Journal of Inorganic Biochemistry最新文献

{"title":"Light-emitting anticancer Pt-cyclometalated phenanthroimidazole complexes","authors":"Somayee Heydari ,&nbsp;Hashem Shahroosvand ,&nbsp;Abbas Bahari ,&nbsp;Sebastiano Bellani","doi":"10.1016/j.jinorgbio.2025.113121","DOIUrl":"10.1016/j.jinorgbio.2025.113121","url":null,"abstract":"<div><div>Designing drugs that selectively target cancer cells while sparing healthy ones remains a major challenge in cancer chemotherapy. In this study, four new Pt-cyclometalated complexes containing a pipyridine core and varied phenanthroimidazole-based ligands were synthesized and comprehensively characterized to evaluate their potential as selective anticancer agents with reduced toxicity toward peripheral blood mononuclear cells. Through molecular engineering <em>via</em> substitution on the imidazole moieties, these complexes exhibit tunable emission properties, with colors ranging from blue (475 nm) to green (610 nm) and high photoluminescence quantum yields exceeding 60 %, underscoring their promise as luminescent anticancer systems. Biological evaluations, including flow cytometry, cell cycle analysis, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays, revealed that complexes with simpler, unsubstituted imidazole frameworks displayed the strongest anticancer activity, correlating with their higher quantum yields and stronger binding affinities toward both double-stranded DNA (dsDNA) and G-quadruplex DNA (G4DNA). Overall, these findings demonstrate that phenanthroimidazole-containing Pt-cyclometalated complexes represent a promising class of light-emitting anticancer agents with potential for selective and efficient cancer therapy.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"275 ","pages":"Article 113121"},"PeriodicalIF":3.2,"publicationDate":"2025-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145501367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review on coordination and biological properties of selenosemicarbazone.","authors":"Vins Daniel, Vipin Singh, Prabal Gupta, Anandaram Sreekanth","doi":"10.1016/j.jinorgbio.2025.113020","DOIUrl":"10.1016/j.jinorgbio.2025.113020","url":null,"abstract":"<p><p>The review highlights the synthesis, coordination behavior, and extensive biological activities of selenosemicarbazones and their metal complexes. Over 110 selenosemicarbazone ligands coordinated with metals such as Cu, Ni, Zn, Pt, and Pd are discussed, showcasing significant structural diversity. These compounds uniquely combine the pharmacophoric semicarbazone moiety with selenium, a redox-active trace element, resulting in enhanced stability, reactivity, and biological performance. Coordinated metal complexes demonstrate potent antibacterial, anticancer, antioxidant, and antiparasitic activities. Mechanistic insights include reactive oxygen species (ROS) generation, metalloenzyme inhibition, and DNA binding. Recent developments in structure-activity relationships and therapeutic targeting are emphasized.</p>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"272 ","pages":"113020"},"PeriodicalIF":3.2,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144803148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient photodynamic and photocatalytic anticancer activity of a Ru(II) polypyridyl complex","authors":"Yanjiang Zhou ,&nbsp;Qiang Tang ,&nbsp;Lingxiu Chen ,&nbsp;Dan He ,&nbsp;Yue Wu ,&nbsp;Yumei Li ,&nbsp;Songxiangyi Xie ,&nbsp;Yongjie Chen","doi":"10.1016/j.jinorgbio.2025.113134","DOIUrl":"10.1016/j.jinorgbio.2025.113134","url":null,"abstract":"<div><div>Ruthenium(II) complexes are considered promising candidates for photodynamic therapy (PDT) owing to their ease of synthesis, low dark toxicity, and favorable photophysical and photochemical properties. However, the therapeutic efficacy of most currently available Ru(II)-based photosensitizers (PSs) is significantly limited by the hypoxic tumor microenvironment and the inherent susceptibility of monotherapy to resistance mechanisms. The development of Ru(II)-based PSs with photocatalytic anticancer activity is expected to solve the above problems. Here, we reported two Ru(II)-based PSs [Ru(dip)₂(dppn)](PF₆)₂ (<strong>Ru1</strong>) and [Ru(dip)₂(dpb)](PF₆)₂ (<strong>Ru2</strong>), where, dip = 4,7-diphenyl-1,10-phenanthroline, dppn = benzo[<em>i</em>]dipyrido[3,2-a:2′,3′-c]phenazine, dpb = 2,3-diphenylbenzo[<em>ghi</em>]perylene, showing photocatalytic anticancer activity. The results demonstrate that the metal-to-ligand charge transfer (MLCT) absorption bands of <strong>Ru1</strong> and <strong>Ru2</strong>, both featuring extended π-conjugated ligands, are red-shifted relative to that of [Ru(bpy)₃]²⁺. Although <strong>Ru1</strong> exhibits comparatively lower cellular uptake, its greater accumulation in nucleus, higher singlet oxygen quantum yield, and superior photocatalytic oxidation efficiency contribute to its higher phototoxicity against human lung cancer cells (A549) than <strong>Ru2</strong>. This enhanced phototoxic effect is mediated through DNA damage and the activation of mitochondrial apoptosis pathways. Notably, <strong>Ru1</strong> retains significant phototoxicity under hypoxic conditions, attributed to its great NADH photo-oxidation capability. The efficient photodynamic and photocatalytic antitumor activity of <strong>Ru1</strong>, along with its distinctive “low uptake, high activity” profile, offers valuable insights for the rational design of effective and low-toxicity Ru(II)-based photosensitizers.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"275 ","pages":"Article 113134"},"PeriodicalIF":3.2,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145487162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigations of gold(I) complexes as inhibitors of caspase-1","authors":"Srirajkumar Ranganathan ,&nbsp;Isabella D. Reda ,&nbsp;Helen A. Gustafson ,&nbsp;Callista G. Polasek ,&nbsp;Ehxciquiel Jaeroume M. Camacho ,&nbsp;Roger D. Sommer ,&nbsp;Kyle A. Grice ,&nbsp;Caitlin E. Karver","doi":"10.1016/j.jinorgbio.2025.113133","DOIUrl":"10.1016/j.jinorgbio.2025.113133","url":null,"abstract":"<div><div>Caspase-1 is a key enzyme in the inflammasome that turns on the inflammation cascade. It has been implicated in a variety of disease conditions, including gout, rheumatoid arthritis and inflammatory diseases. Gold complexes have long been studied for their anti-inflammatory properties. The active site of caspase-1 contains a cysteine thiolate, and given that sulfur is aurophilic, we hypothesized that gold complexes would inhibit caspase-1. In this work, we examined a series of gold(I) molecular species for inhibition of caspase-1. It was found that many of the complexes were effective inhibitors at the nanomolar range, with the most effective being PMe₃AuCl (K_I = 8 nM) and PPh₃AuCl (K_I = 9 nM). This highlights the value of gold(I) complexes as drug molecules that target cysteine-dependent proteins for disease states.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"275 ","pages":"Article 113133"},"PeriodicalIF":3.2,"publicationDate":"2025-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145414165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel cationic gold(I) compounds with 5-nitrofuryl containing thiosemicarbazone ligands exhibit activity against Trypanosoma cruzi","authors":"Carla Albornoz ,&nbsp;José Ortega-Campos ,&nbsp;Germán Barriga-González ,&nbsp;Juan Diego Maya ,&nbsp;Dinorah Gambino ,&nbsp;Lucía Otero ,&nbsp;Pablo Fuentealba ,&nbsp;Claudio Olea Azar ,&nbsp;Esteban Rodríguez-Arce","doi":"10.1016/j.jinorgbio.2025.113131","DOIUrl":"10.1016/j.jinorgbio.2025.113131","url":null,"abstract":"<div><div>Searching for more effective chemotherapeutic agents for the treatment of American Trypanosomiasis, a disease caused by the parasite <em>Trypanosoma cruzi</em> (<em>T. cruzi</em>), the development of gold(I) compounds represents a promising strategy. In this work, four new cationic gold(I) compounds, [Au(HL)₂]Cl, where HL = 5-nitrofuryl-containing thiosemicarbazones, were synthesized and characterized in the solid state and in DMSO solution. Their cationic and radical structures were experimentally and theoretically studied. The formation of intermolecular aurophilic interactions and the lipophilicity of the complexes were also analyzed. Three gold(I) compounds displayed micromolar IC₅₀ values (around 10 μM) against <em>T. cruzi</em> bloodstream trypomastigotes and showed moderate selectivity towards the parasites with respect to human cells of endothelial morphology. Two of these complexes were more active than their respective thiosemicarbazone ligands and exhibited antiparasitic activity comparable to that of Nifurtimox. Lipophilicity and the presence of aurophilic interactions appear to play a key role in their antitrypanosomal activity. The active gold(I) compounds induced cytosolic reactive oxygen species (ROS) generation, disrupted mitochondrial membrane potential, and promoted mitochondrial ROS production, suggesting they may act as crucial precursors to mitochondria-mediated apoptotic cell death. In addition, DNA competitive binding with ethidium bromide, evaluated by fluorescence measurements, demonstrated that the compounds interact with this biomolecule. Overall, these three active gold(I) complexes can be considered promising hits for the development of prospective agents against <em>T. cruzi</em>.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"275 ","pages":"Article 113131"},"PeriodicalIF":3.2,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145413851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infection-adaptive regenerative wound healing through rationally engineered copper-polyphenol artificial enzymes enabling quadruple-modal ROS cascade modulation in pathological microenvironments","authors":"Ziyi Jia ,&nbsp;Lina Sun ,&nbsp;Liman Liu ,&nbsp;Weiwei Shi ,&nbsp;Yujie Yang ,&nbsp;Yan Jiang ,&nbsp;Tianle Cheng ,&nbsp;Jinhong Zhang ,&nbsp;Yuehua Zhao ,&nbsp;Gentao Li ,&nbsp;Baolong Zhou","doi":"10.1016/j.jinorgbio.2025.113132","DOIUrl":"10.1016/j.jinorgbio.2025.113132","url":null,"abstract":"<div><div>While artificial enzyme-based catalytic therapies offer promise for bacterial infection treatment through cost-effectiveness and substrate specificity, conventional systems remain hampered by monofunctionality and inadequate catalytic efficiency. Here, we developed PRSA-Cu, a copper-phenolic coordination polymer artificial enzyme with multi‑copper centers and mixed-valence states (Cu²⁺ and Cu⁺) enabling synergistic antibacterial mechanisms. Initially, this multimodal system amplifies oxidative stress by imitating enzyme processes to generate hydroxyl radicals (•OH) through Cu²⁺/Cu⁺-mediated peroxidase-like (POD-like) reactions. Subsequently, it depletes glutathione (GSH) to neutralize bacterial antioxidant defenses via glutathione peroxidase-like (GPx-like) catalysis. Thirdly, the system enhances catalytic efficiency through photothermal effects that optimize enzymatic kinetics. Finally, it enables oxygen-independent Type I photodynamic activity, producing water-derived •OH even in hypoxic conditions. This self-amplifying cycle emerges from synergistic heat-radical-redox interplay, wherein localized hyperthermia elevates membrane permeability to enable Cu²⁺/Cu⁺ liberation and H₂O₂ activation via ligand-metal charge transfer (LMCT), while concurrent glutathione (GSH) exhaustion suppresses ROS scavenging. In vitro studies confirmed periplasmic membrane disintegration in both <em>S. aureus</em> and <em>E. coli</em> through cytoplasmic component leakage. In vivo evaluations demonstrated near-complete wound closure within 9 days through concurrent biofilm eradication and angiogenesis stimulation. This platform establishes a paradigm shift from single-pathway antimicrobials to spatiotemporally coordinated artificial enzymes, unifying photothermal-photodynamic-multienzyme catalysis for clinical translation.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"275 ","pages":"Article 113132"},"PeriodicalIF":3.2,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145414164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Targeting monocarboxylate transporter 1 with a copper-chelating coumarin-based bioconjugate: Synthesis and characterization","authors":"Matteo Mari ,&nbsp;Silvia Belluti ,&nbsp;Luca Pampanella ,&nbsp;Carol Imbriano ,&nbsp;Alfonso Zambon ,&nbsp;Jennifer Storchi ,&nbsp;Laura Pigani ,&nbsp;Marianna Tosato ,&nbsp;Sara Rubagotti ,&nbsp;Pier Cesare Capponi ,&nbsp;Mattia Asti ,&nbsp;Véronique Patinec ,&nbsp;Raphaël Tripier ,&nbsp;Erika Ferrari","doi":"10.1016/j.jinorgbio.2025.113130","DOIUrl":"10.1016/j.jinorgbio.2025.113130","url":null,"abstract":"<div><div>Monocarboxylate Transporters (MCTs), particularly MCT1, are increasingly recognized as key regulators of cancer metabolism, facilitating lactate exchange and contributing to tumor aggressiveness. Their overexpression in various malignancies makes them attractive targets for both therapeutic and diagnostic strategies. In this study, we report the design, synthesis, and comprehensive characterization of a novel chimeric bioconjugate, L^CPn, integrating a coumarin-based MCT1-targeting moiety with a TACN(1,4,7-triazacyclononane)-containing chelator, optimized for copper radioisotope binding. The synthetic route was refined through strategic modifications, including mono-Boc (<em>tert</em>-butyloxycarbonyl) protecting group protection of the macrocycle and efficient SN₂-type coupling via thionyl chloride activation. Structural confirmation was achieved through nuclear magnetic resonance and mass spectrometry. Five protonation constants were determined for L^CPn, reflecting contributions from both the chelator and targeting domains. Complexation studies with Cu²⁺ and Zn²⁺ confirmed the formation of stable 1:1 metal-to-ligand complexes, while cyclic voltammetry studies indicated a quasi-reversible redox behaviour upon Cu²⁺ to Cu⁺ reduction. Docking simulations and cell-based assays demonstrated that the coumarin-based targeting moiety exhibits high affinity for MCT1 and effectively inhibits lactate uptake in prostate cancer models. These findings underscore the dual functionality of L^CPn as a selective MCT1-targeting agent and a robust copper-chelating platform, paving the way for future theranostics applications in oncology exploiting inorganic bioconjugates.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"275 ","pages":"Article 113130"},"PeriodicalIF":3.2,"publicationDate":"2025-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145413852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antineoplastic and antibacterial activity of new copper(II) complexes with H₂salbu and H₄salbu Schiff base-type ligands","authors":"Cynthia Sinai Novoa-Ramírez ,&nbsp;Rosa Isela López-Palma ,&nbsp;Karen De la Mora-Zarco ,&nbsp;Minerva E. Maya-Yescas ,&nbsp;Luisa Rascón-Valenzuela ,&nbsp;Adrián Espinoza-Guillén ,&nbsp;José Sotero Delgado-Domínguez ,&nbsp;Virginia Gómez-Vidales ,&nbsp;Marcos Flores-Alamo ,&nbsp;Ramón Enrique Robles-Zepeda ,&nbsp;Ingeborg Becker ,&nbsp;Lena Ruiz-Azuara","doi":"10.1016/j.jinorgbio.2025.113113","DOIUrl":"10.1016/j.jinorgbio.2025.113113","url":null,"abstract":"<div><h3>Abstract</h3><div>This study explores the structural, electronic, and biological properties of ten copper(II) complexes with Schiff bases (<em>N</em>,<em>N</em>′-bis(5,5′-R-salicylidene)-1,4-butanediamine)) ([Cu₂(MeO-L1)₂], [Cu₂(Me-L2)₂], [Cu(<em>H</em>−L3)], [Cu(Cl-L4)] and [Cu(NO₂-L5)]), and their hydrogenated ligands (<em>N</em>,<em>N</em>′-Bis(5,5′-R-salicyl)butylenediamine) ([Cu(MeO-LH1)], [Cu(Me-LH2)], [Cu(<em>H</em>−LH3)], [Cu(Cl-LH4)] and [Cu(NO₂-LH5)]). The complexes were characterized by, elemental analysis, IR, Uv-vis, mass spectrometry, EPR, and cyclic voltammetry. The crystal structure of [Cu₂(MeO-L1)₂], [Cu₂(Me-L2)₂], and [Cu(H-L3)] were determined via single crystal X-ray diffraction, revealing orthorhombic and monoclinic systems with space groups P2₁, C222₁, and Pbca, respectively. X-ray diffraction, also, confirmed distorted square-planar geometries for the complexes. EPR spectra, recorded in DMSO solution at 77 K, indicated axial anisotropy and confirmed distorted square-planar geometries for most complexes and suggested a covalent character in metal-ligand bonding. Cyclic voltammetry revealed reversible redox behavior for Schiff base complexes and irreversible processes for hydrogenated ligands, with electron-withdrawing substituents favoring reduction processes. The results demonstrate the significant influence of ligand flexibility and substituent effects on the electronic properties and coordination geometry of the complexes, with electron-withdrawing groups favoring reduction processes. Biological assays demonstrated that [Cu₂(Me-L2)₂] and [Cu(Cl-LH4)] exhibited significant antiproliferative activity against A549 and HeLa cancer cell lines, surpassing cisplatin in efficacy. The leishmanicidal activity of [Cu(Cl-LH4)] and ligands H-L3, H-LH3 and Cl-LH4 showed potent inhibitory effects on <em>Leishmania mexicana</em>, with no cytotoxicity on RAW 264.7 macrophages. These findings underscore the potential of these copper(II) complexes for therapeutic applications, influenced by ligand flexibility and substituent effects.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"275 ","pages":"Article 113113"},"PeriodicalIF":3.2,"publicationDate":"2025-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145443410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oleoyl coenzyme A triggers peroxygenase activity in cytochrome c","authors":"Patrick A. Kates,&nbsp;Sofía E. Gómez,&nbsp;John T. Groves","doi":"10.1016/j.jinorgbio.2025.113115","DOIUrl":"10.1016/j.jinorgbio.2025.113115","url":null,"abstract":"<div><div>The oxidation of cardiolipin by cytochrome <em>c</em> (cyt <em>c</em>) plays a crucial role in cyt <em>c</em> release from mitochondria at the initiation of apoptosis. Herein we report the first evidence of cytochrome <em>c</em> acting as a peroxygenase in the presence of cardiolipin-mimics. The interaction of cyt <em>c</em> and oleoyl-CoA in the presence of primary amines results in conformational change, hydrogen peroxide-mediated substrate oxidation, acyl transfer to form N-acyl fatty acid amides, increased peroxidase activity, and peroxygenase activity such as concerted epoxidation. We investigate the mechanism of earlier reports of acyl transfer activity, the role of cyt <em>c</em>, and how H₂O₂ is utilized. We observe and characterize a catalytic cycle wherein the Met80-Fe bond is first disrupted by the acyl tail of the oleoyl-CoA, the oleoyl-CoA thioester is then oxidized at sulfur by a peroxide-oxidized cyt <em>c</em>, the acyl tail is next transferred via nucleophilic substitution by a primary amine, and finally, an oxygen atom from H₂O₂ is transferred in a concerted fashion from the heme center to form an acyl tail epoxide. We employ several primary amines and acyl-CoAs to determine the scope and necessary tail length for this reaction. Our results suggest that cytochrome <em>c</em> can behave as both a peroxygenase and peroxidase, and that oleoyl-CoA may serve as an important cardiolipin-mimic for future structural studies.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"275 ","pages":"Article 113115"},"PeriodicalIF":3.2,"publicationDate":"2025-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145450506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Iron(III) complexes of tridentate (NNO) ligands: Efficient catalysts for the synthesis of aminophenoxazinones in aqueous medium","authors":"Thasnim P Mohammed ,&nbsp;Kishor Ghimirey Sharma ,&nbsp;Madhuri Priya Sivaramakrishnan ,&nbsp;Sethuraman Muthuramalingam ,&nbsp;Prabha Vadivelu ,&nbsp;Marappan Velusamy ,&nbsp;Muniyandi Sankaralingam","doi":"10.1016/j.jinorgbio.2025.113120","DOIUrl":"10.1016/j.jinorgbio.2025.113120","url":null,"abstract":"<div><div>Ligand systems with precisely tailored electronic and steric properties are crucial for developing complexes that serve as effective biomimetic models. Keeping this in mind, a series of iron(III) complexes [Fe(L)Cl₂] <strong>1</strong>–<strong>3</strong>, featuring ligands <strong>L1</strong>(H) = 2-(1-(pyridin-2-yl)imidazo[1,5-<em>a</em>]pyridin-3-yl)phenol, <strong>L2</strong>(H) = 4-methoxy-2-(1-(pyridin-2-yl)imidazo[1,5-<em>a</em>] pyridin-3-yl)phenol and <strong>L3</strong>(H) = 4-bromo-2-(1-(pyridin-2-yl)imidazo[1,5-<em>a</em>]pyridin-3-yl)phenol were synthesized, characterized, and utilized as biomimetic models for the phenoxazinone synthase. Complexes <strong>1</strong>–<strong>3</strong>, facilitated the oxidation of different aminophenol derivatives in aqueous medium under ambient conditions. Among these, <strong>3</strong> with bromo-substituted ligand achieved the highest product yield (92 %), while the methoxy-substituted complex exhibited a lower product yield (50 %). The parent <em>o</em>-aminophenol showed superior conversion with complex <strong>3</strong>, compared to its derivatives. Remarkably, the complexes demonstrated high catalytic efficiencies with <em>k</em>_cat values ranging from 9.4 × 10⁵ to 5.8 × 10⁴ h⁻¹ in aqueous media. Mechanistic investigations, including both kinetic and mass spectrometric analysis, provided the evidence for the formation of two key adducts, such as [Fe^III(L1−L3)(IPO)]^•+ (<strong>4</strong>) and [Fe^III(L1-L3)(2IPO)]^{<strong>••–</strong>} (<strong>5</strong>), which were further supported by DFT analysis. Furthermore, radical trapping experiments with 5,5-dimethyl-1-pyrroline <em>N</em>-oxide reveal the involvement of radical species in the reaction. Overall, this study highlights the potential of these iron(III) complexes as highly efficient biomimetic catalysts.</div></div>","PeriodicalId":364,"journal":{"name":"Journal of Inorganic Biochemistry","volume":"275 ","pages":"Article 113120"},"PeriodicalIF":3.2,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145407792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}