The [M]+ at m/z 669 led to MS/MS fragments at m/z 507[M−162]+, 46

The [M]+ at m/z 669 led to MS/MS fragments at m/z 507[M−162]+, 465[M−204]+ and 303[M−162-204]+ ( Table 2). In this case, losses of 162 u and 204 u corresponded, respectively, to a unit of hexose and of an acetylated hexose (162 + 42 u) ( Cuyckens & Claeys, 2004), and the fragment at m/z 303 is characteristic of the aglycone delphinidin. Furthermore, the elution order in relation to dpn 3,5-diglucoside is consistent with what is expected from the reversed-phase elution, e.g., the acylated

anthocyanins elute after their corresponding non-acylated anthocyanins ( Wu & Prior, 2005). The major anthocyanins found in jambolão were delphinidin 3,5-diglucoside (45%), petunidin 3,5-diglucoside (32%) and malvidin PLX-4720 research buy 3,5-diglucoside (15%). These results are consistent with those reported in previous studies with jambolão fruits, where the major anthocyanins were identified as 3,5-diglucosides of delphinidin (23–33%), petunidin (32–35%) and malvidin (21–38%) (Brito et al., 2007, Li et al., 2009a and Veigas et al., 2007). In addition to these anthocyanins, Brito et al. (2007) and MK-1775 cost Li et al., 2009a and Li et al., 2009b also identified 3,5-diglucosides of cyanidin and peonidin. The phenolic

compounds shown in Table 3 (chromatogram in Fig. S3 from Supplementary data) were mainly identified by the mass spectra characteristics, since ionisation in the positive and negative modes gave complementary information, such as the case where only the protonated molecule ([M+H]+) with sodium adduct [M+Na]+ was detected in the positive mode. The presence of the deprotonated molecule ([M−H]−) allowed the confirmation of

the molecular weight of the compounds. The identification of gallic acid (peak 2) was based on the characteristics of UV–Vis and mass spectra (Table 3) compared to literature data (Cuyckens and Claeys, 2004 and Nuengchamnong and Ingkaninan, 2009) and confirmed by co-chromatography. This phenolic acid showed λmax at 271 nm, characteristic of phenolic acids derived from hydroxybenzoic acid. Moreover, the mass spectra obtained from both ESI+ (fragment at m/z 153) and ESI− ([M−H]− at m/z 169) showed the same characteristics as the ones obtained from the standard analysed under the same conditions. Flavopiridol (Alvocidib) Peak 1 was tentatively identified as galloyl-glucose ester based on the elution order on reversed phase relative to free gallic acid (peak 2), detection of [M−H]− at m/z 331, and loss of 162 u, equivalent to the elimination of an hexose unit, giving the fragment ion at m/z 169 corresponding to gallic acid. The [M+Na]+ at m/z 355 was observed in the ESI+ analysis. Furthermore, this compound also showed λmax at 278 nm, characteristic of phenolic acids. Moreover, the galloyl-glucose ester (peak 1) showed the same MS/MS fragmentation pattern as the galloyl-glucose ester found in jambolão wine ( Nuengchamnong & Ingkaninan, 2009).

Leave a Reply

Your email address will not be published. Required fields are marked *

*

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>