3.2.5. Xanthonoids

As represented in Figure 10, peak 23 had an [M−H]<sup>−</sup> ion at 583.1311, with a molecular formula of C25 H27 O16. It showed MS2 fragments at *m*/*z* 565 (loss of water), 493 [M−H−90]<sup>−</sup>, and 463 [M−H−120]<sup>−</sup> (both due to cleavage of C-hexoside). The main MS3 fragment at *m*/*z* 331 [M−H−90-162]<sup>−</sup> occurred by the loss of a O-hexoside. Thus, this peak was identified as mangiferin O-hexoside [50].

Peaks 30 and 46 were identified as isomers mangiferin and isomangiferin as they had an [M−H]<sup>−</sup> ion at 421.0787 (C19 H17 O11) and fragments at *m*/*z* 331 [M−H−90]<sup>−</sup> and 301 [M−H−120]<sup>−</sup>, both of them due to cleavage of glicoside. Peaks 39 and 42 showed an [M−H]<sup>−</sup> ion at 573.0891 (C26 H21 O15), with an MS2 fragment at *m*/*z* 421 [M−H−152]<sup>−</sup> and the same MS3 fragments as mangiferin, thus they were identified as the isomers maguiferin O-gallate and isomangiferin O-gallate [16]. Peak 48 ([M−H]<sup>−</sup> = 725.1004, C33 H25 O19) had an MS2 fragment at *m*/*z* 573 ([M−H−152]<sup>−</sup>, loss of galloyl) and MS3 fragments at *m*/*z* 421 (loss of second galloyl) and 403 (loss of O-galloyl), so it was assigned to mangiferin-di-O-gallate [48].

**Figure 10.** Structure and fragments of xanthonoids.
