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Anderson SN, Dederich CT, Elsberg JGD, Benninghoff AD, Berreau LM. Investigating the Combined Toxicity of Cu(II) and Carbon Monoxide (CO); Cellular CO Delivery Using a Cu(II) Flavonolato Complex. ChemMedChem 2024; 19:e202300682. [PMID: 38369675 DOI: 10.1002/cmdc.202300682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 02/20/2024]
Abstract
Carbon monoxide (CO) delivery molecules are of significant current interest as potential therapeutics, including for anticancer applications. A recent approach toward generating new types of materials-based anticancer agents involves combining the Fenton reactivity of a redox active metal ion with CO delivery. However, small molecule examples of these types of entities have not been systematically studied to evaluate the combined effect on cellular toxicity. Herein we describe a Cu(II) flavonolato complex which produces anticancer effects through a combination of copper-mediated reactive oxygen species (ROS) generation and light-induced flavonol CO release. Confocal microscopy studies provide evidence of enhanced flavonol uptake in the copper flavonolato system relative to the free flavonol, which leads to an increased amount of CO delivery within cells. Importantly, this work demonstrates that a metal flavonolato species can be used to produce enhanced toxicity effects resulting from both metal ion-induced Fenton reactivity and increased cellular uptake of a flavonol CO donor.
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Affiliation(s)
- Stephen N Anderson
- Department of Chemistry & Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322-0300, United States
| | - C Taylor Dederich
- Department of Chemistry & Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322-0300, United States
| | - Josiah G D Elsberg
- Department of Chemistry & Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322-0300, United States
| | - Abby D Benninghoff
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, 4815 Old Main Hill, Logan, UT 84322-4815, United States
| | - Lisa M Berreau
- Department of Chemistry & Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322-0300, United States
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2
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Podder N, Saha A, Barman SK, Mandal S. Flavonol dioxygenation catalysed by cobalt(II) complexes supported with 3N(COO) and 4N donor ligands: a comparative study to assess the carboxylate effects on quercetin 2,4-dioxygenase-like reactivity. Dalton Trans 2023; 52:11465-11480. [PMID: 37466296 DOI: 10.1039/d3dt00833a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Two new cobalt(II)-acetato complexes, [CoII(L3NCOO)(OAc)]·0.5H2O (1OAc·0.5H2O) and [CoII(L4N)(OAc)](PF6) (2OAc(PF6)), were synthesised using ligands L3NCOO- (Li+L3NCOO- = lithium 2-(benzyl((6'-methyl-[2,2'-bipyridin]-6-yl)methyl)amino)acetate) and L4N (N-benzyl-1-(6'-methyl-[2,2'-bipyridin]-6-yl)-N-(pyridin-2-ylmethyl)methanamine), respectively, to mimic the functional activity of cobalt(II)-quercetin-2,4-dioxygenase (CoII-2,4-QD). Additionally, Co(II)-flavonolato ternary complexes, [CoII(L3NCOO)(fla)]·H2O (1fla·H2O) and [CoII(L4N)(fla)](PF6) (2fla(PF6)), were synthesised as enzyme-substrate models. All four complexes were thoroughly characterised by elemental analyses and spectroscopic methods. Structural characterisation was performed for 1OAc·0.5H2O, 2OAc(PF6)·CH2Cl2 and 2fla+ with a perchlorate counter anion, 2fla(ClO4)·1.5H2O. Furthermore, density functional theory (DFT) calculations, time-dependent DFT (TD-DFT) and molecular orbital (MO) analysis were performed for the flavonolato adducts 1fla and 2fla+. The catalytic activities of complexes 1OAc·0.5H2O and 2OAc(PF6) in the oxygenative degradation of flavonol (multiple-turnover reactions) were investigated at 70 °C in DMF to determine the effect of the carboxylate substituent over a pyridyl donor residue on reactivity. Complex 1OAc·0.5H2O showed a higher catalytic rate than complex 2OAc(PF6). The same reactivity order was observed for single-turnover dioxygenation reactions with ternary complexes (1fla > 2fla+). The formation constants (Kf) of 1fla and 2fla+ species are comparable, implying that catalyst-substrate adduct formation occurs in similar amounts for both catalytic reactions. Therefore, the Kf values have a similar impact on reactivities. However, the oxidation potential of the bound fla-/fla˙ couple in 1fla is considerably lower than that in 2fla+. DFT calculations predicted that the negatively charged carboxylate group of ligand L3NCOO- determines the higher reactivity of 1fla with dioxygen by decreasing the oxidation potential of the bound fla-/fla˙ couple. During the dioxygenation process, the reactive Co(II)-bound flavonoxy radical was generated via single-electron transfer from the coordinated fla- to dioxygen, simultaneously forming a superoxide ion. The anionic carboxylate group improves the stability of the bound flavonoxy radical by providing substantial electron density to the electron-deficient fla˙ through the Co(II) centre, allowing the reactive fla˙ species to accumulate at an optimal concentration for effective catalysis. EPR spectroscopy successfully detected the cobalt-bound fla˙ species formed through the dioxygenation of 1fla. NBT2+ and EPR spin-trapping experiments confirmed superoxide formation during the dioxygenation process. So, the present work describes CoII-2,4-QD model studies and clarifies the function of carboxylate in quercetinase-like reactivity.
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Affiliation(s)
- Nirmalya Podder
- Department of Chemistry, Indian Institute of Technology (IIT) Kharagpur, Kharagpur 721302, India.
| | - Anannya Saha
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Manauli, 140306, India
| | - Suman K Barman
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Manauli, 140306, India
| | - Sukanta Mandal
- Department of Chemistry, Indian Institute of Technology (IIT) Kharagpur, Kharagpur 721302, India.
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3
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Ajaykamal T, Palaniandavar M. Mononuclear nickel(ii)-flavonolate complexes of tetradentate tripodal 4N ligands as structural and functional models for quercetin 2,4-dioxygenase: structures, spectra, redox and dioxygenase activity. RSC Adv 2023; 13:24674-24690. [PMID: 37601601 PMCID: PMC10436029 DOI: 10.1039/d3ra04834a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 08/01/2023] [Indexed: 08/22/2023] Open
Abstract
Three new nickel(ii)-flavonolate complexes of the type [Ni(L)(fla)](ClO4) 1-3, where L is the tripodal 4N ligand tris(pyrid-2-ylmethyl)amine (tpa, L1) or (pyrid-2-ylmethyl)bis(6-methylpyrid-2-ylmethyl)amine (6-Me2-tpa, L2) or tris(N-Et-benzimidazol-2-ylmethyl)amine (Et-ntb, L3), have been isolated as functional models for Ni(ii)-containing quercetin 2,4-dioxygenase. Single crystal X-ray structures of 1 and 3 reveal that Ni(ii) is involved in π-back bonding with flavonolate (fla-), as evident from enhancement in C[double bond, length as m-dash]O bond length upon coordination [H(fla), 1.232(3); 1, 1.245(7); 3, 1.262(8) Å]. More asymmetric chelation of fla- in 3 than in 1 [Δd = (Ni-Ocarbonyl - Ni-Oenolate): 1, 0.126; 3, 0.182 Å] corresponds to lower π-delocalization in 3 with electron-releasing N-Et substituent. The optimized structures of 1-3 and their geometrical isomers have been computed by DFT methods. The HOMO and LUMO, both localized on Ni(ii)-bound fla-, are highly conjugated bonding π- and antibonding π*-orbitals respectively. They are located higher in energy than the Ni(ii)-based MOs (HOMO-1, dx2-y2; HOMO-2/6, dz2), revealing that the Ni(ii)-bound fla- rather than Ni(ii) would undergo oxidation upon exposure to dioxygen. The results of computational studies, in combination with spectral and electrochemical studies, support the involvement of redox-inactive Ni(ii) in π-back bonding with fla-, tuning the π-delocalization in fla- and hence its activation. Upon exposure to dioxygen, all the flavonolate adducts in DMF solution decompose to produce CO and depside, which then is hydrolyzed to give the corresponding acids at 70 °C. The highest rate of dioxygenase reactivity of 3 (kO2: 3 (29.10 ± 0.16) > 1 (16.67 ± 0.70) > 2 (1.81 ± 0.04 × 10-1 M-1 s-1)), determined by monitoring the disappearance of the LMCT band in the range 440-450 nm, is ascribed to the electron-releasing N-Et substituent on bzim ring, which decreases the π-delocalization in fla- and enhances its activation.
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Affiliation(s)
- Tamilarasan Ajaykamal
- Department of Chemistry, Bharathidasan University Tiruchirapalli 620 024 Tamil Nadu India +91-431-2407043 +91-431-2407125
| | - Mallayan Palaniandavar
- Department of Chemistry, Bharathidasan University Tiruchirapalli 620 024 Tamil Nadu India +91-431-2407043 +91-431-2407125
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4
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Khamespanah F, Patel NM, Forney AK, Heitger DR, Amarasekarage CM, Springer LE, Belecki K, Lucas HR. Flavonol dioxygenase chemistry mediated by a synthetic nickel superoxide. J Inorg Biochem 2023; 238:112021. [PMID: 36395718 DOI: 10.1016/j.jinorgbio.2022.112021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/01/2022] [Accepted: 10/02/2022] [Indexed: 11/16/2022]
Abstract
Nature exploits transition metal centers to enhance and tune the oxidizing power of natural oxidants such as O2 and H2O2. The design and interrogation of synthetic metallocomplexes with similar reactivity to metalloproteins provides one strategy for gaining insight into the mechanistic underpinnings of oxygen-activating enzymes such as oxidases, oxygenases, and dioxygenases like Ni-quercetinase (Ni-QueD). Ni-QueD catalyzes the oxidative ring opening of the polyphenol quercetin, a natural product with antioxidant properties. Herein, we report the synthesis and characterization of Ni(13-DOB), a Ni(II) species complexed by an N4-macrocycle that has been characterized by single crystal X-ray crystallography. Ni(13-DOB) forms a Ni-superoxide intermediate (Ni(13-DOB)O2•-) upon treatment with H2O2 and Et3N, as verified by resonance Raman spectroscopy. We demonstrate through UV/vis and LCMS that Ni(13-DOB)O2•- is capable of the 1-electron oxidation of flavonols, including both 3-hydroxyflavone (3-HF, the simplest flavonol) and quercetin itself. Incorporation of two O-atoms into the flavonol radical via superoxide from Ni(13-DOB)O2•- precedes oxidative cleavage of the flavonol scaffold in each case, consistent with quercetinase ring cleavage by Ni-QueD in Streptomyces sp. FLA. Conversion of 3-HF into 2-hydroxybenzoylbenzoic acid was accomplished with catalytic turnover of Ni(13-DOB) at ambient temperature, as confirmed by HPLC timecourses and GCMS analysis of isotopic labeling studies. The Ni(13-DOB)-mediated oxidative cleavage of quercetin to the corresponding biomimetic phenolic ester was also verified through 18O-isotopic labeling studies. Through the HPLC characterization of both on- and off-pathway products of flavonol dioxygenation by Ni(13-DOB)O2•-, the stringent reaction pathway control provided by enzyme active sites is highlighted.
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Affiliation(s)
- F Khamespanah
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284, United States of America
| | - N M Patel
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284, United States of America
| | - A K Forney
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284, United States of America
| | - D R Heitger
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284, United States of America
| | - C M Amarasekarage
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284, United States of America
| | - L E Springer
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284, United States of America
| | - K Belecki
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284, United States of America.
| | - H R Lucas
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284, United States of America.
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5
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An artificial metalloprotein with metal-adaptive coordination sites and Ni-dependent quercetinase activity. J Inorg Biochem 2022; 235:111914. [PMID: 35841720 DOI: 10.1016/j.jinorgbio.2022.111914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 06/20/2022] [Accepted: 07/03/2022] [Indexed: 11/23/2022]
Abstract
Engineering non-native metal active sites into proteins using canonical amino acids offers many advantages but is hampered by significant challenges. The TIM barrel protein, imidazole glycerol phosphate synthase from the hyperthermophilic organism Thermotoga maritima (tHisF), is well-suited for the construction of artificial metalloenzymes by this approach. To this end, we have generated a tHisF variant (tHisFEHH) with a Glu/His/His motif for metal ion coordination. Crystal structures of ZnII:tHisFEHH and NiII:tHisFEHH reveal that both metal ions bind to the engineered histidines. However, the two metals bind at distinct sites with different geometries, demonstrating the adaptability of tHisF. Only ZnII additionally ligates the Glu residue and adopts a tetrahedral geometry. The pseudo-octahedral NiII site comprises the two His and a native Ser residue. NiII:tHisFEHH catalyzes the oxidative cleavage of the flavanols quercetin and myricetin, providing an unprecedented example of an artificial metalloprotein with quercetinase activity.
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Halevas E, Matsia S, Hatzidimitriou A, Geromichalou E, Papadopoulos T, Katsipis G, Pantazaki A, Litsardakis G, Salifoglou A. A unique ternary Ce(III)-quercetin-phenanthroline assembly with antioxidant and anti-inflammatory properties. J Inorg Biochem 2022; 235:111947. [DOI: 10.1016/j.jinorgbio.2022.111947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 07/15/2022] [Accepted: 07/24/2022] [Indexed: 10/16/2022]
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7
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Podder N, Dey S, Anoop A, Mandal S. Oxygenolysis of a series of copper(II)-flavonolate adducts varying the electronic factors on supporting ligands as a mimic of quercetin 2,4-dioxygenase-like activity. Dalton Trans 2022; 51:4338-4353. [PMID: 35191437 DOI: 10.1039/d1dt04151g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Four copper(II)-flavonolate compounds of type [Cu(LR)(fla)] {where LR = 2-(p-R-benzyl(dipyridin-2-ylmethyl)amino)acetate; R = -OMe (1), -H (2), -Cl (3) and -NO2 (4)} have been developed as a structural and functional enzyme-substrate (ES) model of the Cu2+-containing quercetin 2,4-dioxygenase enzyme. The ES model complexes 1-4 are synthesized by reacting 3-hydroxyflavone in the presence of a base with the respective acetate-bound copper(II) complexes, [Cu(LR)(OAc)]. In the presence of dioxygen the ES model complexes undergo enzyme-type oxygenolysis of flavonolate (dioxygenase type bond cleavage reaction) at 80 °C in DMF. The reactivity shows a substituent group dependent order as -OMe (1) > -H (2) > -Cl (3) > -NO2 (4). Experimental and theoretical studies suggest a single-electron transfer (SET) from flavonolate to dioxygen, rather than valence tautomerism {[CuII(fla-)] ↔ [CuI(fla˙)]}, to generate the reactive flavonoxy radical (fla˙) that reacts further with the superoxide radical to bring about the oxygenative ring opening reaction. The SET pathway has been further verified by studying the dioxygenation reaction with a redox-inactive Zn2+ complex, [Zn(LOMe)(fla)] (5).
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Affiliation(s)
- Nirmalya Podder
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur-721302, India.
| | - Subhasis Dey
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur-721302, India.
| | - Anakuthil Anoop
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur-721302, India.
| | - Sukanta Mandal
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur-721302, India.
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8
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Podder N, Mandal S. The effects of metal cofactors on the reactivity of quercetin 2,4-dioxygenase: synthetic model studies with M( ii)-complexes (M = Mn, Co, Ni, Cu, Zn) and assessment of the regulatory factors in catalytic efficacy. Dalton Trans 2022; 51:17064-17080. [DOI: 10.1039/d2dt02853k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This paper demonstrates the metal ion effects on the dioxygenation of flavonol catalysed by M(ii)-complexes (M = Mn, Co, Ni, Cu, Zn) as functional models of quercetin 2,4-dioxygenase-like reactivity.
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Affiliation(s)
- Nirmalya Podder
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
| | - Sukanta Mandal
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
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9
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A functional model for quercetin 2,4-dioxygenase: Geometric and electronic structures and reactivity of a nickel(II) flavonolate complex. J Inorg Biochem 2021; 226:111632. [PMID: 34700128 DOI: 10.1016/j.jinorgbio.2021.111632] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 10/06/2021] [Accepted: 10/12/2021] [Indexed: 11/22/2022]
Abstract
Quercetin 2,4-dioyxgenase (QueD) has been known to catalyze the oxygenative degradation of flavonoids and quercetin. Recent crystallographic study revealed a nickel ion occupies the active site as a co-factor to support O2 activation and catalysis. Herein, we report a nickel(II) flavonolate complex bearing a tridentate macrocyclic ligand, [NiII(Me3-TACN)(Fl)(NO3)](H2O) (1, Me3-TACN = 1,4,7-trimethyl-1,4,7-triazacyclononane, Fl = 3-hydroxyflavone) as a functional model for QueD. The flavonolatonickel(II) complex was characterized by using spectrometric analysis including UV-vis spectroscopy, electrospray ionization mass spectrometer (ESI-MS), infrared spectroscopy (FT-IR) and 1H nuclear magnetic resonance spectroscopy (NMR). The single crystal X-ray structure of 1 shows two isomers with respect to the direction of a flavonolate ligand. Two isomers commonly are in the octahedral geometry with a bidentate of flavonolate and a monodentate of nitrate as well as a tridentate binding of Me3-TACN ligand. The spin state of 1 is determined to be a triplet state based on the Evans' method. Interestingly, electronic configuration of 1 from density functional theory (DFT) calculations revealed that the two singly occupied molecular orbitals (SOMOs) lie energetically lower than the highest (doubly) occupied molecular orbital (HOMO), that is so-called the SOMO-HOMO level inversion (SHI). The HOMO shows an electron density localized in the flavonolate ligand, indicating that flavonolate ligand is oxidized first rather than the nickel center. Thermal degradation of 1 resulted in the formation of benzoic acid and salicylic acid, which is attributed to the oxygenation of flavonolate of 1.
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A novel nickel complex with 3-Hydroxyflavone: Synthesis, CrystalStructure and reactivity towards O2 of Ni4(C15O3H9)4(CH3O)4(H2O)4. INORG CHEM COMMUN 2021. [DOI: 10.1016/j.inoche.2021.108795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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11
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Mucha P, Skoczyńska A, Małecka M, Hikisz P, Budzisz E. Overview of the Antioxidant and Anti-Inflammatory Activities of Selected Plant Compounds and Their Metal Ions Complexes. Molecules 2021; 26:4886. [PMID: 34443474 PMCID: PMC8398118 DOI: 10.3390/molecules26164886] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/09/2021] [Accepted: 08/10/2021] [Indexed: 12/12/2022] Open
Abstract
Numerous plant compounds and their metal-ion complexes exert antioxidative, anti-inflammatory, anticancer, and other beneficial effects. This review highlights the different bioactivities of flavonoids, chromones, and coumarins and their metal-ions complexes due to different structural characteristics. In addition to insight into the most studied antioxidative properties of these compounds, the first part of the review provides a comprehensive overview of exogenous and endogenous sources of reactive oxygen and nitrogen species, oxidative stress-mediated damages of lipids and proteins, and on protective roles of antioxidant defense systems, including plant-derived antioxidants. Additionally, the review covers the anti-inflammatory and antimicrobial activities of flavonoids, chromones, coumarins and their metal-ion complexes which support its application in medicine, pharmacy, and cosmetology.
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Affiliation(s)
- Paulina Mucha
- Department of the Chemistry of Cosmetic Raw Materials, Faculty of Pharmacy, Medical University of Łódź, Muszyńskiego 1, 90-151 Łódź, Poland
| | - Anna Skoczyńska
- Department of Pharmacology, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Poniatowskiego 15, 41-200 Sosnowiec, Poland;
| | - Magdalena Małecka
- Department of Physical Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 163/165, 90-236 Łódź, Poland;
| | - Paweł Hikisz
- Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Łódź, Poland;
| | - Elzbieta Budzisz
- Department of the Chemistry of Cosmetic Raw Materials, Faculty of Pharmacy, Medical University of Łódź, Muszyńskiego 1, 90-151 Łódź, Poland
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12
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Han X, Sahihi M, Whitfield S, Jimenez I. Tuning excited state of bipyridyl platinum(II) complexes with bio-active flavonolate ligand: Structures, photoreactivity, and DFT calculations. Inorganica Chim Acta 2020. [DOI: 10.1016/j.ica.2020.119952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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13
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Halevas E, Mavroidi B, Antonoglou O, Hatzidimitriou A, Sagnou M, Pantazaki AA, Litsardakis G, Pelecanou M. Structurally characterized gallium-chrysin complexes with anticancer potential. Dalton Trans 2020; 49:2734-2746. [PMID: 32064490 DOI: 10.1039/c9dt04540f] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Chemotherapeutic metal-based compounds are effective anticancer agents; however, their cytotoxic profile and significant side effects limit their wide application. Natural products, especially flavonoids, are a prominent alternative source of anticancer agents that can be used as ligands for the generation of new bioactive complexes with metal ions of known biochemical and pharmacological activities. Herein, we present the synthesis and detailed structural and physicochemical characterizations of three novel complex assemblies of Ga(iii) with the flavonoid chrysin and the ancillary aromatic chelators 1,10-phenanthroline, 2,2'-bipyridine and imidazole. The complexes constitute the only crystallographically characterized structures having a metal core from the boron group elements and a flavonoid as the ligand. The in vitro biological evaluation of the three complexes in a series of cancer cell lines of different origin established their cytotoxicity and ROS generating potential. In particular, the Ga(iii)-chrysin-imidazole complex displayed the highest anticancer efficacy against all cancer cell lines with IC50 values in the low micromolar range (<1.18 μM), a result worth further investigation.
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Affiliation(s)
- Eleftherios Halevas
- Laboratory of Materials for Electrotechnics, Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece and Institute of Biosciences & Applications, National Centre for Scientific Research "Demokritos", 15310 Athens, Greece.
| | - Barbara Mavroidi
- Institute of Biosciences & Applications, National Centre for Scientific Research "Demokritos", 15310 Athens, Greece.
| | - Orestis Antonoglou
- Laboratory of Inorganic Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Antonios Hatzidimitriou
- Laboratory of Inorganic Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Marina Sagnou
- Institute of Biosciences & Applications, National Centre for Scientific Research "Demokritos", 15310 Athens, Greece.
| | - Anastasia A Pantazaki
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - George Litsardakis
- Laboratory of Materials for Electrotechnics, Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Maria Pelecanou
- Institute of Biosciences & Applications, National Centre for Scientific Research "Demokritos", 15310 Athens, Greece.
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14
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Sun Y, Liu Y, Zhang J, Li Y. Structure‐Reactivity Relationship in ES Models of Co(II)‐Containing Quercetin 2,4‐Dioxygenase. ChemistrySelect 2019. [DOI: 10.1002/slct.201903205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Ying‐Ji Sun
- Department of ChemistryDalian University of Technology 2 Linggong Road Dalian 116024 China
| | - Yan‐Fang Liu
- Department of ChemistryDalian University of Technology 2 Linggong Road Dalian 116024 China
| | - Jian‐Jun Zhang
- Department of ChemistryDalian University of Technology 2 Linggong Road Dalian 116024 China
| | - Yan‐Qin Li
- Department of ChemistryDalian University of Technology 2 Linggong Road Dalian 116024 China
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15
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Synthesis, characterization and CO-releasing property of palladium(II) bipyridine flavonolate complexes. TRANSIT METAL CHEM 2019. [DOI: 10.1007/s11243-019-00373-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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16
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Hoof S, Limberg C. The Behavior of Trispyrazolylborato-Metal(II)-Flavonolate Complexes as Functional Models for Bacterial Quercetinase-Assessment of the Metal Impact. Inorg Chem 2019; 58:12843-12853. [PMID: 31502453 DOI: 10.1021/acs.inorgchem.9b01795] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A series of five compounds TpMesMFla (TpMes = hydrotris(3-mesityl)pyrazolylborate; M = Mn, Fe, Co, Ni, Zn; Fla = 3-hydroxyflavonolate) has been synthesized as models for the 2,4-quercetin dioxygenase, QueD. The structures have been determined and the complexes proved to be isomorphous. Considering the structures more closely revealed that they differ in the degree of delocalization in the chelate ring formed through the binding of the two O donors of the flavonolate to the metal center, which is also supported by the results of UV-vis and IR spectroscopic investigations. The resulting trend (Zn/Fe > Co > Mn > Ni) is, however, not in line with the one that was found investigating the redox properties of the complexes by cyclic voltammetry (Zn > Fe > Ni > Co > Mn). Notably, from CV clear-cut information could be derived, as the complexes exhibited exceptionally well-behaved quasi-reversible redox transitions, indicating that the Tp ligand stabilizes the flavonolate radical formed in the oxidation process rather well. The fact that the rates, with which the complexes react with O2 in DMF solution, correlate with the position of the flavonolate redox couples, suggest that these reactions proceed via the initial electron transfer from the flavonolate to O2. After the O2 reaction, salicylic acid was identified as one of the products, the formation of which can be explained by the hydrolysis of the depside that should form upon a dioxygenation similar to the QueD enzyme-catalyzed reaction. 18O labeling experiments confirmed the presence of O2 derived O atoms. Mechanistic inferences based on the above results are discussed.
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Affiliation(s)
- Santina Hoof
- Institut für Chemie , Humboldt-Universität zu Berlin , Brook-Taylor-Str. 2 , 12489 Berlin , Germany
| | - Christian Limberg
- Institut für Chemie , Humboldt-Universität zu Berlin , Brook-Taylor-Str. 2 , 12489 Berlin , Germany
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17
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Schutte-Smith M, Roodt A, Alberto R, Twigge L, Visser HG, Kirsten L, Koen R. Structures of rhenium(I) complexes with 3-hydroxyflavone and benzhydroxamic acid as O,O'-bidentate ligands and confirmation of π-stacking by solid-state NMR spectroscopy. ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY 2019; 75:378-387. [PMID: 30957783 DOI: 10.1107/s2053229619002717] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 02/21/2019] [Indexed: 11/10/2022]
Abstract
The synthesis and crystal structures of two new rhenium(I) complexes obtained utilizing benzhydroxamic acid (BHAH) and 3-hydroxyflavone (2-phenylchromen-4-one, FlavH) as bidentate ligands, namely tetraethylammonium fac-(benzhydroxamato-κ2O,O')bromidotricarbonylrhenate(I), (C8H20N)[ReBr(C7H6NO2)(CO)3], 1, and fac-aquatricarbonyl(4-oxo-2-phenylchromen-3-olato-κ2O,O')rhenium(I)-3-hydroxyflavone (1/1), [Re(C15H9O3)(CO)3(H2O)]·C15H10O3, 3, are reported. Furthermore, the crystal structure of free 3-hydroxyflavone, C15H10O3, 4, was redetermined at 100 K in order to compare the packing trends and solid-state NMR spectroscopy with that of the solvate flavone molecule in 3. The compounds were characterized in solution by 1H and 13C NMR spectroscopy, and in the solid state by 13C NMR spectroscopy using the cross-polarization magic angle spinning (CP/MAS) technique. Compounds 1 and 3 both crystallize in the triclinic space group P-1 with one molecule in the asymmetric unit, while 4 crystallizes in the orthorhombic space group P212121. Molecules of 1 and 3 generate one-dimensional chains formed through intermolecular interactions. A comparison of the coordinated 3-hydroxyflavone ligand with the uncoordinated solvate molecule and free molecule 4 shows that the last two are virtually completely planar due to hydrogen-bonding interactions, as opposed to the former, which is able to rotate more freely. The differences between the solid- and solution-state 13C NMR spectra of 3 and 4 are ascribed to inter- and intramolecular interactions. The study also investigated the potential labelling of both bidentate ligands with the corresponding fac-99mTc-tricarbonyl synthon. All attempts were unsuccessful and reasons for this are provided.
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Affiliation(s)
- Marietjie Schutte-Smith
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
| | - Andreas Roodt
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
| | - Roger Alberto
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, Zürich CH-8057, Switzerland
| | - Linette Twigge
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
| | - Hendrik Gideon Visser
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
| | - Leo Kirsten
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
| | - Renier Koen
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
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Soboleva T, Berreau LM. 3-Hydroxyflavones and 3-Hydroxy-4-oxoquinolines as Carbon Monoxide-Releasing Molecules. Molecules 2019; 24:E1252. [PMID: 30935018 PMCID: PMC6479552 DOI: 10.3390/molecules24071252] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 03/26/2019] [Accepted: 03/27/2019] [Indexed: 12/26/2022] Open
Abstract
Carbon monoxide-releasing molecules (CORMs) that enable the delivery of controlled amounts of CO are of strong current interest for applications in biological systems. In this review, we examine the various conditions under which CO is released from 3-hydroxyflavones and 3-hydroxy-4-oxoquinolines to advance the understanding of how these molecules, or derivatives thereof, may be developed as CORMs. Enzymatic pathways from quercetin dioxygenases and 3-hydroxy-4-oxoquinoline dioxygenases leading to CO release are examined, along with model systems for these enzymes. Base-catalyzed and non-redox-metal promoted CO release, as well as UV and visible light-driven CO release from 3-hydroxyflavones and 3-hydroxy-4-oxoquinolines, are summarized. The visible light-induced CO release reactivity of recently developed extended 3-hydroxyflavones and a 3-hydroxybenzo[g]quinolone, and their uses as intracellular CORMs, are discussed. Overall, this review provides insight into the chemical factors that affect the thermal and photochemical dioxygenase-type CO release reactions of these heterocyclic compounds.
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Affiliation(s)
- Tatiana Soboleva
- Department of Chemistry & Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322-0300, USA.
| | - Lisa M Berreau
- Department of Chemistry & Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322-0300, USA.
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Hoof S, Limberg C. Bioinspired Trispyrazolylborato Nickel(II) Flavonolate Complexes and Their Reactivity Toward Dioxygen. Z Anorg Allg Chem 2018. [DOI: 10.1002/zaac.201800457] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Santina Hoof
- Institut für Chemie; Humboldt-Universität zu Berlin; Brook-Taylor-Str. 2 12489 Berlin Germany
| | - Christian Limberg
- Institut für Chemie; Humboldt-Universität zu Berlin; Brook-Taylor-Str. 2 12489 Berlin Germany
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20
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Vogler A, Hischa B. Synthesis, crystal structure, photoluminescence and photochemistry of bis(triphenylphosphine)silver(I) flavonolate. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES 2018. [DOI: 10.1515/znb-2018-0162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The complex Ag(I)(flavonolate)(PPh3)2 has been prepared and characterized including the crystal structure. This compound shows in degassed solution two emission bands, a fluorescence at λ
max=505 nm and a phosphorescence at λ
max=780 nm. Both emissions originate from lowest-energy flavonolate intraligand excited singlet and triplet states, respectively. In the presence of oxygen, the phosphorescence disappears and the complex becomes light-sensitive. The flavonolate ligand undergoes a photooxidation by oxygen.
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Affiliation(s)
- Arnd Vogler
- Institute of Inorganic Chemistry, University of Regensburg , Universitätsstraße 31 , 93053 Regensburg , Germany
| | - Birgit Hischa
- X-ray Central Analytics, University of Regensburg , Universitätsstraße 31 , 93053 Regensburg , Germany
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21
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Han X, Kumar MR, Hoogerbrugge A, Klausmeyer KK, Ghimire MM, Harris LM, Omary MA, Farmer PJ. Mechanistic Investigations of Photoinduced Oxygenation of Ru(II) Bis-bipyridyl Flavonolate Complexes. Inorg Chem 2018; 57:2416-2424. [PMID: 29461051 DOI: 10.1021/acs.inorgchem.7b01384] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We previously reported that a Ru-bound flavonolate model of flavonol dioxygenases, [RuII(bpy)2(3-hydroxyfla)][PF6], photochemically reacts with dioxygen in two different manners. Broad-band excitation generates mixtures of products characteristic of 1,3-addition of dioxygen across the central pyrone ring, as is observed in enzymatic reactions. However, low temperature excitation at wavelengths longer than 400 nm generates a unique Ru-bound 2-benzoatophenylglyoxylate product resulting from a 1,2-dioxetane intermediate. Herein, we investigate this reactivity in a series of Ru(II)bis-bipyridyl flavonolate complexes [RuII(bpy)2(3-hydroxyflaR)][PF6] (bpy = 2,2'-bipyridine; fla = flavonolate; R = p-OMe (1), p-Me (2), p-H (3), p-Cl (4)), and [RuII(bpy)2(5-hydroxyfla)][PF6] (5). The complexes' structures, photophysical and electrochemical properties, and photochemical reactivity with oxygen were investigated in detail. Two different reaction product mixtures, from 1,2- and 1,3-additions of dioxygen, are observed by illumination into distinct excitation/emission manifolds. By analogy to previous reports of excited state intramolecular proton transfer, the two manifolds are attributed to tautomeric diradicals that predict the observed reactivity patterns.
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Affiliation(s)
- Xiaozhen Han
- Department of Chemistry and Biochemistry , Baylor University , Waco , Texas 76798 , United States.,Department of Chemistry and Biochemistry , Stephen F. Austin State University , Nacogdoches , Texas 75962 , United States
| | - Murugaeson R Kumar
- Department of Chemistry and Biochemistry , Baylor University , Waco , Texas 76798 , United States
| | - Amanda Hoogerbrugge
- Department of Chemistry and Biochemistry , Baylor University , Waco , Texas 76798 , United States
| | - Kevin K Klausmeyer
- Department of Chemistry and Biochemistry , Baylor University , Waco , Texas 76798 , United States
| | - Mukunda M Ghimire
- Department of Chemistry , University of North Texas , Denton , Texas 76203 , United States.,Department of Chemistry , Lebanon Valley College , Annville , Pennsylvania 17003 , United States
| | - Lauren M Harris
- Department of Chemistry , University of North Texas , Denton , Texas 76203 , United States
| | - Mohammad A Omary
- Department of Chemistry , University of North Texas , Denton , Texas 76203 , United States
| | - Patrick J Farmer
- Department of Chemistry and Biochemistry , Baylor University , Waco , Texas 76798 , United States
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22
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Anderson SN, Larson MT, Berreau LM. Solution or solid - it doesn't matter: visible light-induced CO release reactivity of zinc flavonolato complexes. Dalton Trans 2018; 45:14570-14580. [PMID: 27711794 DOI: 10.1039/c6dt01709f] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two types of zinc flavonolato complexes ([(6-Ph2TPA)Zn(flavonolato)]ClO4 and Zn(flavonolato)2) of four extended flavonols have been prepared, characterized, and evaluated for visible light-induced CO release reactivity. Zinc coordination of each flavonolato anion results in a red-shift of the lowest energy absorption feature and in some cases enhanced molar absorptivity relative to the free flavonol. The zinc-coordinated flavonolato ligands undergo visible light-induced CO release with enhanced reaction quantum yields relative to the neutral flavonols. Most notable is the discovery that both types of zinc flavonolato derivatives undergo similar visible light-induced CO release reactivity in solution and in the solid state. A solid film of a Zn(flavonolato)2 derivative was evaluated as an in situ CO release agent for aerobic oxidative palladium-catalyzed alkoxycarbonylation to produce esters in ethanol. The CO release product was found to undergo ester alcolysis under the conditions of the carbonylation reaction.
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Affiliation(s)
- Stacey N Anderson
- Department of Chemistry & Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322-0300, USA.
| | - Michael T Larson
- Department of Chemistry & Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322-0300, USA.
| | - Lisa M Berreau
- Department of Chemistry & Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322-0300, USA.
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23
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Su Y, Yang W, Yang X, Zhang R, Zhao J. Visible Light-Induced CO-Release Reactivity of a Series of ZnII–Flavonolate Complexes. Aust J Chem 2018. [DOI: 10.1071/ch18192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A series of zinc–flavonolate complexes of the general formula [(L)Zn(R)]ClO4 (L = TPA (tris-2-(pyridylmethyl)amine)), 6-MeTPA (N,N-(6-methyl-2-pyridyl)methyl)bis(2-pyridylmethyl)amine)), 6-Me2TPA (N,N-bis(6-methyl-2-pyridyl)methyl)(2-pyridylmethyl) amine), BPQA (bis(2-pyridylmethyl)(2-quinolinemethyl)amine), and BQPA (bis(2-quinolinemethyl)(2-pyridylmethyl)amine), R = FLH (flavonol), 4-MeOFLH (4-methoxyflavonol), and 4-MeOFLTH (4-methoxyflavothione)) have been prepared and characterised by X-ray crystallography, elemental analysis, FT-IR, ESI-MS, 1H NMR, 13C NMR, UV-vis and fluorescence spectroscopy. All the complexes can be induced to release CO by visible light (λmax ranges from 414 to 503 nm). The maximum absorption wavelength of the complexes followed the order 4-MeOFLTH > 4-MeOFLH > FLH. Exposure of the complexes to visible light under aerobic conditions results in oxidative C–C bond cleavage and almost quantitative CO release. Cytotoxicity tests showed that the complexes had a low toxicity to HeLa cells in the concentration range of 1 to 50 μM. These advantages indicate that the series of complexes are likely to be applied to biological systems.
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24
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Zahirović A, Kahrović E, Cindrić M, Kraljević Pavelić S, Hukić M, Harej A, Turkušić E. Heteroleptic ruthenium bioflavonoid complexes: from synthesis to in vitro biological activity. J COORD CHEM 2017. [DOI: 10.1080/00958972.2017.1409893] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Adnan Zahirović
- Faculty of Science, Department of Chemistry, University of Sarajevo, Sarajevo, Bosnia and Herzegovina
| | - Emira Kahrović
- Faculty of Science, Department of Chemistry, University of Sarajevo, Sarajevo, Bosnia and Herzegovina
| | - Marina Cindrić
- Faculty of Science, Department of Chemistry, University of Zagreb, Zagreb, Croatia
| | - Sandra Kraljević Pavelić
- Department of Biotechnology, Centre for High-Throughput Technologies, University of Rijeka, Rijeka, Croatia
| | - Mirsada Hukić
- Institute for Biomedical Research and Diagnostics NALAZ, Sarajevo, Bosnia and Herzegovina
| | - Anja Harej
- Department of Biotechnology, Centre for High-Throughput Technologies, University of Rijeka, Rijeka, Croatia
| | - Emir Turkušić
- Faculty of Science, Department of Chemistry, University of Sarajevo, Sarajevo, Bosnia and Herzegovina
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25
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Huang QQ, Sun YJ, Wu HW, Wang YL. RETRACTED: A structural and functional model of copper(II)-flavonolate ES complex of flavonol 2,4-dioxygenase. Inorganica Chim Acta 2017. [DOI: 10.1016/j.ica.2017.07.037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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26
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Sun YJ, Huang QQ, Zhang JJ. Set of Fe(II)-3-Hydroxyflavonolate Enzyme-Substrate Model Complexes of Atypically Coordinated Mononuclear Non-Heme Fe(II)-Dependent Quercetin 2,4-Dioxygenase. ACS OMEGA 2017; 2:5850-5860. [PMID: 31457842 PMCID: PMC6644611 DOI: 10.1021/acsomega.7b00927] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 08/31/2017] [Indexed: 06/10/2023]
Abstract
With the aim of revealing the catalytic role of atypically coordinated (3His-1Glu) active site mononuclear non-heme Fe(II)-dependent quercetin 2,4-dioxygenase (Fe-2,4-QD) and the electronic effects of the model ligands on the reactivity toward dioxygen, a set of p/m-R-substituted carboxylate-containing ligand-supported Fe(II)-3-hydroxyflavonolate complexes, [FeIILR(fla)] (LRH: 2-{[bis(pyridin-2-ylmethyl)amino]methyl}-p/m-R-benzoic acid; R: p-OMe (1), p-Me (2), m-Br (4), and m-NO2 (5); fla: 3-hydroxyflavonolate), were synthesized and characterized as structural and functional models for the ES (enzyme-substrate) complexes of Fe-2,4-QD. [FeIILR(fla)] show relatively high enzyme-type reactivity (dioxygenative ring opening of the coordinated substrate fla, single-turnover reaction) at low temperatures (30-65 °C). The reaction shows a linear Hammett plot (ρ = -1.21), and electron donating groups enhance the reaction rates. The notable difference on the reactivity can be rationalized from the electronic nature of the substituent in the ligands, which could tune the reactivity via tuning Lewis acidity of the Fe(II) ion, electron density, and the redox potential of fla. The properties and the reactivity show approximately linear correlations between λmax or E 1/2 of fla and the reaction rate constant k. This work sheds light not only on understanding of electronic effects of the ligands and the property-reactivity relationship but also on the role of the catalytic reaction by Fe-2,4-QD.
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Sorenson S, Popova M, Arif AM, Berreau LM. A bipyridine-ligated zinc(II) complex with bridging flavonolate ligation: synthesis, characterization, and visible-light-induced CO release reactivity. ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY 2017; 73:703-709. [PMID: 28872068 DOI: 10.1107/s2053229617011366] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 08/02/2017] [Indexed: 12/14/2022]
Abstract
Metal-flavonolate compounds are of significant current interest as synthetic models for quercetinase enzymes and as bioactive compounds of importance to human health. Zinc-3-hydroxyflavonolate compounds, including those of quercetin, kampferol, and morin, generally exhibit bidentate coordination to a single ZnII center. The bipyridine-ligated zinc-flavonolate compound reported herein, namely bis(μ-4-oxo-2-phenyl-4H-chromen-3-olato)-κ3O3:O3,O4;κ3O3,O4:O3-bis[(2,2'-bipyridine-κ2N,N')zinc(II)] bis(perchlorate), {[Zn2(C15H9O3)2(C10H8N2)2](ClO4)2}n, (1), provides an unusual example of bridging 3-hydroxyflavonolate ligation in a dinuclear metal complex. The symmetry-related ZnII centers of (1) exhibit a distorted octahedral geometry, with weak coordination of a perchlorate anion trans to the bridging deprotonated O atom of the flavonolate ligand. Variable-concentration conductivity measurements provide evidence that, when (1) is dissolved in CH3CN, the complex dissociates into monomers. 1H NMR resonances for (1) dissolved in d6-DMSO were assigned via HMQC to the H atoms of the flavonolate and bipyridine ligands. In CH3CN, (1) undergoes quantitative visible-light-induced CO release with a quantum yield [0.004 (1)] similar to that exhibited by other mononuclear zinc-3-hydroxyflavonolate complexes. Mass spectroscopic identification of the [(bpy)2Zn(O-benzoylsalicylate)]+ ion provides evidence of CO release from the flavonol and of ligand exchange at the ZnII center.
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Affiliation(s)
- Shayne Sorenson
- Department of Chemistry & Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322-0300, USA
| | - Marina Popova
- Department of Chemistry & Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322-0300, USA
| | - Atta M Arif
- Department of Chemistry, University of Utah, 315 S. 1400 E., Rm 1170, Salt Lake City, UT 84112-0850, USA
| | - Lisa M Berreau
- Department of Chemistry & Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322-0300, USA
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Oxygen activation by mononuclear Mn, Co, and Ni centers in biology and synthetic complexes. J Biol Inorg Chem 2016; 22:407-424. [PMID: 27853875 DOI: 10.1007/s00775-016-1402-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 10/21/2016] [Indexed: 10/20/2022]
Abstract
The active sites of metalloenzymes that catalyze O2-dependent reactions generally contain iron or copper ions. However, several enzymes are capable of activating O2 at manganese or nickel centers instead, and a handful of dioxygenases exhibit activity when substituted with cobalt. This minireview summarizes the catalytic properties of oxygenases and oxidases with mononuclear Mn, Co, or Ni active sites, including oxalate-degrading oxidases, catechol dioxygenases, and quercetin dioxygenase. In addition, recent developments in the O2 reactivity of synthetic Mn, Co, or Ni complexes are described, with an emphasis on the nature of reactive intermediates featuring superoxo-, peroxo-, or oxo-ligands. Collectively, the biochemical and synthetic studies discussed herein reveal the possibilities and limitations of O2 activation at these three "overlooked" metals.
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Characterization of the Initial Intermediate Formed during Photoinduced Oxygenation of the Ruthenium(II) Bis(bipyridyl)flavonolate Complex. Inorg Chem 2016; 55:7320-2. [PMID: 27437831 DOI: 10.1021/acs.inorgchem.6b00852] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A ruthenium(II) flavonolate complex, [Ru(II)(bpy)2fla][BF4], was synthesized to model the reactivity of the flavonol dioxygenases. The treatment of dry CH3CN solutions of [Ru(II)(bpy)2fla][BF4] with dioxygen under light leads to the oxidative O-heterocyclic ring opening of the coordinated substrate flavonolate, resulting in the formation of [Ru(II)(bpy)2(carboxylate)][BF4] (carboxylate = O-benzoylsalicylate or benzoate) species, as determined by electrospray ionization mass spectrometry. Moderation of the excitation and temperature allowed isolation and characterization of an intermediate, [Ru(II)(bpy)2bpg][BF4] (bpg = 2-benzoyloxyphenylglyoxylate), generated by the 1,2-addition of dioxygen to the central flavonolate ring.
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30
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Sun YJ, Huang QQ, Li P, Zhang JJ. Catalytic dioxygenation of flavonol by M(II)-complexes (M = Mn, Fe, Co, Ni, Cu and Zn) - mimicking the M(II)-substituted quercetin 2,3-dioxygenase. Dalton Trans 2016; 44:13926-38. [PMID: 26153684 DOI: 10.1039/c5dt01760b] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In order to get insights into the metal ion effects and the carboxylate effects on enzymatic activity, a series of the carboxylate ligand supported transition metal complexes [M(II)L(OAc)] (M = Mn (), Fe (), Co (), Ni (), Cu () and Zn (); LH = 2-{[bis-(pyridin-2-ylmethyl)amino]methyl}-4-methoxy benzoic acid) were synthesized and characterized as structural and functional models for the active sites of various M(II)-substituted resting quercetin 2,3-dioxygenases (2,3-QD). Their structures, spectroscopic features, redox properties, as well as the catalytic reactivity toward the substrate flavonol and O2 have been investigated in detail. The model complexes show higher enzymatic reactivities in the catalytic dioxygenation (oxidative ring opening) of the substrate flavonol at lower temperatures (55-100 °C), presumably caused by the carboxylate group in the supporting model ligand, which could lower the redox potential of the bound substrate flavonolate by electron donation. The catalytic reactivity of [M(II)L(OAc)] exhibits notable differences and it is in a metal ion dependent order of Co () > Ni () > Zn () > Fe () > Mn () > Cu (). The differences in the reactivities among them could be ascribed to the redox potential of the bound substrate flavonolate, which was drastically influenced by the metal ions via tuning the electron density of flavonolate, providing important insights into the metal ion effects and the carboxylate effects on the enzymatic activity of various M(II)-substituted 2,3-QD. Our model complexes [M(II)L(OAc)] are the first examples of a series of structural and functional models of various M(II)-substituted resting 2,3-QD.
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Affiliation(s)
- Ying-Ji Sun
- Department of Chemistry, Dalian University of Technology, Linggong Road 2, 116024, Dalian, China.
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32
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Kasprzak MM, Erxleben A, Ochocki J. Properties and applications of flavonoid metal complexes. RSC Adv 2015. [DOI: 10.1039/c5ra05069c] [Citation(s) in RCA: 225] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Flavonoid metal complexes have a wide spectrum of activities as well as potential and actual applications.
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Affiliation(s)
- Maria M. Kasprzak
- Department of Bioinorganic Chemistry
- Medical University of Lodz
- Lodz
- Poland
| | - Andrea Erxleben
- School of Chemistry
- National University of Ireland
- Galway
- Ireland
| | - Justyn Ochocki
- Department of Bioinorganic Chemistry
- Medical University of Lodz
- Lodz
- Poland
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Anderson SN, Noble M, Grubel K, Marshall B, Arif AM, Berreau LM. Influence of supporting ligand microenvironment on the aqueous stability and visible light-induced CO-release reactivity of zinc flavonolato species. J COORD CHEM 2014. [DOI: 10.1080/00958972.2014.977272] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Stacey N. Anderson
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, USA
| | - Mark Noble
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, USA
| | - Katarzyna Grubel
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, USA
| | - Brooks Marshall
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, USA
| | - Atta M. Arif
- Department of Chemistry, University of Utah, Salt Lake City, UT, USA
| | - Lisa M. Berreau
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, USA
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Allpress CJ, Berreau LM. A Nickel‐Containing Model System of Acireductone Dioxygenases that Utilizes a C(1)‐H Acireductone Substrate. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201402254] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Caleb J. Allpress
- Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322‐0300, USA, http://lisaberreau.org/
| | - Lisa M. Berreau
- Department of Chemistry and Biochemistry, Utah State University, 0300 Old Main Hill, Logan, UT 84322‐0300, USA, http://lisaberreau.org/
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Sun YJ, Huang QQ, Zhang JJ. Series of Structural and Functional Models for the ES (Enzyme–Substrate) Complex of the Co(II)-Containing Quercetin 2,3-Dioxygenase. Inorg Chem 2014; 53:2932-42. [DOI: 10.1021/ic402695c] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Ying-Ji Sun
- School of Chemistry, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Qian-Qian Huang
- School of Chemistry, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Jian-Jun Zhang
- School of Chemistry, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
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New Zn(II) complexes with N2S2 Schiff base ligands. Experimental and theoretical studies of the role of Zn(II) in disulfide thiolate-exchange. Polyhedron 2014. [DOI: 10.1016/j.poly.2013.12.040] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Sun YJ, Huang QQ, Zhang JJ. A series of NiII-flavonolate complexes as structural and functional ES (enzyme-substrate) models of the NiII-containing quercetin 2,3-dioxygenase. Dalton Trans 2014; 43:6480-9. [DOI: 10.1039/c3dt53349b] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Grubel K, Saraf SL, Anderson SN, Laughlin BJ, Smith RC, Arif AM, Berreau LM. Synthesis, characterization, and photoinduced CO-release reactivity of a Pb(II) flavonolate complex: Comparisons to Group 12 analogs. Inorganica Chim Acta 2013. [DOI: 10.1016/j.ica.2013.07.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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40
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Matuz A, Giorgi M, Speier G, Kaizer J. Structural and functional comparison of manganese-, iron-, cobalt-, nickel-, and copper-containing biomimic quercetinase models. Polyhedron 2013. [DOI: 10.1016/j.poly.2013.07.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Sun YJ, Huang QQ, Tano T, Itoh S. Flavonolate Complexes of MII (M = Mn, Fe, Co, Ni, Cu, and Zn). Structural and Functional Models for the ES (Enzyme–Substrate) Complex of Quercetin 2,3-Dioxygenase. Inorg Chem 2013; 52:10936-48. [DOI: 10.1021/ic400972k] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Ying-Ji Sun
- School
of Chemistry, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Qian-Qian Huang
- School
of Chemistry, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Tetsuro Tano
- Department
of Material and Life Science, Division of Advanced Science and Biotechnology,
Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Shinobu Itoh
- Department
of Material and Life Science, Division of Advanced Science and Biotechnology,
Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan
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Tay WM, da Silva GFZ, Ming LJ. Metal Binding of Flavonoids and Their Distinct Inhibition Mechanisms Toward the Oxidation Activity of Cu2+–β-Amyloid: Not Just Serving as Suicide Antioxidants! Inorg Chem 2013; 52:679-90. [DOI: 10.1021/ic301832p] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- William Maung Tay
- Department of Chemistry, University of South Florida, Tampa,
Florida 33620-5250, United States
| | - Giordano F. Z. da Silva
- Department of Chemistry, University of South Florida, Tampa,
Florida 33620-5250, United States
| | - Li-June Ming
- Department of Chemistry, University of South Florida, Tampa,
Florida 33620-5250, United States
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Tomco D, Xavier FR, Allard MM, Verani CN. Probing chemical reduction in a cobalt(III) complex as a viable route for the inhibition of the 20S proteasome. Inorganica Chim Acta 2012. [DOI: 10.1016/j.ica.2012.06.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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44
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Grubel K, Marts AR, Greer SM, Tierney DL, Allpress CJ, Anderson SN, Laughlin BJ, Smith RC, Arif AM, Berreau LM. Photoinitiated Dioxygenase-Type Reactivity of Open-Shell 3d Divalent Metal Flavonolato Complexes. Eur J Inorg Chem 2012. [DOI: 10.1002/ejic.201200212] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Matsumoto J, Suzuki T, Kajita Y, Masuda H. Synthesis and characterization of cobalt(II) complexes with tripodal polypyridine ligand bearing pivalamide groups. Selective formation of six- and seven-coordinate cobalt(II) complexes. Dalton Trans 2012; 41:4107-17. [PMID: 22301678 DOI: 10.1039/c2dt12056a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The reactions of CoX(2) (X = Cl(-), Br(-), I(-) and ClO(4)(-)) with the tripodal polypyridine N(4)O(2)-type ligand bearing pivalamide groups, bis(6-(pivalamide-2-pyridyl)methyl)(2-pyridylmethyl)amine ligand (H(2)BPPA), afforded two types of Co(II) complexes as follows. One type is purple-coloured Co(II) complexes, [CoCl(2)(H(2)BPPA)] (1(Cl)) and [CoBr(2)(H(2)BPPA)] (1(Br)) which were prepared when X = Cl(-) and Br(-), respectively. The other type is pale pink-coloured Co(II) complexes, [Co(MeOH)(H(2)BPPA)](ClO(4)(-))(2) (2·(ClO(4)(-))(2)) and [Co(MeCN)(H(2)BPPA)](I(-))(2) (2·(I(-))(2)), which were obtained when X = I(-) and ClO(4)(-), respectively. From the reaction of 1(Cl) and NaN(3), a purple-coloured complex, [Co(N(3))(2)(H(2)BPPA)] (1(azide)), was obtained. These Co(II) complexes were characterized by X-ray structural analysis, IR and reflectance spectroscopies, and magnetic susceptibility measurements. All these Co(II) complexes were shown to be in a d(7) high-spin state based on magnetic susceptibility measurements. The former Co(II) complexes revealed a six-coordinate octahedron with one amine nitrogen, three pyridyl nitrogens, and two counter anions, and one coordinated anion, Cl(-), Br(-) and N(3)(-), forming intramolecular hydrogen bonds with two pivalamide N-H groups. On the other hand, the latter Co(II) complexes showed a seven-coordinate face-capped octahedron with one amine nitrogen, three pyridyl nitrogens, two pivalamide carbonyl oxygens and MeCN or MeOH. In these structures, intramolecular hydrogen bonding interaction was not observed, and the metal ion was coordinated by the pivalamide carbonyl oxygens and solvent molecule instead of the counter anions. The difference in coordination geometries might be attributable to the coordination ability and ionic radii of the counteranions; smaller strongly binding anions such as Cl(-), Br(-) and N(3)(-) gave the former complexes, whereas bulky weakly binding anions such as I(-) and ClO(4)(-) afforded the latter ones. In order to demonstrate this hypothesis, the small stronger coordinating ligand, azide, was added to complexes 2·(ClO(4)(-))(2) to obtain the dinuclear cobalt(II) complex in which two six-coordinate octahedral cobalt(II) species were bridged with azide, 3·(ClO(4)(-)). Also, the abstraction reaction of halogen anions from complexes 1(Cl) by AgSbF(6) gave a pale pink Co(II) complex assignable to 2·(SbF(6)(-))(2).
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Affiliation(s)
- Jun Matsumoto
- Department of Frontier Materials, Graduate School of Engineering, Nagoya Institute of Technology, Showa-ku, Nagoya, 466-8555, Japan
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Grubel K, Laughlin BJ, Maltais TR, Smith RC, Arif AM, Berreau LM. Photochemically-induced dioxygenase-type CO-release reactivity of group 12 metal flavonolate complexes. Chem Commun (Camb) 2011; 47:10431-3. [DOI: 10.1039/c1cc13961d] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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