The biosynthesis of the antioxidant caffeic acid derivative subulatin by the liverwort Jungermannia subulata cultured in vitro

The in vitro cultured liverwort Jungermannia subulata produces the unique molecule subulatin. In this study, we examined the incorporation of [1-13C] and [1,2-13C2] glucose, [2-13C] arabinose, [2-13C] caffeic acid, and [1-13C] phenylalanine into subulatin. The trilobatinoic acid C unit of subulatin incorporated 13C atoms from [1-13C] and [1,2-13C2] glucose and from [2-13C] arabinose but not from any other of the other precursors. Based on these results and labeling patterns, the trilobatinoic acid C unit of subulatin appears to be biosynthesized from arabinose-5-phosphate and phosphoenolpyruvate.