Table 1 Identification of metabolites in Clausena lansium (Lour.) Skeels by MALDI-MS analysis in positive ion mode.
Compound name Ion formula m/z Fragment ion Ref.
Alkaloids

a Confirmed by standard substance.

b The mass fragments used to infer the chemical identities of the various compounds are based on published literature provided for each of the alkaloids in the supplementary information.

c Hypothesis.
DL-Stachydrine a [C H NO +K]+ 7 13 2 182.06 100.11
[C H N O –CO +H]+ 14 26 2 4 2 243.21 100.11, 144.10
[C H N O +K]+ 14 26 2 4 325.15 182.06, 144.10, 100.11
3-Methylcarbazole b [C H N H]+ 13 11 + 182.10 95.05, 167.07, 116.97, 105.05 (Cui et al., 2002)
Murrayanine b [C H NO H]+ 14 11 2+ 226.09 198.09,183.07,167.07,155.07 (Sripisut et al., 2012)
Heptaphylline b [C H NO H]+ 17 17 + 252.14 234.13, 133.09, 91.05 (Songsiang et al., 2011)
5-methyl-2-vinyl-3,11-dihydropyrano carbazole c [C H NO H]+ 18 15 + 262.12 205.10, 234.13, 91.05
Girinimbine a [C H NO + H]+ 18 17 264.14 131.05, 103.05, 205.10,
Murrastinine b [C H NO +H]+ 18 17 2 280.13 174.09, 205.10, 262.12 (Liu et al., 2019)
Unknown [C H NO +K]+ 30 37 11 626.20 103.05, 131.05, 264.14, 500.16, 524.16
Unknown [C H NO K]+ 28 40 15+ 668.19 103.05, 131.05, 264.14, 282.15
Coumarin
8-Hydroxylpsoralen [C H O H]+ 11 6 4+ 203.03 147.04,175.04, 131.05 (Huang et al., 2017)
Wampetin b [C H O H]+ 21 18 6+ 367.12 203.03, 147.04, 131.05, 165.09 (Liu et al., 2014)
2′,3′-Epoxyindicolactone b [C H O +H]+ 21 18 7 383.11 203.03, 163.08, 181.09 (Lakshmi et al., 1984)
Anisolactone b [C H O +K]+ 21 18 6 405.07 – (Liu et al., 2014)
Dihydroindicolactone b [C H O K]+ 21 20 6+ 407.09 203.03, 147.04, 167.11, 369.13 (Liu et al., 2014)
Wampetin dimer c [C H O K]+ 42 36 12 + 771.18 405.07
Other metabolites
Sucrose [C H O K]+ 12 22 11+ 381.08 219.03, 201.02
Hexose [C H O +K]+ 6 12 6 219.03 –
Citric acid [C H O +K]+ 6 8 7 231.00 –
4-Methylmethamphetamine [C H N + H]+ 11 17 164.14 –