Development of 1,2,3-Triazole-Based Sphingosine Kinase Inhibitors and Their Evaluation as Antiproliferative Agents

Two series of N-(aryl)-1-(hydroxyalkyl)pyrrolidine-2-carboxamides (2a–2g and 3a–3g) and 1,4-disubstituted 1,2,3-triazoles (5a–5h and 8a–8h) were synthesized. All the compounds, containing a lipophilic tail and a polar headgroup, were evaluated as sphingosine kinase (SphK) inhibitors by assessing their ability to interfere with the acetylcholine (Ach) induced relaxation of aortic rings pre-contracted with phenylephrine. Moreover, their antiproliferative activity was tested on several cell lines expressing both SphK1 and SphK2. Compounds 5h and 8f, identified as the most efficient antiproliferative agents, showed a different selectivity profile, with 8f being selective for SphK1.