Complexation of iron(III) by catecholate-type polyphenols

Elhabiri, Mourad; Carrër, Charlotte; Marmolle, F.; Traboulsi, Hussein

doi:10.1016/j.ica.2006.07.110

Cited by 78 publications

(60 citation statements)

References 44 publications

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“…The absorption spectrophotometric data sets of quercetin and its methylated analogues, (+)-catechin and rutin have been statistically processed [48] to determine the successive stability constants ( Table 1 ). Stoichiometric 1:1:1 Fe NTA complexes were systematically evidenced and confirmed the previous studies on catecholate [65] or hydroxamate [71] based systems with Fe NTA . The ternary complexes with Fe NTA were also further characterized by ESI-MS which reveals the presence of monocharged (positively or negatively) isotopic patterns that agree with the simulated data ( i .…”

Section: Resultssupporting

confidence: 88%

“…Polyaminocarboxylate-type ligands such as citrate and nitrilotriacetic acid (NTA) are currently used in model systems to ensure Fe(III) solubility [62]. For instance, they have been used to study Fe(III) uptake processes by siderophores [63], polyphenols [64, 65], hydroxamic acids [66] or transferrin [67] at physiological pH. The aminotricarboxylate chelator NTA can be considered as a model of citric acid and is one of the most studied organic chelators.…”

Section: Resultsmentioning

confidence: 99%

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In Vitro Antioxidant versus Metal Ion Chelating Properties of Flavonoids: A Structure-Activity Investigation

et al. 2016

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Natural flavonoids such as quercetin, (+)catechin and rutin as well as four methoxylated derivatives of quercetin used as models were investigated to elucidate their impact on the oxidant and antioxidant status of human red blood cells (RBCs). The impact of these compounds against metal toxicity was studied as well as their antiradical activities with DPPH assay. Antihemolytic experiments were conducted on quercetin, (+)catechin and rutin with excess of Fe, Cu and Zn (400 μM), and the oxidant (malondialdehyde, carbonyl proteins) and antioxidant (reduced glutathione, catalase activity) markers were evaluated. The results showed that Fe and Zn have the highest prooxidant effect (37 and 33% of hemolysis, respectively). Quercetin, rutin and (+)catechin exhibited strong antioxidant properties toward Fe, but this effect was decreased with respect to Zn ions. However, the Cu showed a weak antioxidant effect at the highest flavonoid concentration (200 μM), while a prooxidant effect was observed at the lowest flavonoid concentration (100 μM). These results are in agreement with the physico-chemical and antiradical data which demonstrated that binding of the metal ions (for FeNTA: (+)Catechin, KLFeNTA = 1.6(1) × 106 M-1 > Rutin, KLFeNTA = 2.0(9) × 105 M-1 > Quercetin, KLFeNTA = 1.0(7) × 105 M-1 > Q35OH, KLFeNTA = 6.3(8.7) × 104 M-1 > Quercetin3’4’OH and Quercetin 3OH, KLFeNTA ~ 2 × 104 M-1) reflects the (anti)oxidant status of the RBCs. This study reveals that flavonoids have both prooxidant and antioxidant activity depending on the nature and concentration of the flavonoids and metal ions.

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Section: Resultssupporting

confidence: 88%

Section: Resultsmentioning

confidence: 99%

In Vitro Antioxidant versus Metal Ion Chelating Properties of Flavonoids: A Structure-Activity Investigation

et al. 2016

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“…Enterobactin, a naturally occurring triscatechol siderophore, is the most powerful Fe(III) chelator known with an overall stability constant of 10 49 (Scheme ). More recently researchers have been trying to mimic the structure of this siderophore to design iron chelators with relatively high affinity and selectivity toward iron 25, 26…”

Section: Introductionmentioning

confidence: 99%

Siderophore‐Mimetic hydrogel for iron chelation therapy

Mohammadi

Xie

Golub

et al. 2011

J of Applied Polymer Sci

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Two, three dihydroxybenzoic acid (DHBA), a portion of the metal chelating domain of enterobactin, was immobilized on crosslinked organic polymer polyallylamine (PAAm) and used as a chelating agent for iron removal from aqueous solutions. The swelling behavior of PAAm and PAAm hydrogels conjugated with dihydroxybenzoic acid and the effect of contact time on the swelling and binding capacity of the hydrogel was investigated at several pH values to define the absorption mechanism. Iron uptake kinetics followed the pseudosecond order Ho model and equilibrium was described by either Temkin or Freundlich isotherms. Maximum chelating capacities of the hydrogels were found to be 500-1500 mg Fe 3þ g À1 and 1500-2500 mg Fe 2þ g À1 forPAAm and PAAm/DHBA hydrogels, respectively, depending on the pH of the media. The selectivity of the conjugate hydrogel toward ferric ions was studied at several different pH values. At every pH ranging from 2 to 7.5, the conjugate hydrogel showed relatively high binding affinity for ferric ions. The selective and rapid, high affinity binding of iron by this siderophore-mimetic hydrogel offers potential application as a nonabsorbed chelator for iron in the gastrointestinal tract of patients suffering from iron overload diseases.

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“…Polyphenolic compounds, especially catechins, have been reported to have the ability to reduce and chelate with ions of iron and to form Fe-polyphenol complexes. [13][14][15][16] This leads to lower iron bioavailability and therefore it is advisable that one should not consume too much green tea. 17,18 Based on this report, it seemed possible that green tea could be utilized as a complexing agent for the quantification of iron.…”

Section: Introductionmentioning

confidence: 99%