Table 1.
UHPLC-HRMS/MS data of detected compounds in “Ramata di Montoro” (M) and “Rossa di Tropea” (T) onion-dried skin extracts.
| N° | Compound | Molecular Formula | RT(UV) (min) |
Measured (m/z) [M − H]− (m/z) |
Error (ppm) | Product Ion MS/MS |
Measured (m/z) [M + H]+ (m/z) |
Error (ppm) | Product Ion MS/MS |
Onion Cultivar |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Protocatechuic acid | C7H6O4 | 1.0 | 153.1235 | 1.6 | / | / | / | / | M, T |
| 2 | 2-(3,4-Dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (Qox) | C15H10O8 | 6.0 | 317.0303 | 3.3 | 299; 191; 207; 273 | / | / | / | M, T |
| 3 | Cyanidin 3-glucoside (CyG) | C21H21O11 | 6.2 | / | / | / | 449.1077 | −0.3 | 287 | T |
| 4 | Quercetin dihexoside | C27H30O17 | 6.6 | 625.1405 | 0.9 | 463; 301 | 627.1557 | 0.3 | 465; 303 | M, T |
| 5 | Cyanidin 3-laminaribioside | C27H31O16 | 7.0 | / | / | / | 611.1609 | 0.3 | 287 | T |
| 6 | Quercetin 3,4’-diglucoside (QdG) | C27H30O17 | 7.4 | 625.1410 | −0.3 | 463; 301 | 627.1559 | 0.6 | 465; 303 | M, T |
| 7 | Isorhamnetin dihexoside | C28H32O17 | 8.2 | 639.1571 | 0.04 | 477; 315 | 641.1716 | 0.5 | 317; 479 | M, T |
| 8 | Cyanidin 3-malonilglucoside | C24H23O14 | 10.5 | / | / | / | 535.1084 | 0.3 | 287 | T |
| 9 | Cyanidin 3-malonillaminaribioside | C30H33O19 | 11.4 | / | / | / | 697.1609 | 0.2 | 287 | T |
| 10 | Quercetin-3-glucoside | C21H20O12 | 11.6 | 463.0874 | 0.6 | 301 | 465.1027 | −0.2 | 303 | M, T |
| 11 | Quercetin-4’-glucoside (QG) | C21H20O12 | 12.4 | 463.0873 | 0.8 | 301 | 465.1025 | −0.6 | 303 | M, T |
| 12 | Isorhamnetin-O-hexoside | C22H22O12 | 13.3 | 477.1031 | 0.7 | 315 | 479.1186 | 0.5 | 317 | M, T |
| 13 | Quercetin (Q) | C15H10O7 | 14.3 | 301.0350 | 0.6 | 179; 151 | 303.0496 | −1.0 | 285; 257; 229; | M, T |
| 14 | Protocatecoyl quercetin | C22H14O11 | 14.8 | 453.0454 | 0.4 | 299 | 455.0610 | 0.1 | 437; 301; | M, T |
| 15 | Protocatecoyl quercetin | C22H14O11 | 14.9 | 453.0455 | 0.6 | 299 | 455.00609 | 0.1 | 437; 301; | M, T |
| 16 | Kaempferol | C15H10O6 | 16.3 | 285.0399 | 2.1 | / | 287.0548 | −0.6 | / | M, T |
| 17 | Isorhamnetin | C16H12O7 | 16.9 | 315.0503 | 1.2 | 300; 257 | 317.0656 | 0.0 | 302, 285; 257 | M, T |
| 18 | Quercetin dimer 4’-glucoside (Q2Ga) | C36H28O19 | 17.2 | 763.1140 | −0.2 | 611; 449; | 765.1300 | 0.3 | 603; 451 | M, T |
| 19 | Quercetin dimer 4’-glucoside (Q2Gb) | C36H28O19 | 18.3 | 763.1139 | −0.3 | 611; 600; 299 | 765.1298 | 0.1 | 603; 585 | M, T |
| 20 | Quercetin dimer hexoside | C36H28O19 | 18.8 | 763.1139 | −0.2 | 611; 600; 299 | 765.1299 | 0.2 | 603; 585 | M, T |
| 21 | Quercetin dimer (Q2) | C30H18O14 | 19.4 | 601.0617 | 0.8 | 449; 299 | 603.0772 | 0.5 | 585; 313; 303 | M, T |
| 22 | Quercetin trimer (Q3) | C45H26O21 | 20.8 | 901.0881 | −0.2 | 299; 449; 599; 601 | 903.1044 | 0.5 | 885; 751; 585; 613 | M, T |