Abstract
A central step in xanthone biosynthesis is the formation of the C13 skeleton, i.e. an intermediate benzophenone. Biosynthesis of 2,3',4,6-tetrahydroxybenzophenone from m-hydroxybenzoyl-CoA and malonyl-CoA was shown in cell-free extracts from cultured cells of Centaurium erythraea. The enzyme catalyzing this reaction was named benzophenone synthase.