title: Antioxidant activity and total phenolic content of aqueous and methanolic extracts of Jordanian plants: an ICBG project.
abstract: As part of an International Cooperative Biodiversity Groups (ICBG) program to study Jordan's biodiversity, the relative levels of antioxidant activity and the total phenolic content of aqueous and methanolic extracts of a total of 95 plant species, all of Jordanian origin and those collected at random, have been measured. The total phenolic content of aqueous and methanolic extracts of the investigated plant species ranged from 4.4 to 78.3 mg and from 2.1 to 52.8 mg gallic acid equivalents g(-1) dry weight, respectively, while the total antioxidant capacity ranged from 20.0 to 916.7 and from 15.1 to 915.6 micromol Trolox equivalents g(-1) dry weight, respectively. Based on this collection, approximately 5% of assayed plants showed high levels of antioxidant activity. There was a significant linear correlation between antioxidant activity and total phenolic content for aqueous and methanolic extracts, suggesting that phenolic compounds were the predominant antioxidant components in the investigated plant species. Interestingly, a few of the collected plants had high-antioxidant activity yet "low" phenolic content includes Ceratonia siliqua and Viscum cruciatum. These plants may serve as sources of antioxidants with new chemotypes.
authors.affiliation: Faculty of Pharmacy, Department of Medicinal Chemistry and Pharmacognosy, Jordan University of Science and Technology, Irbid 22110, Jordan. falali@just.edu.jo
authors.forename: Feras Q
authors.initials: FQ
authors.lastname: Alali
authors.forename: Khaled
authors.initials: K
authors.lastname: Tawaha
authors.forename: Tamam
authors.initials: T
authors.lastname: El-Elimat
authors.forename: Maha
authors.initials: M
authors.lastname: Syouf
authors.forename: Mosa
authors.initials: M
authors.lastname: El-Fayad
authors.forename: Khaled
authors.initials: K
authors.lastname: Abulaila
authors.forename: Samara Joy
authors.initials: SJ
authors.lastname: Nielsen
authors.forename: William D
authors.initials: WD
authors.lastname: Wheaton
authors.forename: Joseph O
authors.initials: JO
authors.lastname: Falkinham
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: Oberlies
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D007391:International Cooperation; D000432:Methanol; D010636:Phenols / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D010944:Plants / Q000737:chemistry*; D014867:Water
chemical_list: D000975:Antioxidants; D010636:Phenols; D010936:Plant Extracts; D014867:Water; D000432:Methanol