Antitumour activity of fatty acid maltotriose esters obtained by enzymatic synthesis

The antitumour properties of two fatty acid esters of maltotriose, 6''-O-dodecanoylmaltotriose and 6''-O-palmitoylmaltotriose, in which the 6-OH at the non-reducing end of the maltotriose has been regioselectively acylated, were studied. Both compounds were synthesized by transesterification of vinyl laurate or vinyl palmitate with maltotriose, in the presence of immobilized lipase from Thermomyces lanuginosus. A mixture of 2-methylbutan-2-ol and DMSO (80:20, v/v) was the reaction medium. Their cytotoxic activities against two human cancer cell lines, Hep-G2 and HeLa, were studied. 6''-O-palmitoylmaltotriose showed IC50 values of 2.3 microM (1.7 microg/ml) for Hep-G2 and 3.6 microM (2.7 microg/ml) for HeLa cells, whereas 6''-O-dodecanoylmaltotriose displayed a lower inhibitory effect. 6''-O-palmitoylmaltotriose showed a marginal cytotoxicity to rat hepatocytes, confirming its potential as a new antitumour agent.