Antioxidant Activities and Phenolics Contents of Avocado ( Persea americana Mill.) Peel in vitro ]]>

摘要

in vitro method of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2?-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS + ) radical scavenging, reducing power of iron (III) as well as total phenolic and flavonoid contents. Materials and Methods: Ethyl acetate fraction of AP is fractionated using vacuum liquid chromatography and gravitation column chromatography methods. To identify the chemical structure of the active compound of antioxidants in AP, FTIR spectroscopy and gas chromatography-mass spectrometry (GC-MS) are used. Results: Among extracts evaluated, methanol extract has the strongest > antioxidant activity . Further fractionation of m > ethanolic extract showed that fraction 8 is the most active fraction with IC ₅₀ values of 4.221±0.137 mg mL -1 (DPPH assay) and 0.855±0.013 mg mL -1 (ABTS assay), with reducing power of iron (III) of 723.067±18.849 mg > ascorbic acid g -1 fraction. Phenolics contents contributed 37, 40.78 and 47.45%, compared with the contribution of flavonoids compounds of 26.71, 19.25 and 34.62% for DPPH radical scavenging, ABTS radical scavenging and reducing power of iron (III) to iron (II), respectively. Isolation of the fraction 8 of methanol extract indicated the presence of 1,2,4-trihidroksiheptadek-12,16-diyne and isolation of the ethyl acetate extract indicated the presence of 1,2,4-trihidroksiheptadek-16-yne-18-ene. Conclusion: The AP is potential to be used as food supplement due to its antioxidant activities.]]>