Biosynthesis of theobroxide and its related compounds, metabolites of Lasiodiplodia theobromae

2H and 13C NMR analyses of theobroxide 1, a potato-tuber inducing substance, and its carbonyldioxy derivative 2, produced by Lasiodiplodia theobromae in the presence of 2H and 13C-labeled acetates clarified the tetraketide origin of 1 and 2 and the incorporation of the carboxy carbon of acetate into a carbonyl carbon in 2.