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Papers by elena vismara

Research paper thumbnail of Suivi et optimisation d’une station de décontamination des eaux usées de la filière traitement de surface : abattement chimique et impact écotoxicologique

Revue des sciences de l'eau, 2011

Les traitements de surfaces (TS) utilisent des volumes importants d'eau et de produits chimiq... more Les traitements de surfaces (TS) utilisent des volumes importants d'eau et de produits chimiques dans leurs procédés de fabrication. Bien que des efforts considérables en matière d'amélioration des procédés aient été réalisés depuis 20 ans, la filière TS est ...

Research paper thumbnail of Polar effects in free-radical reactions. Rate constants in phenylation and new methods of selective alkylation of heteroaromatic bases

J Org Chem, 1986

... Francesco Minisci,* Elena Vismara,* Francesca Fontana, Giampiero Morini, and Marco Serravalle... more ... Francesco Minisci,* Elena Vismara,* Francesca Fontana, Giampiero Morini, and Marco Serravalle ... (10) Perkins, M. J. In Free Radicals; Kochi, JK, Ed.; Wiley: New (11) Johnston, LJ; Scaiano, JC; Ingold, K. U. J. Am. Chem. SOC. ...

Research paper thumbnail of A general, selective, and convenient procedure of homolytic formylation of heteroaromatic bases

Research paper thumbnail of New General Processes of Homolytic Alkylation of Heteroaromatic Bases by t-BuOOH or (t-BuO)2 and Alkyl Iodides

Research paper thumbnail of Multistep process for the physical depolymerization of heparin and products obtained therefrom

Research paper thumbnail of Electron beam irradiated textile cellulose fibres

Eur Polym J, 2005

Powdered samples of cotton, flax and viscose from textile fibres were subjected to electron beam ... more Powdered samples of cotton, flax and viscose from textile fibres were subjected to electron beam irradiation (20–400 KGy). ESR signals were observed after irradiation. The intensity of the signals depended on the administered dose and exhibited an exponential decay with time. The ESR spectra, whose pattern depended drastically on the crystallinity of the samples, indicated the simultaneous presence of at least three carbon-centred radical species. When the whole irradiated textile fibres were quenched in a solution of glycidyl methacrylate (GMA) a significant increase of the weight was observed, the increase being strongly dependent on the administered dose and on the time interval elapsed between irradiation and quenching. Spectroscopic characterisation evidenced that GMA acted as cellulose radicals scavenger on the unsubstituted carbon of the double bond and was covalently linked to the fibre through a new C–C bond while maintaining unaltered the ester and the epoxide groups, available for further derivatisations. Because irradiation of the whole textile fibres in the range 20–200 KGy does not result in significant degradation of the material, GMA quenching of fibres irradiated in this dose range may represent an attractive route to their functionalisation.

Research paper thumbnail of Polar effects in free-radical reactions. Selectivity and reversibility in the homolytic benzylation of protonated heteroaromatic bases

Research paper thumbnail of Polar effects in free-radical reactions. Solvent and isotope effects and effects of base catalysis on the regio- and chemoselectivity of the substitution of protonated heteroaromatic bases by nucleophilic carbon-centered radicals

Journal of Organic Chemistry, 1987

... Francesco Minisci,* Elena Vismara,* Francesca Fontana, Giampiero Morini, and Marco Serravalle... more ... Francesco Minisci,* Elena Vismara,* Francesca Fontana, Giampiero Morini, and Marco Serravalle Dipartimento di Chimica del Politecnico, 20133 Milano, Italy Claudio Giordano Zambon Chimica SpA, Cormano (MI), Italy Received October 17, 1986 ... (4) Bunce, NJ; Ingold, K. U ...

Research paper thumbnail of Mimetics of sulfated oligosaccharides

Research paper thumbnail of ChemInform Abstract: Electrochemical Reduction of Halogenosugars on Silver: A New Approach to C-Disaccharide-Like Mimics

Research paper thumbnail of A new general method of homolytic alkylation of protonated heteroaromatic bases

Tetrahedron Letters, 1984

Research paper thumbnail of An ESR approach to hypervalent iodine induced iododecarboxylation

Research on Chemical Intermediates, 1989

Some mechanistic considerations based on the results of an ESR spectroscopic study of the IBDA (i... more Some mechanistic considerations based on the results of an ESR spectroscopic study of the IBDA (iodosobenzene diacetate) induced iododecarbozylation of several aliphatic carbozyIic acids are reported. Both acetoxy units in IBDA are replaced by carboxylate groups in the first step of the reaction, forming a hypervalent iodine eomplez which then undergoes homolytic photodegradation. The R. radicals deriving from decarboxylation of the starting acidz have been trapped by means of thiobenzoyl triphenylsilane and identified using ESR spectroscopy.

Research paper thumbnail of Facile and convenient syntheses of quinones from phenols

Journal of Organic Chemistry, 1989

... known procedures, also with the most se-lective and mild oxidants (thallium nitrate,l ... Mor... more ... known procedures, also with the most se-lective and mild oxidants (thallium nitrate,l ... More convenient oxidants, such as molecular oxygen13 and hydrogen peroxide,14 have therefore attracted ... 6-disubstituted phenols suitable for large-scale works3 It involves the oxidation of the ...

Research paper thumbnail of Heparin and Carboxymethylchitosan Metal Nanoparticles: An Evaluation of Their Cytotoxicity

BioMed Research International, 2013

In the search for noninvasive diagnostic techniques and new therapies, "nanosystems", which are c... more In the search for noninvasive diagnostic techniques and new therapies, "nanosystems", which are capable of binding and targeting bioactive molecules, are becoming increasingly important. In this context, biocompatible coatings are gaining interest, not only for their biological effects but also because they are considered capable to mask nanoparticle toxicity. In this work, we have compared the toxicity of nanoparticles coated with heparin and carboxymethylchitosan in the SKOV-3 cell line. Our results indicate that heparin and carboxymethylchitosan coatings do not guarantee the decrease of nanoparticle intrinsic toxicity which is often envisaged. Nonetheless, these coatings provide the opportunity for further functionalization with a variety of biomolecules for their use in theranostics.

Research paper thumbnail of Polar effects in free-radical reactions. New synthetic developments in the functionalization of heteroaromatic bases by nucleophilic radicals

Tetrahedron, 1985

The synthetic interest of the direct substitution of protonated heteroaromatic bases by nucleophi... more The synthetic interest of the direct substitution of protonated heteroaromatic bases by nucleophilic carbon-centered radicals is furtheron developed by the following new achievements: i) utilization of the redox system &H30H/Ti(III) in several solvents; li) utilization of benzoyl peroxide in alcohols: iii) carbamoylation by HCONH2 and H202 in the presence of catalytic amounts of Fe(II1. These systems allow to obtain either substitution till now tried without success or reactions of industrial interest.Polar effects play a dominat role in determining reactivity, selectivity and synthetic applications; in particular the role of the strongly nucleophilic intermediate radicals of pyridinyl type in the rearomatization step is emphasized.

Research paper thumbnail of Polar effects in the homolytic methylation of pyrimidine: orientation and polysubstitution

Journal of the Chemical Society, Perkin Transactions 2, 1984

... although inversion of this relative reactivity takes place at the isokinetic temperature.&#x2... more ... although inversion of this relative reactivity takes place at the isokinetic temperature.' Also aminolysis of 2,4-dichloropyrimidine generally leads to a slight prevalence of the substitution of the chlorine in position 4; this selectivity is increased by using a protic solvent.' Homolytic ...

Research paper thumbnail of Homolytic alkylation of naphthoquinone and methyl-naphthoquinone. Enthalpic, steric and polar effects

Research paper thumbnail of Reactivity of glucosyl radical in the presence of phenols

Tetrahedron, 1996

... All rights reserved PH: S00404020(96)005583 00404020 96 15.00 + 0.00 Reactivity of Glucosyl R... more ... All rights reserved PH: S00404020(96)005583 00404020 96 15.00 + 0.00 Reactivity of Glucosyl Radical in the Presence of Phenols Angelo Alberti, +a Maria A. Delta Bona, a Dante Macciantelli,a Francesca Pelizzoni,b Guido Sello,b ... Larkin, JP; Norman, ROCJ Chem. Soc. ...

Research paper thumbnail of Sulfated hexasaccharides attenuate metastasis by inhibition of p-selectin and heparanase

Neoplasia, 2011

Development of compounds that target both heparanase and selectins is emerging as a promising app... more Development of compounds that target both heparanase and selectins is emerging as a promising approach for cancer therapy. Selectins are vascular cell adhesion molecules that mediate tumor cell interactions with platelets, leukocytes, and the vascular endothelium. Heparanase is an endoglycosidase that degrades heparan sulfate in the tumor microenvironment, cell surfaces, and vessel wall. Acting together, these molecules facilitate tumor cell arrest, extravasation, and metastasis. Here, we report the preparation of novel semisynthetic sulfated tri mannose C-C-linked dimers (STMCs) endowed with heparanase and selectin inhibitory activity. The P-selectin specificity of the STMC was defined by the anomeric linkage of the C-C bond. This STMC hexasaccharide is an effective inhibitor of P-selectin in vivo. We show that selective inhibition of heparanase attenuates metastasis in B16-BL6 melanoma cells, expressing high levels of this endoglycosidase, but has no effect on the metastasis of MC-38 carcinoma cells that express little or no heparanase activity. P-selectin-specific STMC attenuated metastasis in both animal models, indicating that inhibition of tumor cell interaction with the vascular endothelium is critical for cancer dissemination. Thus, the small size, the stability of the C-C bond, and the chemically defined structure of the newly generated STMCs make them superior to heparin derivatives and signify STMCs as valuable candidates for further evaluation.

Research paper thumbnail of ChemInform Abstract: C-Glucosyl Quinones and Related Spacer-Connected C-Disaccharide

Research paper thumbnail of Suivi et optimisation d’une station de décontamination des eaux usées de la filière traitement de surface : abattement chimique et impact écotoxicologique

Revue des sciences de l'eau, 2011

Les traitements de surfaces (TS) utilisent des volumes importants d'eau et de produits chimiq... more Les traitements de surfaces (TS) utilisent des volumes importants d'eau et de produits chimiques dans leurs procédés de fabrication. Bien que des efforts considérables en matière d'amélioration des procédés aient été réalisés depuis 20 ans, la filière TS est ...

Research paper thumbnail of Polar effects in free-radical reactions. Rate constants in phenylation and new methods of selective alkylation of heteroaromatic bases

J Org Chem, 1986

... Francesco Minisci,* Elena Vismara,* Francesca Fontana, Giampiero Morini, and Marco Serravalle... more ... Francesco Minisci,* Elena Vismara,* Francesca Fontana, Giampiero Morini, and Marco Serravalle ... (10) Perkins, M. J. In Free Radicals; Kochi, JK, Ed.; Wiley: New (11) Johnston, LJ; Scaiano, JC; Ingold, K. U. J. Am. Chem. SOC. ...

Research paper thumbnail of A general, selective, and convenient procedure of homolytic formylation of heteroaromatic bases

Research paper thumbnail of New General Processes of Homolytic Alkylation of Heteroaromatic Bases by t-BuOOH or (t-BuO)2 and Alkyl Iodides

Research paper thumbnail of Multistep process for the physical depolymerization of heparin and products obtained therefrom

Research paper thumbnail of Electron beam irradiated textile cellulose fibres

Eur Polym J, 2005

Powdered samples of cotton, flax and viscose from textile fibres were subjected to electron beam ... more Powdered samples of cotton, flax and viscose from textile fibres were subjected to electron beam irradiation (20–400 KGy). ESR signals were observed after irradiation. The intensity of the signals depended on the administered dose and exhibited an exponential decay with time. The ESR spectra, whose pattern depended drastically on the crystallinity of the samples, indicated the simultaneous presence of at least three carbon-centred radical species. When the whole irradiated textile fibres were quenched in a solution of glycidyl methacrylate (GMA) a significant increase of the weight was observed, the increase being strongly dependent on the administered dose and on the time interval elapsed between irradiation and quenching. Spectroscopic characterisation evidenced that GMA acted as cellulose radicals scavenger on the unsubstituted carbon of the double bond and was covalently linked to the fibre through a new C–C bond while maintaining unaltered the ester and the epoxide groups, available for further derivatisations. Because irradiation of the whole textile fibres in the range 20–200 KGy does not result in significant degradation of the material, GMA quenching of fibres irradiated in this dose range may represent an attractive route to their functionalisation.

Research paper thumbnail of Polar effects in free-radical reactions. Selectivity and reversibility in the homolytic benzylation of protonated heteroaromatic bases

Research paper thumbnail of Polar effects in free-radical reactions. Solvent and isotope effects and effects of base catalysis on the regio- and chemoselectivity of the substitution of protonated heteroaromatic bases by nucleophilic carbon-centered radicals

Journal of Organic Chemistry, 1987

... Francesco Minisci,* Elena Vismara,* Francesca Fontana, Giampiero Morini, and Marco Serravalle... more ... Francesco Minisci,* Elena Vismara,* Francesca Fontana, Giampiero Morini, and Marco Serravalle Dipartimento di Chimica del Politecnico, 20133 Milano, Italy Claudio Giordano Zambon Chimica SpA, Cormano (MI), Italy Received October 17, 1986 ... (4) Bunce, NJ; Ingold, K. U ...

Research paper thumbnail of Mimetics of sulfated oligosaccharides

Research paper thumbnail of ChemInform Abstract: Electrochemical Reduction of Halogenosugars on Silver: A New Approach to C-Disaccharide-Like Mimics

Research paper thumbnail of A new general method of homolytic alkylation of protonated heteroaromatic bases

Tetrahedron Letters, 1984

Research paper thumbnail of An ESR approach to hypervalent iodine induced iododecarboxylation

Research on Chemical Intermediates, 1989

Some mechanistic considerations based on the results of an ESR spectroscopic study of the IBDA (i... more Some mechanistic considerations based on the results of an ESR spectroscopic study of the IBDA (iodosobenzene diacetate) induced iododecarbozylation of several aliphatic carbozyIic acids are reported. Both acetoxy units in IBDA are replaced by carboxylate groups in the first step of the reaction, forming a hypervalent iodine eomplez which then undergoes homolytic photodegradation. The R. radicals deriving from decarboxylation of the starting acidz have been trapped by means of thiobenzoyl triphenylsilane and identified using ESR spectroscopy.

Research paper thumbnail of Facile and convenient syntheses of quinones from phenols

Journal of Organic Chemistry, 1989

... known procedures, also with the most se-lective and mild oxidants (thallium nitrate,l ... Mor... more ... known procedures, also with the most se-lective and mild oxidants (thallium nitrate,l ... More convenient oxidants, such as molecular oxygen13 and hydrogen peroxide,14 have therefore attracted ... 6-disubstituted phenols suitable for large-scale works3 It involves the oxidation of the ...

Research paper thumbnail of Heparin and Carboxymethylchitosan Metal Nanoparticles: An Evaluation of Their Cytotoxicity

BioMed Research International, 2013

In the search for noninvasive diagnostic techniques and new therapies, "nanosystems", which are c... more In the search for noninvasive diagnostic techniques and new therapies, "nanosystems", which are capable of binding and targeting bioactive molecules, are becoming increasingly important. In this context, biocompatible coatings are gaining interest, not only for their biological effects but also because they are considered capable to mask nanoparticle toxicity. In this work, we have compared the toxicity of nanoparticles coated with heparin and carboxymethylchitosan in the SKOV-3 cell line. Our results indicate that heparin and carboxymethylchitosan coatings do not guarantee the decrease of nanoparticle intrinsic toxicity which is often envisaged. Nonetheless, these coatings provide the opportunity for further functionalization with a variety of biomolecules for their use in theranostics.

Research paper thumbnail of Polar effects in free-radical reactions. New synthetic developments in the functionalization of heteroaromatic bases by nucleophilic radicals

Tetrahedron, 1985

The synthetic interest of the direct substitution of protonated heteroaromatic bases by nucleophi... more The synthetic interest of the direct substitution of protonated heteroaromatic bases by nucleophilic carbon-centered radicals is furtheron developed by the following new achievements: i) utilization of the redox system &H30H/Ti(III) in several solvents; li) utilization of benzoyl peroxide in alcohols: iii) carbamoylation by HCONH2 and H202 in the presence of catalytic amounts of Fe(II1. These systems allow to obtain either substitution till now tried without success or reactions of industrial interest.Polar effects play a dominat role in determining reactivity, selectivity and synthetic applications; in particular the role of the strongly nucleophilic intermediate radicals of pyridinyl type in the rearomatization step is emphasized.

Research paper thumbnail of Polar effects in the homolytic methylation of pyrimidine: orientation and polysubstitution

Journal of the Chemical Society, Perkin Transactions 2, 1984

... although inversion of this relative reactivity takes place at the isokinetic temperature.&#x2... more ... although inversion of this relative reactivity takes place at the isokinetic temperature.' Also aminolysis of 2,4-dichloropyrimidine generally leads to a slight prevalence of the substitution of the chlorine in position 4; this selectivity is increased by using a protic solvent.' Homolytic ...

Research paper thumbnail of Homolytic alkylation of naphthoquinone and methyl-naphthoquinone. Enthalpic, steric and polar effects

Research paper thumbnail of Reactivity of glucosyl radical in the presence of phenols

Tetrahedron, 1996

... All rights reserved PH: S00404020(96)005583 00404020 96 15.00 + 0.00 Reactivity of Glucosyl R... more ... All rights reserved PH: S00404020(96)005583 00404020 96 15.00 + 0.00 Reactivity of Glucosyl Radical in the Presence of Phenols Angelo Alberti, +a Maria A. Delta Bona, a Dante Macciantelli,a Francesca Pelizzoni,b Guido Sello,b ... Larkin, JP; Norman, ROCJ Chem. Soc. ...

Research paper thumbnail of Sulfated hexasaccharides attenuate metastasis by inhibition of p-selectin and heparanase

Neoplasia, 2011

Development of compounds that target both heparanase and selectins is emerging as a promising app... more Development of compounds that target both heparanase and selectins is emerging as a promising approach for cancer therapy. Selectins are vascular cell adhesion molecules that mediate tumor cell interactions with platelets, leukocytes, and the vascular endothelium. Heparanase is an endoglycosidase that degrades heparan sulfate in the tumor microenvironment, cell surfaces, and vessel wall. Acting together, these molecules facilitate tumor cell arrest, extravasation, and metastasis. Here, we report the preparation of novel semisynthetic sulfated tri mannose C-C-linked dimers (STMCs) endowed with heparanase and selectin inhibitory activity. The P-selectin specificity of the STMC was defined by the anomeric linkage of the C-C bond. This STMC hexasaccharide is an effective inhibitor of P-selectin in vivo. We show that selective inhibition of heparanase attenuates metastasis in B16-BL6 melanoma cells, expressing high levels of this endoglycosidase, but has no effect on the metastasis of MC-38 carcinoma cells that express little or no heparanase activity. P-selectin-specific STMC attenuated metastasis in both animal models, indicating that inhibition of tumor cell interaction with the vascular endothelium is critical for cancer dissemination. Thus, the small size, the stability of the C-C bond, and the chemically defined structure of the newly generated STMCs make them superior to heparin derivatives and signify STMCs as valuable candidates for further evaluation.

Research paper thumbnail of ChemInform Abstract: C-Glucosyl Quinones and Related Spacer-Connected C-Disaccharide