title: Activity-guided identification of acetogenins as novel lipophilic antioxidants present in avocado pulp (Persea americana).
abstract: Avocado fruit is a rich source of health-related lipophilic phytochemicals such as monounsaturated fatty acids, tocopherols, carotenes, acetogenins and sterols. However, limited information is available on the contribution of specific phytochemicals to the overall antioxidant capacity (AOC) of the fruit. Centrifugal partition chromatography was used as fractionation tool, guided by an in vitro chemical assay of oxygen radical absorbance capacity (ORAC). Subsequent experiments focused on isolation and characterization of the chemical nature of the main contributors to lipophilic AOC of avocado pulp. ORAC values obtained for acetogenins were contrasted with results from an isolated kidney mitochondria membrane lipid peroxidation bioassay. The present study established that lipophilic AOC of the pulp was significantly higher than its hydrophilic AOC. Our results confirmed the presence of acetogenins in the fractions with highest lipophilic AOC, and for the first time linked them as contributors to lipophilic-ORAC values. Further HPLC-PDA/MS-TOF analysis led to structural elucidation of two novel acetogenins, not previously reported as present in avocado pulp, along with five already known related-compounds. Antioxidant properties observed for avocado pulp acetogenins by the ORAC assay suggested that, in the presence of an emulsifying agent, acetogenins could serve as novel lipophilic antioxidants in a food matrix. Results from isolated mitochondria lipid peroxidation bioassay, indicated that L-ORAC values which may have relevance for food matrix applications, should not be interpreted to have a direct relevance in health-related claims, compounds need to be evaluated considering the complexity of biological systems.
authors.affiliation: Department of Biotechnology and Food Engineering, School of Biotechnology and Food, Tecnológico de Monterrey-Campus Monterrey, E. Garza Sada 2501 Sur, C.P. 64849, Monterrey, NL, Mexico; Endowed Chair in Cardiology. School of Medicine. Tecnológico de Monterrey-Campus Monterrey, Monterrey, NL, Mexico.
authors.forename: Dariana
authors.initials: D
authors.lastname: Rodríguez-Sánchez
authors.forename: Christian
authors.initials: C
authors.lastname: Silva-Platas
authors.forename: Rocío P
authors.initials: RP
authors.lastname: Rojo
authors.forename: Noemí
authors.initials: N
authors.lastname: García
authors.forename: Luis
authors.initials: L
authors.lastname: Cisneros-Zevallos
authors.forename: Gerardo
authors.initials: G
authors.lastname: García-Rivas
authors.forename: Carmen
authors.initials: C
authors.lastname: Hernández-Brenes
mesh_terms: D054378:Acetogenins / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology*; D002498:Centrifugation; D002853:Chromatography, Liquid; D005638:Fruit / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D007668:Kidney / Q000166:cytology; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D027421:Persea / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar
chemical_list: D054378:Acetogenins; D000975:Antioxidants; D010936:Plant Extracts
keywords: Acetogenins; Activity-guided isolation; Antioxidant capacity (AOC); Avocado; Centrifugal partition chromatography