Complexes of 3,4-dihydroxyphenyl derivatives—X. Copper(II) complexes of chlorogenic acid and related compounds

Kiss, Tamás; Nagy, Gizella; Pécsi, Magdolna; Kozłowski, Henryk; Micera, Giovanni; Erre, Liliana Strinna

doi:10.1016/s0277-5387(00)80295-8

Cited by 43 publications

(50 citation statements)

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“…The value of pK of dissociation constant for the carboxylic group of quinic acid is equal 3.37 ± 0.02 . Corresponding values of aromatic hydroxyl groups are 8.21 ± 0.02 and 12.5 ± 0.15 . The very low value of the third dissociation constant can be attributed to the formation of hydrogen bond with adjacent hydroxyl group in position para .…”

Section: Physicochemical Properties Of Chlorogenic Acidmentioning

confidence: 90%

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A mystery of a cup of coffee; an insight look by chemist

2017

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Fruits, vegetables as well as processed food products of plant origin are a rich source of beneficial for human health constituents. Among them the polyphenols constitute a large group of compounds. The presented literature survey is devoted to chlorogenic acid the most abundant representative of cinnamate acids esters. Its chemical as well as biological properties are described. © 2017 BioFactors, 43(5):621-632, 2017.

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Section: Physicochemical Properties Of Chlorogenic Acidmentioning

confidence: 90%

“…Chlorogenic acid is a triacid (H 3 L) with three dissociating groups. The value of pK of dissociation constant for the carboxylic group of quinic acid is equal 3.37 ± 0.02 . Corresponding values of aromatic hydroxyl groups are 8.21 ± 0.02 and 12.5 ± 0.15 .…”

Section: Physicochemical Properties Of Chlorogenic Acidmentioning

confidence: 92%

A mystery of a cup of coffee; an insight look by chemist

2017

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“…In the investigation of Cu(II), Zn(II), Ni(II), Cd(II), and Mg(II) complexes with catechol, 3,4-DHBA, and 3,4-DHHCA, the introduction of alkyl groups into the phenol ring decreased their acid strength in the order 3,4-DHBA, 3,4-DHHCA and 3,4-DHPA 19) ; the order of the stability constants was in agreement with that of Irving & Williams order (Mn(II) ϽFe(II)ϽCo(II)ϽNi(II)ϽCu(II)ϽZn(II)). The interaction of 3,4-DHPA with Cu(II) was also investigated by Kiss et al 21) and the ambidentate character of this ligand was observed. In addition to the chelation via the catecholate sites, coordination also occurred from a separate carboxylate binding site.…”

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confidence: 90%

“…1) Some of the hydroxy aromatic ligands are interesting three-protic ligands (H 3 L), 2,3-dihydroxybenzoic acid (2,3-DHBA), 3,4-dihydroxybenzoic acid (3,4-DHBA), 3,4-dihydroxyhydrocinnamic acid (3,, and 3,4-dihydroxyphenylacetic acid (3, are typical examples and they have affinities for metal ions to form stable complexes. 19,20,21,26) , Al(OH)(HL), and Al(OH)(HL) 2 2Ϫ complexes was shown by potentiometric titration. The carboxylate-coordinated Al(HL) 2Ϫ -type complex and the carboxyl-protonated Al(HL) ϩ -type complex were also postulated.…”

mentioning

confidence: 95%

“…1) Some of the hydroxy aromatic ligands are interesting three-protic ligands (H 3 L), 2,3-dihydroxybenzoic acid (2,3-DHBA), 3,4-dihydroxybenzoic acid (3,4-DHBA), 3,4-dihydroxyhydrocinnamic acid (3,4-DHHCA), and 3,4-dihydroxyphenylacetic acid (3,4-DHPA) are typical examples and they have affinities for metal ions to form stable complexes. 19,20,21,26) Some of their complexes do not hydrolyze and precipitate in aqueous solution, since 3,4-DHBA, 3,4-DHHCA, and 3,4-DHPA have one carboxylate binding site besides the catecholate sites that are in chelatable positions. 2,3-DHBA contains three potential binding sites on three adjacent ring carbons.…”

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Potentiometric and Spectroscopic Studies on Aluminium(III) Complexes of Some Catechol Derivatives

Türkel

Berker

Özer

2004

CHEMICAL & PHARMACEUTICAL BULLETIN

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The aqua Al(III) ion is the "hardest" of the trivalent ions commonly found in the environment and in biological systems. Its effective ionic radius is 54 Å, which is smaller than other commonly encountered trivalent metal ions. Therefore the aqua Al(III) ion has the highest charge/size ratio and high affinity for hard anions. As a result, it has a strong tendency to hydrolyze in aqueous solution and its coordination equilibria contain rather complicated hydroxo complexes. 1 2,5) investigated the relations between the basicities of these oxygen donors and the stabilities of their Al(III) complexes. They concluded that the logarithm of protonation constants of monodentate donors and pK sum of bi-or terdentate donors provide a quantative measure for the hardness of each donor. The order of decreasing basicities along with the summation of their approximate logarithms of protonation constants are proposed to be: (catecholate ca. 22)Ͼ(aliphatic monohydroxy acid anion ca. 18) Ͼ(aromatic hydroxy acid anion ca. 16)Ͼ(alkoxide ca. 14)Ͼ(phenoxide ca. 10)Ͼ(carboxylate ca. 4). Therefore the complexes of Al(III) ion that are sufficiently stable to hydrolytic reactions and consequent precipitation in aqueous solution should contain ligands with the highest pK sum.The complexes of catechol derivatives with Al(III) ion including metal ions such as Fe(II), Fe(III), Mg(II), Ca(II), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II), UO 2 (II), and VO(II) were studied by various researchers. 1,2,5-26) They determined that two or three moles of catechol derivatives are coordinated with one mole of these metal ions in their complexes. In particular, the constants of formation equilibria of Al(III) complexes of catechol derivatives have been the subject of a number of investigations. 1) Some of the hydroxy aromatic ligands are interesting three-protic ligands (H 3 L), 2,3-dihydroxybenzoic acid (2,3-DHBA), 3,4-dihydroxybenzoic acid (3,4-DHBA), 3,4-dihydroxyhydrocinnamic acid (3,4-DHHCA), and 3,4-dihydroxyphenylacetic acid (3,4-DHPA) are typical examples and they have affinities for metal ions to form stable complexes. 19,20,21,26) Some of their complexes do not hydrolyze and precipitate in aqueous solution, since 3,4-DHBA, 3,4-DHHCA, and 3,4-DHPA have one carboxylate binding site besides the catecholate sites that are in chelatable positions. 2,3-DHBA contains three potential binding sites on three adjacent ring carbons. It is a good model of the competitive salicylate (COO Ϫ , O Ϫ ) and catecholate type (O Ϫ , O Ϫ ) chelation in the same molecule. 5) Kennedy and Powell 7) investigated Al(III): catechol and 3,4-DHBA complexes using potentiometry in aqueous solution in Iϭ0.1 mol · l Ϫ KCl ionic medium at 25°C. They reported the stability constants for the mononuclear diphenolate complexes of Al(III) with catechol such as AlL, AlL 2 , and AlL 3 . They also indicated that monoand bis-complexes of catechol become hydrolyzed and then AlL(OH) Ϫ , and AlL 2 (OH) 4Ϫ hydroxo complexes formed. In the case of 3,4-DHBA, the existence of Al(HL)...

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Encapsulation of phenolic acids into cyclodextrins: A global statistical analysis of the effects of pH, temperature and concentrations on binding constants measured by ACE methods

et al. 2022

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Affinity capillary electrophoresis was used for the simultaneous measurement of the p𝐾 a values and of the binding constants relative to the encapsulation of naturally occurring phenolic acids (rosmarinic and caffeic acids) with cyclodextrins. A thorough study as a function of pH and temperature was coupled to a detailed statistical analysis of the resulting experimental data. A step-by-step curve fitting process was sufficient for obtaining individual binding constant for each experimental condition, but the influence of temperature remained unclear. A quantitative and qualitative gain was then obtained by supplementing this initial analysis with global multiparameter optimization. This leads to the estimation of both entropy and enthalpy of reaction and to the full description of the binding reactions as a function of pH and temperature. The encapsulation was shown to be very sensitive to pH and temperature, with optimal complexation occurring at low pH and low temperature, gaining up to a factor of 3 by cooling from 36 to 15 • C, and up to a factor of 10 by lowering the pH from 7 to 2.

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Complexes of 3,4-dihydroxyphenyl derivatives—X. Copper(II) complexes of chlorogenic acid and related compounds

Cited by 43 publications

References 10 publications

A mystery of a cup of coffee; an insight look by chemist

A mystery of a cup of coffee; an insight look by chemist

Potentiometric and Spectroscopic Studies on Aluminium(III) Complexes of Some Catechol Derivatives

Encapsulation of phenolic acids into cyclodextrins: A global statistical analysis of the effects of pH, temperature and concentrations on binding constants measured by ACE methods

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