Table 1.
Identification of the free flavonoids of PCR-C by HPLC-Q-TOF-MS/MS.
| No. | RT (min) | Molecular Formula |
[M + H]+ (m/z) (Error, ppm) |
Fragment Ions in the Positive Ion Mode |
[M-H]− (m/z) (Error, ppm) |
Fragment Ions in the Negative Ion Mode |
Identification |
|---|---|---|---|---|---|---|---|
| 1 | 5.563 | C27H30O15 | 595.1665 (−1.27) | 541; 481; 457; 409; 379; 337; 325; 295 | 593.1520 (−1.34) | 503; 473; 455; 383; 353 | Vicenin-2 |
| 2 | 5.974 | C28H32O16 | 625.1769 (−1.03) | 409; 379; 367; 355; 337; 325; 151 | 623.1621 (−0.58) | 533; 503; 413; 383 | Diosmetin-6,8-di-C-glucoside |
| 3 | 9.022 | C22H22O11 | 463.1238 (−1.26) | 445; 427; 367; 343; 313 | 461.1095 (−1.26) | 371; 341; 298 | Diosmetin-8-C-glucoside/Scoparin |
| 4 | 9.278 | C23H24O12 | 493.1345 (−0.92) | 329; 314; 299 | ND | ND | Coccinoside A |
| 5 | 10.167 | C28H34O15 | 611.1984 (−0.03) | 465; 449; 413; 303 | 609.1843 (−0.80) | 301 | Hesperidin |
| 6 | 25.064 | C20H20O8 | 389.1234 (−0.90) | 374; 359; 341 | ND | ND | Monohydroxypentamethoxyflavone (1) |
| 7 | 26.749 | C20H20O7 | 373.1288 (−1.85) | 357; 343; 315; 181 | ND | ND | Isosinensetin |
| 8 | 27.688 | C20H20O8 | 389.1238 (−1.90) | 374; 359; 355; 323; 305 | ND | ND | Monohydroxypentamethoxyflavone (2) |
| 9 | 31.559 | C20H20O7 | 373.1288 (−1.97) | 357; 343; 315; 296; 283; 153 | ND | ND | Sinensetin |
| 10 | 33.255 | C19H18O6 | 343.1182 (−2.12) | 313; 285; 181; 153 | ND | ND | 5,7,8,4′-Tetramethoxyflavone |
| 11 | 36.562 | C21H22O8 | 403.1405 (−1.35) | 373; 355; 327; 211 | ND | ND | Nobiletin |
| 12 | 38.731 | C19H18O6 | 343.1182 (−2.03) | 327; 313; 285; 267; 153 | ND | ND | 5,6,7,4′-Tetramethoxyflavone |
| 13 | 40.827 | C22H24O9 | 433.1501 (−1.83) | 416; 403; 401; 388 | ND | ND | 3,5,6,7,8,3′,4′-Heptamethoxyflavone |
| 14 | 44.243 | C20H20O7 | 373.1288 (−2.06) | 343; 328; 297; 271; 211 | ND | ND | Tangeretin |
| 15 | 46.599 | C20H20O8 | 389.1238 (−1.85) | 373; 359; 341; 313; 197 | ND | ND | 5-Demethylnobiletin |
| 16 | 47.436 | C20H20O9 | 405.1554 (0.84) | 388; 373; 301; 241 | ND | ND | Dihydroxypentamethoxyflavone |
| 17 | 48.127 | C19H18O7 | 359.1129 (−0.91) | 329; 311; 286; 227; 169 | ND | ND | Gardenin B |
[M + H]+, the precursor ion obtained from mass spectrum in positive mode; [M-H]−, the precursor ion obtained from mass spectrum in negative mode. RT: retention time, ND: not detected.