Table 1. Main Polyphenols Identified by Liquid Chromatography Quadrupole Time-of-Flight Tandem Mass Spectrometry (LC-Q-TOF-MS) and Their Contents in the Shui Jing Fruit Extract (SJE).
| no. | compound | RTa (min) | [M – H]− (m/z) | molecular formula | fragment ions (relative abundance) | refs | content (mg/100 g DW) |
|---|---|---|---|---|---|---|---|
| Proanthocyanidins and Derivatives | |||||||
| 1 | bEGCGd | 32.891 | 457.0775 | C22H18O11 | 305.0671(14), 169.0143(100), 125.0247(37.5) | (22) | 1706.09 ± 16.87 |
| 2 | (E)GC-(E)GCG | 23.483 | 761.1366 | C37H30O18 | 609.1294(19), 591.1182(18), 423.0739(100), 305.0675(29) | (23) | 185.37 ± 2.74 |
| 3 | cEGCd | 21.168 | 305.0669 | C15H14O7 | 125.0243(100), 219.0654(30), 221.0451(15), 165.0197(25) | (24) | 127.44 ± 0.67 |
| 4 | (E)GCG-(E)GCG | 30.964 | 913.1485 | C44H34O22 | 761.144(36), 743.133(33), 591.1191(42), 573.1077(23), 423.0738(100), 285.0407(23) | (25) | 98.58 ± 1.00 |
| Flavonoid Glycosides | |||||||
| 5 | myricetin-3-O-α-l-rhamnoside (myricitrin)d | 44.885 | 463.0876 | C21H20O12 | 317.0309(29), 316.0221(100), 287.0193(26), 271.0243(35), 259.0244(7) | (17) | 834.18 ± 4.51 |
| 6 | quercetin-3-O-rhamnoside (quercetrin) | 53.954 | 447.093 | C21H20O11 | 301.0349(61), 300.0271(100), 271.0247(48), 255.03(30), 243.0298(11), 151.0033(7) | (26) | 779.95 ± 4.31 |
| 7 | kaempferol-3-O-rhamnoside | 62.243 | 431.0981 | C21H20O10 | 285.0409(100), 284.033(81), 255.0304(75), 227.0352(40), 229.0508(13) | (27) | 279.14 ± 1.79 |
| 8 | myricetin-3-O-(2″-O-galloyl)-α-l-rhamnopyranoside | 61.781 | 615.0991 | C28H24O16 | 463.0918(9), 317.0309(100), 178.9984(9) | (28) | 118.41 ± 1.35 |
| 9 | cyanidin-3-O-glucosided | 18.304 | 449.1078 | C21H20O11 | 284.0324(100), 447.0954(74) | (17) | 78.52 ± 0.16 |
| Phenolic Acid and Derivatives | |||||||
| 10 | 3′-O-methyl-4-O-(β-d-xylopyranosyl) ellagic acid | 52.823 | 447.0576 | C20H16O12 | 315.0153(100), 299.9921(96), 285.0401(7), 284.0329(21), 255.0293(12), 227.034(12) | (29) | 92.31 ± 0.04 |
a
RT: Retention time.
b
EGCG: Epigallocatechin gallate.
c
EGC: Epigallocatechin.
d
Further confirmed in comparison with authentic standard and its quantitative analysis was absolute. Others were relatively quantified.