Analysis and quantification of flavonoidic compounds from Portuguese olive (Olea europaea L.) leaf cultivars.

Twenty three samples of 18 Portuguese olive leaf cultivars were analysed by a reversed-phase HPLC/DAD procedure and eight flavonoidic compounds were identified and quantified (luteolin 7,4'-O-diglucoside, luteolin 7-O-glucoside, rutin, apigenin 7-O-rutinoside, luteolin 4'-O-glucoside, luteolin, apigenin and diosmetin). Luteolin 7,4'-O-diglucoside and luteolin 4'-O-glucoside were identified by HPLC/DAD/MS/MS - ESI. The studied olive leaf samples showed a common phenolic pattern, in which luteolin 4'-O-glucoside was almost always the major compound.

Phenolic profile of hazelnut (Corylus avellana L.) leaves cultivars grown in Portugal.

In this study, phenolic compounds of hazelnut leaves of 10 different cultivars with the same cultural, geographical, geological and climatic conditions were analyzed by HPLC/DAD and HPLC/DAD/MS/MS - ESI. Eight phenolic compounds (3-caffeoylquinic acid, 5-caffeoylquinic acid, caffeoyltartaric acid, p-coumaroyltartaric acid, myricetin 3-rhamnoside, quercetin 3-glycoside, quercetin 3-rhamnoside and kaempferol 3-rhamnoside) were identified and quantified. All of the analyzed samples showed a similar phenolic profile, in which myricetin 3-rhamnoside and quercetin 3-rhamnoside were the major compounds and caffeoyltartaric and p-coumaroyltartaric acids were present in vestigial amounts.

The drinking of a Salvia officinalis infusion improves liver antioxidant status in mice and rats.

In this study, we evaluate the biosafety and bioactivity (antioxidant potential) of a traditional water infusion (tea) of common sage (Salvia officinalis L.) in vivo in mice and rats by quantification of plasma transaminase activities and liver glutathione-S-transferase (GST) and glutathione reductase (GR) enzyme activities. The replacement of water by sage tea for 14 days in the diet of rodents did not affect the body weight and food consumption and did not induce liver toxicity.

Composition of quince (Cydonia oblonga Miller) seeds: phenolics, organic acids and free amino acids.

Phenolic compounds, organic acids and free amino acids of quince seeds were determined by HPLC/DAD, HPLC/UV and GC/FID, respectively. Quince seeds presented a phenolic profile composed of 3-O-caffeoylquinic, 4-O-caffeoylquinic, 5-O-caffeoylquinic and 3,5-dicaffeoylquinic acids, lucenin-2, vicenin-2, stellarin-2, isoschaftoside, schaftoside, 6-C-pentosyl-8-C-glucosyl chrysoeriol and 6-C-glucosyl-8-C-pentosyl chrysoeriol. Six identified organic acids constituted the organic acid profile of quince seeds: citric, ascorbic, malic, quinic, shikimic and fumaric acids.

Quince (Cydonia oblonga miller) fruit characterization using principal component analysis.

This paper presents a large amount of data on the composition of quince fruit with regard to phenolic compounds, organic acids, and free amino acids. Subsequently, principal component analysis (PCA) is carried out to characterize this fruit. The main purposes of this study were (i) the clarification of the interactions among three factors-quince fruit part, geographical origin of the fruits, and harvesting year-and the phenolic, organic acid, and free amino acid profiles; (ii) the classification of the possible differences; and (iii) the possible correlation among the contents of phenolics, organic acids, and free amino acids in quince fruit.

Mitochondrial activation and the pyruvate paradox in a human cell line.

Pyruvate promotes hyperpolarization of the inner mitochondrial membrane. However, in isolated mitochondria, pyruvate could participate in a futile cycle leading to mitochondrial depolarization. Here, we investigated this paradox in intact human cells by measuring parameters reflecting mitochondrial activation in response to 1 mM pyruvate and 5 mM glucose.

Hypericum androsaemum infusion increases tert-butyl hydroperoxide-induced mice hepatotoxicity in vivo.

Increasing evidence regarding free radical generating agents indicates that the sustained production of high levels of reactive oxygen species (ROS) can cause hepatotoxicity. Being a short chain analog of lipid peroxide, tert-butyl hydroperoxide (t-BHP) is metabolized into free radical intermediates by cytochrome P450 in hepatocytes, which initiate lipid peroxidation, glutathione depletion and cell damage. The aim of the present study was to evaluate the putative protective effect of Hypericum androsaemum lyophilised infusion against t-BHP-induced mice hepatotoxicity in vivo, which has already been shown to be antioxidant in vitro.

Quince (Cydonia oblonga Miller) fruit (pulp, peel, and seed) and Jam: antioxidant activity.

To study the antioxidant activity of quince fruit (pulp, peel, and seed) and jam, methanolic extracts were prepared. Each extract was fractionated into a phenolic fraction and an organic acid fraction and was analyzed by high-performance liquid chromatography (HPLC)/diode array detection and HPLC/UV, respectively. Antiradical activities of the extracts and fractions were evaluated by a microassay using 1,1'-diphenyl-2-picrylhydrazyl.

A highly active ATP-insensitive K+ import pathway in plant mitochondria.

We describe here a regulated and highly active K+ uptake pathway in potato (Solanum tuberosum), tomato (Lycopersicon esculentum), and maize (Zea mays) mitochondria. K+ transport was not inhibited by ATP, NADH, or thiol reagents, which regulate ATP-sensitive K+ channels previously described in plant and mammalian mitochondria. However, K+ uptake was completely prevented by quinine, a broad spectrum K+ channel inhibitor.

Protective activity of Hypericum androsaemum infusion against tert-butyl hydroperoxide-induced oxidative damage in isolated rat hepatocytes.

Hypericum androsaemum L. (Guttiferae) is a medicinal plant with antioxidant activity. Increasing evidence regarding free radical generating agents suggests that hepatotoxic-related disorders may involve reactive oxygen species (ROS).

Free amino acid composition of quince (Cydonia oblonga Miller) fruit (pulp and peel) and jam.

Twenty-one free amino acids present in several samples of quince fruit (pulp and peel) and quince jam (homemade and industrially manufactured) were analyzed by GC/FID. The analyses showed some differences between quince pulps and peels. Generally, the highest content in total free amino acids and in glycine was found in peels.

Approach to the study of C-glycosyl flavones by ion trap HPLC-PAD-ESI/MS/MS: application to seeds of quince (Cydonia oblonga).

Ion trap HPLC-PAD-ESI/MS/MS has been used to study C-glycosyl flavones in quince seeds. Comparative analysis of the ions [(M-H)-60]-, [(M-H)-90]- and [(M-H)-120]- from 6-C- and 8-C-glycosyl flavone isomers, together with their respective retention times, allowed deductions to be made about the nature of the sugar units and the positions of C-glycosylation. Vicenin-2 (6,8-di-C-glucosyl apigenin), lucenin-2 (6,8-di-C-glucosyl luteolin), stellarin-2 (6,8-di-C-glucosyl chrysoeriol), isoschaftoside (6-C-arabinosyl-8-C-glucosyl apigenin), schaftoside (6-C-glucosyl-8-C-arabinosyl apigenin), 6-C-pentosyl-8-C-glucosyl chrysoeriol and 6-C-glucosyl-8-C-pentosyl chrysoeriol were identified in quince seed.

Determination of phenolic antioxidant compounds produced by calli and cell suspensions of sage (Salvia officinalis L.).

Sage (Salvia officinalis L.) calli were established by culturing internodal segments, excised from aseptic seedlings, on MS basal medium gellied with agar and supplemented with 0.05 mg/L dichlorophenoxyacetic acid (2,4-D) in presence of benzyladenine (BA) or zeatin (ZEA) or kinetin (KIN), at 1.

Development and evaluation of a GC/FID method for the analysis of free amino acids in quince fruit and jam.

A GC/FID methodology for determination of twenty-one free amino acids in quince fruit (pulp and peel) and jam is described. The sample preparation was simple, involving a SCX Solid-Phase Extraction (SPE) purification step and a fast derivatization with ethyl chloroformate for gas chromatographic analysis. The chromatographic separation was achieved using a CP-Sil 19 CB wcot fused-silica capillary column.

Variability in phenolic composition of Hypericum androsaemum.

The methanolic extracts of fifteen Hypericum androsaemum samples, growing spontaneously or cultivated in Portugal, were analysed by HPLC/DAD, allowing the identification of 9 phenolic compounds and the detection of 6 phloroglucinols. Total amounts of phenolics found ranged from 11 to 39 g/kg, and the influence of some factors which may be responsible for this variation is discussed. The individual compounds were also quantified.

Studies on the antioxidant activity of Lippia citriodora infusion: scavenging effect on superoxide radical, hydroxyl radical and hypochlorous acid.

Lippia citriodora is an herbal species which contains several flavonoids and phenolic acids. In view of the pharmacological interest in natural phenolic compounds as antioxidants, this study examined the superoxide radical, hydroxyl radical and hypochlorous acid scavenging activities of L. citriodora infusion.

Antioxidant activity of Hypericum androsaemum infusion: scavenging activity against superoxide radical, hydroxyl radical and hypochlorous acid.

Hypericum androsaemum is a medicinal plant species containing many polyphenolic compounds, namely flavonoids and phenolic acids. Since polyphenolic compounds have high antioxidant potential, the ability of H. androsaemum infusion to act as a scavenger of reactive oxygen species (superoxide radical, hydroxyl radical and hypochlorous acid) was investigated.

Antioxidative properties of cardoon (Cynara cardunculus L.) infusion against superoxide radical, hydroxyl radical, and hypochlorous acid.

Polyphenols are able to act as antioxidants by virtue of their hydrogen-donating and metal-chelating capacities. Cardoon (Cynara cardunculus L.) is a species containing considerable amounts of polyphenolic compounds, namely flavonoids and phenolic acids.

Phenolic profile of quince fruit (Cydonia oblonga Miller) (pulp and peel).

Qualitative and quantitative analyses of phenolic compounds were carried out on quince fruit samples from seven different geographical origins in Portugal. For each origin, both pulp and peel were analyzed by reversed-phase HPLC-DAD and HPLC-DAD/MS. The results revealed differences between the phenolic profiles of pulps and peels in all studied cases.

Study of the organic acids composition of quince (Cydonia oblonga Miller) fruit and jam.

The organic acids present in several samples of quince fruit (pulp and peel) and quince jam (homemade and industrially manufactured) were analyzed by HPLC. The sample preparation was simple, involving only extraction with methanol (40 degrees C) and filtration through a Sep-pack C18 cartridge. The chromatographic separation was achieved using an ion exclusion column, Nucleogel Ion 300 OA (300 x 7.

Methoxylated xanthones in the quality control of small centaury (Centaurium erythraea) flowering tops.

In the course of a phytochemical study of the bitter tonic plant, small centaury (Centaurium erythraea), six methoxylated xanthones (1,5-hydroxy-3-methoxyxanthone, 1-hydroxy-3,5,6-trimethoxyxanthone, 1-hydroxy-3,5,6,7-tetramethoxyxanthone, 1-hydroxy-3,5,6,7,8-pentamethoxyxanthone, 1-hydroxy-3,7,8-trimethoxyxanthone and 1,8-dihydroxy-3,5,6,7-tetramethoxyxanthone) were isolated and identified by spectroscopic means (nuclear magnetic resonance, mass spectroscopy, and UV). Subsequently, a high-performance liquid chromatography/diode array detection method was developed for the determination of these and other methoxylated xanthones occurring in the chloroform extract of small centaury aerial parts. The methodology developed was applied to twelve samples, and in all of them, nine xanthones were identified and quantified.