Synthesis and Cytotoxicity Evaluation of Pentacyclic Triterpene–Phenol Nitrogen Mustard Conjugates

Using a reported pharmacophore, 4-[N,N-bis(2-chloroethyl)-amino]phenol, and pentacyclic triterpenes, pharmacologically and structurally diverse components of natural products, six pentacyclic triterpene-4-[N,N-bis(2-chloroethyl)-amino]phenol conjugates were synthesized by click chemistry. Their cytotoxicities against the BEL-7404 and NCI-H460 tumor cell lines were evaluated by the MTT assay. The in vitro results from the cytotoxicity assay indicated that at a compound concentration of 20 μM, these conjugates showed low toxicity (< 16%) toward the tested tumor cells in culture.