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.
Shu Chen PeiJian Bo WuFan LeiShan QianLi HaiYong Wu
A series of 1-oxacephem analogs were synthesized and their antibacterial properties against five strains of Gram-positive and Gram-negative bacteria were evaluated in vitro while ceftazidine was selected as control.Some of the tested compounds,compound 12c in particular,showed more active against three selected strains than the standard.
