Straightforward Access to Spisulosine and 4,5-Dehydrospisulosine Stereoisomers: Probes for Profiling Ceramide Synthase Activities in Intact Cells
摘要:
A stereoselective synthesis of spisulosine (ES285) and 4,5-dehydrospisulosine stereoisomers is described. Hydrozirconation of 1-pentadecyne with Schwartz reagent, followed by diastereocontrolled addition to L- or D-alaninal afforded the required 2-amino-1,3-diol framework. The resulting sphingoid bases revealed as excellent probes for the profiling of ceramide synthase activity in intact cells. Among the sphingoid bases described in this work, spisulosine (ES285), RBM1-77, and RBM1-73 were the most suitable ones because of their highest acylation rates. These molecules should prove useful to study the role of the different ceramide synthases and the resulting N-acyl (dihydro)ceramides in cell fate.
Exploring Leishmania major Inositol Phosphorylceramide Synthase (LmjIPCS): Insights into the ceramide binding domain
作者:John G. Mina、Jackie A. Mosely、Hayder Z. Ali、Paul W. Denny、Patrick G. Steel
DOI:10.1039/c0ob00871k
日期:——
The synthesis of set of ceramide analogues exploring hydrophobicity in the acyl chains and the degree and nature of hydroxylation is described. These have been assayed against the parasitic protozoan enzymeLmjIPCS. These studies showed that whilst the C-3 hydroxyl group was not essential for turnover it provided enhanced affinity. Reflecting the membrane bound nature of the enzyme a long (C13) hydrocarbon ceramide tail was necessary for both high affinity and turnover. Whilst the N-acyl chain also contributed to affinity, analogues lacking the amide linkage functioned as competitive inhibitors in both enzyme and cell-based assays. A model that accounts for this observation is proposed.
An efficient methodology for the synthesis of sphingoid-type bases is reported. It involves the stereoselective addition of a racemic 3-alkoxy allenylzinc to enantiopure N-tert-butylsulfinyl imines and a cross-metathesis reaction as the key steps. It has been successfully applied to the syntheses of sphinganine and naturally occurring bioactive related compounds, among which the hydrolysis product
Straightforward Access to Spisulosine and 4,5-Dehydrospisulosine Stereoisomers: Probes for Profiling Ceramide Synthase Activities in Intact Cells
作者:José Luis Abad、Ingrid Nieves、Pedro Rayo、Josefina Casas、Gemma Fabriàs、Antonio Delgado
DOI:10.1021/jo400440z
日期:2013.6.21
A stereoselective synthesis of spisulosine (ES285) and 4,5-dehydrospisulosine stereoisomers is described. Hydrozirconation of 1-pentadecyne with Schwartz reagent, followed by diastereocontrolled addition to L- or D-alaninal afforded the required 2-amino-1,3-diol framework. The resulting sphingoid bases revealed as excellent probes for the profiling of ceramide synthase activity in intact cells. Among the sphingoid bases described in this work, spisulosine (ES285), RBM1-77, and RBM1-73 were the most suitable ones because of their highest acylation rates. These molecules should prove useful to study the role of the different ceramide synthases and the resulting N-acyl (dihydro)ceramides in cell fate.