Synthesis and Discovery Novel Anti-Cancer Stem Cells Compounds Derived from the Natural Triterpenoic Acids.

Cancer stem cells (CSCs) have been reported to be involved in tumorigenesis, tumor recurrence, cancer invasion, metastasis, and drug-resistance. Therefore, the development of drug molecules targeting CSCs has become an attractive therapeutic approach. However, the molecules which can selectively ablate CSCs are extremely rare. To explore the leading compounds targeting CSCs, 52 analogues of triterpenoic acids were synthesized in this study, whose biological activities were evaluated. On the basis of the results of tumorsphere assay, two compounds 48 and 51, derived from oleanolic acid, exhibited suppressive effect on elimination of different type of CSCs. Meanwhile, compounds 48 and 51 could significantly inhibit the growth of several tumors both in vitro and in vivo. Furthermore, treatment of cancer cells with both of two compounds would dramatically increase the level of ROS, which might eliminate the CSCs. Collectively, the leading compounds 48 and 51 were promising anti-CSCs agents that merited further validation as a novel class of chemotherapeutics.