Giuseppe Ruisi - Academia.edu (original) (raw)
Papers by Giuseppe Ruisi
Applied Organometallic Chemistry, 1992
J Inorg Organomet Polym Mater, 2009
Two new polymeric triorganotin(IV) complexes R 3 Sn{O 2 CC 6 H 4 [N=C(H)}{C(CH 3)CH(CH 3)-3-OH]-p... more Two new polymeric triorganotin(IV) complexes R 3 Sn{O 2 CC 6 H 4 [N=C(H)}{C(CH 3)CH(CH 3)-3-OH]-p} n ([Me 3 Sn(LH)] n : 1) and ([Ph 3 Sn(LH)] n : 2) containing a 4-[(2Z)-(3hydroxy-1-methyl-2-butenylidene)amino]benzoate (LH) framework were prepared. Both compounds have been characterized by 1 H, 13 C, 119 Sn NMR, IR and 119 Sn Mössbauer spectroscopic techniques in combination with elemental analyses. The crystal structures of complexes 1 and 2 reveal that they exist as polymeric zigzag chains in which the LH-bridged Sn-atoms adopt a trans-R 3 SnO 2 trigonal bipyramidal configuration with R groups in the equatorial positions and the axial sites occupied by an oxygen atom from the carboxylate ligand and the alcoholic oxygen atom of the next carboxylate ligand in the chain. The carboxylate ligands coordinate in the zwitterionic form with the alcoholic proton moved to the nearby nitrogen atom.
Journal of Inorganic Biochemistry, 2002
III III The dynamics of iron nuclei in the condensates obtained by interaction of Fe with DNA, Fe... more III III The dynamics of iron nuclei in the condensates obtained by interaction of Fe with DNA, Fe (DNA monomer) , have been 2 57ï nvestigated by variable temperature Fe Mossbauer spectroscopy. Studies were effected on gel and freeze-dried samples, obtaining nearly coincident values of the parameters isomer shift and nuclear quadrupole splitting in T ranges 20-260 K. Functions ln(A /A) vs. T 77.3 T, here employed to investigate the dynamics of Fe nuclei, showed linear trends in the T ranges 20-150 and 150-260 K, respectively, the latter with larger slopes. Data coincided for gelled and freeze-dried specimens. No variation of d or DE parameters occurred at the two T 2 intervals, which suggests constancy of structure and bonding with the temperature changes. Functions kx l(T) showed trends analogous to the corresponding functions determined for iron proteins, which were attributed to the occurrence of 'conformational substates'.
J Chem Soc Dalton Trans, 1989
Inorganica Chimica Acta, 1985
Applied Organometallic Chemistry, 1992
![Research paper thumbnail of Synthesis and Structures of Two Triorganotin(IV) Polymers R3Sn{O2CC6H4[N=C(H)}{C(CH3)CH(CH3)-3-OH]-p} n (R = Me and Ph) Containing a 4-[(2Z)-(3-Hydroxy-1-methyl-2-butenylidene)amino] benzoic Acid Framework](https://attachments.academia-assets.com/69346357/thumbnails/1.jpg)
](Journal of Inorganic and Organometallic Polymers and Materials, 2009
Two new polymeric triorganotin(IV) complexes R 3 Sn{O 2 CC 6 H 4 [N=C(H)}{C(CH 3)CH(CH 3)-3-OH]-p... more Two new polymeric triorganotin(IV) complexes R 3 Sn{O 2 CC 6 H 4 [N=C(H)}{C(CH 3)CH(CH 3)-3-OH]-p} n ([Me 3 Sn(LH)] n : 1) and ([Ph 3 Sn(LH)] n : 2) containing a 4-[(2Z)-(3hydroxy-1-methyl-2-butenylidene)amino]benzoate (LH) framework were prepared. Both compounds have been characterized by 1 H, 13 C, 119 Sn NMR, IR and 119 Sn Mössbauer spectroscopic techniques in combination with elemental analyses. The crystal structures of complexes 1 and 2 reveal that they exist as polymeric zigzag chains in which the LH-bridged Sn-atoms adopt a trans-R 3 SnO 2 trigonal bipyramidal configuration with R groups in the equatorial positions and the axial sites occupied by an oxygen atom from the carboxylate ligand and the alcoholic oxygen atom of the next carboxylate ligand in the chain. The carboxylate ligands coordinate in the zwitterionic form with the alcoholic proton moved to the nearby nitrogen atom.
Hyperfine Interactions, 2000
Ethanol solutions of Alk n SnCl4−n (Alk = Me, Et; n = 1–3) added to aqueous calf thymus DNA provo... more Ethanol solutions of Alk n SnCl4−n (Alk = Me, Et; n = 1–3) added to aqueous calf thymus DNA provoke DNA condensation (even in the presence of added cysteine) possibly through charge neutralization of DNA phosphodiesters by organotin(IV) cations. The structures of tin bonding environments in binary and ternary condensed systems organotin(IV)-DNA and ligand-organotin(IV)-DNA are determined through point-charge model treatment
Journal of the Chemical Society, Dalton Transactions, 1989
Journal of Molecular Structure-Theochem, 2009
The interaction of proflavine (PR) with two B-DNA decamers of alternating AT and GC sequence, cal... more The interaction of proflavine (PR) with two B-DNA decamers of alternating AT and GC sequence, called [deca(dG-dC)] 2 and [deca(dA-dT)] 2 , respectively, was computationally investigated by the ONIOM method, exploiting a three-layer QM/QM/MM hybrid approach. The highest level QM method was applied to the model system, which comprises the intercalation site (5th and 6th base pairs) and the inserted PR molecule. The connecting sugar phosphate backbone was added in the medium layer region. Both higher and medium level layers, differing in the size of the basis set used, were treated by the DFT MPWB1K functional. The full system in the lower layer was described by the empirical AMBER force field. The calculated values of the interaction energy of PR with [deca(dG-dC)] 2 and [deca(dA-dT)] 2 , as well as with the dinucleotides d(GpC) 2 , and d(ApT) 2 , the latter considered either in vacuo and in the mimicked water solvent, support for a static higher affinity toward G-C compared to the AT DNA base sequences, in agreement with structural results from crystallographic studies. Furthermore, the different structural characteristics of the [deca(dG-dC)] 2 /PR complex compared to those of the [deca(dA-dT)] 2 /PR, furnish a possible interpretation of apparently controversial experimental thermodynamic data, explained in terms of two possible modes of non-covalent binding of ligands with DNA, namely intercalation and external binding, respectively.
Journal of the Chemical Society, Dalton Transactions, 1995
... Renato Barbieri,*Sa Giuseppe Ruisi,a Arturo Silvestri,a Anna Maria Giuliani,a Adriana Barbier... more ... Renato Barbieri,*Sa Giuseppe Ruisi,a Arturo Silvestri,a Anna Maria Giuliani,a Adriana Barbieri,a Gabriele Spina,b Fabrizio Pierallib and Franco Del Giallob a Dipartimento di Chimica lnorganica, Universita di P alermo, 1-90 123 Palermo, Italy Dipartimento di Fisica, Universita ...
Journal of the Chemical Society, Dalton Transactions, 1985
Friedo Huber," Gerhard Roge, and Lothar Carl Lehrstuhl fur Anorganische Chemie, Universitat ... more Friedo Huber," Gerhard Roge, and Lothar Carl Lehrstuhl fur Anorganische Chemie, Universitat Dortmund, D -4600 Dortmund 50, Federal Republic of Germany G hanem Atassi Laboratory for Experimental Chemotherapy and Screening, lnstitut J. Bordet, 1000 Brussels, Belgium ...
Zeitschrift f�r anorganische und allgemeine Chemie, 1995
Page 1. Z. anorg. allg. Chem. 621 (1995) 89-96 Zeitschrift fur anorganische und allgemeine Chemie... more Page 1. Z. anorg. allg. Chem. 621 (1995) 89-96 Zeitschrift fur anorganische und allgemeine Chemie 0 Johann Ambrosius Barth 1995 Tin( IV), Monomet hyltin(IV), and Dimet hyltin( IV) Complexes with T hiol Sulfur and Heterocyclic ...
![Research paper thumbnail of Diorganotin(IV) Complexes of Methyl 2-{[(E)-8-Oxo-5, 8-dihydroquinolin-5-ylidene]hydrazino}benzoate](https://attachments.academia-assets.com/69346355/thumbnails/1.jpg)
](Zeitschrift für anorganische und allgemeine Chemie, 2012
Three cis-bis{5-[(E)-2-(2-carbomethoxyphenyl)-1diazenyl]quinolinolato}-diorganotin(IV), R 2 Sn(L)... more Three cis-bis{5-[(E)-2-(2-carbomethoxyphenyl)-1diazenyl]quinolinolato}-diorganotin(IV), R 2 Sn(L) 2 , complexes [R = Me (1), Ph (2) and Bz (3)] were synthesized and characterized by 1 H-, 13 C-, 119 Sn-NMR, IR, and 119 Sn Mössbauer spectroscopic techniques in combination with elemental analysis. The structure of diphenyltin(IV) complex Ph 2 Sn(L) 2 (2) was determined by single-crys
Journal of Organometallic Chemistry, 2010
Novel diorganotin(IV) derivatives of L-Arginine (HArg), N a-(tert-Butoxycarbonyl)-L-Arginine (Boc... more Novel diorganotin(IV) derivatives of L-Arginine (HArg), N a-(tert-Butoxycarbonyl)-L-Arginine (Boc-Arg-OH) and L-Ala-L-Arg (H 2 Ala-Arg), H 2 NC(@NH)NH(CH 2) 3 CH(NHR 0)CO 2 H, where R 0 = H in HArg, R 0 = C(O)OC(CH 3) 3 in Boc-Arg-OH, R 0 = H 2 NCH(CH 3)CO in H 2 Ala-Arg and triorganotin(IV) derivatives of Boc-Arg-OH have been synthesized and structurally characterized. The complexes were investigated by FT-IR and 119 Sn Mössbauer in the solid state and by 1 H, 13 C, 119 Sn and 1 H-1 H COSY NMR spectroscopy, in solution. The spectroscopic characterization leading to the proposed molecular structures was accomplished on the basis of these experiments. L-Arginine appears to behave as a chelating ligand through carboxylate and-NH 2 groups in Me 2 Sn(Arg) 2 , while in N at -Boc-L-Arginine complex, the N a-protected amino group being exempted from coordination, only the carboxylate groups are effectors of bonding to the organometallic moieties. FT-IR spectra give a clear indication that guanidino groups in all the complexes are not involved in coordination, since m(C@N-H) frequency of the terminal guanidino group is fairly constant and unshifted relative to the free ligand. The biological activity of organotin(IV)-complexes was also investigated by use of human HT29 colorectal carcinoma cells. The cytotoxic activity of the compounds was determined by the MTT quantitative colorimetric assay, capable of detecting viable cells in comparison with that exerted by cisplatin. A marked cytotoxic activity for nearly all complexes, is evident being higher than that exerted by cisplatin, while no significant improvement of activity was observed for Me 2 Sn(Arg) 2 and Me 2 Sn(Ala-Arg), which was confirmed by IC 50 values. Then, we assessed whether the cytotoxicity induced by organotin(IV) complexes was associated with the induction of apoptosis. Light microscopy analysis, performed to study the morphological changes induced in HT29 cells, confirmed the results obtained with MTT test. No significant morphological alterations were observed in HT29 cells after treatment with Me 2 Sn(Ala-Arg) and Me 2 Sn(L-Arg) 2. Cells treated with n Bu 2 Sn(Boc-Arg) 2 , n Bu 2 Sn(Ala-Arg), n Bu 3 Sn(Boc-Arg) and Me 3 Sn(Boc-Arg), appeared rounded, isolated and detached from culture substrate, indicating the commitment to apoptotic cell death.
![Research paper thumbnail of Triorganotin(IV) derivatives of 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid. Synthesis, spectroscopic characterization, in vitro antimicrobial activity and X-ray crystallography](https://attachments.academia-assets.com/69346411/thumbnails/1.jpg)
](Journal of Organometallic Chemistry, 2010
Triorganotin(IV) derivatives of 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxyl... more Triorganotin(IV) derivatives of 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid. Synthesis, spectroscopic characterization, in vitro antimicrobial activity and X-ray crystallography
![Research paper thumbnail of Crystal and solution structures of di-n-butyltin(IV) complexes of 5-[(E)-2-(4-methoxyphenyl)-1-diazenyl]quinolin-8-ol and benzoic acid derivatives: En route to elegant self-assembly via modulation of the tin coordination geometry](https://attachments.academia-assets.com/69346350/thumbnails/1.jpg)
](Journal of Organometallic Chemistry, 2009
Crystal and solution structures of din -butyltin(IV) complexes of 5-[(E)-2-(4-methoxyphenyl)-1-di... more Crystal and solution structures of din -butyltin(IV) complexes of 5-[(E)-2-(4-methoxyphenyl)-1-diazenyl]quinolin-8-ol and benzoic acid derivatives: En route to elegant self-assembly via modulation of the tin coordination geometry
![Research paper thumbnail of Self-assembly of extended Schiff base amino acetate skeletons, 2-{[(2Z)-(3-hydroxy-1-methyl-2-butenylidene)]amino}phenylpropionate and 2-{[(E)-1-(2-hydroxyaryl)alkylidene]amino}phenylpropionate skeletons incorporating organotin(IV) moieties: Synthesis, spectroscopic characterization, crystal stru...](https://attachments.academia-assets.com/69346391/thumbnails/1.jpg)
](Journal of Organometallic Chemistry, 2007
The organotin(IV) compounds, [Ph 3 SnL 1 H] n AE nCCl 4 (1), [Me 2 SnL 2 (OH 2)] (2), [ n Bu 2 Sn... more The organotin(IV) compounds, [Ph 3 SnL 1 H] n AE nCCl 4 (1), [Me 2 SnL 2 (OH 2)] (2), [ n Bu 2 SnL 2 ] (3), [Ph 2 SnL 2 ] n (4), [Ph 3 SnL 2 H] n (5) and [Ph 3 SnL 3 H] n (7) (L 1 = 2-{[(2Z)-(3-hydroxy-1-methyl-2-butenylidene)]amino}phenylpropionate and L 2À3 = 2-{[(E)-1-(2-hydroxyaryl)alkylidene]amino}phenylpropionate), were synthesized by treating the appropriate organotin(IV) chloride(s) with the potassium salt of the ligand in a suitable solvent, while [ n Bu 2 SnL 3 (OH 2)] (6) was obtained by reacting the acid form of L 3 (generated in situ) with n Bu 2 SnO. These complexes have been characterized by 1 H, 13 C, 119 Sn NMR, ESI-MS, IR and 119m Sn Mö ssbauer spectroscopic techniques in combination with elemental analyses. The crystal structures of 1 and 4-7 were determined. The crystal structures of complexes 1, 5 and 7 reveal that the complexes exist as polymeric chains in which the L-bridged Sn-atoms adopt a trans-R 3 SnO 2 trigonal bipyramidal configuration with R groups in the equatorial positions and the axial locations occupied by a carboxylate oxygen from the carboxylate ligand and the alcoholic or phenolic oxygen of the next carboxylate ligand in the chain. The carboxylate ligands coordinate in the zwitterionic form with the alcoholic/phenolic proton moved to the nearby nitrogen atom. A polymeric zigzag cis-bridged chain structure is observed for 4, without considering the weak SnÁ Á ÁO interaction, the Sn-atom having a slightly distorted trigonal bipyramidal coordination geometry with the two O atoms of the tridentate amino propionate ligand in axial positions. On the other hand, the structure of 6 reveals a monomeric molecule in which the Sn-atom has a distorted octahedral coordination geometry involving the tridentate carboxylate ligand, two n-butyl ligands occupying transpositions and one water ligand. The in vitro cytotoxic activity of triphenyltin(IV) compounds, viz., 1, 5 and 7 against WIDR, M19 MEL, A498, IGROV, H226, MCF7 and EVSA-T human tumor cell lines are also reported.
Applied Organometallic Chemistry, 1992
J Inorg Organomet Polym Mater, 2009
Two new polymeric triorganotin(IV) complexes R 3 Sn{O 2 CC 6 H 4 [N=C(H)}{C(CH 3)CH(CH 3)-3-OH]-p... more Two new polymeric triorganotin(IV) complexes R 3 Sn{O 2 CC 6 H 4 [N=C(H)}{C(CH 3)CH(CH 3)-3-OH]-p} n ([Me 3 Sn(LH)] n : 1) and ([Ph 3 Sn(LH)] n : 2) containing a 4-[(2Z)-(3hydroxy-1-methyl-2-butenylidene)amino]benzoate (LH) framework were prepared. Both compounds have been characterized by 1 H, 13 C, 119 Sn NMR, IR and 119 Sn Mössbauer spectroscopic techniques in combination with elemental analyses. The crystal structures of complexes 1 and 2 reveal that they exist as polymeric zigzag chains in which the LH-bridged Sn-atoms adopt a trans-R 3 SnO 2 trigonal bipyramidal configuration with R groups in the equatorial positions and the axial sites occupied by an oxygen atom from the carboxylate ligand and the alcoholic oxygen atom of the next carboxylate ligand in the chain. The carboxylate ligands coordinate in the zwitterionic form with the alcoholic proton moved to the nearby nitrogen atom.
Journal of Inorganic Biochemistry, 2002
III III The dynamics of iron nuclei in the condensates obtained by interaction of Fe with DNA, Fe... more III III The dynamics of iron nuclei in the condensates obtained by interaction of Fe with DNA, Fe (DNA monomer) , have been 2 57ï nvestigated by variable temperature Fe Mossbauer spectroscopy. Studies were effected on gel and freeze-dried samples, obtaining nearly coincident values of the parameters isomer shift and nuclear quadrupole splitting in T ranges 20-260 K. Functions ln(A /A) vs. T 77.3 T, here employed to investigate the dynamics of Fe nuclei, showed linear trends in the T ranges 20-150 and 150-260 K, respectively, the latter with larger slopes. Data coincided for gelled and freeze-dried specimens. No variation of d or DE parameters occurred at the two T 2 intervals, which suggests constancy of structure and bonding with the temperature changes. Functions kx l(T) showed trends analogous to the corresponding functions determined for iron proteins, which were attributed to the occurrence of 'conformational substates'.
J Chem Soc Dalton Trans, 1989
Inorganica Chimica Acta, 1985
Applied Organometallic Chemistry, 1992
Journal of Inorganic and Organometallic Polymers and Materials, 2009
Two new polymeric triorganotin(IV) complexes R 3 Sn{O 2 CC 6 H 4 [N=C(H)}{C(CH 3)CH(CH 3)-3-OH]-p... more Two new polymeric triorganotin(IV) complexes R 3 Sn{O 2 CC 6 H 4 [N=C(H)}{C(CH 3)CH(CH 3)-3-OH]-p} n ([Me 3 Sn(LH)] n : 1) and ([Ph 3 Sn(LH)] n : 2) containing a 4-[(2Z)-(3hydroxy-1-methyl-2-butenylidene)amino]benzoate (LH) framework were prepared. Both compounds have been characterized by 1 H, 13 C, 119 Sn NMR, IR and 119 Sn Mössbauer spectroscopic techniques in combination with elemental analyses. The crystal structures of complexes 1 and 2 reveal that they exist as polymeric zigzag chains in which the LH-bridged Sn-atoms adopt a trans-R 3 SnO 2 trigonal bipyramidal configuration with R groups in the equatorial positions and the axial sites occupied by an oxygen atom from the carboxylate ligand and the alcoholic oxygen atom of the next carboxylate ligand in the chain. The carboxylate ligands coordinate in the zwitterionic form with the alcoholic proton moved to the nearby nitrogen atom.
Hyperfine Interactions, 2000
Ethanol solutions of Alk n SnCl4−n (Alk = Me, Et; n = 1–3) added to aqueous calf thymus DNA provo... more Ethanol solutions of Alk n SnCl4−n (Alk = Me, Et; n = 1–3) added to aqueous calf thymus DNA provoke DNA condensation (even in the presence of added cysteine) possibly through charge neutralization of DNA phosphodiesters by organotin(IV) cations. The structures of tin bonding environments in binary and ternary condensed systems organotin(IV)-DNA and ligand-organotin(IV)-DNA are determined through point-charge model treatment
Journal of the Chemical Society, Dalton Transactions, 1989
Journal of Molecular Structure-Theochem, 2009
The interaction of proflavine (PR) with two B-DNA decamers of alternating AT and GC sequence, cal... more The interaction of proflavine (PR) with two B-DNA decamers of alternating AT and GC sequence, called [deca(dG-dC)] 2 and [deca(dA-dT)] 2 , respectively, was computationally investigated by the ONIOM method, exploiting a three-layer QM/QM/MM hybrid approach. The highest level QM method was applied to the model system, which comprises the intercalation site (5th and 6th base pairs) and the inserted PR molecule. The connecting sugar phosphate backbone was added in the medium layer region. Both higher and medium level layers, differing in the size of the basis set used, were treated by the DFT MPWB1K functional. The full system in the lower layer was described by the empirical AMBER force field. The calculated values of the interaction energy of PR with [deca(dG-dC)] 2 and [deca(dA-dT)] 2 , as well as with the dinucleotides d(GpC) 2 , and d(ApT) 2 , the latter considered either in vacuo and in the mimicked water solvent, support for a static higher affinity toward G-C compared to the AT DNA base sequences, in agreement with structural results from crystallographic studies. Furthermore, the different structural characteristics of the [deca(dG-dC)] 2 /PR complex compared to those of the [deca(dA-dT)] 2 /PR, furnish a possible interpretation of apparently controversial experimental thermodynamic data, explained in terms of two possible modes of non-covalent binding of ligands with DNA, namely intercalation and external binding, respectively.
Journal of the Chemical Society, Dalton Transactions, 1995
... Renato Barbieri,*Sa Giuseppe Ruisi,a Arturo Silvestri,a Anna Maria Giuliani,a Adriana Barbier... more ... Renato Barbieri,*Sa Giuseppe Ruisi,a Arturo Silvestri,a Anna Maria Giuliani,a Adriana Barbieri,a Gabriele Spina,b Fabrizio Pierallib and Franco Del Giallob a Dipartimento di Chimica lnorganica, Universita di P alermo, 1-90 123 Palermo, Italy Dipartimento di Fisica, Universita ...
Journal of the Chemical Society, Dalton Transactions, 1985
Friedo Huber," Gerhard Roge, and Lothar Carl Lehrstuhl fur Anorganische Chemie, Universitat ... more Friedo Huber," Gerhard Roge, and Lothar Carl Lehrstuhl fur Anorganische Chemie, Universitat Dortmund, D -4600 Dortmund 50, Federal Republic of Germany G hanem Atassi Laboratory for Experimental Chemotherapy and Screening, lnstitut J. Bordet, 1000 Brussels, Belgium ...
Zeitschrift f�r anorganische und allgemeine Chemie, 1995
Page 1. Z. anorg. allg. Chem. 621 (1995) 89-96 Zeitschrift fur anorganische und allgemeine Chemie... more Page 1. Z. anorg. allg. Chem. 621 (1995) 89-96 Zeitschrift fur anorganische und allgemeine Chemie 0 Johann Ambrosius Barth 1995 Tin( IV), Monomet hyltin(IV), and Dimet hyltin( IV) Complexes with T hiol Sulfur and Heterocyclic ...
Zeitschrift für anorganische und allgemeine Chemie, 2012
Three cis-bis{5-[(E)-2-(2-carbomethoxyphenyl)-1diazenyl]quinolinolato}-diorganotin(IV), R 2 Sn(L)... more Three cis-bis{5-[(E)-2-(2-carbomethoxyphenyl)-1diazenyl]quinolinolato}-diorganotin(IV), R 2 Sn(L) 2 , complexes [R = Me (1), Ph (2) and Bz (3)] were synthesized and characterized by 1 H-, 13 C-, 119 Sn-NMR, IR, and 119 Sn Mössbauer spectroscopic techniques in combination with elemental analysis. The structure of diphenyltin(IV) complex Ph 2 Sn(L) 2 (2) was determined by single-crys
Journal of Organometallic Chemistry, 2010
Novel diorganotin(IV) derivatives of L-Arginine (HArg), N a-(tert-Butoxycarbonyl)-L-Arginine (Boc... more Novel diorganotin(IV) derivatives of L-Arginine (HArg), N a-(tert-Butoxycarbonyl)-L-Arginine (Boc-Arg-OH) and L-Ala-L-Arg (H 2 Ala-Arg), H 2 NC(@NH)NH(CH 2) 3 CH(NHR 0)CO 2 H, where R 0 = H in HArg, R 0 = C(O)OC(CH 3) 3 in Boc-Arg-OH, R 0 = H 2 NCH(CH 3)CO in H 2 Ala-Arg and triorganotin(IV) derivatives of Boc-Arg-OH have been synthesized and structurally characterized. The complexes were investigated by FT-IR and 119 Sn Mössbauer in the solid state and by 1 H, 13 C, 119 Sn and 1 H-1 H COSY NMR spectroscopy, in solution. The spectroscopic characterization leading to the proposed molecular structures was accomplished on the basis of these experiments. L-Arginine appears to behave as a chelating ligand through carboxylate and-NH 2 groups in Me 2 Sn(Arg) 2 , while in N at -Boc-L-Arginine complex, the N a-protected amino group being exempted from coordination, only the carboxylate groups are effectors of bonding to the organometallic moieties. FT-IR spectra give a clear indication that guanidino groups in all the complexes are not involved in coordination, since m(C@N-H) frequency of the terminal guanidino group is fairly constant and unshifted relative to the free ligand. The biological activity of organotin(IV)-complexes was also investigated by use of human HT29 colorectal carcinoma cells. The cytotoxic activity of the compounds was determined by the MTT quantitative colorimetric assay, capable of detecting viable cells in comparison with that exerted by cisplatin. A marked cytotoxic activity for nearly all complexes, is evident being higher than that exerted by cisplatin, while no significant improvement of activity was observed for Me 2 Sn(Arg) 2 and Me 2 Sn(Ala-Arg), which was confirmed by IC 50 values. Then, we assessed whether the cytotoxicity induced by organotin(IV) complexes was associated with the induction of apoptosis. Light microscopy analysis, performed to study the morphological changes induced in HT29 cells, confirmed the results obtained with MTT test. No significant morphological alterations were observed in HT29 cells after treatment with Me 2 Sn(Ala-Arg) and Me 2 Sn(L-Arg) 2. Cells treated with n Bu 2 Sn(Boc-Arg) 2 , n Bu 2 Sn(Ala-Arg), n Bu 3 Sn(Boc-Arg) and Me 3 Sn(Boc-Arg), appeared rounded, isolated and detached from culture substrate, indicating the commitment to apoptotic cell death.
Journal of Organometallic Chemistry, 2010
Triorganotin(IV) derivatives of 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxyl... more Triorganotin(IV) derivatives of 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid. Synthesis, spectroscopic characterization, in vitro antimicrobial activity and X-ray crystallography
Journal of Organometallic Chemistry, 2009
Crystal and solution structures of din -butyltin(IV) complexes of 5-[(E)-2-(4-methoxyphenyl)-1-di... more Crystal and solution structures of din -butyltin(IV) complexes of 5-[(E)-2-(4-methoxyphenyl)-1-diazenyl]quinolin-8-ol and benzoic acid derivatives: En route to elegant self-assembly via modulation of the tin coordination geometry
Journal of Organometallic Chemistry, 2007
The organotin(IV) compounds, [Ph 3 SnL 1 H] n AE nCCl 4 (1), [Me 2 SnL 2 (OH 2)] (2), [ n Bu 2 Sn... more The organotin(IV) compounds, [Ph 3 SnL 1 H] n AE nCCl 4 (1), [Me 2 SnL 2 (OH 2)] (2), [ n Bu 2 SnL 2 ] (3), [Ph 2 SnL 2 ] n (4), [Ph 3 SnL 2 H] n (5) and [Ph 3 SnL 3 H] n (7) (L 1 = 2-{[(2Z)-(3-hydroxy-1-methyl-2-butenylidene)]amino}phenylpropionate and L 2À3 = 2-{[(E)-1-(2-hydroxyaryl)alkylidene]amino}phenylpropionate), were synthesized by treating the appropriate organotin(IV) chloride(s) with the potassium salt of the ligand in a suitable solvent, while [ n Bu 2 SnL 3 (OH 2)] (6) was obtained by reacting the acid form of L 3 (generated in situ) with n Bu 2 SnO. These complexes have been characterized by 1 H, 13 C, 119 Sn NMR, ESI-MS, IR and 119m Sn Mö ssbauer spectroscopic techniques in combination with elemental analyses. The crystal structures of 1 and 4-7 were determined. The crystal structures of complexes 1, 5 and 7 reveal that the complexes exist as polymeric chains in which the L-bridged Sn-atoms adopt a trans-R 3 SnO 2 trigonal bipyramidal configuration with R groups in the equatorial positions and the axial locations occupied by a carboxylate oxygen from the carboxylate ligand and the alcoholic or phenolic oxygen of the next carboxylate ligand in the chain. The carboxylate ligands coordinate in the zwitterionic form with the alcoholic/phenolic proton moved to the nearby nitrogen atom. A polymeric zigzag cis-bridged chain structure is observed for 4, without considering the weak SnÁ Á ÁO interaction, the Sn-atom having a slightly distorted trigonal bipyramidal coordination geometry with the two O atoms of the tridentate amino propionate ligand in axial positions. On the other hand, the structure of 6 reveals a monomeric molecule in which the Sn-atom has a distorted octahedral coordination geometry involving the tridentate carboxylate ligand, two n-butyl ligands occupying transpositions and one water ligand. The in vitro cytotoxic activity of triphenyltin(IV) compounds, viz., 1, 5 and 7 against WIDR, M19 MEL, A498, IGROV, H226, MCF7 and EVSA-T human tumor cell lines are also reported.