Laurus nobilis L. (Lauraceae) is an evergreen tree widely distributed in the Mediterranean area and the leaves are extensively used as a spice for culinary and flavouring purposes. In the Sardinian traditional medicine the leaves decoction or infusion are widely used in the treatment of different diseases (1). Previous phytochemical investigations lead to the isolation of several classes of secondary metabolites and in particular sesquiterpene lactones, alkaloids, catechin and procyanidine derivatives, flavonoids and megastigmane glucosides (2). In this work the antioxidant properties of L. nobilis extracts were investigated. Sequential extracts were prepared using solvents in increasing polarity (petroleum ether, chloroform and methanol). In addition the leaves infusion was prepared and analysed. The residues were evaluated for their antioxidant activity with different in vitro methods (DPPH, TEAC and BR) (3). The antioxidant activity was established in the methanol extract. Phytochemical investigations lead to the isolation of five kaempferol-O-glycosides, five quercetin-O-glycosides and one catechin. In addition a flavone C-glycoside, 5,7,4’-trihydroxy-6-C--D-glyucopyrano-2’’-O--L-rhamnopyranoside was isolated and characterized. Structures of isolated compounds were achieved on the basis of HR-MS spectra as well as 1D and 2D NMR experiments. The our results showed a linear correlation between the antioxidant activity and the total phenol content of the extracts. The our results showed that the total antioxidant capacities from DPPH, TEAC and BR assays were highly correlated with phenolic content (r2 = 0,915, 0,971 and 0,952, respectively). References: 1. Loi M.C.et al.. (2004) Fitoterapia 75, 277-295. 2. De Marino S. et al.( 2004) J. Agric. Food. Chem.52, 7525-7531 and references therein. 3. Cervellati R. et al. (2002) J. Agric. Food Chem., 50, 7504-7509.
Antioxidant activity of Laurus nobilis
LOI, MARIA CECILIA;
2005-01-01
Abstract
Laurus nobilis L. (Lauraceae) is an evergreen tree widely distributed in the Mediterranean area and the leaves are extensively used as a spice for culinary and flavouring purposes. In the Sardinian traditional medicine the leaves decoction or infusion are widely used in the treatment of different diseases (1). Previous phytochemical investigations lead to the isolation of several classes of secondary metabolites and in particular sesquiterpene lactones, alkaloids, catechin and procyanidine derivatives, flavonoids and megastigmane glucosides (2). In this work the antioxidant properties of L. nobilis extracts were investigated. Sequential extracts were prepared using solvents in increasing polarity (petroleum ether, chloroform and methanol). In addition the leaves infusion was prepared and analysed. The residues were evaluated for their antioxidant activity with different in vitro methods (DPPH, TEAC and BR) (3). The antioxidant activity was established in the methanol extract. Phytochemical investigations lead to the isolation of five kaempferol-O-glycosides, five quercetin-O-glycosides and one catechin. In addition a flavone C-glycoside, 5,7,4’-trihydroxy-6-C--D-glyucopyrano-2’’-O--L-rhamnopyranoside was isolated and characterized. Structures of isolated compounds were achieved on the basis of HR-MS spectra as well as 1D and 2D NMR experiments. The our results showed a linear correlation between the antioxidant activity and the total phenol content of the extracts. The our results showed that the total antioxidant capacities from DPPH, TEAC and BR assays were highly correlated with phenolic content (r2 = 0,915, 0,971 and 0,952, respectively). References: 1. Loi M.C.et al.. (2004) Fitoterapia 75, 277-295. 2. De Marino S. et al.( 2004) J. Agric. Food. Chem.52, 7525-7531 and references therein. 3. Cervellati R. et al. (2002) J. Agric. Food Chem., 50, 7504-7509.
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