Munoz-Olaya Jose M, Matabosch Xavier, Bedia Carmen, Egido-Gabás Meritxell, Casas Josefina, Llebaria Amadeu, Delgado Antonio, Fabriàs Gemma
Research Unit on BioActive Molecules, Departamento de Química Orgánica Biológica, Instituto de Investigaciones Químicas y Ambientales de Barcelona, CSIC, Jordi Girona 18, 08034 Barcelona, Spain.
ChemMedChem. 2008 Jun;3(6):946-53. doi: 10.1002/cmdc.200700325.
A novel mechanism-based dihydroceramide desaturase inhibitor (XM462) in which the substrate C5 methylene group is replaced by a sulfur atom is reported. Dihydroceramide desaturase inhibition occurred both in vitro and in cultured cells with IC(50) values of 8.2 and 0.78 microM, respectively, at a substrate concentration of 10 microM. In vitro experiments showed that XM462 produced a mixed-type inhibition (K(i)=2 microM, alpha=0.83). LC-MS analyses showed that accumulation of endogenous dihydroceramides occurred in cells upon treatment with XM462 in serum-free medium, whereas ceramides built up in controls. In addition, XM462 was found to be metabolised to its 1-glucosyl and 1-phosphocholine derivatives, and to the products of N-deacylation and reacylation with palmitoyl and stearoyl groups. In Jurkat A3 cells cultured in serum-free medium, viability, as the percentage of trypan blue unstained cells in total cells, was reduced upon XM462 treatment (5 microM, 24 h), but not in controls. The interest of this compound is discussed.
报道了一种新型的基于机制的二氢神经酰胺去饱和酶抑制剂（XM462），其中底物的C5亚甲基被硫原子取代。在底物浓度为10μM时，二氢神经酰胺去饱和酶在体外和培养细胞中均受到抑制，IC（50）值分别为8.2和0.78μM。体外实验表明，XM462产生混合型抑制作用（K（i）=2μM，α=0.83）。液相色谱-质谱分析表明，在无血清培养基中用XM462处理细胞后，内源性二氢神经酰胺积累，而对照中神经酰胺积累。此外，发现XM462被代谢为其1-葡萄糖基和1-磷酸胆碱衍生物，以及N-脱酰化和与棕榈酰基和硬脂酰基再酰化的产物。在无血清培养基中培养的Jurkat A3细胞中，用XM462处理（5μM，24小时）后，作为总细胞中台盼蓝未染色细胞百分比的活力降低，但对照中未降低。讨论了该化合物的意义。
