New reagent for oxidative phenol coupling.The transformation of the monocyclic spermine base (S)-dihydroxyverbacine to the bicyclic alkaloid (S,S,S)-aphelandrine by cell free extract fo barley seedlings

摘要

The soluble protein fraction of barley seedlings (Hordeum vulgare,Gramineae) in the presence of O_2 stereoselectively catalyzes the intramolecular phenol coupling of the monocyclic spermine base (S)-dihydroxyverbacine to the bicyclic aphelandirne in preparative yield.Teh expected microsomal-bond cytochrome P-450 enzyme system does not contribute to this reaction.The nature of the involved biocatalyst still remains uncertain.The catalytic potential of the cell free extract of barley seedlings suggests its possible use as an efficient tool for large scale stereoselective chemoenzymatic synthesis of aphelandrine type alkaloids.