title: Flavonoids with prolyl oligopeptidase inhibitory activity isolated from Scutellaria racemosa Pers.
abstract: Prolyl oligopeptidase (POP) is a serine protease highly expressed in the brain that hydrolyses peptide bonds at the carboxyl terminal of prolyl residues. There is evidence that this enzyme participates in several functions of the central nervous system. Scutellaria racemosa Pers demonstrated significant and selective POP inhibition. Fractionation of the hydroalcoholic extract resulted in the isolation of four main constituents identified for the first time from S. racemosa Pers, the triterpenoid lupeol (1) and the flavonoids oroxylin A (5,7-dihydroxy-6-methoxyflavone, 2), hispidulin (4',5,7-trihydroxy-6-methoxyflavone, 3), and oroxyloside (oroxylin A 7-O-glucuronide, 4). Inhibitory assays indicated that 3 and 4 at a concentration of 100 microM inhibit 43 and 34% of total POP activity, respectively.
authors.affiliation: Núcleo de Pesquisa de Produtos Naturais, Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil.
authors.forename: Micaela R
authors.initials: MR
authors.lastname: Marques
authors.forename: Caroline
authors.initials: C
authors.lastname: Stüker
authors.forename: Nessim
authors.initials: N
authors.lastname: Kichik
authors.forename: Teresa
authors.initials: T
authors.lastname: Tarragó
authors.forename: Ernest
authors.initials: E
authors.lastname: Giralt
authors.forename: Ademir F
authors.initials: AF
authors.lastname: Morel
authors.forename: Ionara I
authors.initials: II
authors.lastname: Dalcol
mesh_terms: D054873:Dipeptidyl-Peptidase IV Inhibitors; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification; D047309:Flavones / Q000737:chemistry / Q000302:isolation & purification*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification*; D020719:Glucuronides / Q000737:chemistry / Q000302:isolation & purification*; D015394:Molecular Structure; D053978:Pentacyclic Triterpenes / Q000302:isolation & purification*; D010946:Plants, Medicinal / Q000737:chemistry; D000085822:Prolyl Oligopeptidases; D031363:Scutellaria / Q000737:chemistry*; D012697:Serine Endopeptidases / Q000737:chemistry*; D000094042:Lupanes
chemical_list: D054873:Dipeptidyl-Peptidase IV Inhibitors; D004791:Enzyme Inhibitors; D047309:Flavones; D005419:Flavonoids; D020719:Glucuronides; D053978:Pentacyclic Triterpenes; D000085822:Prolyl Oligopeptidases; D012697:Serine Endopeptidases; C000596749:oroxylin A-7-O-glucuronide; C010480:lupeol; D000094042:Lupanes