Synthesis, crystal structures, in vitro biological evaluation of zinc(II) and bismuth(III) complexes of 2-acetylpyrazine N(4)-phenylthiosemicarbazone

Biological Activities of Bismuth Compounds: An Overview of the New Findings and the Old Challenges Not Yet Overcome

Bismuth-based drugs have been used primarily to treat ulcers caused by Helicobacter pylori and other gastrointestinal ailments. Combined with antibiotics, these drugs also possess synergistic activity, making them ideal for multiple therapy regimens and overcoming bacterial resistance. Compounds based on bismuth have a low cost, are safe for human use, and some of them are also effective against tumoral cells, leishmaniasis, fungi, and viruses. However, these compounds have limited bioavailability in physiological environments. As a result, there is a growing interest in developing new bismuth compounds and approaches to overcome this challenge. Considering the beneficial properties of bismuth and the importance of discovering new drugs, this review focused on the last decade's updates involving bismuth compounds, especially those with potent activity and low toxicity, desirable characteristics for developing new drugs. In addition, bismuth-based compounds with dual activity were also highlighted, as well as their modes of action and structure-activity relationship, among other relevant discoveries. In this way, we hope this review provides a fertile ground for rationalizing new bismuth-based drugs.

Biological Characteristics of Polyurethane-Based Bone-Replacement Materials

A study is presented on four polymers of the polyurethane family, obtained using a two-stage process. The first composition is the basic polymer; the others differ from it by the presence of a variety of fillers, introduced to provide radiopacity. The fillers used were 15% bismuth oxide (Composition 2), 15% tantalum pentoxide (Composition 3), or 15% zirconium oxide (Composition 4). Using a test culture of human fibroblasts enabled the level of cytotoxicity of the compositions to be determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay, along with variations in the characteristics of the cells resulting from their culture directly on the specimens. The condition of cells on the surfaces of the specimens was assessed using fluorescence microscopy. It was shown that introducing 15% bismuth, tantalum, or zinc compounds as fillers produced a range of effects on the biological characteristics of the compositions. With the different fillers, the levels of toxicity differed and the cells' proliferative activity or adhesion was affected. However, in general, all the studied compositions may be considered cytocompatible in respect of their biological characteristics and are promising for further development as bases for bone-substituting materials. The results obtained also open up prospects for further investigations of polyurethane compounds.

Synthesis, characterization, and biological properties of mono-, di- and poly-nuclear bismuth(III) halide complexes containing thiophene-2-carbaldehyde thiosemicarbazones

In order to investigate the coordination chemistry and pharmacological applications of bismuth compounds, a series of new bismuth(III) halide thiosemicarbazone complexes were synthesized. The reactions of thiophene-2-carbaldehyde-N-substituted thiosemicarbazones with bismuth(III) halides resulted in the formation of the {[[BiCl₂(η¹-S-Httsc)₄]⁺.Cl^-][BiCl₂(μ₂-Cl)(η¹-S-Httsc)₂]₂} (1), {[BiCl₃(η¹-S-Htmtsc)₃].CH₃OH} (2), {[BiCl₃(η¹-S-Htetsc)₃].CH₃OH} (3), {[BiBr₂(μ₂-Br)(η¹-S-Httsc)₂]₂.CH₃OH} (4), {[BiBr₂(μ₂-Br)(η¹-S-Htmtsc)₂]_n} (5), and {[BiI₂(μ₂-I)(η¹-S-Httsc)₂]₂} (6) complexes (Httsc: thiophene-2-carbaldehyde thiosemicarbazone, Htmtsc: thiophene-2-carbaldehyde-N-methyl thiosemicarbazone, Htetsc: thiophene-2-carbaldehyde-N-ethyl thiosemicarbazone). The complexes were characterized by a number of different spectroscopic techniques and the crystal structures of all bismuth(III) complexes (1-6) were determined by using single crystal X-ray diffraction study. In addition, the thermal stability of the complexes was compared using Thermogravimetric-differential thermal analysis. Crystal structures of the two free ligands, thiophene-2-carbaldehyde-N-methyl-thiosemicarbazone and thiophene-2-carbaldehyde-N-ethyl-thiosemicarbazone, were also determined by using single crystal X-ray diffraction analysis. The Hirshfeld surface of the bismuth(III) complexes and free ligands were additionally analyzed to verify the intermolecular interactions. Biological studies showed that all six bismuth(III) thiosemicarbazone complexes (1-6) exhibited biological activities against selected bacteria and the human breast adenocarcinoma (MCF-7) cell line.

Bismuth-213 for Targeted Radionuclide Therapy: From Atom to Bedside

In contrast to external high energy photon or proton therapy, targeted radionuclide therapy (TRNT) is a systemic cancer treatment allowing targeted irradiation of a primary tumor and all its metastases, resulting in less collateral damage to normal tissues. The α-emitting radionuclide bismuth-213 (213Bi) has interesting properties and can be considered as a magic bullet for TRNT. The benefits and drawbacks of targeted alpha therapy with 213Bi are discussed in this review, covering the entire chain from radionuclide production to bedside. First, the radionuclide properties and production of 225Ac and its daughter 213Bi are discussed, followed by the fundamental chemical properties of bismuth. Next, an overview of available acyclic and macrocyclic bifunctional chelators for bismuth and general considerations for designing a 213Bi-radiopharmaceutical are provided. Finally, we provide an overview of preclinical and clinical studies involving 213Bi-radiopharmaceuticals, as well as the future perspectives of this promising cancer treatment option.

Crystal structure of bis [1-(phenylsulfonyl)-2-(1-(pyrazin-2-yl)ethylidene)hydrazin-1-ido-κ3 N,N′,O]cobalt(II), C24H22N8O4S2Co

C24H22N8O4S2Co, orthorhombic, Aba2 (no. 41), a = 12.043(5) Å, b = 21.723(9) Å, c = 9.961(4) Å, V = 2605.9(18) Å3, Z = 4, R gt(F) = 0.0366, wR ref(F 2) = 0.0764, T = 296(2) K.

Single-crystal structure and intracellular localization of Zn(II)-thiosemicarbazone complex targeting mitochondrial apoptosis pathways

Tracking of drugs in cancer cells is important for basic biology research and therapeutic applications. Therefore, we designed and synthesised a Zn(II)-thiosemicarbazone complex with photoluminescent property for organelle-specific imaging and anti-cancer proliferation. The Zn(AP44eT)(NO₃)₂ coordination ratio of metal to ligand was 1:1, which was remarkably superior to 2-((3-aminopyridin-2-yl) methylene)-N, N-diethylhydrazinecarbothioamide (AP44eT·HCl) in many aspects, such as fluorescence and anti-tumour activity. Confocal fluorescence imaging showed that the Zn(AP44eT)(NO₃)₂ was aggregated in mitochondria. Moreover, Zn(AP44eT)(NO₃)₂ was more effective than the metal-free AP44eT·HCl in shortening the G2 phase in the MCF-7 cell cycle and promoting apoptosis of cancer cells. Supposedly, the effects of these complexes might be located mainly in the mitochondria and activated caspase-3 and 9 proteins.

Crystal structure of bis[2-(1-(3-ethylpyrazin-2-yl)ethylidene)-1-tosylhydrazin-1-ido-κ3-N,N′,O]copper(II), C30H34N8O4S2Cu

C30H34N8O4S2Cu, triclinic, P1̄ (no. 2), a = 12.9537(9) Å, b = 15.2802(10) Å, c = 17.1041(11) Å, α = 78.748(1)°, β = 79.684(1)°, γ = 79.270(1)°, V = 3226.4(4) Å3, Z = 4, R gt(F) = 0.0488, wR ref(F 2) = 0.1178, T = 296 K.

Recent Research Trends on Bismuth Compounds in Cancer Chemoand Radiotherapy

Background:

Application of coordination chemistry in nanotechnology is a rapidly developing research field in medicine. Bismuth complexes have been widely used in biomedicine with satisfactory therapeutic effects, mostly in Helicobacter pylori eradication, but also as potential antimicrobial and anti-leishmanial agents. Additionally, in recent years, application of bismuth-based compounds as potent anticancer drugs has been studied extensively.

Methods:

Search for data connected with recent trends on bismuth compounds in cancer chemo- and radiotherapy was carried out using web-based literature searching tools such as ScienceDirect, Springer, Royal Society of Chemistry, American Chemical Society and Wiley. Pertinent literature is covered up to 2016.

Results:

In this review, based on 213 papers, we highlighted a number of current problems connected with: (i) characterization of bismuth complexes with selected thiosemicarbazone, hydrazone, and dithiocarbamate classes of ligands as potential chemotherapeutics. Literature results derived from 50 papers show that almost all bismuth compounds inhibit growth and proliferation of breast, colon, ovarian, lung, and other tumours; (ii) pioneering research on application of bismuth-based nanoparticles and nanodots for radiosensitization. Results show great promise for improvement in therapeutic efficacy of ionizing radiation in advanced radiotherapy (described in 36 papers); and (iii) research challenges in using bismuth radionuclides in targeted radioimmunotherapy, connected with choice of adequate radionuclide, targeting vector, proper bifunctional ligand and problems with 213Bi recoil daughters toxicity (derived from 92 papers).

Conclusion:

This review presents recent research trends on bismuth compounds in cancer chemo- and radiotherapy, suggesting directions for future research.

Synthesis of 2-acetylpyridine-N-substituted thiosemicarbazonates of copper(ii) with high antimicrobial activity against methicillin resistant S. aureus, K. pneumoniae 1 and C. albicans

The basic interest in the present study pertains to developing metal based antimicrobial agents, as several microorganisms have built resistance to the conventional drugs.

Rational Approach Towards Designing Metallogels From a Urea-Functionalized Pyridyl Dicarboxylate: Anti-inflammatory, Anticancer, and Drug Delivery

A structural rationale was adopted to design a series of metallogels from a newly synthesized urea-functionalized dicarboxylate ligand, namely, 5-[3-(pyridin-3-yl)ureido]isophthalic acid (PUIA), that produces metallogels upon reaction with various metal salts (Cu^II , Zn^II , Co^II , Cd^II , and Ni^II salts) at room temperature. The gels were characterized by dynamic rheology and transmission electron microscopy (TEM). The existence of a coordination bond in the gel state was probed by FTIR and ¹ H NMR spectroscopy in a Zn^II metallogel (i.e., MG2). Single crystals isolated from the reaction mixture of PUIA and Co^II or Cd^II salts characterized by X-ray diffraction revealed lattice inclusion of solvent molecules, which was in agreement with the hypothesis based on which the metallogels were designed. MG2 displayed anti-inflammatory response (prostaglandin E₂ assay) in the macrophage cell line (RAW 264.7) and anticancer properties (cell migration assay) on a highly aggressive human breast cancer cell line (MDA-MB-231). The MG2 metallogel matrix could also be used to load and release (pH responsive) the anticancer drug doxorubicin. Fluorescence imaging of MDA-MB-231 cells treated with MG2 revealed that it was successfully internalized.

In vitro evaluation of the antitumor effect of bismuth lipophilic nanoparticles (BisBAL NPs) on breast cancer cells

Aim

The objective of this study was to evaluate the antitumor activity of lipophilic bismuth nanoparticles (BisBAL NPs) on breast cancer cells.

Materials and methods

The effect of varying concentrations of BisBAL NPs was evaluated on human MCF-7 breast cancer cells and on MCF-10A fibrocystic mammary epitheliocytes as noncancer control cells. Cell viability was evaluated with the MTT assay, plasma membrane integrity was analyzed with the calcein AM assay, genotoxicity with the comet assay, and apoptosis with the Annexin V/7-AAD assay.

Results

BisBAL NPs were spherical in shape (average diameter, 28 nm) and agglomerated into dense electronic clusters. BisBAL NP induced a dose-dependent growth inhibition. Most importantly, growth inhibition was higher for MCF-7 cells than for MCF-10A cells. At 1 µM BisBAL NP, MCF-7 growth inhibition was 51%, while it was 11% for MCF-10A; at 25 µM BisBAL NP, the growth inhibition was 81% for MCF-7 and 24% for MCF-10A. With respect to mechanisms of action, a 24-hour exposure of 10 and 100 µM BisBAL NP caused loss of cell membrane integrity and fragmentation of tumor cell DNA. BisBAL NPs at 10 µM were genotoxic to and caused apoptosis of breast cancer cells.

Conclusion

BisBAL NP-induced growth inhibition is dose dependent, and breast cancer cells are more vulnerable than noncancer breast cells. The mechanism of action of BisBAL NPs may include loss of plasma membrane integrity and a genotoxic effect on the genomic DNA of breast cancer cells.

Crystal structure of bis(1-(phenylsulfonyl)-2-(1-(pyrazin-2-yl)ethylidene)hydrazin-1-ido-κ3 N,N′,O)nickel(II), C24H22N8O4S2Ni

C24H22N8O4S2Ni, orthorhombic, Aba2 (no. 41), a = 11.845(6) Å, b = 21.937(11) Å, c = 9.907(5) Å, V = 2574(2) Å3, Z = 4, R gt(F) = 0.0285, wR ref(F 2) = 0.0657, T = 296(2) K.

Crystal Structure of bis(1-(phenylsulfonyl)-2-(1-(pyrazin-2-yl)ethylidene)hydrazin-1-ido-κ3 N,N′,O)copper(II), C24H22N8O4S2Cu

C24H22N8O4S2Cu, orthorhombic, Aba2 (no. 41), a = 11.9395(18) Å, b = 21.813(3) Å, c = 10.1184(15) Å, V = 2635.2(7) Å3, Z = 4, R gt(F) = 0.0395, wR ref(F 2) = 0.0912, T = 296(2) K.

Autophagy associated cytotoxicity and cellular uptake mechanisms of bismuth nanoparticles in human kidney cells

Bismuth compounds have been used for treatment of bacterial infection, and recently bismuth nanoparticles (BiNP) were synthesized for imaging and diagnostic purpose, while safety concern of bismuth cannot be ignored. Here, we prepared ultrasmall BiNP and showed an enhanced tumor imaging, but BiNP revealed a differentiated cytotoxicity in human embryonic kidney 293 cells (HEK293) compared to other cell types. For the first time, we found that BiNP can induce autophagy, shown as the increase of monodansylcadaverine fluorescence staining and the amount of LC3II that can be inhibited by 3-MA. BiNP were capable of entering cells in a dose and time dependent manner by fluorescence and element detection methods BiNP were found to be localized in the cytoplasm observed by transmission electron microscopy and intracellular bismuth element confirmed by energy dispersive X-ray analysis. Using endocytic inhibitors, BiNP were found to require ATP and endosomal trafficking pathways for their cellular uptake. Internalized BiNP did not co-localize with EEA1, but co-localized with Lysotracker/LAMP1/LAMP2 at late time points, indicating BiNP may be retained in the non-early endosomal vacuoles and late endosomes. With our novel finding of bismuth induced autophagy and endocytic mechanisms, potential approaches may be applied to reduce the toxicity by bismuth.

Design and synthesis of novel N()-substituted thiosemicarbazones bearing a pyrrole unit as potential anticancer agents

A series of N(4)-substituted thiosemicarbazones (TSCs) bearing pyrrole unit (1a-1e) were synthesized and fully characterized by elemental analyses, infrared spectra, ¹H nuclear magnetic resonance and single crystal X-ray diffraction. The compounds were assessed as potential chemotherapeutic agents. All newly synthesized compounds were screened for their anticancer activity against lung cancer PC-9, esophageal cancer Eca-109 and gastric cancer SGC-7901 cell lines. The results of MTT, Terminal deoxynucleotidyl transferase dUTP nick end labeling and fluorescence-activated cell sorting assays indicated that all the prepared compounds exhibited cytotoxicity against PC-9, Eca-109 and SGC-7901 cells in vitro. All the compounds significantly induced cancer cell apoptosis accompanied by increasing the Bax/Bcl-2 ratio and activation of caspase-3. The structure-activity association was discussed and the potential pre-clinical trials may be conducted. The present findings have a great potential in biomedical applications of novel N(4)-substituted TSCs.

Potent anticancer activity of a new bismuth (III) complex against human lung cancer cells

The aim of this work is experimental study of an interesting bismuth(III) complex derived from pentadentate 2,6-pyridinedicarboxaldehyde bis(⁴N-methylthiosemicarbazone), [BiL(NO₃)₂]NO₃ {L=2,6-pyridinedicarboxaldehyde bis(⁴N-methylthiosemicarbazone)}. A series of in vitro biological studies indicate that the newly prepared [BiL(NO₃)₂]NO₃ greatly suppressed colony formation, migration and significantly induced apoptosis of human lung cancer cells A549 and H460, but did not obviously decrease the cell viability of non-cancerous human lung fibroblast (HLF) cell line, showing much higher anticancer activities than its parent ligands, especially with half maximum inhibitory concentration (IC₅₀) <3.5μM. Moreover, in vivo study provides enough evidence that the treatment with [BiL(NO₃)₂]NO₃ effectively inhibited A549 xenograft tumor growth on tumor-bearing mice (10mgkg^-1, tumor volume reduced by 97.92% and tumor weight lightened by 94.44% compared to control) and did not indicate harmful effect on mouse weight and liver. These results suggest that the coordination of free ligand with Bi(III) might be an interesting and potent strategy in the discovery of new anticancer drug candidates.

Novel Zinc(II) Complexes [Zn(atc-Et)₂] and [Zn(atc-Ph)₂]: In Vitro and in Vivo Antiproliferative Studies

Cisplatin and its derivatives are the main metallodrugs used in cancer therapy. However, low selectivity, toxicity and drug resistance are associated with their use. The zinc(II) (Zn(II)) thiosemicarbazone complexes [Zn(atc-Et)₂] (1) and [Zn(atc-Ph)₂] (2) (atc-R: monovalent anion of 2-acetylpyridine N4-R-thiosemicarbazone) were synthesized and fully characterized in the solid state and in solution via elemental analysis, Fourier transform infrared (FTIR), ultraviolet-visible (UV-Vis) and proton nuclear magnetic resonance (¹H NMR) spectroscopy, conductometry and single-crystal X-ray diffraction. The cytotoxicity of these complexes was evaluated in the HepG2, HeLa, MDA-MB-231, K-562, DU 145 and MRC-5 cancer cell lines. The strongest antiproliferative results were observed in MDA-MB-231 and HepG2 cells, in which these complexes displayed significant selective toxicity (3.1 and 3.6, respectively) compared with their effects on normal MRC-5 cells. In vivo studies were performed using an alternative model (Artemia salina L.) to assure the safety of these complexes, and the results were confirmed using a conventional model (BALB/c mice). Finally, tests of oral bioavailability showed maximum plasma concentrations of 3029.50 µg/L and 1191.95 µg/L for complexes 1 and 2, respectively. According to all obtained results, both compounds could be considered as prospective antiproliferative agents that warrant further research.

Crystal structure of bis-(aceto-phenone 4-benzoyl-thio-semicarbazonato-κ(2) N (1),S)nickel(II)

In the asymmetric unit of the title complex, [Ni(C16H14N3OS)2], the nickel ion is tetra-coordinated in a distorted square-planar geometry by two independent mol-ecules of the ligand which act as mononegative bidentate N,S-donors and form two five-membered chelate rings. The ligands are in trans (E) conformations with respect to the C=N bonds. The close approach of hydrogen atoms to the Ni(2+) atom suggests anagostic inter-actions (Ni⋯H-C) are present. The crystal structure is built up by a network of two C-H⋯O inter-actions. One of the inter-actions forms inversion dimers and the other links the mol-ecules into infinite chains parallel to [100]. In addition, a weak C-H⋯π inter-action is also present.

Synthesis, crystal structure and biological properties of a bismuth(iii) Schiff-base complex

Synthesis, crystal structure and biological properties of a bismuthoxide Schiff-base complex derived from salen-like ligands and bismuth(iii) salt.

Main group bismuth(III), gallium(III) and diorganotin(IV) complexes derived from bis(2-acetylpyrazine)thiocarbonohydrazone: synthesis, crystal structures and biological evaluation

Up to now, the metal complexes with thiocarbonohydrazones have been comparatively rare. Herein, three main group monometallic complexes formulated as [Bi(HL)(NO3)2(H2O)] (1), [Ga(HL)2]OAc·EtOH (2) and [(Ph)2Sn(HL)(OAc)]·DMF (3), where H2L = bis(2-acetylpyrazine)thiocarbonohydrazone, have been synthesized and characterized. The crystal structures of complexes 2 and 3 have been determined by single-crystal X-ray diffraction. Growth inhibition assays have indicated that both the free ligand and the title complexes are capable of inhibiting cell proliferation growth and could slightly distinguish the human hepatocellular carcinoma HepG2 cells from normal hepatocyte QSG7701 cells. Of particular note is the fact that the bismuth(III) complex 1 is the most active compound of this study and is 14-fold more cytotoxic than H2L with an IC50 value of 2.96 ± 0.25 μM. Its possible apoptotic mechanism has been evaluated in HepG2 cells. Complex 1 promotes a dose-dependent apoptosis in HepG2 cells and the apoptosis is associated with an increase in intracellular reactive oxygen species (ROS) production and reduction of mitochondrial membrane potential (MMP).

Current and potential applications of bismuth-based drugs

: Bismuth compounds have been used extensively as medicines and in particular for the treatment of gastrointestinal ailments. In addition to bismuth's well known gastroprotective effects and efficacy in treating H. pylori infection it also has broad anti-microbial, anti-leishmanial and anti-cancer properties. Aspects of the biological chemistry of bismuth are discussed and biomolecular targets associated with bismuth treatment are highlighted. This review strives to provide the reader with an up to date account of bismuth-based drugs currently used to treat patients and discuss potential medicinal applications of bismuth drugs with reference to recent developments in the literature. Ultimately this review aims to encourage original contributions to this exciting and important field.

Synthesis, structure, spectroscopy of four novel supramolecular complexes and cytotoxicity study by application of multiple parallel perfused microbioreactors

Synthesis of four supramolecular complexes and study of their cytotoxicity using multiple parallel perfused microbioreactors.

Novel antitumor agent, trilacunary Keggin-type tungstobismuthate, inhibits proliferation and induces apoptosis in human gastric cancer SGC-7901 cells

A new one-dimensional chain-like compound of tungstobismuthate, [(W(OH)2)2 (Mn(H2O)3)2(Na3(H2O)14)(BiW9O33)2](Himi)2·16H2O (1) (imi = iminazole), has been synthesized in aqueous solution. The structure of 1 was identified by elemental analysis, IR, thermogravimetry (TG), X-ray photoelectron spectroscopy (XPS), (183)W-NMR, and single crystal X-ray diffraction. To investigate the inhibitory effect of 1 on human gastric adenocarcinoma SGC-7901 cells, cell proliferation and apoptosis initiation were examined by MTT assay (MTT = 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazoliumbromide), flow cytometry, nuclear staining, transmission electron microscopy, single cell gel electrophoresis, DNA fragmentation, and Western blotting. The results showed that 1 inhibited cell proliferation and induced apoptosis in SGC-7901 cells in dose-dependent manner. In addition, 1 also decreased the expression of bcl-2 protein and nuclear factor-κB p65 protein in SGC-7901 cells. And expression of bcl-2 protein exhibits a decreasing trend with increase of concentration of 1. Thus, 1 possessed a potential antitumor activity in SGC-7901 cells. This suggests that polyoxotungstates will provide a promising and novel antitumor agent in prevention and treatment of gastric adenocarcinoma.

Crystal structure, antibacterial and cytotoxic activities of a new complex of bismuth(III) with sulfapyridine

A new complex of Bi(III) and sulfapyridine was synthesized and characterized by elemental analysis, atomic absorption spectrometry, conductivity analysis, electrospray ionization mass spectrometry (ESI-MS), infrared spectroscopy, and single crystal X-ray diffraction methods. The antimicrobial and the cytotoxic activities of the compound were investigated. Elemental and conductivity analyses are in accordance to the formulation [BiCl₃(C₁₁H₁₁N₃O₂S)₃]. The structure of the complex reveals a distorted octahedral geometry around the bismuth atom, which is bound to three sulfonamidic nitrogens from sulfapyridine, acting as a monodentate ligand, and to three chloride ions. The presence of the compound in solution was confirmed by ESI-MS studies. The complex is 3 times more potent than the ligand against Salmonella typhimurium, 4 times against Staphylococcus aureus, Shigella dysenteriae, and Shigella sonnei and 8 times more potent against Pseudomonas aeruginosa and Escherichia coli. The compound inhibits the growth of chronic myelogenous leukemia cells with an IC₅₀ value of 44 μM whereas the free ligand has no effect up to 100 μM.

One dodecahedral bismuth(III) complex derived from 2-acetylpyridine N(4)-pyridylthiosemicarbazone: synthesis, crystal structure and biological evaluation

One dodecahedral bismuth(III) complex [Bi(HL)(NO(3))(3)] (1) (HL = 2-acetylpyridine N(4)-pyridylthiosemicarbazone) has been synthesized and structurally characterized. The analytical data reveals the formation of 1 : 1 (metal : ligand) stoichiometry. The bismuth(III) ion is nine-coordinated by one electron pair (6s(2)) of the bismuth(III) atom, two nitrogen and one sulfur atoms from the N(2)S tridentate ligand and five oxygen atoms from three nitrate ions. Biological studies, carried out in vitro against eight selected bacteria, and four human cancer cells, respectively, have indicated that 1 shows better growth-inhibiting properties. Upon further investigation, 1 might produce cytotoxicity through apoptosis.