Synthesis and Pharmacological Activity of Betulin, Betulinic Acid, and Allobetulin Esters

A series of new triterpene hemisuccinates, hemiphthalates and nicotinates have been obtained with 52 – 95% yields via reactions of monoacetates of betulin, betulinic acid, and allobetulin with succinic and phthalic anhydrides and with nicotinic acid chloroanhydride. 3-O-Acetylbetulin-28-O-hemiphthalate showed the most pronounced antiinflammatory activity comparable with the effect of ortophen (diclofenac). 3-O-Acetylbetulin-28-O-hemisuccinate...