title: Secondary metabolites of ponderosa lemon (Citrus pyriformis) and their antioxidant, anti-inflammatory, and cytotoxic activities.
abstract: Column chromatography of the dichloromethane fraction from an aqueous methanolic extract of fruit peel of Citrus pyriformis Hassk. (Rutaceae) resulted in the isolation of seven compounds including one coumarin (citropten), two limonoids (limonin and deacetylnomilin), and four sterols (stigmasterol, ergosterol, sitosteryl-3-beta-D-glucoside, and sitosteryl-6'-O-acyl-3-beta-D-glucoside). From the ethyl acetate fraction naringin, hesperidin, and neohesperidin were isolated. The dichloromethane extract of the defatted seeds contained three additional compounds, nomilin, ichangin, and cholesterol. The isolated compounds were identified by MS (EI, CI, and ESI), 1H, 13C, and 2D-NMR spectral data. The limonoids were determined qualitatively by LC-ESI/MS resulting in the identification of 11 limonoid aglycones. The total methanolic extract of the peel and the petroleum ether, dichloromethane, and ethyl acetate fractions were screened for their antioxidant and anti-inflammatory activities. The ethyl acetate fraction exhibited a significant scavenging activity for DPPH free radicals (IC50 = 132.3 microg/mL). The petroleum ether fraction inhibited 5-lipoxygenase with IC50 = 30.6 microg/mL indicating potential anti-inflammatory properties. Limonin has a potent cytotoxic effect against COS7 cells [IC50 = (35.0 +/- 6.1) microM] compared with acteoside as a positive control [IC50 = (144.5 +/- 10.96) microM].
authors.affiliation: Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany.
authors.forename: Dalia
authors.initials: D
authors.lastname: Hamdan
authors.forename: Mahmoud Zaki
authors.initials: MZ
authors.lastname: El-Readi
authors.forename: Ahmad
authors.initials: A
authors.lastname: Tahrani
authors.forename: Florian
authors.initials: F
authors.lastname: Herrmann
authors.forename: Dorothea
authors.initials: D
authors.lastname: Kaufmann
authors.forename: Nawal
authors.initials: N
authors.lastname: Farrag
authors.forename: Assem
authors.initials: A
authors.lastname: El-Shazly
authors.forename: Michael
authors.initials: M
authors.lastname: Wink
mesh_terms: D000893:Anti-Inflammatory Agents / Q000302:isolation & purification / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D002957:Citrus / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000893:Anti-Inflammatory Agents; D000972:Antineoplastic Agents, Phytogenic; D000975:Antioxidants; D010936:Plant Extracts