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Cleaning chemistries are detergent-based formulations that are used during the processing of reusable medical devices. Manufacturers are responsible for demonstrating the safety of cleaning formulations when they are used during a device processing cycle, including the risk of device-associated cytotoxicity over the concentration ranges for recommended use and rinsing during cleaning. However, no regulation currently exists requiring manufacturers to demonstrate such safety. Although manufacturers' safety data sheets (SDSs) provide information on the safe use of chemicals for users, this information may not provide sufficient detail to determine the risks of residual chemicals on device surfaces. SDSs are not required to contain a comprehensive list of chemicals used, only those of risk to the user. They should be supplemented with information on the correct concentrations that should be used for cleaning, as well as instructions on the rinsing required to reduce the levels of chemicals to safe (nontoxic) levels prior to further processing. Supporting data, such as toxicity profiles or cytotoxicity data that support the instructions for use, would provide medical device manufacturers and healthcare personnel with the necessary information to make informed decisions about selection and correct use of detergents. In the current work, cytotoxicity profiles for eight commonly used cleaning formulations available internationally were studied. Although all of these products are indicated for use in the cleaning of reusable medical devices, results vary across the serial dilution curves and are not consistent among detergent types. The information presented here can be leveraged by both medical device manufacturers and processing department personnel to properly assess residual detergent risks during processing. This work also serves as a call to cleaning formulation manufacturers to provide this information for all chemistries.

A two new series of ferrocene containing quinolinones – 1-allyl-2-ferrocenyl-2,3-dihydroquinolin-4(1H)-ones and 1-allyl-2-ferrocenylquinolin-4(1H)-ones – were prepared and characterized by standard spectroscopic techniques and cyclic voltammetry. The in vitro antitumor activity of all synthesized compounds was investigated against Human Cervix Carcinoma (HeLa), Chronic Myelogenous Leukemia (K562) and normal endothelial (HUVEC) cell lines using the MTT method. Quinolone derivative 5c exhibited the highest cytotoxic activity in the cell growth inhibition of HeLa cell line while 5f was the most toxic against K562 cells.

Five ruthenium(II) half-sandwich complexes containing arene and coumarin ligands with the general formula [Ru(arene)(L)Cl2] or [Ru(arene)(L2)Cl]Cl were synthesized. L: 3-aminocoumarin and 7-amino-4-methylcoumarin were used for the synthesis of complex compounds. The complexes were characterized by 1H NMR, IR, UV–Vis spectroscopy, electrospray mass spectrometry (ESI MS), elemental analysis and cyclic voltammetry measurement. X-ray crystallography found one molecular structure to be of pseudo-octahedral geometry. All compounds were also tested on Chronic Myelogenous Leukemia (K562), Human Cervix Carcinoma (HeLa), Human Pancreatic Carcinoma (CFPAC) cancer cell lines, and the viability of cells was evaluated by MTT assay.

A series of variously functionalized selenium-containing compounds were purposely synthesized and evaluated against a panel of cancer cell lines. Most of the compounds showed an interesting cytotoxicity profile with compound 5 showing a potent activity on MCF7 cells. The ethyl amino derivative 5 acts synergistically with cis-platin and inhibits the GST enzyme with a potency that well correlates with the cytotoxicity observed in MCF7 cells. A computational analysis suggests a possible binding mode on the GST enzyme. As the main outcome of the present study, the ethyl amino derivative 5 emerged as a valid lead compound for further, future developments.

Hydrazone hesperetin Schiff base (HHSB) - N-[(±)-[5,7-dihydroxy-2-(3-hydroxy-4-methoxy-phenyl)chroman-4-ylidene]amino]benzamide has been synthesized and its crystal structure was determined. This compound was used for the formation of Cu(II) complexes in solid state and in solution which were characterized using different spectroscopic methods. The analyses of potentiometric titration curves revealed that monomeric and dimeric complexes of Cu(II) are formed above pH7. The ESI-MS (electrospray ionization-mass spectrometry) spectra confirmed their formation. The EPR and UV-visible spectra evidenced the involvement of oxygen and nitrogen atoms in Cu(II) coordination. Hydrazone hesperetin Schiff base can show keto-enol tautomerism and coordinate Cu(II) in the keto (O(-), N, Oket) and in the enolate form (O(-), N, O(-)enol). The semi-empirical molecular orbital method PM6 and DFT (density functional theory) calculations have revealed that the more stable form of the dimeric complex is that one in which the ligand is present in the enol form. The CuHHSB complex has shown high efficiency in the cleavage of plasmid DNA in aqueous solution, indicating its potential as chemical nuclease. Studies on DNA interactions, antimicrobial and cytotoxic activities have been undertaken to gain more information on the biological significance of HHSB and copper(II)-HHSB chelate species.

Platelets are essential for normal hemostasis, but close regulation is required to avoid the destructive effects of either inappropriate platelet activation or excessive responses to injury. Here, we describe a novel complex comprising the scaffold protein, spinophilin (SPL), and the tyrosine phosphatase, SHP-1, and show that it can modulate platelet activation by sequestering RGS10 and RGS18, 2 members of the regulator of G protein signaling family. We also show that SPL/RGS/SHP1 complexes are present in resting platelets where constitutive phosphorylation of SPL(Y398) creates an atypical binding site for SHP-1. Activation of the SHP-1 occurs on agonist-induced phosphorylation of SHP-1(Y536), triggering dephosphorylation and decay of the SPL/RGS/SHP1 complex. Preventing SHP-1 activation blocks decay of the complex and produces a gain of function. Conversely, deleting spinophilin in mice inhibits platelet activation. It also attenuates the rise in platelet cAMP normally caused by endothelial prostacyclin (PGI2). Thus, we propose that the role of the SPL/RGS/SHP1 complex in platelets is time and context dependent. Before injury, the complex helps maintain the quiescence of circulating platelets by maximizing the impact of PGI2. After injury, the complex gradually releases RGS proteins, limiting platelet activation and providing a mechanism for temporal coordination of pro thrombotic and antithrombotic inputs.

Quaternary ammonium and phosphonium salts have been screened for their toxic effect on HeLa and K562 cancer cell lines, as well as on normal HUVEC cells. Tri-n-butyl-n-hexadecylphosphonium bromide, the first phosphonium salt with a halogen anion tested against HeLa cells, was 12 times more potent (IC505 μm after 24 and 48 h) than the clinically used reference compound cisplatin and 17 times more potent than tri-n-hexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide, which, to the best of our knowledge, is the first phosphonium salt to be evaluated in HeLa cells. However, it was inactive against K562 cells (24 and 48 h). According to a caspase-3/7 assay, its toxicity has not been connected with the induction of apoptosis. In contrast, triphenylalkylphosphonium iodides with shorter C1-5 alkyl chains were inactive against HeLa cells but very active against K562 cells (IC50=6-10 μm after 48 h). Phosphonium cations with halide counterions proved to be more potent than those with (CF3SO2)2N(-) as the anion, as in the anticancer agent NSC 747251, or other anions in molecules with similar alkyl chain lengths. On the other hand, a series of ammonium salts containing a short methylthiomethyl or methoxymethyl side chain revealed low cytotoxicity (IC50500 μm after 24 and 48 h) against both HeLa and K562 cancer cell lines as well as normal HUVEC cells, showing that the nontoxic N(+)CH2YMe (Y=S, O) structural motif in ammonium salts could be suitable for further optimization and development, especially in transfection experiments.

Identification of de novo minisatellite mutations in the offspring of parents exposed to mutagenic agents offers a potentially sensitive measure of germ line genetic events induced by ionizing radiation and genotoxic chemicals. Germ line minisatellite mutations (GMM) are usually detected by hybridizing Southern blots of unamplified size-fractionated genomic DNA with minisatellite probes. However, this consumes a relatively large amount of DNA, requires several steps and may lack sensitivity. We have developed a polymerase chain reaction (PCR)-based GMM assay, which we applied to the hypermutable minisatellite, CEB1. Here, we compare the sensitivity and specificity of this assay with the conventional Southern hybridization method using DNA from 10 spouse pairs, one parent of each pair being a survivor of cancer in childhood, and their 20 offspring. We report that both methods have similar specificity but that the PCR method uses 250 times less DNA, has fewer steps and is better at detecting GMM with single repeats provided that specific guidelines for allele sizing are followed. The PCR GMM method is easier to apply to families where the amount of offspring DNA sample is limited.

Semaphorin 4D (sema4D; CD100) is an integral membrane protein and the ligand for two receptors, CD72 and plexin-B1. Soluble sema4D has been shown to evoke angiogenic responses from endothelial cells and impair monocyte migration, but the origin of soluble sema4D, particularly at sites of vascular injury, has been unclear. Here we show that platelets express sema4D and both of its receptors and provide evidence that these molecules promote thrombus formation. We also show that the surface expression of sema4D and CD72 increases during platelet activation, followed by the gradual shedding of the sema4D extracellular domain. Shedding is blocked by metalloprotease inhibitors and abolished in mouse platelets that lack the metalloprotease ADAM17 (TACE). Mice that lack sema4D exhibit delayed arterial occlusion after vascular injuryin vivo, and their platelets show impaired collagen responsesin vitro. In resting platelets, as in B lymphocytes, CD72 is associated with the protein tyrosine phosphatase SHP-1. Platelet activation causes dissociation of the complex, as does the addition of soluble sema4D. These findings suggest a dual role for sema4D in vascular responses to injury. As thrombus formation begins, platelet-associated sema4D can bind to its receptors on nearby platelets, promoting thrombus formation. As thrombus formation continues, sema4D is shed from the platelet surface and becomes available to interact with receptors on endothelial cells and monocytes, as well as continuing to interact with platelets.

Ionic liquids have attracted considerable interest in various areas as new, nonvolatile and nonflammable organic solvents, catalysts, reaction additives, ligands, drugs, and other dedicated materials. Ionic liquids exhibit solubility both in organic solvents and in water. They also constitute very good solvents for many inorganic, organic, and organometallic compounds. Yet, the most important feature of ionic liquids is that they provide the possibility of obtaining substances of optimal properties for a given process through modification of the cation structure and selection of the appropriate anion. Therefore, the term designer solvents has been invented for these salts. The above characteristics and relatively low production cost may soon lead to the situation, in which huge amounts of these chemicals will be brought into environment via industry, agriculture, and commercial trading. Their general use, sometimes in bulky quantities, requires determination of their potential ecotoxicity on sele...

A novel approach based on DNA-cleaving deoxyribozymes (DNAzymes) was developed to control expression of beta(1) and beta(3) integrins in endothelial cells. To engineer a specific cleavage site in mRNA, the flanking domains of DNAzymes were derived from oligodeoxynucleotides complementary to sequences corresponding to 1053-1070 and 1243-1267 in beta(1) and beta(3) mRNA, respectively. Phosphorothioate analogues of these antisense oligodeoxynucleotides, designated beta1-1053 and beta3-1243, significantly inhibited expression of beta(1) and beta(3) integrin subunits in endothelial and K562 cells at the level of mRNA and protein synthesis. They also specifically decreased the cell surface expression of corresponding subunits in endothelial cells and K562 cells, as measured by flow cytometry. In functional tests, beta1-1053 and beta3-1243 markedly reduced adhesion of cells to fibronectin and vitronectin, respectively. We designed DNAzymes to beta(1) and beta(3) mRNAs containing a 15-deoxynucleotide catalytic domain that was flanked by two substrate recognition segments of 8 and 10 deoxynucleotides for beta(1) and beta(3) DNAzymes, respectively. Both DNAzymes in the presence of Mg(2+) specifically cleaved their substrates, synthetic beta(1) and beta(3) mRNA fragments. Although DNAzymes were partially modified with phosphorothioate and with 2'-O-methyl groups at both the 5' and 3' ends indicated similar kinetic parameters, they were significantly more potent than the unmodified DNAzymes because of their much higher resistance to nuclease degradation. Similar to the antisense oligonucleotides, DNAzymes abolished microvascular endothelial cell capillary tube formation in fibrin and Matrigel. In conclusion, DNAzymes to beta(1) and beta(3) mRNAs with 2'-O-methyl modifications are potentially useful as gene-inactivating agents and may ultimately provide a therapeutic means to inhibit angiogenesis in vivo.

The spatial relationship between the binding sites for two cyclic peptides, cyclo(S,S)KYGCRGDWPC (cRGD) and cyclo(S,S)KYGCHarGDWPC (cHarGD), high affinity analogs for the RGD and HLGGAKQAGDV peptide ligands, in integrin alphaIIbbeta3 (GPIIb-IIIa) has been characterized. For this purpose, cRGD and cHarGD were labeled with fluorescein isothiocyanate and tetramethylrhodamine 5-isothiocyanate, respectively. Both cyclic peptides were potent inhibitors of fibrinogen binding to alphaIIbbeta3, particularly in the presence of Mn2+; IC50 values for cRGD and cHarGD were 1 and0.1 nM in the presence of Mn2+. Direct binding experiments and fluorescence resonance energy transfer analysis using the purified receptor showed that both peptides interacted simultaneously with distinct sites in alphaIIbbeta3. The distance between these sites was estimated to be 6.1 +/- 0.5 nm. Although cRGD bound preferentially to one site and cHarGD to the other, the sites were not fully specific, and each cyclic peptide or its linear counterpart could displace the other to some extent. The binding affinity of the cHarGD site was dramatically affected by Mn2+. cRGD, but not cHarGD, bound to recombinant beta3-(95-373) in a cation-dependent manner, indicating that the cRGD site is located entirely within this fragment. With intact platelets, binding of c-RGD and cHarGD to alphaIIbbeta3 resulted in distinct conformational alterations in the receptor as indicated by the differential exposure of ligand-induced binding site epitopes and also induced the opposite on membrane fluidity as shown by electron paramagnetic resonance analyses using 5-doxylstearic acid as a spin probe. These data support the concept the two peptide ligands bind to distinct sites in alphaIIbbeta3 and initiate different functional consequences within the receptor itself and within platelets.

Gemcitabine (dFdC) is a cytidine analog remarkably active against a wide range of solid tumors. Inside a cell, gemcitabine is phosphorylated by deoxycytidine kinase to yield gemcitabine monophosphate, further converted to gemcitabine di- and triphosphate. The most frequent form of acquired resistance to gemcitabine in vitro is the deoxycytidine kinase deficiency. Thus, proper prodrugs carrying the 5'-pdFdC moiety may help to overcome this problem. A series of new derivatives of gemcitabine possessing N-acyl(thio)phosphoramidate moieties were prepared and their cytotoxic properties were determined. N-Acyl-phosphoramidate derivatives of gemcitabine have similar cytotoxicity as gemcitabine itself, and have been found accessible to the cellular enzymes. The nicotinic carboxamide derivative of gemcitabine 5'-O-phosphorothioate occurred to be the best inhibitor of bacterial DNA polymerase I and human DNA polymerase α.

A new approach to the synthesis of 5-arylisoxazolidine-3-phosphonates (III) (10 examples) utilizing 1,3-dipolar cycloaddition of nitrone (I) to styrenes is accomplished.

The cycloaddition reaction between nitrone (I) and chalcones (II) leads to isolated major isoxazolidines (III).

Efficient Pd(0)-catalysed synthesis of 5-alkynyl-1-β-D-ribofuranosyl-1H-[1,2,3]triazole-4-carboxylic acid amide depends on the presence of different protecting groups of the ribose moiety. Peracetylated 5-iodo substrate (15) couples with terminal alkynes or trimethyl-[(tributylstannyl)ethynyl]silane in 50-71% and 72% yield (ETCAR), respectively, although its hydrodehalogenation to 19 is noticeable. On the other hand, hydrodehalogenation of acetonide (16) predominates over coupling with terminal alkyne and slightly decreases a yield of cross-coupling reaction with trimethyl[(tributylstannyl)ethynyl]silane. Alternative conditions of reaction with terminal alkynes, to exclude so far identified hydride sources to produce hydridopalladium species, have been established for acetonide 16 and allowed to achieve 72% of coupling. Fluoromethyl derivative (42) was prepared from its 5-hydroxymethyl precursor by fluorination with DAST. Additionally, X-ray structural analysis of 42 was performed. All 1,2,3-triazolonucleosides and two synthesized cycloSal-pronucleotides were evaluated for cytotoxic activity against K562, HeLa and HUVEC cells.

The synthesis and characterization of three novel iridium(III) complexes and one rhodium(III) complex with 1-nitroso-2-naphthol (3) chelating as a 1,2-naphthoquinone-1-oximato ligand are described. The reaction of mu(2)-halogenido-bridged dimers [(eta(5)-C(5)Me(5))IrX(2)](2) [X is Cl (1a), Br (1b), I (1c)] and [(eta(5)-C(5)Me(5))RhCl(2)](2) (2a) with 3 in CH(2)Cl(2) yields the mononuclear complexes (eta(5)-C(5)Me(5))IrX(eta(2)-C(10)H(6)N(2)O) (4a, 4b, 4c) and (eta(5)-C(5)Me(5))RhCl(eta(2)-C(10)H(6)N(2)O) (5a). All compounds were characterized by their (1)H and (13)C NMR, IR, and mass spectra, UV/vis spectra were recorded for 4a and 5a. The X-ray structure analyses revealed a pseudo-octahedral "piano-stool" configuration for the metals with bidentate coordination through oximato-N and naphthoquinone-O, forming a nearly planar five-membered metallacycle. The metal complexes 4a and 5a were evaluated in respect to their cytotoxicity and binding affinity toward double-stranded DNA. As determined in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, both exerted a much stronger cytotoxic effect toward HeLa and HL60 cancer cell lines than did cisplatin. The remarkable cytotoxicity of the compounds tested may be attributed to necrosis, rather than to apoptosis, as it is evidenced by the caspase-3/7 activation assay. No clear evidence was found for interaction with double-stranded DNA. The melting experiments showed no significant differences between thermodynamic parameters of intact DNA and DNA incubated with 3, 4a, or 5a, although these derivatives altered DNA recognition by the BamHI restriction enzyme. Therefore, the screened iridium and rhodium complexes 4a and 5a may still be interesting as potential anticancer drugs owing to their high cytotoxicity toward cancer cell lines, whereas they do not modify DNA in a way similar to that of cisplatin.

A series of water-soluble polycationic dendrimers with a phosphoramidothioate backbone (P-dendrimers) was studied in human cell culture. Preliminary studies have shown that P-dendrimers of series 1 and 2, possessing N,N-diethyl-ethylenediamine hydrochloride functions at the surface, show rather moderate cytotoxicity toward HeLa, HEK 293, and HUVEC cells in a standard MTT assay in serum-containing medium, generally lower than lipofectin. The experiments of cellular uptake have shown the necessity for the presence of serum for transfection with P-dendrimers of series 1 and 2. These compounds efficiently delivered fluorescein-labeled oligodeoxyribonucleotide into HeLa cells in serum-containing medium, but they failed to do so in HUVEC cell culture. The dendrimers were found to be successful mediators of transfection of the HeLa cells with a DNA plasmid containing the functional gene of enhanced green fluorescent protein (EGFP).

The intracellular ability of the “10–23” DNAzyme to efficiently inhibit expression of targeted proteins has been evidenced by in vitro and in vivo studies. However, standard conditions for kinetic measurements of the DNAzyme catalytic activity in vitro include 25 mm Mg2+, a concentration that is very unlikely to be achieved intracellularly. To study this discrepancy, we analyzed the folding transitions of the 10–23 DNAzyme induced by Mg2+. For this purpose, spectroscopic analyzes such as fluorescence resonance energy transfer, fluorescence anisotropy, circular dichroism, and surface plasmon resonance measurements were performed. The global geometry of the DNAzyme in the absence of added Mg2+ seems to be essentially extended, has no catalytic activity, and shows a very low binding affinity to its RNA substrate. The folding of the DNAzyme induced by binding of Mg2+ may occur in several distinct stages. The first stage, observed at 0.5 mm Mg2+, corresponds to the formation of a compact structure with limited binding properties and without catalytic activity. Then, at 5 mm Mg2+, flanking arms are projected at right position and angles to bind RNA. In such a state, DNAzyme shows substantial binding to its substrate and significant catalytic activity. Finally, the transition occurring at 15 mm Mg2+ leads to the formation of the catalytic domain, and DNAzyme shows high binding affinity toward substrate and efficient catalytic activity. Under conditions simulating intracellular conditions, the DNAzyme was only partially folded, did not bind to its substrate, and showed only residual catalytic activity, suggesting that it may be inactive in the transfected cells and behave like antisense oligodeoxynucleotide.

Abstract 161 Platelets play an essential role in hemostasis, but excessive platelet responses to vascular injury or disease can be catastrophic. We have recently reported that members of the RGS protein family can modulate platelet responses to injury by limiting the duration of G protein-dependent signaling initiated by platelet agonists. Here we show that platelets contain a previously-unrecognized regulatory complex comprised of the 130 kDa scaffold protein, spinophilin (SPL) with at least two RGS proteins (RGS10 and RGS18) and the protein tyrosine phosphatase, SHP-1. In resting platelets, this complex is phosphorylated on spinophilin residues Y398 and Y483. Mutating both tyrosines to phenylalanine inhibits the binding of SHP-1 to spinophilin. Platelet activation by thrombin or thromboxane A2, but not ADP or collagen, stimulates a transient increase in spinophilin-associated SHP-1 tyrosine phosphatase activity and causes dephosphorylation and decay of the SPL/RGS/SHP-1 complex. Conversely, blocking SHP-1 phosphatase activity in platelets or omitting SHP-1 in transfected CHO cells inhibits dephosphorylation of spinophilin and prevents dissociation of the SPL/RGS/SHP-1 complex. While we have shown previously that inhibiting interactions between G proteins and RGS proteins produces a gain of function in platelets, knocking out spinophilin in mice inhibits platelet aggregation. This aggregation defect does not occur with all agonists, but is selective for those that are able to trigger decay and dephosphorylation of the SPL/RGS/SHP-1 complex. In addition to inhibiting platelet aggregation in vitro, the spinophilin knockout delays carotid artery occlusion in vivo following application of FeCl3 and reduces platelet accumulation following laser injury in cremaster muscle arterioles. Underlying these effects of the knockout is a decrease in Rap1 activation, an event that supports integrin activation, and attenuation of the cAMP increase otherwise caused by endothelial PGI2. Collectively, these observations show for the first time that a regulatory complex based on spinophilin helps to regulate platelet responses to injury and suggest that it does this by sequestering RGS proteins in resting platelets and releasing them after activation begins. Dissociation of the SPL/RGS complex is regulated by an agonist-induced increase in the activity of SHP-1 associated with spinophilin. Disclosures: No relevant conflicts of interest to declare.

Proteins that are expressed on the platelet surface can participate in contact-dependent signaling events which modulate thrombus formation or, after being shed from the platelet surface, serve as bioactive messengers that affect the function of nearby cells. Here we show for the first time that platelets express the class IV semaphorin known as sema4D or CD100, and that platelet activation causes the regulated shedding of the sema4D extracellular domain in a biologically-active form. Sema4D is a glycosylated 150 kDa disulfide-linked homodimer that has previously been implicated in interactions between T-cells and B-cells. Platelet activation by collagen, thrombin or PMA causes a transient increase in sema4D surface expression peaking at 15 min, followed by a complete loss of expression over 30–60 minutes. These events are accompanied by the release of the sema4D exodomain as a 130 kDa fragment, leaving a 25–30 kDa transmembrane and cytoplasmic domain fragment that is retained by the platelets. The cleavage event required to produce these fragments is inhibited by metalloprotease inhibitors and abolished in platelets from chimeric mice lacking the metalloprotease known as ADAM17 or TACE (TNF alpha converting enzyme). Incubation of recombinant sema4D with ADAM17 identified a single cleavage site just outside the predicted transmembrane domain. Western blots show that human platelets express ADAM17 in both its immature (zymogen) and mature (active) forms, and indicate that at least some of the ADAM17 is located on the platelet surface. ADAM17-dependent cleavage of sema4D does not require platelet aggregation, but the rate is accelerated when aggregation is allowed to occur and slowed when aggregation is prevented. Under both sets of conditions, cleavage of sema4D occurs to a greater extent and more rapidly than the ADAM17-dependent cleavage of GP Ib alpha, suggesting that there is a hierarchy of proteolytic events when platelets are activated. In terms of biological impact, the shedding of sema4D following platelet activation raises the possibility that the soluble extracellular domain of sema4D serves as a bioactive messenger. Two receptors for sema4D have been identified previously: CD72, which is present on lymphocytes where it regulates the activity of the tyrosine phosphatase, SHP-1, and plexin-B1, which is expressed in endothelial cells. Western blots suggest that both of these receptors are expressed on human platelets and show that SHP-1 is associated with CD72 in resting, but not activated platelets. Taken together, these results demonstrate that sema4D undergoes regulated ADAM17-dependent shedding when platelets are activated, and suggest that this results in the production of a bioactive form of the molecule that can affect responses in nearby platelets, lymphocytes and endothelial cells at sites of thrombosis.

A series of seven derivatives of 1,1'-(5,6-dimethoxy-3-methyl-1-benzofuran-2,7-diyl)diethanone was synthesized and characterized by (1)HNMR and ESI MS spectra and elemental analyses. The obtained new compounds and three halogen derivatives of benzofuran, reported in our earlier work, were tested for their cytotoxic properties in human chronic (K562) and acute (HL60) leukemia cells, human cervical cancer (HeLa), and normal endothelial cells (HUVEC). Four compounds (2, 3, 4, 5), which contain halogens in their structure showed significant anticancer activity. The most promising was 1,1'-[3- (bromomethyl)-5,6-dimethoxy-1-benzofuran-2,7-diyl]diethanone (2), which was highly and selectively toxic for K562 cells (IC50 of 5µM) and HL60 cells (IC50 of 0.1µM), which showed no cytotoxicity toward HeLa and HUVEC cells. Moreover, the observed remarkable cytotoxicity of this compound toward K562 cells resulted from cells apoptosis.

A series of variously functionalized selenium-containing compounds were purposely synthesized and evaluated against a panel of cancer cell lines. Most of the compounds showed an interesting cytotoxicity profile with compound 5 showing a potent activity on MCF7 cells. The ethyl amino derivative 5 acts synergistically with cis-platin and inhibits the GST enzyme with a potency that well correlates with the cytotoxicity observed in MCF7 cells. A computational analysis suggests a possible binding mode on the GST enzyme. As the main outcome of the present study, the ethyl amino derivative 5 emerged as a valid lead compound for further, future developments.