The anticancer properties of the derivatives of natural pentacyclic triterpenoids have received much attention recently. Here we present the preparation and the evaluation of the anticancer activity of a novel group of derivatives: quaternary ammonium esters.
The esters were synthesized by quaternization of the respektive 2-bromoethyl esters of betulinic, dihydrobetulinic, platanic, oleanolic, ursolic, and 3b-acetoxy-21-oxolup-18-en-28-oic acids with common low-molecular-weight tertiary amines, namely trimethylamine, triethylamine, pyridine, and triethanolamine