Resumen de In vitro characterization of antioxidant properties of cuban endemic varieties of erythroxylum alaternifolium a. Rich. Isolation of two flavonol glycosides

Wilmer H Perera Córdova, Mislén Gómez Matos, Jessica Tabart, Arnaud Sipel, Claire Kevers, Jacques Dommes

• The total antioxidant capacity from leaves of three Cuban endemic varieties of Erythroxylum alaternifolium was measured using three techniques: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) and Oxygen radical absorbance capacity (ORAC). The highest values of antioxidant capacity and total phenols were measured in polar n-butyl alcohol extracts. Among the varieties of E. alaternifolium assayed, the var. parvifolium showed the strongest antioxidant capacity: ABTS (6.49 ± 0.05 mg TE/g dw); DPPH (11.16 ± 0.01 mg TE/g dw) and ORAC (35.1 ± 1.5 mg TE/g dw). Additionally, n-butyl alcohol extract of E. alaternifolium var. parvifolium also showed the highest content in phenolics with 284.2 ± 7.3 mg CAE/g dw and in flavonols with skeleton quercetin, kaempferol and myricetin with 471 μg/g dw. Moreover, two flavonol glycosides: ombuin-3-O-rutinoside and quercetin-3-O-rutinoside were isolated for the first time from n-butyl alcohol extract of E. alaternifolium var. alaternifolium.