Synthesis Conjugates Of Oleanolic Acid Derivatives And Chalcones

Oleanolic acid （OA） is widespread in plants in the form free acid or derivatives,which has been first used in traditional Asian medicine due to its anti-inflammatoryactivity, and has a wide rang of biological activity. During recent decades, OA and itsderivatives have been widely studied for their-glucosidase inhibition activity, someof them showed excellent-glucosidase inhibition activity. Therefore, much attentionis being given toward the production of synthetic OA derivatives.Chalcones are useful intermediates in organic synthesis. Many chalcones with veryinteresting pharmacological and biological activities, such as antibacterial, antifungal,antimalarial and antilipidemic activity which makes them an attractive pharmacophoricscaffold. An area of particular interest is their potential as-glucosidase inhibitors forwhich some modes of action have been reported. Based on the diverse bioactivities ofabove-mentioned OA as well as chalcone, we were motivated to synthesize OAderivative-chalcone conjugates which would allow us to find more potent-glu-cosidase inhibitors. These merge pharmacophore may be addressing the activity site ofdifferent targets and offering the possibility to overcome drug resistance.In this paper, conjugations of chalcone with OA derivatives were synthesized by awell-known esterification procedure by activating the free carboxylic with1-（3-dimethylaminopropyl）-3-ethylcarbodiimide hydrochloride （EDC） in the presenceof4-N, N-dimethylaminopyridine （DMAP）, we present the synthesis of32newconjugates and their structure were characterized by IR,¹H NMR,¹³C NMR, MStechniques and some were further confirmed by2D NMR techniques.