Analogs of the dihydroceramide desaturase inhibitor GT11 modified at the amide function: synthesis and biological activities
作者:Carmen Bedia、Gemma Triola、Josefina Casas、Amadeu Llebaria、Gemma Fabriàs
DOI:10.1039/b510198k
日期:——
Dihydroceramide desaturase is the last enzyme in the biosynthesis of ceramide de novo. The cyclopropene-containing sphingolipid GT11 is a competitive inhibitor of dihydroceramide desaturase. The biological effects of chemical modification of the GT11 amide linkage are reported in this article. Either N-methyl substitution or replacement of the amide α-carbonyl methylene by oxygen result in inactive compounds. In contrast, both urea (3) and thiourea (4) analogs of GT11, as well as three α-ketoamides (5–7), did inhibit the desaturation of N-octanoylsphinganine to N-octanoylsphingosine, although with significantly lower potency than GT11. Furthermore, the α-ketoamides 5–7 inhibit the acidic ceramidase with similar potencies (IC50 52–83 µM). Inhibition of the neutral/alkaline ceramidase by these compounds requires around 20-fold higher concentrations. Structure–activity relationships and the biological interest of these compounds are discussed.
二氢酰胺去饱和酶是神经酰胺新合成中的最后一个酶。含环丙烯的鞘脂GT11是二氢酰胺去饱和酶的竞争性抑制剂。本文报告了对GT11酰胺键的化学修饰的生物学效应。N-甲基取代或将酰胺α-羰基亚甲基替换为氧会导致化合物失活。相比之下,GT11的脲化合物(3)和硫脲化合物(4)以及三种α-酮酰胺(5–7)确实抑制了N-辛酰鞘氨醇向N-辛酰神经酰胺的去饱和,尽管其效力显著低于GT11。此外,α-酮酰胺5–7也以相似的效力抑制酸性神经酰胺酶(IC50 52–83 µM)。这些化合物对中性/碱性神经酰胺酶的抑制需要约20倍的更高浓度。文中讨论了这些化合物的结构-活性关系和生物学兴趣。