The phosphohydrolysis of hydroxycinnamoyl-coenzyme a thioesters in plant extracts

Abstract

In barley seedling extracts, p-coumaroyl-CoA is rapidly hydrolysed to p-coumaroyl-dephospho-CoA, p-coumaroyl-4′-phosphopantetheine and p-coumaroyl-pantetheine. p-Coumaroyl-4′-phosphopantetheine is active as a substrate of agmatine coumaroyl transferase in the formation of p-coumaroyl-agmatine, but p-coumaroyl-pantetheine is inactive. The phosphohydrolysis can be partly inhibited by inorganic pyrophosphate, sodium fluoride and purine nucleotides. A simplified method for the synthesis of N-hydroxysuccinimide esters of hydroxycinnamic acids, used in the synthesis of CoA thioesters, is also described.