Lac-l-TTA, a novel lactose-based amino acid–sugar conjugate for anti-metastatic applications

Here we describe the synthesis, chromatographic purification, MS and NMR characterization of a new lactosyl-derivative, i.e. a lactosyl thiophenyl-substituted triazolyl-thione L-alanine (Lac-L-TTA). This amino acid-sugar conjugate was prepared by solution synthesis in analogy to the natural fructosyl-amino acids. Furthermore, we investigated the inhibition of PC-3 prostate cancer cell colony formation by this lactose derivative in comparison with the less polar fructose-based derivative, Fru-L-TTA. This let us to compare the properties of the artificial derivative, object of the present work, with the monosaccharide-based counterpart and to obtain a preliminary information on the influence of polarity on such biological activity. A significantly higher anticancer effect of Lac-L-TTA with respect to the fructose analogue emerged from our study suggesting that the anti-metastatic potential of fructosyl-amino acids can be enhanced by increasing the polarity of the compounds, for example by introducing disaccharide moieties in place of fructose.