Band 42, Heft 1

Soil contamination with heavy metal content is a growing concern throughout the world as a result of industrial, mining, agricultural and domestic activities. Fungi are the most common and efficient group of heavy metal resistant microbe family which have potential for metal bioleaching. The use of filamentous fungi in bioleaching of heavy metals from contaminated soil has been developed recently. The current study intends to isolate a strain with the ability to degrade the pH value of the liquid medium. Identification results based on morphological and molecular biological analysis gave a 98% match to Aspergillus flavus . Batch experiments were conducted to select the optimal conditions for bioleaching process which indicated that 130 mg/ L sucrose, neutral pH and temperature of 30°C were more suitable during 15-day bioleaching experiments using A. flavus . In one-step bioleaching, the bioleaching efficiencies were 18.16% for Pb, 39.77% for Cd and 58.22% for Zn +2 , while two-step bioleaching showed efficiencies of 16.91% for Pb, 49.66% for Cd and 65.73% for Zn +2 . Overall, this study indicates that bioleaching of heavy metals in contaminated soil using A. flavus has the potential for contaminated soil remediation.

Based on a semirigid tricarboxylate ligand 5-((4-carboxyphenoxy)methyl)benzene-1,3-dioic acid (H 3 L), a new Pb(II)-based coordination polymer formulated as [Pb(HL)(H 2 O)](H 2 O) ( 1 ) was synthesized under solvothermal conditions and characterized by single-crystal X-ray structural analysis, power X-ray diffraction, and elemental analysis. Compound 1 is a two-dimensional layered structure formed by the connection of the one-dimensional Pb(II)-based secondary building unit chains with the partly deprotonated HL ligands, which are further extended into three-dimensional supermolecular structures through the H-bonds. Furthermore, the size of the as-prepared 1 could be downsized into the nano region through a simple ultrasonic method. Finally, the antilung cancer activities of 1 and the nanosized 1 have been probed via the MTT assay against three human lung cancer cell lines (A549, H1299, and PC9).

A new lead(II)-organic architecture [Pb(HL) (dipyrido[3,2-a:2′,3′-c]phenazine (dppz))](H 2 O) 2 ( 1 ) was successfully prepared under hydrothermal conditions by using organic-acid linker 5-((4-carboxyphenoxy)methyl) benzene-1,3-dioic acid (H 3 L) and N-donor chelating ligand dppz. The as-prepared complex was characterized by single-crystal X-ray structural analysis, powder X-ray diffraction (PXRD), and elemental analyses, which reveals that complex 1 shows a one-dimensional (1D) chain-like structure that is further extended to the 3D supermolecular network through H-bond and π-π interactions. Complex 1 was transformed to the nanoscale regime (ca. 190 nm) by mechanical grinding to yield the nano- 1 , maintaining its structure and crystallinity. Furthermore, the anticancer activity of the nano- 1 toward the human neuroglioma cells (U251, U87, SHG-44, and A172) was evaluated via the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay.

We report here the coordination-mediated resolution of methyl o -chloromandelate, which is a key intermediate for clopidogrel, in preparative scale. The reaction of CaO, optically pure (2 R , 3 R )- O , O ′-dibenzoyltartaric acid, and methyl o -chloromandelate in ethanol solution afforded a mixed-ligands calcium(II) complex that was further purified by stirring of the crystals in hot methanol. Methyl ( R )- o -chloromandelate was obtained in good enantiomeric excess value (>99.5%) and yield (71%) by treatment of the complex with acid. At the same time, (2 R , 3 R )- O , O ′-dibenzoyltartaric acid was recovered in 72% yield. In addition, methyl ( S )- o -chloromandelate was obtained in good enantiomeric excess value (>99.5%) and yield (73%) by recovery from the mother liquor and resolution with the same procedure for methyl ( R )- o -chloromandelate, except that (2 S , 3 S )- O , O ′-dibenzoyltartaric acid was used as the resolving reagent.

1-(3-trifluoromethylphenyl)piperazine (TFMPP) is one of the commonly abused drugs in the illicit drug market. Its detection or identification is important to investigate. In this work, density function theory (DFT) approach was used to analyse silicon or aluminium doped C 60 fullerenes and TFMPP interactions for possible sensor applications. Stabilities of the investigated systems were examined in terms of the adsorption energies of TFMPP onto Si and Al decorated fullerenes. It was found that AlC 59 +TFMPP resulted in higher adsorption energies compared to SiC 59 +TFMPP. We also considered the band gap energy and concluded that Si and Al decorated fullerenes are sensitive to the presence of TFMPP in both the gas phase and aqueous medium.

Reaction of anhydrous tin(IV) chloride with mono functional bidentate Schiff bases (sb n H), in 1:2 molar ratios, gives complexes of the type, [(sb n ) 2 SnCl 2 ] (1-4) (where, n=1-4; sb=2-(((4-chlorophenyl)imino)methyl)phenol, sb 1 H, I; 2-(((4-bromophenyl)imino)methyl) phenol, sb 2 H, II; 2-(((4-chlorophenyl)imino)methyl)-6-methoxyphenol, sb 3 H, III and 2-(((4-bromo phenyl)imino)methyl)-6-methoxyphenol, sb 4 H, IV . All the tin(IV) complexes (1-4) were colored solid and soluble in organic solvents. The synthesized complexes were characterized by elemental analysis (C, H, N and Sn), IR, UV-Vis, NMR ( 1 H, 13 C and 119 Sn) spectroscopy and mass spectrometry. On the basis of spectroscopic studies, six coordination around tin atom has been proposed tentatively. The computational calculations using density functional theory (DFT) of ligands and complexes were also performed to obtained optimized molecular geometry, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) and other parameter.

The complexes of 2-(menthoxycarbonyl)ethyltin chloride, MenOCOCH 2 CH 2 SnCl 3 ⋅L (Men = Menthyl, L = benzyl phenyl sulfoxide (bpSO), 1 ; 2,2’-bipyridine (bpy), 2 ; 1,10-phenanthroline (phen), 3 ) and [MenOCOCH 2 CH 2 SnCl 2 (OCH 3 )] 2 ( 4 ), have been synthesized and characterized by means of elemental analysis, FT-IR, NMR ( 1 H, 13 C and 119 Sn) spectra. The crystal structures of 1 , 3 and 4 have been determined by single crystal X-ray diffraction. The tin atoms in 1 - 4 are all hexa-coordinated. The tin atom in 1 adopts a distorted [CSnCl 3 O 2 ] octahedral geometry with an oxygen atom of the ligand and an intramolecular coordination of the oxygen atom from the carbonyl group to the tin atom. Complex 3 possesses a distorted [CSnCl 3 N 2 ] octahedral geometry with two nitrogen atoms of a chelating phen ligand. The carbonyl oxygen atom of the ester moiety is not coordinating. Compound 4 is a centrosymmetric dimer with a four-membered Sn 2 O 2 ring, and the tin atom has a distorted [CSnCl 2 O 3 ] octahedral geometry with an intramolecular C=O→Sn coordination and intermolecular methoxy bridging.

We report on the synthesis of a new bismuth aryloxide molecule Bi[OC 6 H 4 (CH 2 C 6 H 5 )-2] 3 ( 1 ), which was characterized by NMR and IR spectroscopy as well as single-crystal X-ray diffraction analysis. A characteristic structural feature is the dimeric unit with a central Bi 2 O 2 core resulting from μ -binding phenolates. In addition, both bismuth atoms show a Bi⋅⋅⋅π arene interaction with a quite short Bi⋅⋅⋅π centroid distance of 3.11 Å in the solid state.

A new mixed-ligand diorganotin(IV) complex, [μ-(4-dpe){Me 2 Sn(cup) 2 } 2 ] ( 1 ), was synthesized by reacting dimethyltin(IV) dichloride with 1,2-di(4-pyridyl)ethylene (4-dpe) and ammonium N-Nitroso-N-phenylhydroxylamine (cup). The prepared complex was fully characterized by PXRD, 1 H, 13 C and 119 Sn NMR, IR, and UV spectra and elemental analysis (CHN). The structural analysis of complex 1 by X-ray diffraction showed that this compound consists of centrosymmetric binuclear units that crystallize in the monoclinic system with the space group of P 2 1/ c . Thermal behavior of this complex was interrogated by thermogravimetric and differential thermal analysis (TGA and DTA) under air atmosphere. The study of thermal behavior and luminescence properties of prepared diorganotin(IV) complex exhibited that this complex can be used as a emitting layer in the preparation of optical devices. The prepared coordination compound was used in two different concentrations in the manufacture of two light-emitting diodes (OLEDs).

A new Pb(II) complex, [Pb(8-OQ)(4-NB)], where 8-OQ = 8-hydroxyquinolinate, 4-NB = 4-nitrobenzoate, has been synthesized and characterized by elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction. The single crystal X-ray analysis reveals that the complex possesses a tetranuclear Pb 4 O 4 cubane structure. The Pb(II) atom is coordinated by three triply bridging phenolic hydroxyl O atoms of 8-OQ ligands, then the tetranuclear Pb system is formed resulting in a tetrahedral cage. The interaction of complex with HS-DNA in Tris buffer was studied by UV−vis absorption spectrum and fluorescence ethidium bromide displacement experiment with an intrinsic binding constant of 1.52×10 4 M -1 and a linear Stern–Volmer quenching constant of 6.77×10 3 M -1 . Anticancer activity against MCF-7, HepG-2 and A549 cell lines of complex was also determined by the MTT-based assay. The results showed the complex can inhibit proliferation of these three kinds of tumor cells and is less cytotoxic than cisplatin.

This article focuses on the aqueous complexation between two flavonoids (morin and morinsulfonate) and Pb 2+ at constant ionic strength I=0.5 M (NaClO 4 ). The determination of stability constants of ML complexes were performed at wide pH range. Two obtained constants are 14.8 ± 0.1 and 15.2 ± 0.1 logarithmic units for morin and morin-5’-sulfonic acid, respectively. For estimating the thermodynamic stability of the complexes studied, the Def2-SV(P)/DFT/PBE0/SMD method has been used. Different computational models were tested to describe the data obtained. The theoretical values of logK reproduce the experimental parameters within reasonable errors.

Lead as a potent environmental and occupational pollutant, exerts its toxic effect mainly through oxidative stress induction. Currently, chelation therapy is the only medical management of metal intoxications in clinic, but its administration is associated with various side effects as well. In this study the protective effect of synthetized Piroxicam derivative was evaluated against lead toxicity in vitro. First the chelating activity of Piroxicam derivative was studied through Jobs method and 13 C{ 1 H} NMR spectroscopy. Then the cytoprotective effect of Piroxicam derivative (10, 20, 50, 100 and 200 μg/mL) was evaluated and compared with that of EDTA (30 μg/mL) in the presence of lead nitrate (30 μg/mL). The EC50 value of Piroxicam derivative was calculated as well. Finally, the chelation efficacy and antioxidant effects of Piroxicam derivative in EC50 and 2EC50 values was assessed and compared with that of EDTA. Results showed that Piroxicam derivative chelates lead ion as much as EDTA. Moreover, Piroxicam derivative prevented lead-induced cells death more effectively than EDTA which is may due to its potent innate antioxidant activity. In conclusion, the synthetized Piroxicam derivative with possessing potent chelating activity as well as potent antioxidant activity, could be considered as potential drug target in management of toxic metals poisoning.

Geometry optimization of the mixed Si n Re (n=12, 16, 20, 24, 28, 32, 36, and 40) cages with doublet, quartet, and sextet spin configurations is carried out systematically at the UHF/LanL2DZ level. Equilibrium structures, total energies, and stabilities of Re@Si n cages are presented and discussed. The calculated results show that all Re@Si n cages of highest symmetry undergo slight distortion into much more stable structures of lower symmetry. The Re atom in the Re@Si n (n=12, 16, 20, 24, 28, 32, 36, and 40) cages deviates from the cage center site of Si n fullerenes. Charge-transfer between Re and Si atoms makes a contribution to the stability of the Si n fullerenes; In addition, the relative stability is discussed, the most stable geometry is assigned.

Two new diorganotin(IV) complexes with the general formula (RC 7 H 6 ) 2 Sn(L) (where RC 7 H 6 = p -ClBn, C1 ; and p -FBn, C2 ) were prepared based on the reaction of 2,3- bis (4-hydroxysalicylidene-amino)-maleic nitrile ( L ) with substituted dibenzyltin(IV) dichloride. The structures were confirmed by elemental analysis, Fourier transform infrared (FT-IR), proton and carbon nuclear magnetic resonance ( 1 H and 13 C NMR). They were tested against several cancer cell lines by using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. C1 , which was most effective against MCF-7 breast cancer cell line, was further investigated in formulation and encapsulation studies, including drug encapsulation efficiency, particle size, morphology and in vitro drug release. An encapsulation of about 90% was achieved with particles of 128 nm average diameter. Field emission scanning electron microscopy (FESEM) confirmed a spherical shape for the encapsulated C1 . The cumulative drug release over a period of 60 days in phosphate buffered saline (PBS) at pH 7.4 was 75%. Based on these results, the formulated drug has the potential of a slow release drug for cancer chemotherapy.

In the present work ternary composite InBiS 3 -In 2 S 3 -Bi 2 S 3 (IBS) thin films are developed using a homogeneous mixture of precursors [Bi(S 2 CN(C 2 H 5 ) 2 ) 3 ] 2 (1) and [In(S 2 CNCy 2 ) 3 ]‧2py (2) , separately in toluene and chloroform solutions at 500°C under an inert atmosphere of argon gas via aerosol assisted chemical vapor deposition (AACVD) technique. The phase purity, chemical composition and morphological study of both the films deposited from toluene and chloroform solutions are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and Field emission scanning electron microscopy (FESEM). The surface morphology showed rod like structure of the films developed from toluene while the films grown from chloroform solution give flake like shapes. The UV-visible spectroscopy explicated that the thin films developed from toluene and chloroform solutions show wide range absorption in whole visible region. Linear Scan voltammetry results show that both the films give negligible dark current, however, the films fabricated from toluene solution give a sharp steep curve with maximum photocurrent density of 2.3 mA‧cm -2 at 0.75 V vs Ag/AgCl/3M KCl using 0.05 M sodium sulphide solution under AM 1.5 G illumination (100 mW‧cm -2 ), while the film grown from chloroform generates a photocurrent density of 2.1 mA‧cm -2 under similar conditions. The LSV outcomes are further supported by electrochemical impedance spectroscopy (EIS) that gives charge transfer resistance (R ct ) value of 8,571 Ω for the films developed from toluene as compared to films fabricated from chloroform with R ct value of 12,476 Ω. Graphical Abstract

Density functional theory (DFT) studies at B3LYP/6-31G (d) (Becke, 3-parameter, Lee-Yang-Parr) level were performed to evaluate adsorption interactions between ethylene oxide (EO) molecule, and pristine and transition metals (TM) (i.e., Sc, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu) doped ZnO nanocluster (TM-doped Zn 12 O 12 ). The adsorption energy (E ad ), band gap energy (E g ), Mulliken charge transfer (Q T ) and molecular electrostatic potential (MEP) were calculated to examine the sensitivity of the Zn 12 O 12 and its TM-doped forms toward EO detection. It was found that in contrast to the pristine Zn 12 O 12 , the electronic properties of TM-doped Zn 12 O 12 were sharply sensitive to the presence of EO gas molecules. The results revealed that among the studied TM-doped Zn 12 O 12 , Cr- and V-doped Zn 12 O 12 have great potential applicability as EO sensor, due to their highest E g change (ΔE g ) values, after the EO adsorption. Moreover, the density of state (DOS) calculations confirmed that strong electronic interaction between Cr- and V-doped Zn 12 O 12 and EO molecules can makes them interesting empirical candidate for detection and adsorptive removal of EO gas molecules.

Thermal rearrangement of the 1,2-bis(silylene), [{(4-Bu t Ph)C(NDip) 2 }Si−] 2 (Dip = 2,6-diisopropylphenyl, leads to the silyl-silylene, {(4-Bu t Ph)C(NDip) 2 }Si−Si(H) {N(Dip)C(=NDip)(4-Bu t Ph -H )}, via an intramolecular C−H activation reaction. The X-ray crystal structure, and limited spectroscopic data, for the compound are reported. The structure of the silyl-silylene incorporates an exocyclic imine fragment, which is unprecedented for this compound class.

Arsenic (As) is a semi-metal which causes health problems in human, and immune system has been documented as one of the main target of arsenic toxicity. Apoptosis has a crucial role in regulation of immune system, but it can also have an important role in As immune suppression. So, we decided to assess the comprehensive mechanism of As cytotoxic effect on lymphocytes isolated from human blood. We determine the direct effect of arsenic on human lymphocytes which have a key role in immune system functionality. To evaluate the mechanism of arsenic toxicity on human lymphocytes, we use accelerated cytotoxicity mechanisms screening (ACMS) technique. Lymphocytes were isolated from blood of healthy persons using Ficoll-paque PLUS standard method. Following treatment of human lymphocytes with 0.05-50 μM of arsenic for 12 h, cell viability was measured. For determination of mechanistic parameters, isolated human lymphocytes incubated with 1/2IC 5012h (7.5 μM), IC 5012h (15 μM) and 2IC 5012h (30 μM) for 2, 4 and 6 h. The results of this study demonstrate arsenic-associated apoptosis in human lymphocytes is mainly through enhancement of intracellular calcium which causes oxidative stress and following adverse effect on lymphocytes organelles (like mitochondria and lysosome). Involvement of cellular proteolysis, activation of caspase-3, lipid peroxidation and stimulation of cytokines (IL 2 , INF-gamma and TNF-alpha) production were also associated with arsenic induced lymphocyte toxicity.

Fullerenes, with their extensive application potentials, have been receiving attention for their possible usage as drug delivery vehicles and devices for sensor technologies. In this work, the optimized molecular geometries, some diagnostic geometric parameters, electronic characteristics, natural bond orbital examinations and the interaction phenomena between C 60 , Si- or Al-doped C 60 and phenylalanine amino acid molecule were investigated by the quantum mechanical calculations. It is observed that the impurity addition and using water as the solvent intensify the interaction between fullerene and amino acid system. These lead to various alterations in the electronic properties and NH stretching values of the clusters studied.

Fullerenes have received attentions due to their versatile properties. Molecular structures and electronic properties namely binding energy, band gap, electrophilicity index and molecular topological analysis were studied for undoped and silicon doped C 20 fullerenes and favipiravir in order to search for possible application of the systems as drug delivery vehicles. Density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM) were used for the research. Molecular structures having the interaction edges of SiC 19 … OH in water and SiC 19 …C=O in gas phase were found as those most stable with binding energies of -57.28 kcal/mol and -43.46 kcal/mol correspondingly. The results and parameters found in this research may provide additional insights into drug delivery systems.

The oxidation of phenoxatellurine (PT) with conc. H 2 SO 4 was reinvestigated. Two crystalline products, namely [PT 2 ][H 3 O](SO 4 H) 3 ( 1 ) and [PT](SO 4 ) ( 2 ) were isolated and fully characterized by X-ray crystallography. The structure of 1 features [PT 2 ] 2+ dications giving rise to double-decker structures with two parallel PT layers that arise from dimerisation of two radical cations [PT]˙ + . The [PT 2 ] 2+ dications and the hydrogensulfate ions are associated via secondary Te···O interations. The oxonium ion and the hydrogensulfate ions are involved in hydrogen bonding. The structure of 2 comprises ion pairs consisting of [PT] 2+ dications and sulfate ions, which form a 2D coordination polymer. In addition, adjacent sulfate ions in the crystal lattice bind to tellurium atoms via secondary secondary Te···O interations.