title: Tyrosinase inhibitors from Calceolaria integrifolia s.l.: Calceolaria talcana aerial parts.
abstract: As a defense mechanism of the aerial parts of Calceolaria talcana (Calceolariaceae; formerly Scrophulariaceae) against herbivore offenses and insect pest attack, diterpenoids, triterpenoids, phenylethanoids, flavonoids, and iridoids are rapidly accumulated along the aerial parts, resulting in a unique natural biopesticide complex from this plant. In addition to verbascoside a series of known compounds were screened for their inhibitory activity against mushroom tyrosinase and protease enzymes. Ethyl acetate and n-hexane extracts, together with cyclopropyl-7,15-ent-pimaradiene (1), abietatriene (2), ursolic acid (3), α-lupeol (4), β-sitosterol (5), 2-hydroxy-3-(1,1-dimethylallyl)-1,4-naphthoquinone (6), α-dunnione (7), verbascoside (8), martynoside (9), and some known model compounds proved to be inhibitors of oxidation of L-3,4-dihydroxyphenylalanine (L-DOPA) catalyzed by tyrosinase (EC 1.14.18.1) with an IC50 between 10.0 and 200 ppm or μM, respectively, suggesting that phenolic moieties in the molecules assayed are important for the activity.
authors.affiliation: Phytochemical-Ecology Laboratory, Department of Basic Sciences, Faculty of Sciences, University of Bío-Bío, Chillán, Chile.
authors.forename: Evelyn
authors.initials: E
authors.lastname: Muñoz
authors.forename: Jose G
authors.initials: JG
authors.lastname: Avila
authors.forename: Julio
authors.initials: J
authors.lastname: Alarcón
authors.forename: Isao
authors.initials: I
authors.lastname: Kubo
authors.forename: Enrique
authors.initials: E
authors.lastname: Werner
authors.forename: Carlos L
authors.initials: CL
authors.lastname: Céspedes
mesh_terms: D000085:Acetates / Q000737:chemistry; D000363:Agaricales / Q000201:enzymology; D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D061046:Biological Control Agents; D004224:Diterpenes / Q000302:isolation & purification / Q000494:pharmacology; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology; D006586:Hexanes / Q000737:chemistry; D020128:Inhibitory Concentration 50; D007313:Insecta; D039823:Iridoids / Q000302:isolation & purification / Q000494:pharmacology; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010575:Pesticides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D011480:Protease Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D028083:Scrophulariaceae / Q000737:chemistry*
chemical_list: D000085:Acetates; D000975:Antioxidants; D061046:Biological Control Agents; D004224:Diterpenes; D005419:Flavonoids; D006586:Hexanes; D039823:Iridoids; D010575:Pesticides; D010936:Plant Extracts; D011480:Protease Inhibitors; C026385:n-hexane; C007650:ethyl acetate; D014442:Monophenol Monooxygenase