Oxovanadium Complexes Research Articles

Synthesis, Characterization and In-vitro Antibacterial Activity Studies of Oxovanadium (IV) Complexes of α-Amino Acid Schiff Bases and 1,10-Phenanthroline Ligands

Oxovanadium(IV) complexes of the type [VO(L)(phen)] (VO-1 to VO-5) have been synthesized and characterized by FTIR and UV-Vis spectra, molar conductance, melting points, and magnetic susceptibilities measurements, where L= N-salicylidene-β-alanine (sal-ala), N-salicylidene-glycine (sal-gly), N-salicylidene-DL-β-phenylalanine (sal-pheala), N-salicylidene-leucine (sal-leu), and N-salicylidene-DL-methionine (sal-met), and phen is 1,10-phenanthtroline. The infrared spectral data reveals that the tridentate nature of the amino acid-based Schiff base ligand and the coordination of the ligand through azomethine nitrogen, phenolic oxygen and carboxylate oxygen with vanadyl (VO2+) ion. All of these complexes were determined to be non-electrolyte in nature, according to conductivity measurements. The magnetic moment measurements have been attributed that these complexes are paramagnetic and have d1 configuration of vanadium (IV) ion. The antimicrobial activity of the synthesized complexes was evaluated against four pathogenic bacteria viz. Escherichia coli, Proteus vulgaris, Bacillus subtilis and Staphylococcus aureus.

Studies on a novel oxo-vanadium(V) complex of a tridentate ONO Schiff base ligand: Synthesis, characterization, X-ray crystal structure, Hirshfeld surface analysis, biological and catalytic activity

This study reports the successful synthesis and characterization of a novel oxovanadium(V) complex, [VO(L)(MeOH)(MeO)], prepared from 2-hydroxy-3-methoxybenzaldehyde and 2-methyl-3-aminoquinazoline. To elucidate the structure of the complex, we employed comprehensive characterization techniques such as CHN analysis, molar conductivity measurements, FT-IR, 1H NMR, UV-Vis spectroscopy, and single-crystal X-ray diffraction. The X-ray analysis confirmed an octahedral geometry around the V(V) center, coordinated with donor atoms from the deprotonated Schiff base ligand, an oxido group, a methanol molecule, and a methoxy group. Hirshfeld surface analysis was employed to evaluate intermolecular interactions.Furthermore, the complex exhibited impressively efficient catalytic activity in glucose oxidation under mild conditions (aqueous solution, room temperature, O2 oxidant), achieving a conversion rate of 98 %. Additionally, the antibacterial activity of the ligand and complex against various bacterial strains, including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus cereus, was evaluated. The results demonstrated promising antibacterial potential of the [VO(L)(MeOH)(MeO)] complex, particularly against E. coli, P. aeruginosa, and B. cereus. These findings suggest potential applications of this new oxovanadium(V) complex in both catalysis and antibacterial treatments.

Sensitization of TiO2 Nanotube Arrays by Mixed Oxovanadium(IV) Complex for Enhanced Photoelectrochemical Cells Performance

Sensitization of TiO2 Nanotube Arrays by Mixed Oxovanadium(IV) Complex for Enhanced Photoelectrochemical Cells Performance

Nickel and Oxo-Vanadium Complexes of Adenine on Modified Mesoporous MCM-41 as Chemoselective, Efficient, and Reusable Catalysts in the Oxidation of Sulfides and Oxidative Coupling of Thiols.

A highly efficient superior catalyst of Ni (II) and VO (IV) metal complexes supported on MCM-41 has been synthesized and developed for chemoselective oxidation of sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides using H2O2 as a green and efficient procedure. All sulfoxides and disulfides were obtained in short reaction times with excellent yields. The over-oxidation of sulfides or thiols was not observed and all products were synthesized in high purity. These catalysts could be recovered and reused several times without any significant loss in their catalytic activity. Compared to the old catalysts in the literature, these catalysts showed better activity and selectivity for the synthesis of sulfoxide and disulfide derivatives, which shows the novelty of this work. At first, the mesoporous MCM-41 was synthesized, and further, its surface was modified by (3-chloropropyl)-triethoxysilane (CPTES). Then, the modified MCM-41 (nPrCl-MCM- 41) was functionalized by adenine. In the next step, the functionalized MCM-41 (6AP-MCM- 41) was used as support for the immobilization of nickel and oxo-vanadium as final catalysts (Ni-6AP-MCM-41 or VO-6AP-MCM-41). The structure and properties of these catalysts have been identified by XRD, SEM, TGA, FT-IR, and AAS spectral analyses. These catalysts were used in the chemoselective oxidation of sulfides and oxidative coupling of thiols. These complexes catalyzed all reactions well at room temperature. According to the results obtained, the hydroxyl groups of some derivatives, including 2-(methylthio) ethanol or 2,2-(phenylthio) ethanol, remained unchanged during the reaction. The method has been found to possess the advantages of low cost, high efficiency, high yields, recovery, and reusability for several runs without significant loss in the catalytic activity.

Oxidovanadium(V) complexes with tridentate hydrazone ligands as oxygen atom transfer catalysts

Four isostructural oxovanadium(V) complexes with hydrazone ligands have been synthesised, characterised, and evaluated as epoxidation and sulfoxidation catalysts. The reactions between [VO(acac)2] (acac– = acetylacetonate) and H2Ln (n = 1–4), precursors for monoanionic tridentate hydrazone ligands, afford complexes formulated as [VO(Ln)(bzh)·MeOH] (1–4) when bidentate benzohydroxamic acid (Hbzh) is included as a co-ligand. Single crystal X-ray structure analyses showed that complexes 1–3 have a distorted octahedral coordination geometry with an O5N coordination environment. Cyclic voltammetry showed that all complexes undergo two quasi-irreversible reduction peaks and a single irreversible oxidation peak. The bonding in 1 has been investigated by electronic structure calculations, and these data are discussed with respect to the electrochemical results. Complexes 1–4 were tested as catalysts for the epoxidation of cis-cyclooctene at 50 °C and sulfoxidation of methyl-p-tolylsulfide at room temperature using tert-butyl hydroperoxide (tBuOOH) and aqueous H2O2 as the terminal oxidants.

Oxovanadium (IV) Complexes of α-Amino Acid Schiff Bases and 2,2'-Bipyridine Ligands: Synthesis, Characterization and Investigation of their Biological Potency

Five new oxovanadium(IV) complexes of the type [VO(L)(bpy)], [where L= 3-hydroxybenzaldehyde-α-alanine (hb-ala), 3-hydroxybenzaldehyde-DL-phenylalanine (hb-pheala), 3-hydroxybenzaldehyde-leucine (hb-leu), 3-hydroxybenzaldehyde-glycine (hb-gly) and 3-hydroxybenzaldehyde-DL-methionine (hb-met) and bpy = 2,2´-bipyridine] have been synthesized and characterized by some physicochemical properties, molar conductance, magnetic susceptibilities measurements, elemental analysis, UV-Visible and FTIR and ESI-MS spectral studies. The molar conductance values showed that the complexes are non-electrolytic in nature. The magnetic moment values of the complexes are in accordance with the d1 electronic configuration of the VIVO2+ moiety and indicates the paramagnetic nature of the complexes. IR spectral data indicates the coordination of tridentate amino acid Schiff base ligands to the vanadyl (VO2+) ion through O, N, O-donor. ESI-MS spectral studies supports the proposed structure of the complexes. The magnetic moment value coupled with electronic spectral data suggested the distorted octahedral geometry of the complexes. All the complexes were screened for their antibacterial activity against three human pathogenic bacteria- Escherichia coli, Staphylococcus aureus and Bacillus cereus with Kanamycin (K-30) standard. The result shows that all the complexes possess to have moderate to strong potential antibacterial activity against all the tested pathogens.

A computational study on the second-order nonlinear optical response of a new unsymmetrical oxovanadium complex

A new unsymmetrical N2O2 Schiff base oxovanadium (IV) complex, VOLPy, was synthesized with excellent yield and characterized using conventional methods. The crystal structure of the VOLPy complex was determined through X-ray diffraction, revealing a distorted square pyramidal coordination configuration around the central vanadium ion. The solid-state structure is stabilized by various non-covalent short contacts, generating complex 3D supramolecular network. The electrochemical properties of the VOLPy complex were investigated in different media, demonstrating diffusion-controlled reversible or quasi-reversible processes within the potential range of 200–1000 mV, involving a single electron VV/VIV reduction. The diffusion coefficients were calculated using Levich plots Ilim = f(ω1/2). Using quantum calculations at the CAM-B3LYP level with a 6-311G**/LanL2DZ basis set, we systematically assessed various structural parameters, electronic properties, linear and nonlinear optical responses at static and dynamic regimes for oxovanadium complexes, V(V)OL and V(IV)OL, in both gaseous and solvent environments. The results reveal a robust alignment between quantum calculations and experimental data, with only minor deviations. This study anticipates that these specifically designated complexes hold substantial potential as excellent candidates for second-order nonlinear optical (NLO) materials.

Structural and theoretical exploration of an innovative unsymmetrical oxovanadium complex: Electrochemical analysis and in vitro antibacterial screening

2‑hydroxy-1-naphthaldehyde and 3,4-diaminotoluene were reacted with bis(acetylacetonato) oxovanadium to yield a novel NNOO -type chelate complex, VOL. The prepared complex is characterized by employing elemental analysis, electronic and infrared spectra. The expected structure was crystallized and identified by using the single-crystal X-ray diffraction method. The VOL complex crystallizes in the monoclinic system with the P21/c space group. Additionally, we affected a comprehensive analysis of VOV, VOIV and VOIII complexes focusing on their structural, electronic, and optical properties using DFT and TD-DFT calculations in gas. The computed parameters closely matched the experimental data, demonstrating good agreement. The electrochemical behavior of the VOL complex, investigated on a glassy carbon electrode (GCE) by means of cyclic voltammetry (CV), revealing a metal-centered one-electron redox systems corresponding to the VOIV/VOIII and VOV/VOIV at -1206 and 547 mV/SCE respectively. The in vitro antibacterial activities of the free ligand H2L and the corresponding VOL complex were evaluated against Gram-positive strains, Staphylococcus aureus and Streptococcus pyogenes, and Gram-negative strains, Escherichia coli, Proteus mirabilis and Klebseilla pneumoniae. The biological screening revealed that the VOL complex exhibits more potent activity than the free ligand.

Oxovanadium (IV) Complexes of α-Amino Acid Schiff Bases and Polypyridyl Ligands: Synthesis, Characterization and Antimicrobial Activity

Oxovanadium(IV) complexes of the type [VO(L)(bpy)] (V-1 to V-5) have been synthesized and characterized by FTIR and UV-Vis spectra, molar conductance, melting points, and magnetic susceptibilities measurements, where L= N-salicylidene-β-alanine (sal-ala), N-salicylidene-glycine (sal-gly), N-salicylidene-DL-β-phenylalanine (sal-pheala), N-salicylidene-leucine (sal-leu), and N-salicylidene-DL-methionine (sal-met), and bpy is 2,2´-bipyridine. The infrared spectral data reveals that the tridentate nature of the amino acid-based Schiff base ligand and the coordination of the ligand through azomethine nitrogen, phenolic oxygen and carboxylate oxygen with vanadyl (VO2+) ion. All of these complexes were determined to be non-electrolyte in nature, according to conductivity measurements. The magnetic moment measurements have been attributed that these complexes are paramagnetic and have d1 configuration of vanadium (IV) ion. In Virto antimicrobial activity of the synthesized complexes was evaluated against two gram-positive (Bacillus subtilis and Staphylococcus aureus) and two gram-negative (Escherichia coli, Proteus vulgaris) bacterial strains.

Diisatin malonyldihydrazone complexes of high valent oxovanadium and oxozirconium ions for bio-chemical effectiveness and catalytic thiophene oxidation

Bis-tridentate diisatin malonyldihydrazone ligand, H2Lhm, was prepared from the condensed reaction of isatin with malonic dihydrazide. Its ligandated coordination features were explored from its reactivity towards VO2+ and ZrO2+ ions forming two novel complexes of dinuclear homoleptic design (VOLhm and ZrOLhm, respectively). Elucidation of their chemical structures was formulated within various available spectroscopic ways, besides EA (the elemental analyses), conductivity measurements, and magnetic characteristics.Their bio-accomplishment was evaluated depending on their inhibited action against the growing ability of some well-known bacteria, fungi, and cancer/normal cells of human. The biological results appointed the employed role of VO2+ or ZrO2+ ion in its chelated complex over the free ligand, H2Lhm. Their binding mode with ctDNA (i.e. calf thymus DNA) was examined within the viscometric and spectrophotometric titration. VOLhm and ZrOLhm represented a fascinating role in the inhibition of the current microorganisms and the human cancer-normal strains' growth over H2Lhm. VOLhm and ZrOLhm exhibited a notable interaction with ctDNA more than that of their H2Lhm ligand. From the values of binding constant (Kb = 16.36 and 14.49 × 107 mol−1 dm3) and Gibb’s free energy (ΔGb≠ = −47.21 and −44.16 kJ mol−1), VOLhm displayed more bio-action within ctDNA than ZrOLhm and H2Lhm, referring to the role of VO2+ ion with high redox potential enhancing the bio-reactivity of VOLhm.The catalytic behavior of VOLhm and ZrOLhm was given within the oxidation of thiophene (as a desulfurization process), homogeneously using H2O2. The oxidation optimization was enhanced depending on the type of O = M4+ ion in its complex catalyst (through 4 h at 30 °C with 60% yielding of monooxo-product using VOLhm and 4 h and 40 °C with 53% using ZrOLhm).

Dipicolinate Oxovanadium(IV) Complexes – Well‐Defined, Universal Precatalysts for Ethylene Polymerization and Polar Monomers Oligomerization

AbstractIn the field of polymers and organometallic chemistry, a significant gap is apparent in the area of research on well‐defined metal complexes targeted for using in catalysis leading to olefinic oligomers and polymers. Here, we report on the use in these processes the dipicolinate oxovanadium(IV) complexes, without and with auxiliary ligands, i. e. 1,10‐phenanthroline and 2,2’‐bipyridine. The investigated complexes turned out to be versatile precatalysts. After reaction with appropriate activator, they exhibited 11 times higher a catalytic activity than reference vanadium(IV) complexes with salen ligands – so far, precatalysts from a group of vanadium(IV) complexes with the highest known catalytic activity for polymerization of ethylene. In the case of the oligomerization of polar monomers (2‐chloro‐2‐propen‐1‐ol and 3‐buten‐2‐ol) the complexes described in this report have a catalytic activity (very high) similar to vanadium(IV) complexes known in the literature.

Oxovanadium(IV) complexes containing tetradentate N2O2-type ligands: synthesis, crystal structure, antioxidant activity, and spectroscopic characterization

Oxovanadium(IV) complexes containing tetradentate N2O2-type ligands: synthesis, crystal structure, antioxidant activity, and spectroscopic characterization

Oxovanadium(IV) heteromacrocyclic complexes as ionophores for iodide-selective electrodes

Abstract Highly selective poly(vinyl chloride) (PVC) membrane electrodes, based on oxovanadium(IV) complexes of heteromacrocyclic compounds as new iodide-selective ionophores for ion-selective electrodes (ISEs), were fabricated with a composition of PVC (28.1 wt%), plasticizers (69.3 wt%), ionophores (2.6 wt%), and cation excluders (15 mol% relative to the ionophore). The electrode prepared from oxovanadium(IV) tetraphenyl porphyrin with 2-nitrophenyl octyl ether (o-NPOE) as the membrane solvent and tetradodecylammonium chloride (TDDACl) as the cation excluder was found to exhibit the best sensitivity over a wide concentration range from 5.0 × 10–7 to 2.1 × 10–2 M with a Nernstian response of −59.02 mV per decade and the highest ion-selectivity toward I− ions over perchlorate ions (I−/ClO4− = 91).

Prospects for the Search for New Antidiabetic Agents Among Vanadium-containing Complex Compounds (Review)

Introduction. The epidemic increase in the incidence of diabetes mellitus (DM) makes it urgent to search for new antidiabetic agents. In clinical practice, there is an urgent question about improving and/or replacing insulin therapy for the disease. Vanadium compounds are of particular interest in connection with the identification of their multifactorial effects on the body, including insulin-like and hypoglycemic properties, which opens up prospects for the creation of a new generation of therapeutic agents for the treatment of types 1 and 2 diabetes. The focus of this review is on the structure and antidiabetic properties of vanadium complexes.Text. This review is devoted to the analysis of scientific literature on studies of vanadium-containing compounds as potential antidiabetic agents. The mechanisms of antidiabetic activity of vanadium-containing complex compounds are discussed. The prospects for searching for oxovanadium(IV) complexes with O4-coordination have been assessed.Conclusion. As a result of the analysis of the literature data, it was found that vanadium-containing complex compounds have a significant potential for use as antidiabetic agents. The relevance of the search for highly effective oxo-vanadium metal complexes based on ligands close to endogenous substrates, for example, based on derivatives of aroylpyruvic acid, is shown.

Binary and Ternary Oxovanadium (IV) Complexes with Picolinic Acid and Some Potentially Bidentate Amino Acids Studied by Potentiometric Measurements in 1.0 mol·dm−3 NaCl at 25 °C

Binary and Ternary Oxovanadium (IV) Complexes with Picolinic Acid and Some Potentially Bidentate Amino Acids Studied by Potentiometric Measurements in 1.0 mol·dm−3 NaCl at 25 °C

Antioxidant Activity and Protective Effects of an Oxovanadium (IV) Complex on Heart and Aorta Injury of STZ-Diabetic Rats.

Diabetic people have a much higher rate of cardiovascular disease than healthy people. Therefore, heart and aortic tissues are target tissues in diabetic research. In recent years, the synthesis of new vanadium complexes and investigation of their antidiabetic/lowering effect on the blood glucose levels and antioxidant properties are increasing day by day. Our study aimed to examine the effects of synthesized oxovanadium (IV) complex of 2-[(2,4-dihydroxybenzylidene]hydrazine-1-[(N-(2-hydroxybenzylidene)](S-methyl)carbothioamide [VOL] on diabetic heart and aortic tissues, as well as in vitro lactate dehydrogenase (LDH) and myeloperoxidase (MPO) inhibition, antioxidant properties, and reducing power. Electrochemical characterization of the VOL was carried out by using Cyclic Voltammetry (CV) and Linear Sweep Voltammetry (LSV) methods. In addition, in silico drug-likeness and ADME prediction were also investigated. For in vivo study, male Swiss albino rats were randomly selected and separated into four groups which are control, control + VOL, diabetic and diabetic + VOL. After the experimental procedure, biochemical parameters were investigated in homogenates of heart and aorta tissues. The results showed that VOL has a protective effect on heart and aortic tissue against oxidative stress. According to electrochemical experiments, one reversible oxidative couple and one irreversible reductive response were observed for the complex. In addition, in vitro LDH and MPO inhibition of VOL was examined. It was found that VOL had a protective effect on heart and aortic tissues of diabetic rats, and caused the inhibition of LDH and MPO in in vitro studies. On the other hand, evaluating the synthesized VOL according to in silico drug-likeness and absorption, distribution, metabolism, and excretion (ADME) prediction, it was found that VOL has drug-like properties and exhibited high gastrointestinal absorption. The VOL had a therapeutic impact on the heart and aortic tissues of diabetic rats, according to the findings.

Development of nanofunctionalized oxovanadium(IV) complex and its anticancer, antidiabetic, DNA cleavage and cell imaging studies

VO(IV) complex is little toxic and highly effective than vanadium salts. A vanadyl metal complex from 8-formyl-7-hydroxy-4-methyl coumarin derivative has been synthesized and functionalized with copper nanoparticles. The Spectrochemical studies such as UV, FTIR, 1NMR and ESR spectra were recorded to characterize the ligand(CUAP), Vanadyl complex[VO(CUAP)SO4] and nano Cu-VO(IV)complex efficiently. The structural studies of vanadyl complex confirmed that the ligand coordinate with metal through nitrogen atom of azomethine, carbonyl oxygen and phenolic oxygen. ESR spectrum of vanadyl complex revealed the covalent nature. XRD pattern of nano Cu-VO(IV) complex indicated the crystalline nature and the average particle size was 20.91 nm. SEM image of nano Cu-VO(IV) complex showed that the nano particles accumulated to form spherical shaped particles. The particle size obtained from Transmission Electron Microscopy of nano functionalized metal complex is ∼ 20 nm. It is closely matched to the particle size calculated from XRD results. Fluorescence of vanadyl complex and nano Cu-VO(IV) complex exhibit the emission from 270 to 900 nm range with significant fluorescence at ∼ 750 nm. The DNA cleavage of all the compounds was evaluated using Agarose gel electrophoresis technique and showed greater cleavage of vanadyl complex. The anticancer activity of compounds was carried out against two cancer cell lines viz Human Breast Cancer Cell line (MCF-7) and Human Leukemia Cancer Cell Line(K-562). Oxovanadium complex exhibited good anticancer activities than ligand and nano-functionalized complex. The antidiabetic activities of vanadyl and nano functionalized complexes were studied against α-Amylase and β-Glucosidase inhibition assay. In this study vanadyl complex showed higher inhibition activity on α-Amylase compared with standard Acarbose. The bioimaging of nano-functionalized metal complex showed high fluorescent properties. The molecular docking study of ligand and vanadyl complex showed greater docking results with CDK2 receptor.

Syntheses, structures, Hirshfeld surface analyses, BSA interactions and molecular docking studies of two leucine Schiff base complexes of oxovanadium(IV)

Two mixed-ligand oxovanadium(IV) complexes with a Schiff base derived from o-vanillin and leucine and 1,10-phenanthroline or 2,2´-bipyridine as a co-ligand, [VO(o-van-Leu)phen] (1) and [VO(o-van-Leu)bipy]·H2O (2), were prepared and structurally characterized by IR spectra, elemental analyses and single-crystal X-ray diffraction. The crystal structures reveal that each oxovanadium(IV) atom in complexes 1 and 2 is surrounded by a N3O3 coordination sphere to form a distorted octahedron with a Schiff base and neutral bidentate ligand phen or bipy. Hirshfeld surface analyses and 2D fingerprint plots indicated that the molecular packings in crystals were dominated by H···H, O···H/H···O, C···H/H···C and π-π interactions. The interactions of both complexes with bovine serum albumin (BSA) were studied by using various spectroscopic and molecular docking methods. BSA binding constants (K), estimated by UV–Vis spectroscopy, were 2.53 × 104M−1 for 1 and 3.18 × 104M−1 for 2, respectively. Together with results of fluorescence and CD spectral studies, it showed that complex 2 has a better affinity for BSA than complex 1. Molecular docking investigation indicated that the two complexes had the similar mode of binding and located within subdomain IIA of BSA. Complex 2 had greater binding activity with the binding free energy (∆Gbinding) of –6.5 kcal/mol than Complex 1 with ∆Gbinding of–5.42 kcal/mol, consisting with the analyses of spectroscopic experimental results.

Theoretical, antioxidant, antidiabetic and in silico molecular docking and pharmacokinetics studies of heteroleptic oxovanadium(IV) complexes of thiosemicarbazone-based ligands and diclofenac

A series of new heteroleptic oxovanadium(IV) complexes with the general formula [VOL1–6(Dcf)] (1–6), where L1−6 = thiosemicarbazone (TSC)-based ligands and Dcf = diclofenac have been synthesized and characterized. The spectral studies along with the density functional theory calculations evidenced the distorted square-pyramidal geometry around oxovanadium(IV) ion through imine nitrogen and thione sulfur atoms of TSC moiety, and two asymmetric carboxylate oxygen atoms of diclofenac drug. The complexes were evaluated for in vitro antioxidant activity using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2'-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2) and superoxide radical scavenging assays with respect to the standard antioxidant drugs butylated hydroxyanisole (BHA) and rutin. The in vitro antidiabetic activity of the complexes was tested with enzymes such as α-amylase, α-glucosidase and glucose-6-phosphatase. The complexes containing methyl substituent showed higher activity than that containing the nitro substituent due to the electron-donating effect of methyl group. The in silico molecular docking studies of the oxovanadium(IV) complexes with α-amylase and α-glucosidase enzymes showed strong interaction via hydrogen bonding and hydrophobic interactions. The dynamic behavior of the proposed complexes was analyzed by molecular dynamics (MDs) simulations, which revealed the stability of docked structures with α-amylase and α-glucosidase enzymes. The in silico physicochemical and pharmacokinetics parameters, such as Lipinski’s ‘rule of five’, Veber’s rule and absorption, distribution, metabolism and excretion (ADME) properties predicted non-toxic, non-carcinogenic and safe oral administration of the synthesized complexes. Communicated by Ramaswamy H. Sarma

Molecular modeling of [VO(L1–4)(R)] complexes (R = bipyridine, phenanthroline): DFT study of antioxidant activity, DNA binding and evaluation of electron-donating and -withdrawing substituent groups

A DFT (density functional theory) study was conducted with eight oxovanadium complexes (C1 – C8) of general formula [VO(L1–4)(R)] (R = bipyridine, phenanthroline; L1–4 = group of ligands derived from dithiocarbamate). The obtained geometries showed a good correlation with the experimental structures. Molecular orbital analysis revealed that the contribution of the L-ligand in the SOMO (single-occupied molecular orbital) of the complexes correlated with the experimental antioxidant activity (IC50), while the contribution of the R-ligand to the LUMO (lowest unoccupied molecular orbital) of the complexes correlated with the experimental complex-DNA interaction (Kb). It has been identified that the presence of an electron-donating substituent group (such as –NH2) in the C5 – C6 structures should enhance these complexes' antioxidant and DNA interaction activities.