title: Phytochemical composition and antioxidant activity of Laurus nobilis L. leaf infusion.
abstract: Laurus nobilis L. (laurel) leaves are frequently used as a spice for cooking purposes. Folk medicine in many countries uses the infusion of the plant in stomachic and carminative remedies, as well as for the treatment of gastric diseases. Little information is available about the phytochemical composition of the infusion of dried leaves, which is a way to consume this aromatic and medicinal plant. Phytochemical investigations on the infusion were performed by high-performance liquid chromatography (HPLC) with a diode array detector (DAD) and direct electrospray ionization-tandem mass spectrometry. Several flavonoid derivatives were detected. Semipreparative HPLC from the infusion of laurel leaves isolated 10 flavonoid O-glycosides, one flavonoid C-glycoside, catechin, and cinnamtannin B1. Structures of the isolated compounds were computed on the basis of spectral measurements including high-resolution mass spectrometry spectroscopy and one- and two-dimensional nuclear magnetic resonance techniques. The amount of the flavonoids was also determined by HPLC-DAD. The antioxidant activity of the tea and the isolated compounds was also measured using two different in vitro methods: the Briggs-Rauscher oscillating reaction test, at a pH similar to that of the gastric juice, and the Trolox equivalent antioxidant capacity assay, at the pH of blood. For the infusion and the methanol extract the total phenolic content was also measured using the Folin-Ciocalteu reagent.
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Università di Padova, Bologna, Italy. stefano.dallacqua@unipd.it
authors.forename: Stefano
authors.initials: S
authors.lastname: Dall'Acqua
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Cervellati
authors.forename: Ester
authors.initials: E
authors.lastname: Speroni
authors.forename: Stefano
authors.initials: S
authors.lastname: Costa
authors.forename: Maria Clelia
authors.initials: MC
authors.lastname: Guerra
authors.forename: Laura
authors.initials: L
authors.lastname: Stella
authors.forename: Emanuela
authors.initials: E
authors.lastname: Greco
authors.forename: Gabbriella
authors.initials: G
authors.lastname: Innocenti
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology*; D006027:Glycosides / Q000302:isolation & purification / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D027442:Laurus / Q000737:chemistry*; D013058:Mass Spectrometry; D015394:Molecular Structure; D010636:Phenols / Q000302:isolation & purification / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology*; D018515:Plant Leaves
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D006027:Glycosides; D010636:Phenols; D010936:Plant Extracts