'Limoncella' apple, an Italian apple cultivar: Phenolic and flavonoid contents and antioxidant activity

'Limoncella' is a variety of apple traditionally cultivated in south-central Italy since ancient Roman times. The relationship between phenolic composition and antioxidant activity of apple peel and flesh was investigated. Apple extracts analysed by high-performance liquid chromatography, showed that compared with flesh, peel was richer in all the quantified phenols. The most abundant polyphenols were the flavanols catechin and epicatechin, and the chalcones phloridzin and phloretin xyloglucoside. The extracts were evaluated for their radical-scavenging activity by the DPPH{radical dot} and H2O2 methods, and the antioxidant activity through reduction of Mo(VI) and inhibition of the formation of TBARS species. © 2007 Elsevier Ltd. All rights reserved

Identification and assessment of antioxidant capacity of phytochemicals from kiwi fruits

The kiwi fruit is the edible berry of a cultivar group of the woody vine of several Actinidia species. The most common commercially available, green-fleshed kiwi fruit is the cultivar 'Hayward, which belongs to the Actinidia deliciosa species. An antioxidative screening of kiwi fruit components (peel and pulp) crude extracts was carried out using specific assay media characterized for the presence of highly reactive species such as 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH), H2O2, and O2- The Mo(VI) reducing power of the samples was also determined. The phenol and flavonoid contents were quantified. Phytochemical analysis of kiwi peel crude extracts led to the isolation of vitamin E, 2,8-dimethyl-2-(4,8,12-trimethyltridec-11-enyl)chroman-6-ol, as well as α- and δ-tocopherol, 7 sterols, the triterpene ursolic acid, chlorogenic acid, and 11 flavonoids. Chemical fractionation of pulp crude extracts led to the isolation of two caffeic acid glucosyl derivatives and two coumarin glucosydes, besides the three vitamin E, β-sitosterol, stigmasterol, and its Δ7 isomer, campesterol, chlorogenic acid, and some flavone and flavanol molecules. All of the compounds were tested for their radical scavenging and antioxidant capabilities by measuring their capacity to scavenge DPPH and anion superoxide radical and to reduce a Mo(VI) salt. © 2009 American Chemical Society

Free-radical-scavenging and antioxidant activities of secondary metabolites from reddened cv. Annurca apple fruits

Forty-three secondary metabolites were isolated and characterized from cv. Annurca apple fruit, an apple variety cultivated in the south of Italy. This apple cultivar undergoes a typical reddening treatment after collection. All of the compounds were characterized on the basis of their spectroscopic data. The compounds were tested for their radical-scavenging and antioxidant activities by measuring their capacity to scavenge DPPH • (2,2′- diphenyl-1-picrylhydrazyl radical), H 2O 2, and NO (nitric oxide) and to inhibit the formation of methyl linoleate conjugated diene hydroperoxides or TBARS (thiobarbituric acid reactive species). © 2006 American Chemical Society

Isolation and Structure Elucidation of Antioxidant Polyphenols from Quince (Cydonia vulgaris) Peels

Thirteen new compounds, as well as 16 already known, have been isolated from organic extracts of peels of Cydonia vulgaris, a fruit of a shrub belonging to the same tribe as the apple. All of the structures were elucidated by EI- or ESI-MS and 1H and 13C NMR after purification of individual compounds by HPLC. Thirteen fatty acid esters of cinnamyl alcohols, three fatty acid esters of hydroxybenzoic acid, three fatty acid esters of hydroxybenzaldehyde, three glucosides of aromatic acids, four chlorogenic acids, two flavonols, and a benzylamine have been identified. The fatty acid moieties have been identified by GC-MS analysis of the methanolysis products. All of the compounds were tested for their radical scavenging and antioxidant activities by measuring their capacity to scavenge the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical and anion superoxide radical and to induce the reduction of Mo(VI) to Mo(V). The chlorogenic acids and the flavonols exhibited more antioxidant and radical scavenger capacity than the positive standards α-tocopherol and ascorbic acid. The results of the tests were analyzed by cluster analysis that grouped all of the compounds on the basis of the substituents on the aromatic ring

Antioxidant and antiproliferative activities of phytochemicals from Quince (Cydonia vulgaris) peels

Fifty-nine secondary metabolites have been isolated from Cydonia vulgaris peels and characterised on the basis of their spectroscopic features. Among them, five metabolites, 3b-(18-hydroxylinoleoyl)-28- hydroxyurs-12-ene (12), 3b-linoleoylurs-12-en-28-oic acid (15), 3b-oleoyl-24-hydroxy-24-ethylcholesta- 5,28(29)-diene (24), tiglic acid 1-O-b-D-glucopyranoside (35), and 6,9-dihydroxymegastigmasta-5, 7-dien-3-one 9-O-b-D-gentiobioside (46), have been isolated and elucidated for the first time. All of the compounds were tested for their radical-scavenging and antioxidant activities by measuring their capacity to scavenge the 2,20-diphenyl-1-picrylhydrazyl (DPPH) radical, and anion superoxide radical and to induce the reduction of Mo(VI) to Mo(V). The antiproliferative activity of all the most abundant compounds by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) bioassay on murine B16-F1 melanoma cells has been also assessed

delta-Tocomonoenol: A new vitamin E from kiwi (Actinidia chinensis) fruits

A new vitamin E, d-tocomonoenol, has been isolated from Actinidia chinensis (kiwi) fruits. The new structure, 2,8-dimethyl-2-(4,8,12-trimethyltridec-11-enyl)chroman-6-ol, has been elucidated on the basis of EIMS, 1D, and 2D NMR spectral data. GC–MS analysis of peels and pulps of kiwi showed that the new compound, together with d-tocopherol, is mainly present in the fruit peel, whilst a-tocopherol is present in a similar amount in both matrices. The compound was tested for its radical-scavenging and antioxidant capabilities, by measuring its ability to scavenge DPPH (2,20-diphenyl-1-picrylhydrazyl radical) and anion superoxide radical, and inhibit the formation of methyl linoleate conjugated diene hydroperoxides and TBARS (thiobarbituric acid reactive species)

Distachyasin: A new antioxidant metabolite from the leaves of Carex distachya

A novel antioxidant prenylated stilbenoid, distachyasin, has been isolated from the leaves of Carex distachya. Its structure has been elucidated on the basis of the spectroscopic characteristics. Bidimensional NMR, and crystallographic data and computational calculations have furnished important data useful for the characterization and the stereochemistry of the molecule. The compound has a tetracyclic skeleton derived from carexane. The compound has been assayed, for the antioxidant activity, by measuring its capacity to scavenge the H2O2, nitric oxide, superoxide radical and to inhibit formation of TBARS (thiobarbituric acid reactive species). © 2006 Elsevier Ltd. All rights reserved