31P NMR study on aminoacylation of 5′-AMP and its analogs

Abstract

The progress of aminoacylation of 5′-AMP with amino acids in the presence of several condensing reagents was monitored by ³¹P NMR. The resulting products were identified on the basis of their ³¹P NMR chemical shifts. The aminoacylation of 5′-AMP proceeded completely when DCC was used as a condensing reagent under anhydrous conditions. The synthesis of aminoacyl-adenylate analogs substituted with sulfur and a methylene group for the 5′-phosphoryl oxygen and ribosyl 5′-oxygen atoms, respectively, were also examined under various conditions. The ³¹P NMR analysis of these reactions revealed that the 5′-thiophosphate analogs (aa-AMPSs) substituted with sulfur for the 5′-phosphoryl oxygen were formed as main products by the condensation of 5′-AMPS and amino acids by use of diphenyl phosphorochloridate as a condensing reagent, while 5′-methylenephosphonate derivatives (aa-AMPCs) were formed quantitatively by use of DCC as a condensing reagent.