Journal of Inorganic Biochemistry

The present work demonstrates the synthesis, structural diversity and coordination behavior of some selected new Ni(II)-Tpy complexes. The structural analysis revealed the coordination of the selected terpyridine ligands with the core metal atom in two different modes via dimeric species (1:1 fashion) through the Cl-bridging and a bis(Tpy)-Ni complex (2:1 fashion). Perhaps the most striking manifestations of these Ni(II)-Tpy complexes are BSA/DNA binding ability and anticancer activity. In addition, the cytotoxicity studies of Tpy ligand (4-([2,2':6',2″-terpyridin]-4'-yl)phenyl 5-methylthiophene-2-carboxylate) and the Ni(II) complexes were carried out using lung cancer cell line (A549), breast cancer cell line (MCF-7) and normal cell line (Vero cell)...

The clinical success of [223 Ra]RaCl2 (Xofigo®) for the palliative treatment of bone metastases in patients with prostate cancer has highlighted the therapeutic potential of α-particle emission. Expanding the applicability of radium-223 in Targeted Alpha Therapy of non-osseous tumors is followed up with significant interest, as it holds the potential to unveil novel treatment options in the comprehensive management of cancer. Moreover, the use of barium radionuclides, like barium-131 and -135m, is still unfamiliar in nuclear medicine applications, although they can be considered as radium-223 surrogates for imaging purposes...

This work reports on the synthesis of triphenylphosphine-labelled cationic phthalocyanines (Pc) complexed with bovine serum albumin (BSA) and gold nanoparticles (Au NPs). This nano-complex (Pc-BSA-Au) is studied for its photodynamic therapy (PDT) activity compared to the non-complexed Pc counterpart. The photochemical properties and in vitro PDT efficacies of the Pc and the nano-complex were determined and are compared herein. The singlet oxygen (1 O2 ) yields of the Pcs were determined and are reported in DMF...

A water-soluble colorimetric chemosensor NHOP ((E)-1-(2-(2-(2-hydroxy-5-nitrobenzylidene)hydrazineyl)-2-oxoethyl)pyridin-1-ium) chloride) was developed for the sequential probing of Cu2+ and S2- . NHOP underwent a color change from pale yellow to colorless in the presence of Cu2+ in pure water. The binding ratio between NHOP and Cu2+ was confirmed to be 1:1 by the Job plot and ESI-MS (electrospray ionization mass spectrometry). The detection limit of NHOP for Cu2+ was calculated as 0.15 μM, which was far below the EPA (Environmental Protection Agency) standard (20 μM)...

Triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer, which owned severe resistance to platinum-based anticancer agents. Herein, we report a new metal-arene complex, Ru-TPE-PPh3 , which can be synthesized in vitro and in living cells with copper catalyzed the cycloaddition reaction of Ru-azide and alkynyl (CuAAC). The complex Ru-TPE-PPh3 exhibited superior inhibition of the proliferation of TNBC MDA-MB-231 cells with an IC50 value of 4.0 μM. Ru-TPE-PPh3 could induce the over production of reactive oxygen species (ROS) to initiate the oxidative stress, and further damage the mitochondria both functionally and morphologically, as loss of mitochondrial membrane potential (MMP) and cutting the supply of adenosine triphosphate (ATP), the disappearance of cristae structure...

Recognizing that metal ions play an important role in modifying the pharmacological properties of known organic-based drugs, the present manuscript addresses the complexation of the antifungal agent voriconazole (vcz) with the biologically relevant silver(I) ion as a strategy for the development of new antimycotics. The synthesized silver(I) complexes with vcz were characterized by mass spectrometry, IR, UV-Vis and NMR spectroscopy and single-crystal X-ray diffraction analysis. The crystallographic results showed that complexes {[Ag(vcz)(H2 O)]CH3 SO3 }n (1), {[Ag(vcz)2 ]BF4 }n (2) and {[Ag(vcz)2 ]PF6 }n (3) have polymeric structures in the solid state, in which silver(I) ions have a distorted tetrahedral geometry...

In this paper, a series of cyclometalated bismuth(III) complexes bearing C,O-bidentate ligands were synthesized and characterized by techniques such as UV-vis, NMR, HRMS, and single crystal X-ray diffraction. Meanwhile, their cytotoxicities against various human cell lines, including colon cancer cells (HCT-116), breast cancer cells (MDA-MB-231), lung cancer cells (A549), gastric cancer cells (SGC-7901), and normal embryonic kidney cells (HEK-293) were assessed in vitro. Compared with the clinical cisplatin, most of the synthesized complexes possessed significantly higher degrees of anticancer activity and selectivity, giving a selectivity index of up to 71...

Serine proteases are important enzymes widely used in commercial products and industry. Recently, we identified a new serine protease from the desert bacterium Bacillus subtilis ZMS-2 that showed enhanced activity in the presence of Zn2+ , Ag+ , or H2 O2 . However, the molecular basis underlying this interesting property is unknown. Here, we report comparative studies between the ZMS-2 protease and its homolog, subtilisin E (SubE), from B. subtilis ATCC 6051. In the absence of Zn2+ , Ag+ , or H2 O2, both enzymes showed the same level of proteolytic activity, but in the presence of Zn2+ , Ag+ , or H2 O2 , ZMS-2 displayed increased activity by 22%, 8%, and 14%, whereas SubE showed decreased activity by 16%, 12%, and 9%, respectively...

AS101 (Ammonium trichloro (dioxoethylene-O,O') tellurate) is an important hypervalent Te-based prodrug. Recently, we started a systematic investigation on AS101 with the aim to correlate its promising biological effects as a potent immunomodulator drug with multiple medicinal applications and its specific chemical properties. To date, a substantial agreement on the rapid conversion of the initial AS101 species into the corresponding TeOCl3 - anion does exist, and this latter species is reputed as the pharmacologically active one...

Two conserved second-sphere βArg (R) residues in nitrile hydratases (NHase), that form hydrogen bonds with the catalytically essential sulfenic and sulfinic acid ligands, were mutated to Lys and Ala residues in the Co-type NHase from Pseudonocardia thermophila JCM 3095 (PtNHase) and the Fe-type NHase from Rhodococcus equi TG328-2 (ReNHase). Only five of the eight mutants (PtNHase βR52A, βR52K, βR157A, βR157K and ReNHase βR61A) were successfully expressed and purified. Apart from the PtNHase βR52A mutant that exhibited no detectable activity, the kcat values obtained for the PtNHase and ReNHase βR mutant enzymes were between 1...

The solvated iron(II) salt [Fe(NCMe)6 ](BF4 )2 (Me = methyl) is shown to be a bifunctional catalyst with respect to aziridination of styrene. The salt serves as an active catalyst for nitrene transfer from PhINTs to styrene to form 2-phenyl-N-tosylaziridine (Ph = phenyl; Ts = tosyl, -S{O}2 -p-C6 H4 Me). The iron(II) salt also acts as a Lewis acid in non-coordinating CH2 Cl2 solution, to catalyze heterolytic CN bond cleavage of the aziridine and insertion of dipolarophiles. The 1,3-zwitterionic intermediate is presumably supported by interaction of the metal dication with the anion, and by resonance stabilization of the carbocation...

Six terpyridine‑nickel complexes 1-6 were formed by the coordination of 4'-(4-R-phenyl)-2,2':6',2″-terpyridine (R = hydroxyl (L1 ), methoxyl (L2 ), methylsulfonyl (L3 ), fluoro (L4 ), bromo (L5 ), iodo (L6 )) derivatives to nickel nitrate. The compositions and structures of these complexes were analyzed by Fourier Transform infrared spectroscopy (FT-IR), elemental analyses, electrospray ionization mass spectra (ESI-MS), solid-state ultraviolet-visible (UV-Vis) spectroscopy, and single crystal X-ray diffraction (1, 2 and 4) studies...

In this work, we report the generation and characterization of two new Co(III)-peroxo complexes 2 and 3. 2 is best described as a mononuclear CoIII -(O2 ) complex that exhibits an 18 O-isotope sensitive OO bond stretching vibration at 845(-49) cm-1 , indicating a relatively weak peroxo moiety compared to those of other CoIII -(O2 ) complexes reported previously. Complex 3 is a CoIII -peroxo-arylboronate species having a rare {CoIII OOBO} five-membered metallocycle, which is structurally characterized using X-ray crystallography...

Neuromelanin (NM) plays a well-established role in neurological disorders pathogenesis; the mechanism of action is still discussed and the investigations in this field are limited by NM's complex and heterogeneous composition, insolubility, and low availability from human brains. An alternative can be offered by synthetic NM obtained from dopamine (DA) oxidative polymerization; however, a deep knowledge of the influence of both physicochemical parameters (T, pH, ionic strength) and other compounds in the reaction media (buffer, metal ions, other catecholamines) on DA oxidation process and, consequently, on synthetic NM features is mandatory to develop reliable NM preparation methodologies...

Cisplatin remains the most widely used chemotherapeutic agent in cancer treatment; however, its inherent drawbacks have fueled the development of novel metalloanticancer drugs. In this study, two novel Cu(II) complexes (Cu1 and Cu2) were designed and synthesized. Notably, these Cu(II) complexes showed higher cytotoxicity against HL-7402 cells than cisplatin. Moreover, Cu(II) complexes significantly inhibited liver cancer growth in a xenograft model. A mechanism study revealed that the Cu(II) complexes reduced the mitochondrial membrane potential of cancer cells, produced excessive reactive oxygen species (ROS), induced mitochondrial DNA (mtDNA) damage, and ultimately facilitated cancer cell apoptosis...

Herein, we synthesized and characterized two novel iridium (III) complexes: [Ir(bzq)2 (PPD)](PF6 ) (4a, with bzq = deprotonated benzo[h]quinoline and PPD = pteridino[6,7-f][1,10]phenanthroline-11,13-diamine) and [Ir(piq)2 (PPD)](PF6 ) (4b, with piq = deprotonated 1-phenylisoquinoline). The anticancer efficacy of these complexes, 4a and 4b, was investigated using 3-(4,5-dimethylthiazole)-2,5-diphenltetraazolium bromide (MTT). Complex 4a exhibited no cytotoxic activity, while 4b demonstrated moderate efficacy against SGC-7901, A549, and HepG2 cancer cells...

Transition metal ions are structural and catalytic cofactors of many proteins including human carbonic anhydrase (CA), a Zn-dependent hydrolase. Sulfonamide inhibitors of CA recognize and form a coordination bond with the Zn ion located in the active site of the enzyme. The Zn ion may be removed or substituted with other metal ions. Such CA protein retains the structure and could serve as a tool to study metal ion role in the recognition and binding affinity of inhibitor molecules. We measured the affinities of selected divalent transition metal ions, including Mn, Fe, Co, Ni, Cu, Cd, Hg, and Zn to metal-free CA isozymes CA I, CA II, and CAIX by fluorescence-based thermal shift assay, prepared metal-substituted CAs, and determined binding of diverse sulfonamide compounds...

Resonance Raman (rR) spectroscopy has been applied to study the nature of the iron-oxo (Fe=O) moiety of oxoiron(IV) porphyrin π-cation radical complex (CompI). While the axial ligand effect on the nature of the Fe=O moiety has been studied with rR spectroscopy, the porphyrin ligand effect has not been studied well. Here, we investigated the porphyrin ligand effect on the Fe=O moiety with rR spectroscopy. The porphyrin ligand effect was modulated by the electron-withdrawing effect of the porphyrin substituent at the meso-position...

Two copper(II) complexes [Cu(Hpmoh)(NO3 )(NCS)] (1) and [Cu(peoh)(N3 )]2 (2) were designed and synthesized by reaction of Cu(NO3 )2 ·3H2 O with hydrazone Schiff base ligands,abbreviated with Hpmoh and Hpeoh. Hpmoh and Hpeoh were prepared by condensation reaction of octanoic hydrazide with pyridine-2-carboxyaldehyde and 2-acetylpyridine, respectively. Complexes 1 and 2 were characterized using different analytical techniques such as FT-IR, UV-Vis, IR, EPR and single X-ray diffraction (XRD) analyses as well as computational methods (DFT)...

Our prior studies have illustrated that the uracil ruthenium(II) diimino complex, [Ru(H3 ucp)Cl(PPh3 )] (1) (H4 ucp = 2,6-bis-((6-amino-1,3-dimethyluracilimino)methylene)pyridine) displayed high hypoglycemic effects in diet-induced diabetic rats. To rationalize the anti-diabetic effects of 1, three new derivatives have been prepared, cis-[Ru(bpy)2 (urdp)]Cl2 (2) (urdp = 2,6-bis-((uracilimino)methylene)pyridine), trans-[RuCl2 (PPh3 )(urdp)] (3), and cis-[Ru(bpy)2 (H4 ucp)](PF6 )2 (4). Various physicochemical techniques were utilized to characterize the structures of the novel ruthenium compounds...