Pflanzliche Polyphenole: chemische Eigenschaften, biologische Aktivität und Synthese

Quideau, Stéphane; Deffieux, Denis; Douat, Céline; Pouységu, Laurent

doi:10.1002/ange.201000044

Cited by 110 publications

(65 citation statements)

References 373 publications

(238 reference statements)

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“…a Asymmetric unit of (NBu 4 ) 2 [1] contains two independent molecules I and II. The second oxidation to neutral 1 is accompanied by the formation of an NIR absorption at λ max = 1080 nm, which is of mixed metal/ligand character (Figure 9, Table 4).…”

Section: Inorganic Chemistrymentioning

confidence: 99%

“…The product was purified further on a neutral alumina column, and the green complex (NBu 4 ) 2 [1] was eluted by a 30:1 CH 2 Cl 2 /CH 3 OH mixture. The solvent was removed to yield pure (NBu 4 ) 2 [1] Synthesis of [Ru 2 (bpy) 4 (μ-E)]ClO 4 , [2]ClO 4 . The starting complex cis-Ru(bpy) 2 (Cl) 2 (100 mg, 0.21 mmol) and AgClO 4 (87.07 mg, 0.42 mmol) were taken in 50 mL of EtOH and refluxed for 2 h. The precipitated AgCl was filtered off through a sintered Gooch crucible.…”

Section: Inorganic Chemistrymentioning

confidence: 99%

“…The presence of two chiral metal centers in the complexes leads to the possible formation of two diastereoisomeric forms, namely, meso (ΔΛ) and rac (ΔΔ/ ΛΛ); 14 however, only one form has been selectively obtained in each case. The crystal structure of (NBu 4 ) 2 [1] and the 1 H NMR spectra establish the meso form of (NBu 4 ) 2 [1] and the rac forms of [2]ClO 4 or [3], respectively.…”

Section: ■ Introductionmentioning

confidence: 99%

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Noninnocently Behaving Bridging Anions of the Widely Distributed Antioxidant Ellagic Acid in Diruthenium Complexes

et al. 2015

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Dinuclear compounds [L2Ru(μ-E)RuL2](n) where L is acetylacetonate (acac(-), 2,4-pentanedionate), 2,2'-bipyridine (bpy), or 2-phenylazopyridine (pap) and EH4 is ellagic acid, an antioxidative bis-catechol natural product, were studied by voltammetric and spectroelectrochemical techniques (UV-vis-NIR and electron paramagnetic resonance (EPR)). The electronic structures of the isolated forms (NBu4)2[(acac)2Ru(μ-E)Ru(acac)2] ((NBu4)2[1]), [(bpy)2Ru(μ-E)Ru(bpy)2]ClO4 ([2]ClO4), and [(pap)2Ru(μ-E)Ru(pap)2] ([3]) were characterized by density functional theory (DFT) in conjunction with EPR and UV-vis-NIR measurements. The crystal structure of (NBu4)2[1] revealed the meso form and a largely planar Ru(μ-E)Ru center. Several additional charge states of the compounds were electrochemically accessible and were identified mostly as complexes with noninnocently behaving pap(0/•-) or bridging ellagate (E(n-)) anions (n = 2, 3, 4) but not as mixed-valence intermediates. The free anions E(n-), n = 1-4, were calculated by time-dependent DFT to reveal NIR transitions for the radical forms with n = 1 and 3 and a triplet ground state for the bis(o-semiquinone) dianion E(2-).

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Section: Inorganic Chemistrymentioning

confidence: 99%

Section: Inorganic Chemistrymentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

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Noninnocently Behaving Bridging Anions of the Widely Distributed Antioxidant Ellagic Acid in Diruthenium Complexes

et al. 2015

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“…[1] Members of this large family of compounds include epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epigallocatechin (EGC), and tannic acid (TA), to name a few (Figure 1 B). Plant polyphenols display a rich and complex spectrum of physical and chemical properties, [1a] giving rise to broad chemical versatility including absorption of UV radiation, radical scavenging, and metal ion complexation.…”

mentioning

confidence: 99%

Colorless Multifunctional Coatings Inspired by Polyphenols Found in Tea, Chocolate, and Wine

et al. 2013

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Polyphenolverbindungen, die in Tee, Rotwein und Schokolade vorkommen, bilden auf Trägermaterialien dünne haftende Polyphenolfilme durch spontane Adsorption aus einer Lösung. Auf der Grundlage dieser Beobachtung wurde ein allgemein anwendbarer Prozess zur Oberflächenmodifizierung von festen, porösen und nanopartikulären Metall‐, Keramik‐ und Polymermaterialien entwickelt (siehe Bild; ROS=reaktive Sauerstoffspezies).

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“…[26][27][28] Polyphenolic compounds, which are found in large amounts in fruits and vegetables, have been reported to exhibit beneficial antioxidant and anticancer activities. [29,30] However, they could also exert deleterious effects by generating reactive phenoxyl or semiquinone radicals. [31] Interestingly, 2,9-Me 2 OP was also found to efficiently inhibit cytotoxic effects induced by some of these polyphenolic compounds.…”

Section: Potential Biological Implicationsmentioning

confidence: 99%

Detoxifying Polyhalogenated Catechols through a Copper‐Chelating Agent by Forming Stable and Redox‐Inactive Hydrogen‐Bonded Complexes with an Unusual Perpendicular Structure

Li¹,

Huang²,

Liu³

et al. 2014

Chemistry A European J

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The use of selective metal chelating agents with preference for binding of a specific metal ion to investigate its biological role is becoming increasingly common. We found recently that a well-known copper-specific chelator 2,9-dimethyl-1,10-phenanthroline (2,9-Me 2 OP) could completely inhibit the synergistic toxicity induced by tetrachlorocatechol (TCC) and sodium azide (NaN 3 ). However, its underlying molecular mechanism is still not clear. Here, we show that the protection by 2,9-Me 2 OP is not due to its classic copper-chelating property, but rather due to formation of a multiple hydrogen-bonded complex between 2,9-Me 2 OP and TCC, featuring an unusual perpendicular arrangement of the two binding partners. The two methyl groups at the 2,9 positions in 2,9-Me 2 OP were found to be critical to stabilize the 2,9-Me 2 OP/TCC complex due to steric hindrance, and therefore completely prevents the generation of the reactive and toxic semiquinone radicals by TCC/NaN 3 . This represents the first report showing that an unexpected new protective mode of action for the copper "specific" chelating agent 2,9-Me 2 OP by using its steric hindrance effect of the two CH 3 groups not only to chelate copper, but also to "chelate" a catechol through multiple H-bonding. These findings may have broad biological implications for future research of this widely used copper-chelating agent and the ubiquitous catecholic compounds.

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Pflanzliche Polyphenole: chemische Eigenschaften, biologische Aktivität und Synthese

Cited by 110 publications

References 373 publications

Noninnocently Behaving Bridging Anions of the Widely Distributed Antioxidant Ellagic Acid in Diruthenium Complexes

Noninnocently Behaving Bridging Anions of the Widely Distributed Antioxidant Ellagic Acid in Diruthenium Complexes

Colorless Multifunctional Coatings Inspired by Polyphenols Found in Tea, Chocolate, and Wine

Detoxifying Polyhalogenated Catechols through a Copper‐Chelating Agent by Forming Stable and Redox‐Inactive Hydrogen‐Bonded Complexes with an Unusual Perpendicular Structure

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