title: Total phenolic content, in vitro antioxidant activity and chemical composition of plant extracts from semiarid Mexican region.
abstract: 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.
authors.affiliation: Laboratory of Bioprocesses and Natural Products, Food Research Department, School of Chemistry, Universidad Autónoma de Coahuila, Saltillo, 25280, México.
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Wong-Paz
authors.affiliation: Laboratory of Bioprocesses and Natural Products, Food Research Department, School of Chemistry, Universidad Autónoma de Coahuila, Saltillo, 25280, México.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Contreras-Esquivel
authors.affiliation: Laboratory of Bioprocesses and Natural Products, Food Research Department, School of Chemistry, Universidad Autónoma de Coahuila, Saltillo, 25280, México.
authors.forename: Raúl
authors.initials: R
authors.lastname: Rodríguez-Herrera
authors.affiliation: Laboratory of Biochemistry, Multidisciplinary Academic Unit-Huasteca, Universidad Autónoma de San Luis Potosí, 79060, Cd. Valles, S.L.P., Mexico.
authors.forename: María L
authors.initials: ML
authors.lastname: Carrillo-Inungaray
authors.affiliation: Laboratory of Bioprocesses and Natural Products, Food Research Department, School of Chemistry, Universidad Autónoma de Coahuila, Saltillo, 25280, México.
authors.forename: Lluvia I
authors.initials: LI
authors.lastname: López
authors.affiliation: Department of Microbiology, School of Chemistry, Universidad Autónoma de Chihuahua, 31125 Chihuahua, Mexico.
authors.forename: Guadalupe V
authors.initials: GV
authors.lastname: Nevárez-Moorillón
authors.affiliation: Laboratory of Bioprocesses and Natural Products, Food Research Department, School of Chemistry, Universidad Autónoma de Coahuila, Saltillo, 25280, México. Electronic address: cristobal.aguilar@uadec.edu.mx.
authors.forename: Cristóbal N
authors.initials: CN
authors.lastname: Aguilar
keywords: Heat–reflux system; Mexican plants; Natural antioxidants; Plant–extracts; Polyphenols