Total phenols, flavonoids and anti-radical activity in Annona muricata and Annona purpurea callus culture
Callus cultures of Annona muricata and Annona purpurea were induced in Murashige and Skoog (MS) medium supplemented with different concentrations of 1-naphthylacetic acid (NAA), 6-benzyladenine (BA) and 2,4-dichlorophenoxyacetic acid (2,4-D) utilized hypocotyls with explant. The highest percentage of callus formation frecuency was the treatment supplemented with 3 mgL-1 NAA for A. muricata (100%) while for A. purpurea in lower percentage (75%). BA stimulated the formation of shoots in all the evaluated concentrations, being the concentration of 2 mgL-1 the one that induced the greater formation of shoots for A. muricata (23 shoots/explant) and A. purpurea (28 shoots/explant). The content of total phenols, flavonoids and antiradical activity was measured in the callus obtained from both species. The results showed that the callus of A. purpurea have a higher content of total phenols (27.8 mgg-1 dw) compared to A. muricata (23.2 mgg1 dw). The highest content of total flavonoids was observed in the callus of A. purpurea (8.0 μgg-1 dw). Anti-radical was determined by the 2,2-Diphenyl-1-Picrylhydracil Radical assay. The concentration required for 50% inhibition (IC50) of the 2,2-Diphenyl-1-Picrylhydracil radicals were 4.22 μgmL-1 in methanolic extracts of callus of A. muricata, while in extracts of callus of A. purpurea was 2.86 μgmL-1, in both cases was greater than that found for leaves. Callus culture of the species studied in this work represents an alternative for the production of natural antioxidants.