title: Antioxidant lipoxygenase inhibitors from the leaf extracts of Simmondsia chinensis.
abstract: OBJECTIVE
  To isolate and identify chemical constituents with antioxidant and lipoxygenase inhibitory effects of the ethanolic extract of Simmondsia chinensis (Jojoba) leaves.
  
  
  METHODS
  The alcoholic extract was subjected to successive solvent fractionation. The antioxidant active fractions (chloroform, ethyl acetate and aqueous fractions) were subjected to a combination of different chromatographic techniques guided by the antioxidant assay with DPPH. The structures of the isolated compounds were elucidated on the basis of spectroscopic evidences and correlated with known compounds. The antioxidant activity was assessed quantitively using DPPH and β-carotene methods. The inhibitory potential against enzyme lipoxygenase was assessed on soybean lipoxygenase enzyme.
  
  
  RESULTS
  Ten flavonoids and four lignans were isolated. Flavonoid aglycones showed stronger antioxidant and lipoxygenase inhibitory effects than their glycosides. Lignoid glycosides showed moderate to weak antioxidant and lipoxygenase inhibitory effects.
  
  
  CONCLUSIONS
  A total of 14 compounds were isolated and identified from Simmondsia chinensis; 12 of them were isolated for the first time. This is the first report that highlights deeply on the phenolic content of jojoba and their potential biological activities and shows the importance of this plant as a good source of phenolics in particular the flavonoid content.
authors.affiliation: Pharmacognosy Department, College of Pharmacy, King Saud University, Riyadh 11451, P. O. Box 2457, Saudi Arabia; Pharmacognosy Department, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt. Electronic address: wabdelmageed@ksu.edu.sa.
authors.forename: Wael Mostafa
authors.initials: WM
authors.lastname: Abdel-Mageed
authors.affiliation: Pharmacognosy Department, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt.
authors.forename: Soad Abdel Latief Hassan
authors.initials: SA
authors.lastname: Bayoumi
authors.affiliation: Pharmaceutical Technology Centre, College of Pharmacy, King Saud University, Riyadh 11451, P. O. Box 2457, Saudi Arabia.
authors.forename: Awwad Abdoh Radwan
authors.initials: AA
authors.lastname: Salama
authors.affiliation: Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh 11451, P. O. Box 2457, Saudi Arabia.
authors.forename: Mounir Mohamed
authors.initials: MM
authors.lastname: Salem-Bekhit
authors.affiliation: Biochemistry Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia.
authors.forename: Sherif Hussein
authors.initials: SH
authors.lastname: Abd-Alrahman
authors.affiliation: Pharmacognosy Department, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt.
authors.forename: Hanaa Mohamed
authors.initials: HM
authors.lastname: Sayed
keywords: Antioxidant; Flavonoids; Jojoba; Lignans; Lipoxygenase inhibitors; Simmondsia chinensis