title: Cyclooxygenase inhibitory and antioxidant compounds from crabapple fruits.
abstract: Crabapple trees belong to the Malus genus (Rosaceae) and bear fruits that are sparingly consumed and used in the preparation of fruit beverages. Cyclooxygenase (COX) enzyme inhibitory and antioxidant bioassay-guided fractionation of the aqueous and methanol extracts of Malus x kornicensis and Malus x Indian Summer yielded (+)-catechin (1), (-)-epicatechin (2), cyanidin-3-O-beta-galactopyranoside (3), and amygdalin (4). Pure compounds 1-4 were obtained by HPLC, identified by LC-ES/MS, CD, and NMR spectroscopic methods and evaluated for their COX enzyme inhibitory and antioxidant activities. In COX-1 and -2 enzyme inhibitory assays, compounds 1-3 (all at 80 microM) showed activities of 20.4, 46.3%; 57.6, 47.9%; and 8.2, 13.7%, respectively, compared to naproxen (54.3, 41.3%; 10 microM), ibuprofen (47.5, 39.8%; 10 microM), Celebrex (46.2, 66.3%; 1.67 ppm), and Vioxx (23.8, 88.1%, 1.67 ppm). In the antioxidant assay, the catechins (1-2) and anthocyanin (3) (all at 40 microM) showed activities of 61.3, 62.5, and 60.1%, respectively. The synthetic antioxidants, tert-butylhydroquinone (TBHQ), butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and vitamin E (all tested at 10 microM), gave 75.2, 80.1, 70.0, and 10.2% activities, respectively. The cyanogenic glycoside, amygdalin (4), and its hydrolysis products, mandelonitrile (5) and benzaldehyde (6), were not active in the antioxidant or COX enzyme inhibitory assays at 80 microM concentrations.
authors.affiliation: Bioactive Natural Products and Phytoceuticals, Department of Horticulture, Michigan State University, East Lansing, Michigan 48824, USA.
authors.forename: Navindra P
authors.initials: NP
authors.lastname: Seeram
authors.forename: Robert H
authors.initials: RH
authors.lastname: Cichewicz
authors.forename: Amitabh
authors.initials: A
authors.lastname: Chandra
authors.forename: Muraleedharan G
authors.initials: MG
authors.lastname: Nair
mesh_terms: D000678:Amygdalin / Q000032:analysis; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002392:Catechin / Q000032:analysis; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D005638:Fruit / Q000737:chemistry*; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D027845:Malus / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D011451:Prostaglandin-Endoperoxide Synthases
chemical_list: D000975:Antioxidants; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D010936:Plant Extracts; D000678:Amygdalin; D002392:Catechin; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases