On the influence of the rhodamine substituents onto the cytotoxicity of mitocanic maslinic acid rhodamine conjugates

Maslinic acid was converted via a di-acetylated piperazinyl amide into rhodamine conjugates differing in their alkyl moieties. These conjugates were submitted to cytotoxicity assays employing a panel of human tumor cell lines. These conjugates held high cytotoxicity but also some selectivity especially for A2780 cells. Thereby, a propyl substituted rhodamine conjugate showed EC50 values as low as EC50 = 0.01 mu M and was approx. 15 times more cytotoxic for the cancer cells than for non-malignant fibroblasts (NIH 3 T3). Cytotoxicity obviously parallels the lipophilicity of the residue and suggests - since the compounds act as mitocanes - an interaction of the conjugates with the inner mitochondrial membrane.

Automated summary

Maslinic acid was converted to rhodamine conjugates with different alkyl moieties, which showed high cytotoxicity, especially for A2780 cells. Among them, a propyl substituted rhodamine conjugate exhibited low EC50 values of EC50 = 0.01 μM and was approximately 15 times more cytotoxic to cancer cells than non-malignant fibroblasts (NIH 3 T3). The cytotoxicity was correlated with the lipophilicity of the residues, suggesting an interaction of the conjugates with the inner mitochondrial membrane as they acted as mitocanes.