Synthesis and evaluation of biological activity of the auaternary ammonium salts of lupane-, oleanane-, and ursane-type acids

Article abstract of DOI:10.1055/s-0030-1258293

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 respective 2-bromoethyl esters of betulinic, dihydrobetulinic, platanic, oleanolic, ursolic, and 3-acetoxy-21-oxolup-18-en- 28-oic acids with common low-molecular-weight tertiary amines, namely trimethylamine, triethylamine, pyridine, and triethanolamine. However, the desired quaternary salts were obtained only from trimethylamine, triethylamine, and pyridine. In case of the reaction with triethanol?amine the elimination of one of the 2-hydroxyethyl groups occurred and only tertiary amines were formed. Most of the prepared compounds showed significant in vitro cytotoxic activity on the CEM T-lymfoblastic leukaemia cell line. Three of the six selected compounds {2-(triethylammonio)ethyl 3-hydroxylup-20(29)-en-28-oate bromide, 2-(triethylammonio)ethyl 3b-hydroxylupan-28-oate bromide and 2-[bis(2-hydroxyethyl)amino]ethyl 3-hydroxylupan-28-oate] exhibited strong cytotoxic activity on a panel of ten cell lines, including drug resistant. Georg Thieme Verlag Stuttgart · New York.