Design, synthesis and cytotoxicity of BODIPY FL labelled triterpenoids.

Several triterpenoid acids (betulinic, oleanolic, ursolic, glycyrrhetinic) and triterpene betulin were used as starting material to synthesize BODIPY FL adducts, and these compounds were screened for their cytotoxic activity employing several human tumor cell lines. The cytotoxicity of the compounds strongly depended on the chosen spacer between the triterpenoid core and the BODIPY FL unit. Thus, 3-O-acetyl-betulinic acid derived BODIPY FL conjugate holding an ethylendiamine spacer was cytotoxic for human breast adenocarcinoma cells MCF7 but not cytotoxic for all other cell lines.