Table 5 Assignment of the characteristic peaks
No. | RT (min) | UV (nm) | MS in neg. mode | MS in pos. mode | MS2 in neg. mode | MS2 in pos. mode | Assignment | References |
|---|---|---|---|---|---|---|---|---|
1 | 15.2 | 283 | / | / | / | / | Unknown | / |
2 | 18.3 | 282 | / | / | / | / | Naringin | / |
3 | 19.2 | 253, 347 | 607 [M–H]− | 609 [M+H]+ | 299 [M-Rutinosyl–H]− | 301 [M-Rutinosyl+H]+ | Unknown | / |
631 [M+Na]+ | ||||||||
463 [M-Rhamnosyl+H]+ | ||||||||
301 [M-Rutinosyl+H]+ | ||||||||
4 | 20.1 | 283 | 609 [M–H]− | 611 [M+H]+ | 301 [M-Rutinosyl–H]− | 303 [M-Rutinosyl+H]+ | Hesperidin | |
1219 [2M–H]− | 1243 [2M+Na]+ | 286 [M-Rutinosyl–CH3–H]− | 285 [M-Rutinosyl-H2O+H]+ | |||||
465 [M-Rhamnosyl+H]+ | 257 [M-Rutinosyl–CO2–H]− | 270 [M-Rutinosyl–H2O–CH3+H]+ | ||||||
303 [M-Rutinosyl+H]+ | 242 [M-Rutinosyl-CO2-CH3-H]− | 195 [M-Rutinosyl–C6H4O2+H]+ | ||||||
134 [M-Rutinosyl-CO2–CH3–C6H4O2–H]− | 177 [M-Rutinosyl–C6H4O2–H2O+H]+ | |||||||
5 | 23.3 | 283 | 609 [M–H]− | 611 [M+H]+ | / | / | Neohesperidin | / |
633 [M+Na]+ | ||||||||
465 [M-Rhamnosyl+H]+ | ||||||||
303 [M-Rutinosyl+H]+ | ||||||||
6 | 32.4 | 254, 347 | 723 [M–H]− | 725 [M+H]+ | 417 [M-306–H]− | 419 [M-306+H]+ | Unknown | / |
695 [M–CO–H]− | 747 [M+Na]+ | |||||||
7 | 36.5 | 210, 257, 342 | / | / | / | / | Unknown | / |
8 | 40.3 | 203, 269, 345 | / | 373 [M+H]+ | / | 343 [M–CH2O+H]+ | Unknown | / |
395 [M+Na]+ | ||||||||
358 [M–CH3+H]+ | ||||||||
343 [M–CH2O+H]+ | ||||||||
9 | 42.2 | 206, 253, 270, 355 | / | 403 [M+H]+ | / | 373 [M–CH2O+H]+ | Unknown | / |
425 [M+Na]+ | ||||||||
388 [M–CH3+H]+ | ||||||||
373 [M–CH2O+H]+ | ||||||||
10 | 43.6 | 214, 241, 330 | / | 373 [M+H]+ | / | 343 [M–CH2O+H]+ | Sinensetin | |
395 [M+Na]+ | 312 [M–H2O–CO–CH3+H]+ | |||||||
767 [2M+Na]+ | 297 [M–H2O–CO–CH2O+H]+ | |||||||
358 [M–CH3+H]+ | ||||||||
343 [M–CH2O+H]+ | ||||||||
312 [M–H2O–CO–CH3+H]+ | ||||||||
11 | 43.7 | 270, 295, 341 | / | 343 [M+H]+ | / | 313 [M–CH2O+H]+ | Tetramethyl-O-isoscutellarein | [20] |
707 [2M+Na]+ | 285 [M–CH2O–CO+H]+ | |||||||
328 [M–CH3+H]+ | ||||||||
313 [M–CH2O+H]+ | ||||||||
285 [M–CH2O–CO+H]+ | ||||||||
12 | 46.3 | 208, 336 | / | 403 [M+H]+ | / | 388 [M–CH3+H]+ | Hexamethoxyflavone | [21] |
373 [M–CH2O+H]+ | 373 [M–CH2O+H]+ | |||||||
355 [M–CH2O–H2O+H]+ | ||||||||
327 [M–CH2O–H2O–CO+H]+ | ||||||||
13 | 47.1 | 333 | / | 403 [M+H]+ | / | 388 [M–CH3+H]+ | Nobiletin | |
388 [M-CH3+H]+ | 373 [M–CH2O+H]+ | |||||||
373 [M-CH2O+H]+ | 343 [M–2CH2O+H]+ | |||||||
313 [M–3CH2O+H]+ | ||||||||
283 [M–4CH2O+H]+ | ||||||||
239 [M–C10H12O2+H]+ | ||||||||
211 [M–C10H12O2–CO+H]+ | ||||||||
14 | 47.7 | 266, 322 | / | 343 [M+H]+ | / | 313 [M–CH2O+H]+ | Tetramethyl-O-scutellarein | [20] |
365 [M+Na]+ | 299 [M–CO2+H]+ | |||||||
328 [M-CH3+H]+ | ||||||||
313 [M-CH2O+H]+ | ||||||||
15 | 50.1 | 253, 343 | / | 433 [M+H]+ | / | 403 [M–CH2O+H]+ | 3,5,6,7,8,3′,4′-Heptamethoxyflavone | |
455 [M+Na]+ | 373 [M–2CH2O+H]+ | |||||||
496 [M+Na+CH3CN]+ | 345 [M–2CH2O–CO+H]+ | |||||||
418 [M-CH3+H]+ | ||||||||
403 [M-CH2O+H]+ | ||||||||
16 | 51.8 | 270, 323 | / | 373 [M+H]+ | / | 343 [M–CH2O+H]+ | Tangeretin | |
395 [M+Na]+ | 283 [M–3CH2O+H]+ | |||||||
358 [M-CH3+H]+ | 312 [M–CH3–H2O–CO+H]+ | |||||||
17 | 56.5 | 203, 254, 282, 341 | / | 389 [M+H]+ | / | 374 [M–CH3+H]+ | 5-Hydroxy-6,7,8,3′,4′-pentamethoxyflavone | [7] |
411 [M+Na]+ | 359 [M–CH2O+H]+ | |||||||
374 [M-CH3+H]+ | ||||||||
359 [M-CH2O+H]+ |