89 research outputs found
Interaction of Thioamides, Selenoamides, and Amides With Diiodine
We review the results of our work on the iodine interaction with thioamides, selenoamides, and amides. Complexes with (i) “spoke” or “extended spoke” structures, D · I(2) and D · I(2) · I(2), respectively, (D is the ligand donor) (ii) iodonium salts of {[D(2) − I](+)[I(n)](−)} (n = 3, 7) and {[D(2) − I](+)[FeCl(4)](−)} formulae and (iii) disulfides of the categories (a) [D − D], (b) {[D − DH](+)[I(3)](−)} have been isolated and characterized. A compound of formula {[D(2) − I](+)[I(3)](−)[D · I(2)]} containing both types of complexes (i) and (ii) was also isolated. The interaction of diiodine with selenium analogs of the antithyroid drug 6-n-propyl-2-thiouracil (PTU), of formulae RSeU (6-alkyl-2-Selenouracil) results in the formation of complexes with formulae [(RSeU)I(2)]. All these results are correlated with the mechanism of action of antithyroid drugs. Finally, we review here our work on the diiodine interaction with the amides (LO)
Organotin(IV) Derivatives of L-Cysteine and their in vitro Anti-Tumor Properties
The synthesis and characterization of the organotin compounds [(n-C4H9)2Sn(cys)] (1), [(C6H5)2Sn(cys)]
(2), [(C6H5)3Sn(Hcys).(H2o)] (3), {[(CH3)2Sn(Kcys)2].2(H20)} (4), {[(n-C4H9)2Sn(Kcys)2].2(H20)} (5) and
{[(C6H5)2Sn(Kcys)2].2(H20)} (6) (where H2cys = L-cysteine) are reported. The compounds have been
characterized by elemental analysis and 1H-NMR, Uv-Vis, FT-IR and MOssbauer spectroscopic techniques.
Attempted recrystallization of (2) in DMSO/methanol 2:1 solution yielded after several days unexpectedly
the dimeric compound bis(tri-phenyltin)sulphide {[(C6H5)3Sn]2S} (7) which has been characterized by x-ray
analysis. The structure of the parent complex (2) as well as the mechanism of the decomposition of cysteine
are being further investigated. The in vitro anticancer activity of complexes (I)- (6), against human
leukemia (HL60), human liver (Bel7402), human stomach (BGC823) and human cervix epithelial human
carcinoma (Hela), nasopharyngeal carcinoma (KB) and lung cancer (PG) tumor cells, were evaluated
Bismuth(III) bromide-thioamide complexes: synthesis, characterization and cytotoxic properties
New bismuth(III) bromine compounds of the heterocyclic thioamides were prepared and structurally characterized. The reaction of heterocyclic thioamides with bismuth(III) bromide resulted in the formation of the {[BiBr2(mu(2)-Br)(MMI)(2)](2)center dot CH3COCH3 center dot H2O} (1), {[BiBr2(MBZIM)(4)]center dot Br center dot 2H(2)O} (2), {[BiBr2(mu(2)-Br)(tHPMT)(2)](2)center dot CH3CN} (3), {[BiBr2(mu(2)-Br)(PYT)(2)](2)center dot CH3CN} (4) and {[BiBr2(mu(2)-Br)(MBZT)(2)](2) 2CH(3)OH} (5) complexes (MMI: 2-mercapto-1-methylimidazole, MBZIM: 2-mercaptobenzimidazole, tHPMT: 2-mercapto-3,4,5,6-tetrahydro-pyrimidine, PYT: 2-mercaptopyridine and MBZT: 2-mercaptobenzothiazole). The complexes 1-5 were characterized by melting point (m.p.), elemental analysis (c.a.), molar conductivity, Fourier-transform infrared (FT-IR), Fourier-transform Raman (FT-Raman), nuclear magnetic resonance (H-1 and (CNMR)-C-13) spectroscopy, UV-Vis spectroscopy and thermogravimetric-differential thermal analysis (TG-DTA). The molecular structures of 1-5 were determined by single-crystal X-ray diffraction. Complex 2 is a first ionic monomuclear octahedral bismuth(III) bromide, while the complexes 1,3-5 are the first examples of dinuclear bismuth(III) bromide derivatives. Complexes 1-5 were evaluated in terms of their in vitro cytotoxic activity against human adenocarcinoma breast (MCF-7) and cervix (HeLa) cells. The toxicity on normal human fetal lung fibroblast cells (MRC-5) was also evaluated. Moreover, the complexes 1-5 and free heterocyclic thioamide ligands were studied upon the catalytic peroxidation of the linoleic acid by the enzyme lipoxygenase (LOX).Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114Z457](a) I.I.O. and M.C. acknowledge the financial support from The Scientific and Technological Research Council of Turkey (TUBITAK, Project No. 114Z457). (b) CNB and SKH would like to thank the Unit of Bioactivity Testing of Xenobiotics of the University of Ioannina for providing access to their facilities. (c) The International Graduate Program in 'Biological Inorganic Chemistry', which operates at the University of Ioannina within the collaboration of the Departments of Chemistry of the Universities of Ioannina, Athens, Thessaloniki, Patras, Crete and the Department of Chemistry of the University of Cyprus (http://bic.chem.uoi.gr/BIC-En/index-en.html), is acknowledged for the stimulating discussion forum
Communication: Synthesis of a Novel Triphenyltin(IV) Derivative of 2- Mercaptonicotinic Acid with Potent Cytotoxicity in vitro
A novel triphenyltin(IV) derivative of 2-mercaptonicotinic acid (H2mna) of formula
{[(C6H5)3Sn]2(mna).[(CH3)2CO]} (1) has been synthesized and characterized by elemental analysis and 1H, 13C-NMR, and FT-IR spectroscopic techniques. The crystal structure of complex (1) has been determined by single crystal X-ray diffraction analysis at 173(1) K. Compound (1) contains two triphenyltin moieties linked
by a doubly de-protonated 2,mercaptonicotinic acid (H>2mna). It is an example of a pentacoordinated
Ph3SnXY system with an axial-equatorial arrangement of the phenyl groups at Sn(1). Compound (1), exhibits
potent, in vitro, cytotoxicity against sarcoma cancer cells (mesenchymal tissue) from the Wistar rat,
polycyclic aromatic hydrocarbons (PAH, benzo[a]pyrene) carcinogenesis
Bromidotris(triphenylphosphane)silver acetonitrile monosolvate monohydrate
In the title compound, [AgBr(C18H15P)3]·C2H3N·H2O, the coordination of the Ag atom is close to ideal tetrahedral, with the three Ag—P bond lengths almost equal [2.5441 (10), 2.5523 (9) and 2.5647 (10) ° A] and the Ag—Br bond slightly longer [2.7242 (5) Å]. The coordination tetrahedron is slightly flattened, the Ag atom is closer to the PPP plane; the P—Ag—P angles are wider than the Br—Ag—P angles. The voids in the crystal structure are filled with ordered acetonitrile solvent molecules. The remaining electron density was interpreted as a water molecule, disordered over three alternative positions. Neither of the solvent molecules is connected by any directional specific interactions with the complex
Synthesis, Characterization, and Biological Studies of Organotin(IV) Derivatives with o- or p-hydroxybenzoic Acids
Organotin(IV) complexes with o- or p-hydroxybenzoic acids (o-H2BZA or p-H2BZA) of formulae [R2Sn(HL)2] (where H2L = o-H2BZA and R = Me- (1), n-Bu- (2)); [R3Sn(HL)] (where H2L = o-H2BZA and R = n-Bu- (3), Ph- (4) or H2L = p-H2BZA and R = n-Bu- (5), Ph- (6)) were synthesized by reacting a methanolic solution of di- and triorganotin(IV) compounds with an aqueous solution of the ligand (o-H2BZA or p-H2BZA) containing equimolar amounts of potassium hydroxide. The complexes were characterized by elemental analysis, FT-IR, Far-IR, TGA-DTA, FT-Raman, Mössbauer spectroscopy, 1H, 119Sn-NMR, UV/Vis spectroscopy, and Mass spectroscopy. The X-ray crystal structures of complexes 1 and 2 have also been determined. Finally, the influence of these complexes 1–6 upon the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX) was kinetically studied and the results showed that triorganotin(IV) complex 6 has the lowest IC50 value. Also complexes 1–6 were studied for their in vitro cytotoxicity against sarcoma cancer cells (mesenchymal tissue) from the Wistar rat, and the results showed that the complexes have high activity against these cell lines with triphenyltin((IV) complex 4 to be the most active one
Synthesis, structural characterization and biological studies of novel mixed ligand Ag(I) complexes with tri-phenylphosphine and aspirin or salicylic acid
Two new mixed ligand silver(I) complexes of formulae {[Ag(tpp)3(asp)](dmf)} (1) (aspH = o-acetylsalicylic acid and tpp = triphenylphosphine) and [Ag(tpp)2(o-Hbza)] (2) (o-HbzaH = o-hydroxy-benzoic acid)
were synthesized and characterized by elemental analyses, spectroscopic techniques and X-ray crystallography at ambient conditions. Three phosphorus and one carboxylic oxygen atoms from a de-protonated aspirin ligand in complex 1 and two phosphorus and two carboxylic oxygen atoms from a
chelating o-Hbza anion in complex 2 form a tetrahedral geometry around Ag(I) ions in both complexes.
Complexes 1 and 2 and the silver(I) nitrate, tpp, aspNa and o-HbzaH were tested for their in vitro cytotoxic activity against leiomyosarcoma cells (LMS), human breast adenocarcinoma cells (MCF-7) and normal human fetal lung fibroblasts (MRC-5) cells with Thiazolyl Blue Tetrazolium Bromide (MTT) assay. For
both cell lines 1 and 2 were found to be more active than cisplatin. Additionally, 1 and 2 exhibit lower
activity on cell growth proliferation of MRC-5 cells. The type of LMS cell death caused by 1 and 2 were
evaluated in vitro by use of flow cytometry assay. The results show that at concentrations of 1.5 and
1.9 lV of complex 1, 44.1% and 69.4%, respectively of LMS cells undergo programmed cell death (apoptosis). When LMS cells were treated with 1.6 and 2.3 lM of 2, LMS cells death was by 29.6% and 81.3%,
respectively apoptotic. Finally, the influence of the complexes 1 and 2, upon the catalytic peroxidation of
linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX) was kinetically and theoretically studied. The binding of 1 and 2 towards LOX was also investigated by Saturation Transfer Difference
(STD) 1
H NMR experiment
Cognitive Profile of Students Who Enter Higher Education with an Indication of Dyslexia
For languages other than English there is a lack of empirical evidence about the cognitive profile of students entering higher education with a diagnosis of dyslexia. To obtain such evidence, we compared a group of 100 Dutch-speaking students diagnosed with dyslexia with a control group of 100 students without learning disabilities. Our study showed selective deficits in reading and writing (effect sizes for accuracy between d = 1 and d = 2), arithmetic (d≈1), and phonological processing (d>0.7). Except for spelling, these deficits were larger for speed related measures than for accuracy related measures. Students with dyslexia also performed slightly inferior on the KAIT tests of crystallized intelligence, due to the retrieval of verbal information from long-term memory. No significant differences were observed in the KAIT tests of fluid intelligence. The profile we obtained agrees with a recent meta-analysis of English findings suggesting that it generalizes to all alphabetic languages. Implications for special arrangements for students with dyslexia in higher education are outlined
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