Table 1. Relevant Compounds Detected in Wild-Type C. acuminata
Annotated MetaboliteFormulaRetention Time (min)Calculated m/z for [M+H]+Experimental Precursor m/z for [M+H]+Fragment Ion(s) Observed in MS/MS Spectra (m/z)TDC1-RNAi
No. of Deuterium Atoms
Tryptamine (4)C10H12N28.0161.1079161.10651444
Loganic acid (2)C16H24O1013.6 (2 isomers)a377.1448377.1450359, 215, 197, 179, 161, 151, 137, 133, 123, 109, 810
Secologanic acid (4)C16H22O1015.1 (2 isomers)a375.1291375.1290213, 195, 177, 151, 125, 109, 107, 95, 79, 770
Strictosidinic acid (5)C26H32N2O923.9 (isomer 1)517.2186517.2198500, 355, 338, 320, 269/268, 251, 194, 180/181, 168/170, 151, 156, 144, 130, 125n.d. (isomer 1)
24.8 (isomer 2)4 (isomer 2)
26.5 (isomer 3)4 (isomer 3)
Strictosamide (6)C26H30N2O837.6 (isomer 1)499.2080499.2081337, 319, 267, 171, 1444 (isomer 1)
41.5 (isomer 2)4 (isomer 2)
Strictosamide epoxide (7)C26H30N2O922.8 (isomer 1)515.2030515.2021353, 335, 309, 291, 283, 265, 263, 237, 209, 183, 184, 155, 144n.d. (isomer 1)
24.8 (isomer 2)n.d. (isomer 2)
26.5 (isomer 3)n.d. (isomer 3)
Strictosamide diol (8)C26H32N2O1020.1533.2135533.2170371, 353, 283, 265, 185, 160, 142, 132n.d.
Strictosamide ketolactam (9)C26H30N2O1022.5 (isomer 1)531.1979531.1953369, 351, 341, 299, 281, 271, 253, 194, 176, 158, 148, 130, 124, 106n.d. (isomer 1)
22.7 (isomer 2)n.d. (isomer 2)
Pumiloside (10)C26H28N2O930.2 (isomer 1)513.1873513.1890351, 333, 315, 305, 281, 235, 1402 (isomer 1)
32.9 (isomer 2)n.d. (isomer 2)
Deoxypumiloside (11)C26H28N2O836.1 (isomer 1)497.1924497.1930335, 265, 247, 219, 183, 169, 142, 972 (isomer 1)
38.2 (isomer 2)2 (isomer 2)
Camptothecin (12)C20H16N2O434.3349.1188349.1198305, 277, 249, 219/220, 1682
  • Metabolites in root, stem, shoot apex, and leaf extracts were separated by a 52-min UHPLC/MS/MS method and are listed with their precursor and fragment ions. Fragment ions obtained after loss of a glucose unit (162 D) are highlighted in bold. Only stem tissue contained detectable levels of all metabolite isomers listed here. The last column in the table summarizes the results of in vivo labeling experiments with [α,α,β,β-d4]-tryptamine in TDC1-RNAi plants, which do not accumulate tryptamine-derived MIAs without tryptamine supplementation. After incubation of TDC1-RNAi apical cuttings with [α,α,β,β-d4]-tryptamine for 6 weeks, several deuterated MIAs were detectable in stem extracts. The number of deuterium atoms incorporated into detectable metabolites is indicated in the last column, with n.d. indicating compounds that were below the limit of detection in deuterium labeling experiments.

  • a Loganic acid and secologanic acid exist also as multiple isomers that were not resolved with this UHPLC/MS method but were resolved using a different chromatography system (Supplemental Figures 1 and 2).