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C 3 symmetric trinuclear cis-[MoO2] complexes have been isolated successfully and explored as catalysts for the synthesis of 2-methyl-1,4-naphthoquinone (vitamin K3, Menadione), olefin epoxide and brominated phenol derivatives.

[Abstract] Ligands H4sal-dag (I) and H4Brsal-dag (II) derived from 1,3-diaminoguanidine and salicylaldehyde or 5-bromosalicylaldehyde react with one or 2 mol equivalent of vanadium precursor to give two different series of vanadium complexes. Thus, complexes [VIVO(H2sal-dag) (H2O)] (1) and [VIVO(H2Brsal-dag) (H2O)] (2) were isolated by the reaction of an equimolar ratio of these ligands with [VIVO(acac)2] in MeOH. In the presence of K+/Cs+ ion and using aerially oxidized [VIVO(acac)2], the above reaction gave complexes [K(H2O){VVO2(H2sal-dag)}]2 (3), [Cs(H2O){VVO2(H2sal-dag)}]2 (4), [K(H2O){VO2(H2Brsal-dag)}]2 (5), and [Cs(H2O){VVO2(H2Brsal-dag)}]2 (6), which could also be isolated by direct aerial oxidation of complexes 1 and 2 in MeOH in the presence of K+/Cs+ ion. Complexes [(H2O)VIVO(Hsal-dag)VVO2] (7) and [(H2O)VIVO(HBrsal-dag)VVO2] (8) were isolated upon increasing the ligand-to-vanadium precursor molar ratio to 1:2 under an air atmosphere. When I and II were reacted with aerially oxidized [VIVO(acac)2] in a 1:2 molar ratio in MeOH in the presence of K+/Cs+ ion, they formed [K(H2O)5{(VVO2)2(Hsal-dag)}]2 (9), [Cs(H2O)2{(VVO2)2(Hsal-dag)}]2 (10), [K2(H2O)4{(VVO2)2(Brsal-dag)}]2 (11), and [Cs2(H2O)4{(VVO2)2(Brsal-dag)}]2 (12). The structures of complexes 3, 4, 5, and 9 determined by single-crystal X-ray diffraction study confirm the mono-, bi-, tri-, and tetra-anionic behaviors of the ligands. All complexes were found to be an effective catalyst for the oxidation of benzoin to benzil via oxygen atom transfer (OAT) between DMSO and benzoin. Under aerobic condition, this oxidation also proceeds effectively in the absence of DMSO. Electron paramagnetic resonance and 51V NMR studies demonstrated the active role of a stable V(IV) intermediate during OAT between DMSO and benzoin. M.R.M. thanks the Science and Engineering Research Board (SERB), Department of Science and Technology, New Delhi, India for the financial support (grant no. CRG/2018/000182) Government of India. Science and Engineering Research Board; CRG/2018/000182

Two dioxidomolybdenum(VI) complexes, [MoVIO2{H2dfba(bhz)2}(H2O)] (1) and [MoVIO2{H2dfba(fah)2}(H2O)] (2) of ligands H4dfba(bhz)2 (I) and H4dfba(fah)2 (II) (H2dfba = 3,5-diformyl-4-hydroxybenzoic acid, Hbhz = benzoylhydrazide and Hfah = 2–furanoylhydrazide), respectively and their corresponding heterogenized complexes [MoVIO2{Hdfba(bhz)2}(H2O)]@APTMS-TiO2 (3) and [MoVIO2{Hdfba(fah)2}(H2O)]@APTMS-TiO2 (4) supported on amine-functionalized titanium dioxide (APTMS-TiO2, III) have been isolated and characterized by various spectroscopic techniques (FT-IR, UV–vis, diffusion reflectance, 1H and 13C NMR), elemental analysis (C, H and N), thermal, TEM and powder-XRD studies. Single-crystal X-ray study of [MoVIO2{H2dfba(bhz)2}(EtOH)]·EtOH (1a·EtOH) confirms the octahedral structure. Both homogeneous and heterogeneous complexes have been explored as phenoxazinone synthase mimicking catalysts in the oxidation of 2-aminophenol to 2-aminophenoxazine-3-one in acetonitrile in the presence of aq. H2O2. The kcat value for the phenoxazinone synthase-like activity was found to be 1.46 × 10–3 and 3.26 × 1 0–3 min–1 for catalysts 1 and 2, respectively. Catalysts 1, 2, 3 and 4 also gave 91, 86, 94 and 88 % yield of 2–aminophenoxazine-3-one (APX), respectively, under the optimized reaction conditions.

This article belongs to the Special Issue Multicomponent Catalytic Reactions under Green Conditions [Abstract] Two new monobasic tridentate O⁀N⁀N donor ligands, HL1 (I) and HL2 (II) have been obtained in two steps by reacting phenylhydrazine and salicylaldehyde or 3,5-di-tert-butylsalicylaldehyde and then reacting the resulting compounds with 2-chloromethylbenzimidazole in the presence of triethylamine. The reaction of [VIVO(acac)2] with these ligands in a 1:1 molar ratio in dry methanol led to the formation of homogeneous oxidovanadium(IV) complexes [VIVO(acac)L1] (1) and [VIVO(acac)L2] (2). Immobilization of these complexes on chloromethylated polystyrene (PS-Cl) cross-linked with divinyl benzene resulted in corresponding polymer-supported heterogeneous complexes PS-[VIVO(acac)L1] (3) and PS-[VIVO(acac)L2] (4). Ligands (I and II), homogeneous complexes (1 and 2) and heterogeneous complexes (3 and 4) have been characterized using elemental analysis and various spectroscopic techniques. A single crystal X-ray diffraction study of I and 1 further confirms their structures. The oxidation state IV of vanadium in these complexes was assured by recording their EPR spectra while heterogeneous complexes were further characterized using field emission-scanning electron microscopy (FE-SEM) combined with energy dispersive X-ray analysis (EDS) and atomic force microscopy (AFM). All vanadium complexes have been explored for their catalytic potential to one-pot-three-component reactions (reagents: benzil, ammonium acetate and various aromatic aldehydes) for the efficient synthesis of 2,4,5-triphenyl-1H-imidazole derivatives (nine examples). Various reaction conditions have been optimized to obtain a maximum yield (up to 96%) of catalytic products. It has been found that heterogeneous complexes show excellent catalytic activity and are recyclable up to five catalytic cycles. This research was funded by the Science and Engineering Research Council (CRG/2018/000182), the Department of Science and Technology, New Delhi, the Government of India India. Science and Engineering Research Council; CRG/2018/000182

With the aim to incorporate pharmacophore motifs into the Ru(II)-polypyridyl framework, compounds [Ru(II)(1,10-phenantroline)

International audience; Two homometallic ytterbium dimers are prepared and their solution-state photoluminescence and upconversion properties are investigated. Both complexes exhibit two-photon cooperative luminescence upconversion in the visible region (lambda(em) approximate to 510 nm) upon excitation into the near-infrared Yb F-2(5/2)

In this work four vanadium complexes (compounds 1, 2, 3 and 4) and one molybdenum complex (compound 5) with hydrazone ligands derived from pyridoxal were synthesized and characterized. All compounds are mononuclear species, two of them (compounds 3 and 5) are dioxide complexes and the other three (compounds 1, 2 and 4) monoxide complexes. The vanadium atom of the compound 3 is five-coordinated and all the other compounds have a six coordinated environment polyhedron. The poses for the potential intercalation of the compounds 2 and 3 with DNA were obtained by using AutoDock software. Optimizations were also performed at PM6-D3H4 semi-empirical level whereas the study of the nature of the interaction was carried out by means of the Energy Decomposition Analysis and the Non-Covalent Interaction index by using in both cases Density Functional Theory computations. The cytotoxicity in lung cancer cells (A549 cell line) of all the compounds was also evaluated. After 24 h of treatment, vanadium complexes showed high values of IC50, between 419.93 ± 22.58 and 685.88 ± 46.55 μM. After 48 h, the results showed that the compound 3 had the lowest IC50 value, 65.32 ± 9.95 μM, and the compound 2 the highest value, 375.28 ± 32.09 μM. The molybdenum complex showed the lowest IC50 value at 48 h (11.22 ± 1.34 μM). The toxicity of the compounds 3, 4 and 5 was tested in vivo, using zebrafish model, and the molybdenum complex showed higher toxic effects than the studied vanadium complexes., This research was financially supported by Fundação para a Ciência e a Tecnologia (FCT) by means of the projects PTDC/QUI-QFI/29236/2017, UIDB/04046/2020, and UIDP/04046/2020. V.V. thanks Ministerio de Educación, Cultura y Deporte for a Beatriz Galindo Award [BEAGAL18/00142]. A.G. is thankful to ARAID – Fundación Agencia Aragonesa para la Investigación y el Desarrollo for current funding in the frame of ARAID researchers. We gratefully acknowledge Xunta de Galicia for the collaboration agreement “Development of research strategic actions UDC I+D+i 2021-2022: CICA-Disrupting Projects 2021SEM-A3 [NanoCool]”.

Microtubule affinity-regulating kinase 4 (MARK4) is a serine/threonine kinase involved in the phosphorylation of MAP proteins that regulates microtubule dynamics and abets tumor progression by participating in oncogenic signaling pathways. It is overexpressed in multiple human malignancies and no drug is available for this potential therapeutic target at present. Therefore, using the structure based drug design strategy, a library of hydroxylamine derivatives of morpholine were designed and synthesized as small molecule inhibitors of MARK4. Compound 32 having the CF3 group at the ortho position of the phenyl ring tethered with the >CNOH core and the hinge binder morpholine component was found to be a potent and selective inhibitor of MARK4 over thirty other serine-threonine kinases. Study of cell viability and compound induced morphological changes in MCF-7 cancer cells discovered that molecule 32 caused death of cancerous cells through the mechanism of apoptosis. Compound 32 may be transported and delivered to the target site through the blood stream, and has promising antioxidant potential. Such bio-active molecules could serve as optimized lead candidates in drug discovery for cancer treatment through MARK4 inhibition.

The reaction of dibasic tetradentate ONNO donor Mannich bases, derived from ethylenediamine and 2,4–di–tert–butylphenol (H2L1) (I), 2,4–di–methylphenol (H2L2) (II), 2–tert–butyl–4–methylphenol (H2L3) (III) and 2,4–di–chlorophenol (H2L4) (IV), with UVIO2(MeCOO)2·2H2O in a 1:1 M ratio in refluxing MeOH gave the corresponding mononuclear trans-dioxidouranium(VI) complexes of the type trans-[UVIO2L(MeOH)] (H2L = H2L1 to H2L4) (1–4). The synthesized complexes are stable in air, reddish-brown in color and soluble in most solvents. These complexes are characterized by elemental analysis, various spectroscopic (FT-IR, UV/Vis, 1H and 13C NMR) techniques and single-crystal X-ray analysis of 3 and 4. The complexes adopt distorted pentagonal bipyramidal geometry around the metal centre. The ligand acts as tetradentate, coordinating through two phenolato oxygen and two imino nitrogen atoms; two oxido groups are trans to each other. These complexes are used as catalysts to study the oxidative bromination of thymol and styrene. The catalytic oxidative bromination of thymol resulted in the formation of three products namely, 2-bromothymol, 4-bromothymol and 2,4-dibromothymol while oxidative bromination of styrene gave two products, 2-bromo-1-phenylethane-1-ol and 1-phenylethane-1,2-diol. In order to find out the optimized reaction conditions for the fixed concentration (10 mmol) of substrate, effects of different amounts of catalyst, KBr, HClO4, and oxidant (H2O2) have been investigated. Under the optimized reaction conditions, all the complexes have shown good catalytic potentials for the oxidative bromination of substrates, establishing the functional similarity to vanadium dependent haloperoxidases. Changes in the UV–visible absorption spectra of dioxidouranium(VI) complexes upon addition of H2O2 suggest the formation of the corresponding oxidoperoxidouranium(VI) complexes.

Two N-substituted 2-methyl-4-/5-nitroimidazole derivatives (3 & 4) have been synthesized by K2CO3 catalyzed reaction between 2-methyl-5-nitro-1H-imidazole (1) or metronidazole (2) and acrylonitrile. The derivates were obtained in good yields and characterized by IR spectroscopy, 1H-NMR spectroscopy, and ESI-MS mass spectrometry. Single-crystal X-ray structure analysis supported the formation of the derivatives, which were further complemented by DFT studies. The in-vitro anticancer activity against human colon cancer cell line (SW-480) has also been performed. To underpin the affinity of the reported derivatives towards nucleic acids, both in-vitro (ct-DNA binding studies) and in-silico (docking studies) techniques were employed. Despite their small sizeand the presence of pharmacologically active core, both 3 (IC50 > 160 μg/mL, Kb = 0.3 × 105 M−1, ΔG = −5.4 kcal/mol) and 4 (IC50 > 160 μg/mL, Kb = 3.0 × 105 M−1, ΔG = −5.6 kcal/mol) exhibited moderate anticancer activity and DNA affinity.

The soil water content is one of the main factors influencing the beginning of soil particle movement by the wind. Although, some authors studied the effect of soil water content on threshold wind velocity and have defined a value to prevent wind erosion, the critical relative soil water content (HRc), most of them used disturbed and/or sieved soil samples. Under these conditions, the effect of aggregation, i.e. the natural state of the soil, cannot be evaluated. So, our objective was to determine HRc in soils with different textures in Semiarid Argentinian Pampas Region (SAPR) using uncrushed soil samples under variable wind velocities. Wind tunnel simulations were performed at three wind speeds (2.1, 8.0 and 10.5 m s−1) during 3 min in each case. Results indicated that the quantity of collected soil (Q) decreased with increasing relative soil water contents (HR) up to a HRc value at which it became negligible. HRc values were lower in fine textured soils than in coarse soils. All soils showed increasing HRc values as wind velocity increased from 2.1 to 10.5 m s−1, while the wind velocity effect is more important in coarse textured soils. HRc was negatively related to micro-aggregation in a linear way. For that reason, soils with high fine silt and clay content need lower HRc values to inhibit wind erosion. In conclusion, not only texture is important factor in defining the HRc value at a specific wind velocity but also the micro and macro-aggregation of the soils. Fil: de Oro, Laura Andrea. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Patagonia Confluencia. Instituto de Ciencias de la Tierra y Ambientales de la Pampa. Grupo Vinculado Fundacion Centro de Salud E Investigaciones Medicas | Universidad Nacional de la Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de la Pampa. Grupo Vinculado Fundacion Centro de Salud E Investigaciones Medicas.; Argentina Fil: Colazo, Juan Cruz. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Avecilla, Fernando. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Buschiazzo, Daniel Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina Fil: Asensio, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina

International audience; Two new ruthenium complexes, [Ru(h 5-Cp)(PPh 3)(2,2'-bipy-4,4'-R)] þ with R ¼-CH 2 OH (Ru1) or dibiotin ester (Ru2) were synthesized and fully characterized. Both compounds were tested against two types of breast cancer cells (MCF7 and MDA-MB-231), showing better cytotoxicity than cisplatin in the same experimental conditions. Since multidrug resistance (MDR) is one of the main problems in cancer chemotherapy, we have assessed the potential of these compounds to overcome resistance to treatments. Ru2 showed exceptional selectivity as P-gp inhibitor, while Ru1 is possibly a substrate. In vivo studies in zebrafish showed that Ru2 is well tolerated up to 1.17 mg/L, presenting a LC 50 of 5.73 mg/L at 5 days post fertilization.

The stable dibasic tetradentate ligand 1,4-bis-(2-hydroxy-3,5-dimethylbenzyl)piperazine (H2pip-2,4-dmp, I) prepared by reacting 2,4-dimethylphenol with piperazine in the presence of formaldehyde reacts with [MoVIO2(acac)2] and [UVIO2(CH3COO)2] in equimolar ratio to give neutral hexa-coordinated [MoVIO2(pip-2,4-dmp)] (1) and hepta-coordinated [UVIO2(pip-2,4-dmp)(MeOH)] (2), respectively. After characterizing these complexes by spectroscopic (IR, UV/Vis, 1H and 13C NMR) data, elemental and thermal analyses (and single crystal X-ray diffraction study of uranium complex), they are used as catalysts to study the oxidative bromination of thymol. Such catalytic reactions are observed by many model vanadium complexes and are considered as a functional mimic of haloperoxidases. The catalytic oxidation resulted in the formation of three products namely, 2-bromothymol, 4-bromothymol and 2,4-dibromothymol. The optimized reaction conditions are obtained considering concentration of KBr, HClO4, and oxidant for the maximum yield of brominated products. Under the optimized reaction conditions, the product selectivity for both the prepared complexes is investigated. They are found to be competent homogeneous catalysts to afford the products in good yield.

A derivative of 4-Thiazolidinone derivative endowing cyclopropyl ring substituted at 3-nitrogen positioned was synthesized that was further evaluated against cancerous cell lines MCF-7. The structure of synthesized compound (6) was well characterized by different spectral techniques such as FT-IR, UV-Visible, 1H-NMR, 13C-NMR and mass spectrophotometer. X-ray single crystal structure and Computational study (DFT) study revealed that compound (6) adopted (2Z, 5Z)-configuration. Preliminary In vitro study suggested that compound (6) displayed moderate activity bearing IC50(161.0 μM). The DNA binding studies (Ct-DNA) with compound (6) was performed. The study suggested that bound with DNA exhibiting binding constant Kb = 3.3 x 104 LMol-1). Furthermore, the binding study was complemented by Molecular docking possessingDNA binding studies (Ct-DNA) were performed. Final compound (6) exhibited moderate cytotoxicity effect (IC50 = 161.0 μM) and DNA binding ability (Kb = 3.3 x 104 LMol-1). The experimental findings were completed by molecular docking study.

(VO)-O-IV-complexes formulated as [(VO)-O-IV(OSO3)(phen)(2)] (1) (phen = 1,10-phenanthroline), [(VO)-O-IV(OSO3) (Me(2)phen)(2)] (2) (Me(2)phen = 4,7-dimethyl-1,10-phenanthroline) and [(VO)-O-IV(OSO3)(amphen)(2)] (3) (amphen = 5-amino-1,10-phenanthroline) were prepared and stability in cell incubation media evaluated. Their cytotoxicity was determined against the A2780 (ovarian), MCF7 (breast) and PC3 (prostate) human cancer cells at different incubation times. While at 3 and 24 h the cytotoxicity differs for complexes and corresponding free ligands, at 72 h incubation all compounds are equally active presenting low IC50 values. Upon incubation of A2780 cells with 1-3, cellular distribution of vanadium in cytosol, membranes, nucleus and cytoskeleton, indicate that the uptake of V is low, particularly for 1, and that the uptake pattern depends on the ligand. Nuclear microscopic techniques are used for imaging and elemental quantification in whole PC3 cells incubated with 1. Once complexes are added to cell culture media, they decompose, and with time most V-IV oxidizes to V-V-species. Modeling of speciation when [(VO)-O-IV(OSO3)(phen)(2)] (1) is added to cell media is presented. At lower concentrations of 1, (VO)-O-IV- and phen-containing species are mainly bound to bovine serum albumin, while at higher concentrations [(VO)-O-IV (phen)n](2+)-complexes become relevant, being predicted that the species taken up and mechanisms of action operating depend on the total concentration of complex. This study emphasizes that for these (VO)-O-IV-systems, and probably for many others involving oxidovanadium or other labile metal complexes, it is not possible to identify active species or propose mechanisms of cytotoxic action without evaluating speciation occurring in cell media. Centro de Quimica Estrutural; Centro de Quimica Estrutural - Fundacao para a Ciencia e Tecnologia (FCT) [UID/BIO/04565/2020, UIDB/00100/2020, UID/Multi/04349/2019]; Centro de Ciencias e Tecnologias Nucleares - Fundacao para a Ciencia e Tecnologia (FCT) [UID/BIO/04565/2020, UIDB/00100/2020, UID/Multi/04349/2019]; Programa Operacional Regional de Lisboa 2020 [007317]; FCTPortuguese Foundation for Science and TechnologyEuropean Commission [IF/00841/2012] info:eu-repo/semantics/publishedVersion

[Abstract] Microtubule affinity-regulating kinase 4 (MARK4), a member of the serine/threonine kinase family, is an emerging therapeutic target in anticancer drug discovery paradigm due to its involvement in regulation of microtubule dynamics, cell cycle regulation, and cancer progression. Therefore, to identify the novel chemical architecture for the design and development of novel MARK4 inhibitors with concomitant radical scavenging property, a series of small-molecule arylaldoxime/5-nitroimidazole conjugates were designed and synthesized via multistep chemical reactions following the pharmacophoric hybridization approach. Compound 4h was identified as a promising MARK4 inhibitor with high selectivity toward MARK4 inhibition as compared to the panel of screened 30 kinases pertaining to the serine/threonine family, which was validated by molecular docking and fluorescence binding studies. The comprehensive cell-based examination divulged the promising apoptotic, antiproliferative, and antioxidant potential for the chemotype 4h. The compound 4h was endowed with the Ka value of 3.6 × 103 M–1 for human serum albumin, which reflects its remarkable transportation and delivery properties to the target site via blood. The present study impedes that in the future, such compounds may stand as optimized pharmacological lead candidates in drug discovery for targeting cancer via MARK4 inhibition with a remarkable anticancer profile. Council of Scientific and Industrial Research (India); 09/466 (0220) 2K19 EMR-I Government of India; EMR/2015/002372 Government of India; BT/PR12828/AAQ/1/622/2015 Indian Council of Medical Research; 45/9/2019-PHA/BMS

Novel dibasic Schiff bases with three tridentate sites were obtained from the condensation of the triketone 2,4,6-triacetylphloroglucinol (H3ptk) with four different hydrazides, benzoyl hydrazide (bhz), furoyl hydrazide (fah), isonicotinoyl hydrazide (inh) and nicotinoyl hydrazide (nah): H6ptk(bhz)3I, H6ptk(fah)3II, H6ptk(inh)3III and H6ptk(nah)3IV. These ligand precursors I-IV, each being an ONO donor, are tricompartmental building blocks able to form trinuclear complexes having C3 symmetry. The reaction of I-IV with [VIVO(acac)2] leads to the formation of [{VIVO(H2O)}3(ptk(bhz)3)] 1, [{VIVO(H2O)}3(ptk(fah)3)] 2, [{VIVO(H2O)}3(ptk(inh)3)] 3, and [{VIVO(H2O)}3(ptk(nah)3)] 4. In methanol/aqueous solutions of M2CO3 (M+ = Na+, K+ and Cs+), these complexes are slowly converted into dioxidovanadium(v) compounds, namely, M3[(VVO2)3{ptk(bhz)3}]·6H2O [M+ = K+5, Na+9, Cs+13], M3[(VVO2)3{ptk(fah)3}]·6H2O [M+ = K+6, Na+10, Cs+14], M3[(VVO2)3{ptk(inh)3}]·6H2O [M+ = K+7, Na+11, Cs+15] and M3[(VVO2)3{ptk(nah)3}]·6H2O [M+ = K+8, Na+12, Cs+16]. All ligand precursors and complexes are characterized by various techniques such as FT-IR, UV/Visible, EPR, NMR (1H, 13C and 51V), elemental analysis, thermal studies, cyclic voltammetry (CV) and single-crystal X-ray analysis. X-ray diffraction studies of complexes K2.7[{(VVO2)3ptk(fah)3}]·11.5H2O·MeOH 6a, Cs3[{(VVO2)3ptk(bhz)3}]·7H2O 13a and Cs3[{(VVO2)3ptk(nah)3}]·7.3H2O 16a reveal their distorted square pyramidal geometry by coordinating through phenolate oxygen (of ptk), azomethine nitrogen and enolate oxygen (of hydrazide) atoms. The reactivity of complexes 5-16 and their catalytic potential were screened towards their peroxidase mimetic activity in the oxidation of dopamine to aminochrome driven by H2O2 as an oxidant. The conversion of dopamine to aminochrome with different catalysts was monitored by HPLC showing high activity under mild conditions with good conversions within 1 h. Kinetic studies using compounds 13-16 as catalyst precursors reveal that the reaction follows a Michaelis-Menten-like kinetics.

PM10 emission largely depends on the characteristics of the saltation process, which involves the movement of aggregate and isolated particles. Studies analyzing the relationship between the fragmentation of saltating aggregates and the dust emission along the fetch distance are very scarce. The objective of the present study was to analyze, on a loamy texture soil, the changes in the size distribution of the eroded sediment along the fetch distance under field conditions. Changes in the particle size distribution of the transported material were measured at four different heights above the soil surface every 25 m on a 200 m plot, during three strong wind erosion events. Statistically significant differences were found both for particle size distribution and aggregation when comparing the eroded sediment at the windward and leeward sides of the experimental plot. A greater proportion of coarser particles was found as the distance traveled by the eroded sediment increased. From the change in average particle size distribution at the beginning and at the end of the 200 m experimental plot, it was estimated that around 12% of the particles smaller than 62.5 μm were lost by vertical transport (dust plume) producing an average concentration of 48 µg m−3 at 2 m height and 200 m fetch. Under the conditions of this experiment, a soil aggregate transported by saltation was fragmented at a rate of 38% every 100 m traveled (R2 = 0.88; p < 0.001). Particle size analysis of the eroded sediment and open-air PM10 concentration measurements indicated that the fragmentation of aggregates during saltation can be considered as the main mechanism of dust emission on this soil. Fil: Avecilla, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina Fil: Panebianco, Juan Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina Fil: Buschiazzo, Daniel Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional La Pampa-San Luis. Estación Experimental Agropecuaria Anguil; Argentina. Universidad Nacional de La Pampa. Facultad de Agronomía; Argentina Fil: de Oro, Laura Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina

The reaction of dibasic tetradentate ONNO donor Mannich bases derived from ethylenediamine and 2,4-di-tert-butylphenol (H2L1I), 2,4-di-methylphenol (H2L2II), 2-tert-butyl-4-methylphenol (H2L3III), 2,4-di-chlorophenol (H2L4IV) and 2-naphthol (H2L5V) with [MoVIO2(acac)2] (Hacac = acetylacetone) in a 1 : 1 molar ratio in refluxing MeOH gave the corresponding cis-dioxidomolybdenum(VI) complexes [MoVIO2(L1)] 1, [MoVIO2(L2)] 2, [MoVIO2(L3)] 3, [MoVIO2(L4)] 4, and [MoVIO2(L5)] 5, respectively. All complexes were characterized by elemental analysis, various spectroscopic (FT-IR, UV/Vis, 1H and 13C NMR) techniques and single-crystal X-ray analysis (of 1, 2, 3 and 5). These complexes adopt a distorted six-coordinated octahedral geometry where the ligands act in a tetradentate manner, coordinating through the two Ophenolate and two Namine atoms in a cis-α type binding mode involving coordination with one of the Namine atoms in the apical position and one Ooxido terminal oxygen atom in the equatorial position. These complexes catalyze oxygen atom transfer between benzoin and dimethyl sulfoxide (DMSO) in acetonitrile at 80 °C. The formation of benzil could easily be monitored by HPLC. The electronic effect caused by the para substituent and the steric effect caused by the ortho substituent influence the formation of benzil and therefore the conversion varied between 66 and 99% in 18 h of reaction time under optimized conditions; the most active catalyst was [MoVIO2(L5)]. A similar trend has also been obtained with 4-chlorobenzoin. The pseudo first order rate constant for [MoVIO2(L5)] was found to be 0.0998 h−1. During catalytic reaction, the formation of the binuclear intermediate and its fast decay into the initial dioxidomolybdenum(VI) complex were established by time dependent UV/Vis studies.

Cattle feedlot surfaces can be an important aerosol source, but they have barely been studied. The action of the hooves on the loose, dry layer of soil and manure creates ideal conditions for particulate matter (PM) emissions. The objectives of this work were: a) to quantify the soil loss (Q) and the consequent emission of PM10 (FvPM10) from different surfaces within the feedlot: unpaved roads (UR), cropland (C) and cattle pen (CP); and b) to evaluate the cattle trampling effect in UR, C and CP on Q and FvPM10. The study was carried out in three feedlots with different soil textures: Trenel (FT), Santa Rosa (FSR) and General Acha (FGA). In a wind tunnel, erosion events were simulated at 10.5 m s−1 (µ*: 0.26 m s−1) during 5 min. The results showed that Q and FvPM10 were UR > C > CP and that the cattle trampling effect was generally directly proportional to Q and FvPM10 (p

A new family of piano stool iron-cyclopentadienyl compounds bearing different phosphane co-ligands has been synthesized. All the compounds, with the general structure [Fe(Cp)(CO)(PR3)(L)]n (PR3 = triphenylphosphane, 4-(diphenylphosphino) benzoic acid or tris(4-fluorophenyl)phosphane; when L = I, n = 0; when L = 4-aminobenzonitrile, n = +1) were fully characterized by the usual analytical and spectroscopic techniques. Interestingly, compound [Fe(Cp)(CO)(PPh3)I] 1 crystalizes in the orthorhombic space group P212121 and its crystal packing only contains one enantiomer, while compound [Fe(η5-Cp)(CO)(P(Ph-p-F)3)I] 3 crystalizes in the centrosymmetric space group Pbca presenting an important disorder in the structure, probably due to the presence of the two enatiomers in the crystal packing. All the compounds presented adequate stability in aqueous solution and they were tested against cervical HeLa human cancer cells. The cationic complexes bearing triphenylphosphane ( 4 ) or tris(4-fluorophenyl)phosphane ( 6 ) were found to be highly cytotoxic, causing cell death by apoptosis. The results point out that the electronic features of the new compounds might be related to their cytotoxic activity.

Soil wind erosion and consequent PM10 emission is a complex process that has been related to surface propertiesand meteorological conditions. Most of the studies have emphasized on the relationship between the surfaceconditions and the dust emission, in general on deserts and dry lakes or playas. Little is known about theinfluence of meteorological variables on PM10 emission from agricultural soils. The objective of this study was toidentify the most important meteorological variables involved in the emission of PM10, identify their thresholdvalues, and to analyze their interaction with the soil surface conditions. Measurements were made on a loam soil(Entic Haplustoll) in the semiarid Argentinian Pampa. Horizontal mass transport (Q) and PM10 emission weremeasured during two years on a bare and flat surface that was tilled periodically. The meteorological variablesmeasured were: average and maximum wind speed, wind direction, air temperature, relative humidity and soiltemperature. In 30% of the events, the PM10 concentration at 1.8 m height exceeded the average values allowedby the World Health Organization (50 μg m−3 for a 24 h period). Maximum values exceeded 1000 μg m−3. Theslope of the PM10 concentration gradient changed between spring − summer and autumn − winter periods.Threshold values of the studied variables were set when PM10 concentration values at 1.8 m height wereconsistently above the 50 μg m−3 limit. The highest PM10 emission rates were observed when relative humidityvalues were below 20% and the air temperature was higher than 30 °C. In addition when the wind speedexceeded 8 m s−1, dust emission increased significantly. From a multiple regression analysis, results indicatedthat PM10 emission was well correlated (p< 0.001) with maximum wind speed, relative humidity, and airtemperature. Maximum wind speed and relative humidity conditioned the PM10 emission in a synergistic way.However, the regression explained only 32% of the variability. Although higher average PM10 emission valueswere measured during events with a crusted surface, lower average values of Q were measured during eventswith a crust. Field observations indicated that the complex interaction between the weather conditions and soilsurface properties such as soil crusts, aggregate size distribution, soil moisture and even the soil condition whenthe tilling is done, Fil: Avecilla, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina Fil: Panebianco, Juan Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina Fil: Buschiazzo, Daniel Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina. Instituto Nacional de Tecnología Agropecuaria; Argentina

Thiazolidi-4-one is a significant pharmacophore and has been known to exhibit a diverse range of biological activities for a long time. A new compound (6), thiazolidi-4-one was synthesized and characterized by spectroscopic techniques and X-ray single crystal structure. The stereochemistry of compound (6) was determined theoretically (DFT level) and experimentally (single crsytal X-ray structure) both. The DNA binding ability of the compound 6 has been assessed as using UV–Visible absorption studies and docking studies, MTT-assay study on MCF-7 cell line revealed non-toxic nature of the compound (6) in the concentration range 10–320 μM.

Four binuclear dioxidomolybdenum(VI) complexes with Schiff base ligands, H4dar(bhz)2 (I), H4dar(inh)2 (II), H4dar(nah)2 (III) and H4dar(fah)2 (IV) (H2dar=4,6-diacetyl resorcinol and Hbhz=benzoylhydrazide, Hinh=isonicotinoylhydrazide, Hnah=nicotinoylhydrazide, and Hfah=2-furoylhydrazide) have been prepared by the reaction of ligand with [MoVIO2(acac)2] (Hacac=acetylacetone) in 1:2 ratio in methanol. Isolated complexes[(MoVIO2)2{dar(bhz)2}(H2O)2] (1), [(MoVIO2)2{dar(inh)2}(H2O)2] (2), [(MoVIO2)2{dar(nah)2}(H2O)2] (3) and [(MoVIO2)2{dar(fah)2}(H2O)2] (4) are characterized by elemental (CHN) analysis, spectral (FT-IR, UV-vis, 1H and 13C NMR) and thermogravimetric analysis. Single crystal X-ray diffraction analysis of complexes 1, 2 and 4 confirms their binuclear structure and distorted octahedral geometry around each molybdenum where ligands behave as bis(dibasic tridentate) coordinating through phenolic oxygen, azomethine nitrogen and enolic oxygen atoms of each unit. These complexes have successfully been used as catalyst precursors in solvent as well as solvent free conditions for the one-pot three components (ethylacetoacetate, benzaldehyde and ammonium acetate) dynamic covalent assembly, via Hantzsch reaction using hydrogen peroxide as an oxidant.

Thiourea derivative,3-(4-methoxyphenyl)-1-(pyridin-2-ylmethyl)thiourea, was synthesized. The structure of the synthesized compound (3) was elucidated by IR, UV–visible, 1H NMR, mass Spectrometry, and X-ray single crystal structure. The computational quantum chemical studies like, IR, UV, NBO analysis were performed by DFT with Becke-3-Lee-Yang- Parr (B3LYP) exchange-correlation functional in combination with 6–311++G(d,p) basis sets. It was observed experimentally and theoretically that compound (3) exhibited syn-anti-conformation around sulphur atom. The DNA-binding constant Kb was found 3.3 × 106 Lmol−1. The docking energy of compound (3) with 1BNA was found −6.2 kcal/mol. MTT-assay against HepG2 (IC50 = 140.39) and Siha (IC50 = 119.87 μM) cell lines revealed that compound (3) wasnon-toxic up to140.39 μM against HepG2 and 119.87 μM against Siha cells respectively. It was also found that compound (3) is non-toxic against normal human cell line HEK-293(IC50 = 148.67 μM). Cell cycle analyses displayed that treated HepG2 cells at 40 μM and 80 μM showed 65% and 70% arrest in G0/G1with respect to untreated controls (60%) and Siha cells at the same concentration displayed 59% and 65% arrest with respect to G0/G1 as compared to untreated control (45%).