Synthesis and evaluation of the biological properties of boron-containing and boron-omitted capsaicin derivatives on human cancer cell lines

Boron-containing and boron-omited derivatives based on the structural motif of capsaicin have been synthesized. The vanillyl amide moiety of the parent capsaicin molecule was retained and the boron atom was incorporated into the aliphatic region. All new compounds have been fully characterized using various analytical techniques including multinuclear NMR spectroscopy and elemental analysis. Thereafter, their antiproliferative activity was evaluated on 3 cancer cell lines (HT-29, M21 and MCF7) leading to the selection of compounds 4c and 7c for assessment of their antitumoral activities on HT-29 tumors grafted onto the chorioallantoic membrane of developing chick embryos. The boro-capsaicinoid 4c exhibits good antitumoral activity with a 55% decrease in tumor mass.