title: Chemical analysis of the resinous exudate isolated from Heliotropium taltalense and evaluation of the antioxidant activity of the phenolics components and the resin in homogeneous and heterogeneous systems.
abstract: H. taltalense (Phil.) Johnst. (Heliotropiaceae) is an endemic species of the northern coast of Chile that produces a resinous exudate that covers its foliar surface and stems. Its chemical composition was analyzed for the first time, and two aromatic geranyl derivatives: filifolinol and filifolinyl senecionate and three flavonoids - naringenin, 3-O-methylgalangin and 7-O-methyleriodictiol - were isolated. The antioxidant activity of the flavonoids and the resinous exudates was carried out by measuring the 1,1-diphenyl-2-picrylhydrazyl (DPPH) bleaching effect in ethanolic solution and in sodium dodecyl sulfate (SDS) micelles. The influence of the reaction medium was analyzed. The initial velocity reactions for the pure compounds and for the extract were higher in SDS media than in ethanolic solution. The velocity of reaction observed was interpreted in terms of the reaction medium environment in the micelle.
authors.affiliation: Departamento de Ciencias del Ambiente, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile. brenda.modak@usach.cl
authors.forename: Brenda
authors.initials: B
authors.lastname: Modak
authors.forename: Macarena
authors.initials: M
authors.lastname: Rojas
authors.forename: René
authors.initials: R
authors.lastname: Torres
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000737:chemistry; D044950:Flavanones / Q000737:chemistry; D005419:Flavonoids / Q000737:chemistry*; D028162:Heliotropium / Q000737:chemistry*; D015394:Molecular Structure; D010851:Picrates / Q000737:chemistry; D012116:Resins, Plant / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D044950:Flavanones; D005419:Flavonoids; D010851:Picrates; D012116:Resins, Plant; C004931:1,1-diphenyl-2-picrylhydrazyl; C005273:naringenin