Table 2.
Authentication of CGA and STL in chicory flour by negative-ion UPLC-HRMS analysis.
| Metabolitesa | Formula | M − H+ | RDB | RT | M − H+ | Precision (ppm) |
|---|---|---|---|---|---|---|
| theoretical | min | average ± SD | average ± SD | |||
| 5-CQA | C16H18O9 | 353.08726 | 8.5 | 1.85 | 353.08856 ± 8.83E − 05 | 5.244 ± 0.250 |
| DHLc | C15H18O5 | 277.10760 | 7.5 | 2.07 | 277.10884 ± 3.74E − 05 | 6.460 ± 0.135 |
| Lc | C15H16O5 | 275.09970 | 8.5 | 2.30 | 275.09316 ± 5.10E − 05 | 6.397 ± 0.186 |
| 3,5-diCQA | C25H24O12 | 515.11895 | 14.5 | 3.65 | 515.12061 ± 1.02E − 04 | 4.156 ± 0.260 |
| DHdLc | C15H18O4 | 261.11260 | 7.5 | 4.04 | 261.11376 ± 4.19E − 05 | 6.209 ± 0.160 |
| dLc | C15H16O4 | 259.09700 | 8.5 | 4.04 | 259.09803 ± 5.44E − 05 | 6.000 ± 0.197 |
| DHLp | C23H24O7 | 411.14430 | 12.5 | 6.82 | 411.14657 ± 6.60E − 05 | 6.658 ± 0.160 |
| Lp | C23H22O7 | 409.12870 | 13.5 | 6.91 | 409.13055 ± 2.46E − 04 | 5.802 ± 0.601 |
a5-CQA: 5-mono-O-caffeoylquinic acid; DHLc: 11(S),13-dihydrolactucin; Lc: lactucin; 3,5-diCQA: 3,5-di-O-caffeoylquinic acid; DHdLc: 11(S),13-dihydro-8-deoxylactucin; dLc: 8-deoxylactucin; DHLp: 11(S),13-dihydrolactucopicrin; Lp: lactucopicrin.
M − H+: molecular weight without one hydrogen.
RDB: ring double bond.
RT: retention times.
SD: standard deviations obtained by three repetitions.