Synthesis and anticancer activities of fatty acid analogs of podophyllotoxin

Derivatives of podophyllotoxin were prepared by coupling 10 FA with the C4-alpha-hydroxy function of podophyllotoxin. The coupling reactions between FA and podophyllotoxin were carried out by dicyclohexylcarbodiimide in the presence of a catalytic amount of dimethylaminopyridine to produce quantitative yields of desired products. FA incorporated were the following: 10-hydroxydecanoic, 12-hydroxydodecanoic, 15-hydroxypentadecanoic, 16-hydroxyhexadecanoic, 12-hydroxyoctadec-Z-9-enoic, eicosa-Z-5,8,11,14-tetraenoic, eicosa-Z-8,11, 14-trienoic, eicosa-Z-11,14-dienoic, eicosa-Z-11-enoic, and eicosanoic acids. Spectroscopic studies confirmed the formation of the desired products. New molecules were investigated for their in vitro anticancer activity against a panel of human cancer cell lines including SK-MEL, KB, BT-549, SK-OV-3 (solid tumors), and HL-60 (human leukemia) cells. Most of the analogs were cytotoxic against cancerous cells, whereas no effect was observed against normal cells, unlike the parent compound podophyllotoxin, the use of which is limited due to its severe side effects.