title: Phenolic content and antioxidant activity of Hibiscus cannabinus L. seed extracts after sequential solvent extraction.
abstract: A sequential solvent extraction scheme was employed for the extraction of antioxidant compounds from kenaf (Hibiscus cannabinus L.) seeds. Yield of extracts varied widely among the solvents and was the highest for hexane extract (16.6% based on dry weight basis), while water extract exhibited the highest total phenolic content  (18.78 mg GAE/g extract), total flavonoid content (2.49 mg RE/g extract), and antioxidant activities (p &lt; 0.05). DPPH and hydroxyl radical scavenging, &#946;-carotene bleaching, metal chelating activity, ferric thiocyanate and thiobarbituric acid reactive substances assays were employed to comprehensively assess the antioxidant potential of different solvent extracts prepared sequentially. Besides water, methanolic extract also exhibited high retardation towards the formation of hydroperoxides and thiobarbituric acid reactive substances in the total antioxidant activity tests (p &lt; 0.05). As conclusion, water and methanol extracts of kenaf seed may potentially serve as new sources of antioxidants for food and nutraceutical applications.
authors.affiliation: Laboratory of Molecular Biomedicine, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
authors.forename: Noordin Mohd
authors.initials: NM
authors.lastname: Yusri
authors.forename: Kim Wei
authors.initials: KW
authors.lastname: Chan
authors.forename: Shahid
authors.initials: S
authors.lastname: Iqbal
authors.forename: Maznah
authors.initials: M
authors.lastname: Ismail
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry / Q000302:isolation & purification; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000302:isolation & purification; D005609:Free Radicals / Q000737:chemistry; D006586:Hexanes / Q000737:chemistry; D031584:Hibiscus / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D059625:Liquid-Liquid Extraction; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D012639:Seeds / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D017392:Thiobarbituric Acid Reactive Substances / Q000737:chemistry; D013861:Thiocyanates / Q000737:chemistry; D014867:Water / Q000737:chemistry; D019207:beta Carotene / Q000737:chemistry
chemical_list: D001713:Biphenyl Compounds; D002614:Chelating Agents; D005419:Flavonoids; D016166:Free Radical Scavengers; D005609:Free Radicals; D006586:Hexanes; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D012997:Solvents; D017392:Thiobarbituric Acid Reactive Substances; D013861:Thiocyanates; D019207:beta Carotene; D014867:Water; C103724:ferric thiocyanate; C004931:1,1-diphenyl-2-picrylhydrazyl; D007501:Iron