title: COX-2 inhibitory activity of homoisoflavanones and xanthones from the bulbs of the Southern African Ledebouria socialis and Ledebouria ovatifolia (Hyacinthaceae: Hyacinthoideae).
abstract: The bulbs of Ledebouria socialis (Hyacinthaceae) yielded the benzocyclobutene homoisoflavonoid, (R)-2',5-dihydroxy-3',4',7-trimethoxyspiro{2H-1-benzopyran-3-(4H)-9-bicyclo[4.2.0]octa[1,3,5]triene}-4-one, socialinone (1). Ledebouria ovatifolia yielded (2ε,3R)-2,5-dihydroxy-7-methoxyspiro[2H-1-benzopyran-3(4H), 5'(6'H)-cyclobuta[f][1,3]benzodioxol]-4-one (2) and the homoisoflavanone, (E)-3-(3',4'-dihydroxybenzylidene)-5,7-dihydroxychroman-4-one, ovatifolionone (5), the dihydrochalcone, 4,4'-dihydroxy-2',6'-dimethoxydihydrochalcone (3), and xanthone, 1,6-dihydroxy-2,3,5-trimethoxy-8-methyl-9H-xanthen-9-one (4) along with 21 known compounds. Structures were determined using spectroscopic techniques. The anti-inflammatory activities of the homoisoflavonoids and xanthones isolated were evaluated against cyclooxygenase-1 and -2 isoenzymes. (R)-3-(3',4'-Dihydroxybenzyl)-7-hydroxy-5-methoxychroman-4-one (7), (E)-3-(3',4'-dihydroxybenzylidene)-7-hydroxy-5-methoxychroman-4-one (10), 1,3,6-trihydroxy-2-methoxy-8-methylxanthen-9-one (6) and ovatifolionone acetate (5Ac) exhibited significant activity against cyclooxygenase-2 at <10μM.
authors.affiliation: Natural Products Research Group, Department of Chemistry, University of Surrey, Guildford, GU2 7XH Surrey, UK.
authors.forename: Catherine P
authors.initials: CP
authors.lastname: Waller
authors.forename: Alfred E
authors.initials: AE
authors.lastname: Thumser
authors.forename: Moses K
authors.initials: MK
authors.lastname: Langat
authors.forename: Neil R
authors.initials: NR
authors.lastname: Crouch
authors.forename: Dulcie A
authors.initials: DA
authors.lastname: Mulholland
mesh_terms: D000353:Africa, Southern; D052246:Cyclooxygenase 2 Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D007529:Isoflavones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D019668:Liliaceae / Q000737:chemistry*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry; D044004:Xanthones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D007529:Isoflavones; D010936:Plant Extracts; D044004:Xanthones
keywords: Anti-inflammatory; Cyclooxygenase activity; Homoisoflavanone; Hyacinthaceae; Ledebouria ovatifolia; Ledebouria socialis; Ovatifolionone; Socialinone; Xanthone