Different Mode of Incorporation of o-Succinylbenzoic Acid into the Naphthoquinones Juglone and Lawsone in Higher Plants

Abstract

[1-13C]o-Succinylbenzoic acid is incorporated to approximately 50% into each of the keto groups of the quinone ring of juglone in JugIans regia. The same labelled precursor is transformed into the keto group of position 1 in lawsone, the pigment of Impatiens balsamina, suggesting two different intermediates in the biosynthesis of these simple 2- or 5-hydroxy-1,4-naphthoquinones.