title: Habitat influence on antioxidant activity and tannin concentrations of Spondias tuberosa.
abstract: BACKGROUND
  Different habitat conditions can be responsible for the production of secondary metabolites and for the antioxidant properties of plant products.
  
  
  OBJECTIVE
  Thus, the aim of this study was to evaluate whether the antioxidant activity and tannin concentrations in the stem bark of Spondias tuberosa Arruda (Anacardiaceae) varied with collection site.
  
  
  METHODS
  The bark was collected from 25 individual trees, distributed in five different landscape units, as follows: agroforestry gardens, areas of pastures, maize cultivation areas, mountain areas and mountain bases, with the former 3 being considered as anthropogenic habitats, and the latter 2 considered as habitats with native coverage. The study was conducted in the rural area of the city of Altinho, Pernambuco State (Northeast Brazil). The DPPH (1,1-diphenyl-2-picrylhydrazyl) method was used to measure the antioxidant activity and tannin concentrations were evaluated by using the radial diffusion method.
  
  
  RESULTS
  The results demonstrated that there were no significant differences among the tannin concentrations of the individuals from the native (6.27% ± 1.75) or anthropogenic areas (4.63% ± 2.55), (H = 2.24; p > 0.05). In contrast, there were significant differences (H = 5.1723; p < 0.05) among the CE₅₀ means of the antioxidant activities of the individuals from the native (32.10 µg/ml ± 5.27) and anthropogenic areas (27.07 µg/ml ± 2.29). However, correlations between the tannin concentrations and antioxidant activity of the extracts were not observed in the native (r = 0.39; p > 0.05) or in the anthropogenic areas (r = 0.38; p > 0.05).
  
  
  CONCLUSIONS
  Because the variation of the antioxidant capacity of S. tuberosa bark was not accompanied by a variation in the tannin concentration, this property may be related to the presence of other metabolite(s).
authors.affiliation: Laboratório de Etnobotânica Aplicada, Departamento de Biologia, Universidade Federal Rural de Pernambuco, Recife, Pernambuco, Brazil.
authors.forename: Thiago Antônio
authors.initials: TA
authors.lastname: de Sousa Araújo
authors.forename: Valerium Thijan Nobre
authors.initials: VT
authors.lastname: de Almeida e Castro
authors.forename: Elba Lúcia Cavalcanti
authors.initials: EL
authors.lastname: de Amorim
authors.forename: Ulysses Paulino
authors.initials: UP
authors.lastname: de Albuquerque
mesh_terms: D000531:Altitude; D027926:Anacardiaceae / Q000254:growth & development* / Q000378:metabolism*; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D001938:Brazil; D017753:Ecosystem; D020834:Ethnopharmacology; D024301:Plant Bark / Q000254:growth & development / Q000378:metabolism*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification; D018547:Plant Stems / Q000254:growth & development / Q000378:metabolism*; D013634:Tannins / Q000302:isolation & purification / Q000378:metabolism*; D014197:Trees
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D013634:Tannins