Purpose: To investigate the antioxidant and phenolic profiles of methanol extracts from
Rhizophora
mangle
L,
Krameria erecta
,
Lycium berlandieri
Dunal,
Vallesia glabra
Link and
Forchammeria watsonii
Rose.
Methods: The free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method was used for antioxidant
assay of methanol plant extracts. Phenolic compounds determination was carried out by high
performance liquid cromatography (HPLC) using an analytical C18 column eluting with acetonitrile on a
gradient program.
Results: Extract from
Rhizophora mangle L and
Krameria erecta displayed 5-fold higher antioxidant
capacity than ascorbic acid with DPPH reduction values of 95.71 and 91 %, respectively. Anti-radical
kinetic analysis and stoichiometric constant values suggest that the compounds responsible for
antioxidant activity are polyphenols and flavonoids with a free or mono-substituted catechol group.
Ferulic and vanillic acids had higher contents in Rhizophora mangle L (688.45 ± 18.21 and 7.13 ± 0.125
mg/g, respectively) and
Krameria erecta (619.92 ± 28.16 mg/g and 22.29 ± 0.72 mg/g, respectively)
than the other constituents.
Conclusion: Rhizophora mangle and
Krameria erecta possess five times the antioxidant activity of
ascorbic acid and also demonstrate high phenolic contents, which supports the beneficial properties
attributed to these plants in traditional medicine, and also justifies the use of the plants as alternative
medicines.
