Objective To determinate the recovery of total polyphenolic compounds content, in vitro antioxidant activity and HPLC/ESI/MS characterization of extract from Nephelium lappaceum L. (Mexican rambutan). Methods The rambutan husk extract was obtained by aqueous extraction and a polyphenolic fraction was recovered using Amberlite XAD-16. The total polyphenolic compounds content was determined by the Folin Ciocalteu and butanol-HCI methods. In vitro antioxidant activity was performed using ABTS and ferric reducing antioxidant power methods. Results Mexican rambutan husk showed a total polyphenolic content of 582 mg/g and an evident antioxidant activity by ABTS and ferric reducing antioxidant power analysis. The HPLC/ESI/MS assay allowed the identification of 13 compounds, most of which belong to ellagitannins. Geraniin, corilagin and ellagic acid were present in the sample; the mineral composition was also evaluated. Conclusions Rambutan husk cultivated in Mexico is a promising source for the recovery of added value bioactive compounds with antioxidant activity, which have potential applications as bioactive antioxidant agents for the treatment of diseases.

Objective: To determine the extraction suitable conditions of total phenolic content (TPC) by heat-reflux system, antioxidant activities and HPLC characterization of the aqueous-ethanolic extracts of Jatropha dioica (J. dioica) (Dragon's blood), Flourensia cernua (F. cernua) (Tar bush), Eucalyptus camaldulensis (E. camaldulensis) (Eucalyptus) and Turnera diffusa (T. diffusa) (Damiana). Methods: TPC was evaluated by the well-known colorimetric assay using Folin-Ciocalteu reagent. The antioxidant activities were assayed by three methods based on scavenging of DPPH, ABTS and by lipid oxidation inhibition. The chemical composition of the extracts obtained was subject to HPLC analysis. Results: TPC in the plant extracts ranged from 2.3 to 14.12 mg gallic acid equivalents/g for J. dioica and E. camaldulensis, respectively. The plant extracts of F. cernua, E. camaldulensis and T. diffusa showed similar strong antioxidant activities on scavenging of DPPH and lipid oxidation inhibition. In contrast, J. dioica extracts had lowest potential antioxidant in three assays used. HPLC assay showed the presence of several phenolic compounds in the extracts used. Conclusions: The results obtained suggest that F. cernua, E. camaldulensis and T. diffusa are potential sources to obtain bioactive phenolic compounds with high antioxidant properties which can be used in the factories as antioxidant agents or for treatments in diseases.