Extended Data Fig. 7: Hydroponic feedings to the roots of 4-month-old S. nux-vomica seedlings with deuterium labelled Wieland-Gumlich aldehyde.

a. Hydroponic feedings of S. nux-vomica in 50 mL falcon tube with 20 mL 1 mM deuterium labelled Wieland-Gumlich aldehyde. b. HRMS (ESI) [M+H]⁺ chromatogram of synthetic deuterium labelled Wieland-Gumlich aldehyde mixture. The major component (49%) is d2-Wieland-Gumlich aldehyde. c. Extracted ion chromatograms for prestrychnine 9 (m/z [M+H]⁺ = 397.1758 ± 0.005), d2-prestrychnine (m/z [M+H]⁺ = 399.1884 ± 0.005), d2-isostrychnine (m/z [M+H]⁺ = 337.1880 ± 0.005), d2-strychnine (m/z [M+H]⁺ = 337.1880 ± 0.005). d. MS/MS (20 to 50 eV) spectrum and putative ion fragments of generated d2-prestrychnine (m/z [M+H]⁺ = 399.1884, blue) compared to prestrychnine (m/z [M+H]⁺ = 397.1758, red). e. MS/MS (20 to 50 eV) spectra and putative ion fragments of generated d2-strychnine (m/z [M+H]⁺ = 337.1880, blue) compared to strychnine standard (m/z [M+H]⁺ = 335.1754, red). f. MS/MS (20 to 50 eV) spectra and putative ion fragments of generated d2-isostrychnine (m/z [M+H]⁺ = 337.1880, blue) compared to isostrychnine standard (m/z [M+H]⁺ = 335.1754, red). This experiment was repeated three times with similar results.