1,375 research outputs found
Effects of garcinol and guttiferone K isolated from Garcinia cambogia on oxidative/nitrative modifications in blood platelets and plasma
No full textGiffonins A-I, antioxidant cyclized diarylheptanoids from the leaves of the hazelnut tree (corylus avellana), source of the italian PGI product "nocciola di Giffoni"
No full textEight new diaryl ether heptanoids, giffonins A-H (1-8), and one diaryl heptanoid, giffonin I (9), were isolated from the methanol extract of the leaves of Corylus avellana. Its hazelnut is the PGI product of the Campania region (Italy) known as "Nocciola di Giffoni". The MeOH extract of C. avellana leaves and giffonins A-I (1-9) were evaluated for their inhibitory effects on human plasma lipid peroxidation induced by H2O2 and H2O2/Fe(2+), by measuring the concentration of TBARS (thiobarbituric acid reactive substances). Compounds 4 and 8 at 10 μM reduced both H2O2- and H2O2/Fe(2+)-induced lipid peroxidation by more than 60% and 50%, respectively, indicating higher activity than curcumin used as reference compound
Corylus avellana "Nocciola Piemonte": metabolomics focused on polar lipids and phenolic compounds in fresh and roasted hazelnuts
No full textThe common hazel plant (Corylus avellana L., Betulaceae) is one of the most popular tree nuts widespread in Europe and Asia. In Italy, there are different cultivars among which the cultivar affording the valuable hazelnut "Tonda Gentile Trilobata," also known as "Tonda Gentile delle Langhe," covered by the Protected Geographical Indication (PGI) label "Nocciola Piemonte" (NP), known for its sweetness, cooked-bread aroma, and the low intensity of the burnt aroma. In order to obtain a detailed and in-depth characterization of the polar fraction of fresh (NPF) and roasted (NPR) kernels of NP the analysis of the n-butanol extracts by liquid chromatography coupled to electrospray ionization and high-resolution mass spectrometry (LC-ESI/HRMS) was carried out. Moreover, to evaluate the quantitative distribution of the most representative polar lipids in NPF and NPR, the analysis by liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) was performed. To unambiguously identify the phenolic compounds highlighted by the LC-ESI/HRMS profiles, they were isolated from the n-butanol extract and characterized by Nuclear Magnetic Resonance (NMR) experiments. Finally, the ability of the isolated compounds to exert radical scavenging activity and to inhibit the lipid peroxidation induced by H2O2 or H2O2/Fe2+ was tested by Trolox Equivalent Antioxidant Capacity (TEAC) and thiobarbituric acid reactive substances (TBARS) assays, respectively. The LC-ESI/HRMS allowed to ascertain the presence of phenolic compounds and multiple classes of polar lipids including phospholipids, glycolipids, sphingolipids, and oxylipins. The quantitative analysis highlighted in NPR fraction a lipid content three times higher than in NPF, evidencing lyso-phospholipids and phospholipids as the most represented lipid classes in both NPF and NPR, together accounting for 94 and 97% of the considered lipids, respectively. Furthermore, phytochemical analysis permitted to identify flavonoid and diarylheptanoid derivatives. In particular, quercetin 3-O-beta-D-galactopyranosyl-(1 -> 2)-beta-D-glucopyranoside and myricetin-3-O-alpha-L-rhamnopyranoside showed the highest antioxidant activity, exhibiting TEAC values similar to that of quercetin, used as reference compound (2.00 +/- 0.03 and 2.06 +/- 0.03 mM vs 2.03 +/- 0.03 mM, respectively). Moreover, most of the tested compounds were found to reduce lipid peroxidation induced by H2O2 and H2O2/Fe2+ more than curcumin used as positive control, with myricetin-3-O-alpha-L-rhamnopyranoside determining 44.4 % and 34.1 % inhibition percentage, respectively
Quali-quantitative analysis of the phenolic fraction of the flowers of Corylus avellana, source of the Italian PGI product "Nocciola di Giffoni": Isolation of antioxidant diarylheptanoids
No full textThere is only limited information available on the chemical composition of the non-edible parts of Corylus avellana, source of the Italian PGI product "Nocciola di Giffoni" (hazelnut). An initial LC-MS profile of the methanolic extract of the male flowers of C. avellana, cultivar 'Tonda di Giffoni' led to the isolation of 12 compounds, of which the structures were elucidated by NMR spectroscopy. These were identified as three previously undescribed diarylheptanoids, named giffonins Q-S, along with nine known compounds. Furthermore, the quantitative determination of the main compounds occurring in the methanolic extract of C. avellana flowers was carried out by an analytical approach based on LC-ESI(QqQ)MS, using the Multiple Reaction Monitoring (MRM) experiment. In order to explore the antioxidant ability of C. avellana flowers, the methanolic extract and the isolated compounds were evaluated for their inhibitory effects on human plasma lipid peroxidation induced by H2O2 and H2O2/Fe2+, by measuring the concentration of TBARS
Cyclic Diarylheptanoids from Corylus avellana Green Leafy Covers: Determination of Their Absolute Configurations and Evaluation of Their Antioxidant and Antimicrobial Activities
No full textThe methanol extract of the leafy covers of Corylus avellana, source of the Italian PGI (protected geographical indication) product "Nocciola di Giffoni", afforded two new cyclic diarylheptanoids, giffonins T and U (2 and 3), along with two known cyclic diarylheptanoids, a quinic acid, flavonoid-, and citric acid derivatives. The structures of giffonins T and U were determined as highly hydroxylated cyclic diarylheptanoids by 1D and 2D NMR experiments. Their relative configurations were assigned by a combined quantum mechanical/NMR approach, comparing the experimental (13)C/(1)H NMR chemical shift data and the related predicted values. The absolute configurations of carpinontriol B (1) and giffonins T and U (2 and 3) were assigned by comparison of their experimental electronic circular dichroism curves with the TDDFT-predicted curves. The ability of the compounds to inhibit the lipid peroxidation induced by H2O2 and H2O2/Fe(2+) was determined by measuring the concentration of thiobarbituric acid reactive substances. Furthermore, the antimicrobial activity of the methanol extract of leafy covers of C. avellana and of the isolated compounds against the Gram-positive strains Bacillus cereus and Staphylococcus aureus and the Gram-negative strains Escherichia coli and Pseudomonas aeruginosa was evaluated. Carpinontriol B (1) and giffonin U (3) at 40 μg/disk caused the formation of zones of inhibition
The Antioxidant Potential of Graviola and Its Potential Medicinal Application
No full textGraviola (Annunona muricata L.), a plant growing in tropical regions, has many names and a range of ethnomedicinal uses. The leaves are used to treat insomnia, diabetes, cystitis, and headaches, the crushed seeds have anthelmintic properties, and the fruits are used in the preparation of ice creams, candy, syrups, shakes, and other beverages. The key active components are believed to be annonaceous acetogenins, with more than 100 such compounds having been isolated from A. muricata. The plant is also a source of a range of phenolic compounds, essential oils, alkaloids, flavonol triglycosides, and megastigmanes, together with various minerals, including Mg, Fe, Cu, K, and Ca. Its key phenolic compounds are rutin, kaempferol, and quercetin. This paper provides an overview of the current state of knowledge about the antioxidant properties of various graviola organs and their major constituents, based on a review of various electronic databases. However, few findings have been obtained from clinical trials, and few in vitro and animal studies suggest that graviola preparations have antioxidant properties; as such, the antioxidant potential of graviola, and its safety, remain unclear
Bee Products as Interesting Natural Agents for the Prevention and Treatment of Common Cardiovascular Diseases
No full textApitherapy is a form of alternative therapy that relies on the use of bee products, i.e., honey, royal jelly, propolis, pollen, and bee venom (known as apitoxin), for the prevention and treatment of various diseases. Various in vitro and in vivo studies suggest that these products may be effective in the prophylaxis and treatment of cardiovascular diseases (CVDs). This mini-review of papers identified in various electronic databases describes new aspects of the bioactivity of certain bee products, viz. bee pollen, royal jelly, bee venom, propolis, and bee bread, as natural interesting products for the prevention and treatment of common CVDs
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No full textEinige überlegungen zu der zweiten gruppe navigantes in augustins dialog de beata vita
No full textAt the beginning of the series of Augustine’s earliest extant literary works are the three philosophical dialogues Contra Academicos, De beata vita and De ordine, which were composed in the autumn of 386 during Augustine’s otium philosophandi in Cassiciacum. In the introductions of all three works, the marine metaphors are widely used. The author compares human life with a stormy sea and sees as the only salvation the port of philosophy. In beata v. 1. 2 Augutin compares the people to whom philosophy can accommodate with navigantes, which he groups in tria genera. Although the people who belong to the respective group are described in detail, the author does not mention names. This arouses research interest and justifies the attempt to propose a representing person for each group.
The present work sets itself the goal by parallel reading of beata v. 1. 2, with some passages from Cicero’s Epistulae, Tusculanae disputationes and De officiis to make a new proposal. And this in addition to the currently existing assumption that Romanianus, to whom the dialogue Contra Academicos is dedicated, should be considered as a representative of the second group of seafarers. However, the author of the present work now ventures a completely new approach, in which Cicero can be accepted as a representative of this group
Berry Phenolic Antioxidants – Implications for Human Health?
No full textAntioxidants present in the diet may have a significant effect on the prophylaxis and progression of various diseases associated with oxidative stress. Berries contain a range of chemical compounds with antioxidant properties, including phenolic compounds. The aim of this review article is to provide an overview of the current knowledge of such phenolic antioxidants, and to discuss whether these compounds may always be natural gifts for human health, based on both in vitro and in vivo studies. It describes the antioxidant properties of fresh berries (including aronia berries, grapes, blueberries, sea buckthorn berries, strawberries and other berries) and their various products, especially juices and wines. Some papers report that these phenolic compounds may sometimes behave like prooxidants, and sometimes demonstrate both antioxidant and prooxidant activity, while others note they do not behave the same way in vitro and in vivo. However, no unwanted or toxic effects (i.e., chemical, hematological or urinary effect) have been associated with the consumption of berries or berry juices or other extracts, especially aronia berries and aronia products in vivo, and in vitro, which may suggest that the phenolic antioxidants found in berries are natural gifts for human health. However, the phenolic compound content of berries and berry products is not always well described, and further studies are required to determine the therapeutic doses of different berry products for use in future clinical studies. Moreover, further experiments are needed to understand the beneficial effects reported so far from the mechanistic point of view. Therefore, greater attention should be paid to the development of well-controlled and high-quality clinical studies in this area
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