Table 2.
Identification of UHPLC/DAD/ESI-MSn data, and quantification of the most relevant compounds from the ethanolic extract of S. stellata (Retention time (Rt), wavelength of maximum absorption in the UV-Vis region (λmax), pseudomolecular and MSn fragment ions, quantification (mean ± SD) and identification of the phenolic compounds).
| Rt (min) | λmax | [M − H]− (m/z) ♦ | ESI-MS2; (MS3) (m/z) ♠ | Quantity ♣ | Compound |
|---|---|---|---|---|---|
| 1.38 | 191, 267 | 387 | 341, 369; (179, 143, 161) | 8.24 ± 0.03 | 1-Caffeoylglucose derivative (b) |
| 1.74 | 193, 202 | 128 | 85, 109 | 4.30 ± 0.02 | Cyanuric acid (a) |
| 4.35 | 204, 324 | 353 | 191, 179, 135; (173, 127, 109) | nq | 1-O-Caffeoylquinic acid (c) |
| 5.30 | 211, 278, 323 | 223 | 205, 115, 143, 159 | 0.26 ± 0.01 | Sinapic acid (a) |
| 6.66 | 217, 298, 325 | 353 | 191, 179, 173, 135; (111, 93) | 26.41 ± 0.30 | 4-O-Caffeoylquinic acid (c) |
| 7.12 | 216, 299, 325 | 353 | 191, 179; (173, 127, 85) | 8.93 ± 0.12 | 3-O-Caffeoylquinic acid (a) |
| 8.40 | 206, 269, 348 | 609 | 489, 447, (357, 327, 285) | 1.84 ± 0.03 | Luteolin-6-C-glucoside-7-O-glucoside (b) |
| 8.55 | 199, 214, 270, 304 | 353 | 191, 179, 135; (173, 127, 85) | 1.47 ± 0.01 | 5-O-Caffeoylquinic acid (c) |
| 8.83 | 220, 274, 310 | 337 | 191, 173; (127, 110, 93) | tr | 5-O-p-Coumaroylquinic acid (c) |
| 9.83 | 230, 326 | 367 | 191; (173, 85) | 0.97 ± 0.02 | 5-O-Feruloylquinic acid (c) |
| 10.14 | 209, 269, 350 | 447 | 429, 357, 327; (309, 297, 285) | 66.31 ± 0.30 | Isoorientin (luteolin-6-C-glucoside) (a) |
| 10.40 | 211, 269, 350 | 579 | 561, 447, 357, 327; (309, 297, 285) | 9.78 ± 0.26 | Luteolin-2″-O-pentosyl-6-C-hexoside (b) |
| 10.65 | 211, 270, 346 | 461 | 371, 341, 313; (299, 231) | 13.97 ± 0.11 | Diosmetin-6(or 8)-C-glucoside (b) |
| 11.90 | 225, 270, 338 | 563 | 443, 431; (311, 283, 269) | 2.82 ± 0.01 | Apigenin-2″-O-pentosyl-8-C-glucoside (b) |
| 12.38 | 232, 256, 353 | 463 | 301; (268, 179, 151) | 0.97 ± 0.04 | Quercetin-3-O-glucoside (hyperoside) (b) |
| 13.99 | 220, 241, 327 | 515 | 353; (191, 173) | 16.03 ± 0.03 | 4,5-O-Dicaffeoylquinic acid (a) |
| 14.21 | 237, 267, 337 | 609 | 489, 369; (298, 285, 231) | 1.23 ± 0.01 | Lucenin 2 (luteolin-6,8-di-C-glucoside) (b) |
| 14.38 | 242, 326 | 515 | 353, 335; (173,111) | tr | 3,4-O-Dicaffeoylquinic acid (c) |
| 14.93 | 240, 268, 314 | 639 | 616, 315 | tr | Tamarixetin-O,O-dihexoside (b) |
| 15.18 | 242, 326 | 515 | 353; (191, 171, 127) | 3.74 ± 0.02 | 3,5-O-Dicaffeoylquinic acid (c) |
| 18.26 | 239, 270, 351 | 613 | 489, 447, 429; (369, 309, 285) | 0.43 ± 0.02 | Luteolin-6-C-glucoside derivative (b) |
| 19.02 | 243, 267, 314 | 593 | 447, 285 | 0.37±0.02 | Tiliroside (b) |
| 20.86 | 237, 267, 314 | 635 | 477, 315 | 14.49 ± 0.02 | Tamarixetin derivative (b) |
| 20.94 | 237, 267, 313 | 769 | 623, 477, 315 | nq | Tamarixetin glycoside (a) |
| 21.30 | 243, 269, 313 | 739 | 593, 447, 285 | 10.85 ± 0.01 | Kaempferol-3-O-rutinoside derivative (b) |
| 57.55 ± 0.11 ♥ | Total chlorogenic acids | ||||
| 108.20 ± 0.17 ♥ | Total flavonoids |
♦ molecular ion; ♠ main fragments; ♣ mg of compound/g dried extract; nq—not quantified; tr—traces; ♥ obtained by propagation. Compounds were identified by (a) comparison with pure standards, commercially available or isolated; (b) comparison with pure aglycone and literature data; (c) comparison with pure cinnamic acid derivative and literature data.