Iron-chelation properties of phenolic acids bearing catechol and galloyl groups

Andjelković, Mirjana; Camp, John Van; Meulenaer, Bruno De; Depaemelaere, Griet; Socaciu, Carmen; Verloo, Marc; Verhé, Roland

doi:10.1016/j.foodchem.2005.05.044

Cited by 522 publications

(345 citation statements)

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“…EDTA complexes of e.g. iron are more stable than complexes of polyphenolics, as shown for HT, PCA and CA by (Andjelković et al, 2006), and comparing the complex formation constants of acteoside and EDTA with iron, the same applies to acteoside as well (Zhao et al, 2005). Therefore, we think that acteoside was protected by EDTA by removing it from its metal complexes, thereby inhibiting its oxydation by transition metals.…”

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confidence: 71%

Filamentous fungi from Plantago lanceolata L. leaves: Contribution to the pattern and stability of bioactive metabolites

et al. 2013

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The aim of this study was to test contribution of plant-associated microorganism (PAMs) to metabolite stability/instability in a medicinal plant matrix.Therefore, PAM strains were isolated and identified based on relevant DNA sequences from Plantago lanceolata leaves. Sterile water extracts of P. lanceolata were incubated with the isolated strains and antioxidants (ascorbic acid (AA), and EDTA) for 15 days, and changes in the concentrations of chief bioactive constituents (aucubin, catalpol, acteoside (= verbascoside)) were quantified by capillary electrophoresis. Phenolic breakdown-products were identified by GC-MS.PAMs were identified from the genera Epicoccum, Bipolaris, Cladosporium, Leptosphaerulina, Aspergillus, Eurotium and Penicillium (pathongens, endophytes, and other species). Some fungi caused significant decomposition of the chief constituents (p < 0.001). Surprisingly, some strains inhibited breakdown of acteoside (p < 0.001). Meanwhile, concentration of several phenolic acids increased in fungi-infested extracts (p<0.001). Gentisic acid, 4-hydroxyphenyl acetic acid, 4-hydroxybenzoic acid and hydroxytyrosol were only present when the extract was infested with a PAM. The products are powerful antioxidants and chelators. Concentrations of phenolic acids influenced acteoside stability significantly (p < 0.01), as shown by basic data-mining techniques. AA and EDTA also significantly inhibited acteoside breakdown in sterile model solutions (p < 0.05).Our results suggest, that the phenolic acid mixture (produced during the fungal proliferation) protected acteoside from breakdown, possibly via its antioxidant activity and metal complexing ability.It was shown, that PAMs can increase or decrease the stability of chief metabolites in herbal matrices, and can significantly alter the chemical pattern of the plant matrix. 2 KeywordsPlantago lanceolata L., ribwort plantain, endophyte, plant-associated microorganism, metabolite stability, phenolic acids, acteoside 3

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confidence: 71%

Filamentous fungi from Plantago lanceolata L. leaves: Contribution to the pattern and stability of bioactive metabolites

et al. 2013

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“…Figure 6A). A broad absorption band appeared in the spectra centered at 600 nm, which is characteristic of Fe 2+ [17,45] or Fe 3+ [46,47] chelates of gallic acid. The dark purple color resembles that of the famous gall ink.…”

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confidence: 99%

Mechanism of in Situ Surface Polymerization of Gallic Acid in an Environmental-Inspired Preparation of Carboxylated Core–Shell Magnetite Nanoparticles

et al. 2014

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Corresponding authorsM. Szekeres (szekeres@chem.u-szeged.hu) and E. Tombácz (tombacz@chem.u-szeged.hu) Graphical abstract AbstractMagnetite nanoparticles (MNPs) with biocompatible coatings are good candidates for MRI (magnetic resonance imaging) contrasting, magnetic hyperthermia treatments and drug delivery systems. The spontaneous surface induced polymerization of dissolved organic matter on environmental mineral particles inspired us to prepare carboxylated core-shell MNPs by using a ubiquitous polyphenolic precursor. Through the adsorption and in-situ surface polymerization of gallic acid (GA), a polygallate (PGA) coating is formed on the nanoparticles (PGA@MNP) with possible antioxidant capacity. The Polygallate on magnetite nanoparticles Humic matter on clays 2This is a PDF file of an unedited manuscript that has been accepted for publication. Final edited form is published in Langmuir, 2014, 30:15451−15461. http://dx.doi.org/10.1021/la5038102 present work explores the mechanism of polymerization with the help of potentiometric acid-base titration, dynamic light scattering (for particle size and zeta potential determination), UV-Vis (UVvisible light spectroscopy), FTIR-ATR (Fourier-transformed infrared spectroscopy by attenuated total reflection) and XPS (X-ray photoelectron spectroscopy) techniques. We observed the formation of ester and ether linkages between gallate monomers both in solution and in the adsorbed state. Higher polymers were formed in the course of several weeks both on the surface of nanoparticles and in the dispersion medium. The ratio of the absorbances of PGA supernatants at 400 and 600 nm (i.e., the E4/E6 ratio commonly used to characterize the degree of polymerization of humic materials) was determined to be 4.3, similar to that of humic acids. Combined XPS, dynamic light scattering and FTIR-ATR results revealed that prior to polymerization, the GA monomers became oxidized to polycarboxylic acids due to ring opening while Fe 3+ ions reduced to Fe 2+ . Our published results on the colloidal and chemical stability of PGA@MNPs are referenced thoroughly in the present work. Detailed studies on biocompatibility, antioxidant property and biomedical applicability of the particles will be published.

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“…The other fractions showed no chelating activity of iron. Iron chelating ability of EDTA was higher than that of phenolic compounds [37].…”

Section: Fig 4: Metal Chelating Activity Of T Communis Extracts Andmentioning

confidence: 79%

Antioxidant Activity Assessment of Tamus Communis L. Roots

Zerargui

Baghiani

Khennouf

et al. 2016

Int J Pharm Pharm Sci

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Objective: The aim of this study was to evaluate the antioxidant activities of Tamus communis L. (T. communis) roots. This plant is used in folk medicine in the treatment of rheumatism, arthritis and lumbago. Methods:The extraction of polyphenols has been followed by the determination of total polyphenols and flavonoids. The methanol extract (MeOHE) was chromatographied on a silica gel column. The column was eluted with chloroform and then with chloroform/methanol mixtures of increasing polarity, 6 main fractions (FI--FVI)) were collected and grouped according to their TLC (Thin layer chromatography). Several methods were used to evaluate the in vitro antioxidant activity such as DPPH (2, 2'-diphenyl-1-picrylhydrazy), bleaching of β-carotene for 24 h, lipid peroxidation and anti-hemolytic activity. An in vivo approach was carried out on mice treated with CE (crud extract) at a dose of 100 mg/Kg/day for 21 consecutive days, and one group was treated with vitamin C (Vit C 50 mg/kg) as a standard drug. To determine the improvement of antioxidant potential, basic biochemical parameters were used in tissue (liver), plasma and whole blood. Results:The results showed that the highest level of polyphenols was recorded in FII (73.143±0.009 mg GA-Eq/g extract (Gallic Acid Equivalent))/g of extract) followed by MeOHE (69.786±0.10 mg GA-Eq/g extract). Total flavonoid contents of extracts/fractions showed that MeOHE contains the highest level. Inhibition of DPPH radical showed that MeOHE (0.1187±0.025 mg/ml) and CE (0.2363±0.019 mg/ml) have the most efficient antioxidant activity. All the extracts were capable of inhibiting the bleaching of β-carotene by scavenging linoleate derived free radicals, and all the studied extracts have a very important antihemolytic activity (p<0.001) and revealed an extension of hemolysis half time from 70.34±2.15 min of CTL (AAPH (2,2-azo-bis (2-amidinopropane) dihydrochloride)) and 207±5.65 min for FI. The in vivo assay was exhibited a significant decrease (54.09%) of the content of malondialdehyde (MDA) in the liver and increased glutathione (GSH) and catalase (47.30% and 46.87% respectively). Conclusion:These findings suggest that the extract obtained from T. communis have active substances contributing to the increase in natural antioxidant potential.

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Iron-chelation properties of phenolic acids bearing catechol and galloyl groups

Cited by 522 publications

References 48 publications

Filamentous fungi from Plantago lanceolata L. leaves: Contribution to the pattern and stability of bioactive metabolites

Filamentous fungi from Plantago lanceolata L. leaves: Contribution to the pattern and stability of bioactive metabolites

Mechanism of in Situ Surface Polymerization of Gallic Acid in an Environmental-Inspired Preparation of Carboxylated Core–Shell Magnetite Nanoparticles

Antioxidant Activity Assessment of Tamus Communis L. Roots

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