Supplementary Material
Compounds identification by LC-MSn
The chromatographic peak (1) was identified as quinic acid. The deprotonated molecule at m/z 191 [M-H]-
- loses 18 Da, attributed to the loss of water, originating the ion at m/z 173[M-H-H2O] [53], that loses another
- water molecule (36 Da) originating the ion at m/z 155[M-H-2H2O] . The fragment ion at m/z 111, was produced
- by loss of carbonic acid and water molecule (-80 Da) [M-H-CH2O3-H2O] .
The chromatographic peaks (2) and (3) were identified as proantocyanidin B and proantocyanidin C, respectively. The fragments obtained by Retro-Diels-Alder (RDA) fission, heterocyclic ring fission (HRF), and quinone methide (QM) fission enabled identification of proantocyanidins. For dimers and trimers, HRF, RDA reaction, and QM fission cleavage were favoured. Peak (2) shows a deprotonated molecule at m/z 577 [M-H]- producing the fragment ions shown in Table 3. In the MS2 spectrum the fragment ion at m/z 425 can be
- produced by RDA fission (-152Da) [M-H-C8H8O3] from the deprotonated molecule. The ion at m/z 407, that is the base peak, loses 152 Da attributed to the loss of an RDA fragment followed by the loss of 18 Da
- corresponding to the elimination of a water molecule [M-H- C8H8O3-H2O] . The deprotonated molecule also produces the fragment ion at m/z 289 which is produced from a QM fragment, the ion at m/z 451 is formed
- from an HRF fragment with loss of 126 Da, corresponding to a C6H6O3 [M-H- C6H6O3] , and ion at m/z 559 from
- - the loss of a water molecule [M-H- H2O] . Peak (3) with a [M-H] ion at m/z 865 produces the fragment ions shown in Table 3. The ion at m/z 695, that is the base peak in the MS2 spectrum can be attributed to the
- product of a RDA fission (-152 Da) followed by the loss of one water molecule (-18 Da) [M-H- C 8H8O3- H2O] .
Secondary peaks, as the ion at m/z 713 is produced by RDA fission [M-H-152]- from deprotonated molecule,
the ion at m/z 739 is produced from an HRF fragment with loss of 126 Da, corresponding to a C 6H6O3 [M-H-
- C6H6O3] . Through QMlower fission carry the fragment ions with m/z 575 and m/z 289. The QMupper of deprotonated molecule produce the fragment ion at m/z 287 and m/z 577. The ion with m/z 577 loses 152Da
- by RDA fission [M-H-C8H8O3] originating the ion at m/z 425 that loses 18 Da, corresponding to water molecule
- [M-H- C8H8O3-H2O] producing the ion at m/z 407. The chromatographic peak (4) was identified as quercetin 3-
O-rutinoside-7-O-glucoside. The deprotonated molecule at m/z 771 [M-H]- loses 162 Da, corresponding to a glucose moiety [M- H-glucose]- producing the fragment ion at m/z 609. The MS3 spectrum of the peak at m/z
609 exhibits the fragment ions at m/z 301 and m/z 463. The ion at m/z 301 is the more abundant ion in the MS3 spectrum and this ion can be produced by loss of 308 Da, corresponding to a rutinoside moiety. The ion at m/z 463 results of the loss of 146 Da (rhamnose moiety) from the fragment ion at m/z 609. [39].
The chromatographic peak (5) showing deprotonated molecule with m/z value 609 in their full MS spectra were identified as quercetin 3-O-rhamnoside 7-O-glucoside. The deprotonated molecule of quercetin 3-O- rhamnoside-7-O-glucoside produces the fragment ions at m/z 447, by loss of glucose moiety [M-H-162]-, at m/z 463, by loss of a rhamnose moiety [M-H-146]- and at m/z 301 corresponding to the loss of saccharides
(glucose and rhamnose moiety) [M-H-162-146]-
The chromatographic peak (6) was identified as myricitrin (myricetin 3-ramnoside). The deprotonated molecule at m/z 463 [M-H]- loses 146 Da, attributed to the loss of the rhamnose moiety, originating the ion at
- - 2 m/z 317[Y0 ] and m/z 316 [Y0-H] . The other ions present in the MS spectrum show close resemblance to the peaks in the tandem mass spectrum of myricetin (m/z 271, m/z 179 and m/z 151).
The chromatographic peaks (7) and (8) were identified as rutin and quercitrin, respectively by comparing retention times, UV and MS data with the reference standard. The possible structures of another seven peaks in the chromatogram were tentatively characterized on the basis of literature data, due to the lack of standard phenolic compounds. The identification of these compounds is briefly discussed below. The chromatographic peak (8) of the extract was identified as quercitrin (quercetin 3-O-rhamnoside). The deprotonated molecule
[M-H]- at m/z 447, loses 146 Da, attributed to the loss of the rhamnose moiety, originating the ions at m/z
- - 301[Y0 ] and at m/z 300 [Y0-H] . The chromatographic peak (7) was identified as rutin. The deprotonated molecule [M-H]- at m/z 609, produces a quercetin fragment ion at m/z 301 by the loss of 308 Da, corresponding to a rutinoside moiety [M-H-glucose-rhamnose]-. For the chromatographic peaks (7) and (8) the
MS3 spectrum of the peak at m/z 301 shows close resemblance to the tandem mass spectrum of quercetin
(m/z 151 and m/z 179). [39 ].
The chromatographic peak (9) was identified as triterpen acid-O-hexoside. The ion at m/z 711 is an adduct ion [M+HCOO]-. The ion at m/z 711 loses formic acid (-46 Da) giving rise to an ion at m/z 665 that appears to be the deprotonated molecule [M-H]-. The fragment ion at m/z 503 is attributed to the loss of 162 Da, corresponding to a hexose moiety [M-H-hexose]-, from the deprotonated molecule (m/z 665). The MS3 spectrum of peak 9 shown a typical fragmentation of a triterpene acid.