Synthesis of oleanolic disaccharide derivatives

Oleanolic acid 1 exists widely in food, medicinal herbs and other plants and possesses many attractive biological activities. Recently, some oleanolic derivatives were reported to have interesting anti-tumor activities. Herein, using association principle of drug design, OA disaccharide 17 was designed and synthesized by coupling a-L-rhamnopyranosyl-(1→2)-a-L-arabinopyranosyl disaccharide moiety, which has proved to be a unique sugar sequence with strongly antitumor activity, and modified OA with a nitrile at C-17.