Mass Spectrometry-Based Metabolite Profiling and Antioxidant Activity of Aloe vera (Aloe barbadensis Miller) in Different Growth Stages

Metabolite profiling of four different-sized Aloe vera plants was performed using gas chromatography–ion trap–mass spectrometry (GC-IT-MS) and ultra performance liquid chromatography–quadrupole–time of flight–mass spectrometry (UPLC-Q-TOF-MS) with multivariate analysis. Amino acids, sugars, and organic acids related to growth and development were identified by sizes. In particular, the relative contents of glucose, fructose, alanine, valine, and aspartic acid increased gradually as the size of the aloe increased. Anthraquinone derivatives such as 7-hydroxy-8-<i>O</i>-methylaloin, 7-hydroxyaloin A, and 6′-malonylnataloins A and B increased gradually, whereas chromone derivatives decreased continuously as the size of the aloe increased. The A30 aloe (size = 20–30 cm) with relatively high contents of aloins A and B, was suggested to have antioxidant components showing the highest antioxidant activity among the four different sizes of aloe. These data suggested that MS-based metabolomic approaches can illuminate metabolite changes associated with growth and development and can explain their change of antioxidant activity