetwo: berberrubine reacted with dibromoalkanes of varying length from two to fourcarbons, followed by reduction with sodium borohydride, afforded correspondingbromides which were reacted with appropriate amines. Finally, the target compoundsH13-H24were obtained. Route three: in this rout5-hydroxyl-3,4-halogenated-5H-furan-2-ones were used as the starting material, which reacted with methylchloroformate to yield5-methoxycarbonyloxy-3,4-halogenated-5H-furan-2-ones,these intermediates, then reacted with tetrahydoberberine bromides to give thedesired compounds H25-H27.（2） Evaluation of biological activity: cell cytotoxicitywas evaluated by MTT method and the inhibitory activity on NO production of allsynthesized compounds, which were performed by LPS-induced nitric oxideproduction on RAW264.7cell line.Results:（1） Totally twenty-seven end-products and four new intermediateswere obtained. All the structures of these compounds were verified by MS,¹HNMR,¹³CNMR.（2） MTT assay showed most of compounds were quite cytotoxic on RAW264.7cell line. The cytotoxicity IC50values of twenty-two compounds were lower than50μM, among them, compound H13、H17、H21and H24even possessedcytotoxicity IC50values of2.7μM、1.54μM、1.49μM and8.3μM, correspondingly.（3）Compound H11、H26and H27which possessed activity IC50values of7.4μM、7.3μM and8.4μM correspondingly, exhibited good inhibitory profiles onLPS-induced NO production without obvious cytotoxicity.