Fig. 3: Characterization of stephanotic acid-burpitides with a Tyr-Phe-crosslinked second ring.

a Mercurialis annua from University of Michigan herbarium. b Mercurialin detection in methanolic leaf extracts of M. annua and of transgenic N. benthamiana 6 days after infiltration with A. tumefaciens LBA4404 pEAQ-HT-ManBURP. c Mercurialin structure. d Key HMBC correlations of mercurialin side-chain-crosslinks. EIC: extracted ion chromatogram. Source data are provided as a Source Data file.