- Rende, Calabria, Italy
Research Interests:
ABSTRACT An efficient, solvent-free protocol for the N-fluorenylmethoxycarbonylation and N-benzyloxycarbonylation of amines is described. The reaction of aliphatic and aromatic amines with FmocOSu and Cbz-Osu in [Bmim][BF4] at room... more
ABSTRACT An efficient, solvent-free protocol for the N-fluorenylmethoxycarbonylation and N-benzyloxycarbonylation of amines is described. The reaction of aliphatic and aromatic amines with FmocOSu and Cbz-Osu in [Bmim][BF4] at room temperature afforded the corresponding N-urethane derivatives in excellent yields and do not require any further purification. The method has been extended to the N-Fmoc and N-Cbz protection of amino acids. Absence of bases, very short reaction times, high yields, selectivity and ease of product separation are some advantages of this protocol.
Research Interests: RSC()
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This work reports an efficient Lewis acid catalysed N-methylation procedure of lipophilic α-amino acid methyl esters in solution phase. The developed methodology involves the use of the reagent system AlCl3 /diazomethane as methylating... more
This work reports an efficient Lewis acid catalysed N-methylation procedure of lipophilic α-amino acid methyl esters in solution phase. The developed methodology involves the use of the reagent system AlCl3 /diazomethane as methylating agent and α-amino acid methyl esters protected on the amino function with the (9H-fluoren-9-yl)methanesulfonyl (Fms) group. The removal of Fms protecting group is achieved under the same conditions to those used for Fmoc removal. Thus the Fms group can be interchangeable with the Fmoc group in the synthesis of N-methylated peptides using standard Fmoc-based strategies. Finally, the absence of racemization during the methylation reaction and the removal of Fms group were demonstrated by synthesising a pair of diastereomeric dipeptides. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.
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ABSTRACT An expeditious, practical, and mild method for the reduction of amides to amines is reported. The procedure is based on the activation of amides with titanium tetrachloride followed by reduction with lithium aluminum hydride. The... more
ABSTRACT An expeditious, practical, and mild method for the reduction of amides to amines is reported. The procedure is based on the activation of amides with titanium tetrachloride followed by reduction with lithium aluminum hydride. The reducing system can be applied to the reduction of tertiary and secondary amides giving the corresponding amines in good yields. The protocol was also extended to the reduction of amides of Nα-protected amino acid and dipeptides. The corresponding 1,2 diamines and diaminoalcohols were produced in high yields and with retention of configuration at the chiral centers.
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ABSTRACT A mild method for the aminolysis of carboxylic acid chlorides to give amides is disclosed. Reactions are carried out in the presence of silver acetate in non-aqueous environments under heterogeneous phase conditions. Amides are... more
ABSTRACT A mild method for the aminolysis of carboxylic acid chlorides to give amides is disclosed. Reactions are carried out in the presence of silver acetate in non-aqueous environments under heterogeneous phase conditions. Amides are easily recovered in very good to excellent yields and without racemization. The approach is successful in forming peptide bonds starting from N-(4-nitrobenzenesulfonyl)-amino acid chlorides and allows the formation of dipeptides also when N-methylated amino acid derivatives are used.
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A facile and convenient approach to 17-ketosteroids is described. Treatment of steroids containing the C-17-dihydroxy acetone side chain with an excess of sodium methoxide in dry 1,4-dioxane under reflux, affords high yields of the... more
A facile and convenient approach to 17-ketosteroids is described. Treatment of steroids containing the C-17-dihydroxy acetone side chain with an excess of sodium methoxide in dry 1,4-dioxane under reflux, affords high yields of the corresponding 17-ketosteroids that are recovered as pure products, without the need of further purification.
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In this paper we describe a reductive amination procedure that can be employed in the preparation of a novel class of pseudopeptides in which a specific amide bond is replaced by a CH(Ar)NH group. The developed methodology, performed... more
In this paper we describe a reductive amination procedure that can be employed in the preparation of a novel class of pseudopeptides in which a specific amide bond is replaced by a CH(Ar)NH group. The developed methodology, performed using NaBH(3)CN and TiCl(4), is characterized by the formation of diastereomeric intermediates in a relative 1:1 ratio. It provides aryl aminomethin pseudopeptides in moderate but satisfactory yields and with definite stereochemistry on the asymmetric centres next to the modified peptide bond.
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An efficient and stereocontrolled synthesis of 2-substituted tetrahydrofurans has been achieved. The approach employs the asymmetric reduction of γ-phenylseleno ketones obtained by three different procedures that are peculiarly applied to... more
An efficient and stereocontrolled synthesis of 2-substituted tetrahydrofurans has been achieved. The approach employs the asymmetric reduction of γ-phenylseleno ketones obtained by three different procedures that are peculiarly applied to the synthesis of such compounds. Finally, the intramolecular substitution of the phenylselenone residue by the oxygen atom of a hydroxy group gives the tetrahydrofuran ring.
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A total synthesis of D-erythro-sphinganine [(2S,3R)-2-aminooctadecane-1,3-diol] starting from commercial N-tert-butyloxycarbonyl-L-serine methyl ester is described. The approach is based on the completely stereoselective preparation of an... more
A total synthesis of D-erythro-sphinganine [(2S,3R)-2-aminooctadecane-1,3-diol] starting from commercial N-tert-butyloxycarbonyl-L-serine methyl ester is described. The approach is based on the completely stereoselective preparation of an α-amino epoxide obtained by treating a protected L-serinal derivative with dimethylsulfoxonium methylide. The oxirane synthon is obtained with an anti configuration fitting the (2S,3R) stereochemistry of the 2-amino-1,3-diol polar head of D-erythro-sphinganine. The synthetic procedure afforded the target compound in a 68% overall yield based on the initial amount of the starting L-serine material.
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This paper compares some important parameters and the free amino acid and biogenic amine contents of cured industrial and homemade meat products. To this aim, industrial and homemade... more
This paper compares some important parameters and the free amino acid and biogenic amine contents of cured industrial and homemade meat products. To this aim, industrial and homemade "soppressata" and "salsiccia", typical dry fermented sausages produced in Southern Italy, were analyzed. The homemade sausages showed a higher level of free biogenic amines than that manufactured industrially, most likely because biogenic amine formation in industrial products is limited by the use of starter cultures. The industrial sausages are characterized by a higher total free amino acid content than the homemade products. Overall, free amino acid and biogenic amine contents demonstrated that appreciable differences exist between homemade and industrial sausages.
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High resolution (1)H NMR spectroscopy was proposed for the determination of the fatty acid chain profile of lipids in pork meat products during ripening. Two typical Mediterranean PDO salami produced in Calabria, a region in the Southern... more
High resolution (1)H NMR spectroscopy was proposed for the determination of the fatty acid chain profile of lipids in pork meat products during ripening. Two typical Mediterranean PDO salami produced in Calabria, a region in the Southern Italy, were chosen as a case of study. Quantitative NMR analysis provided the fatty acid chain profiles of total lipid extracts. The transesterification of total lipid extracts furnished FAME mixtures that enabled quantitation of fatty acid acyl chains in the acylglycerol and FFA portions. In all cases, oleyl chains were predominant, and high amounts of polyunsaturated fatty acid chains were observed. The proposed spectroscopic method allowed also the estimation of the most important nutritional parameters of dry fermented meat products.
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ABSTRACT 5,8-Dimethyl-1,12-dimethylene-2,11-dithia[3.3]cyclophane 2,11-dioxides with planar and central chirality were synthesized in high yields, starting from 2,5-dimethyl-1,4-benzenedimethanethiol, through the formation of suitable... more
ABSTRACT 5,8-Dimethyl-1,12-dimethylene-2,11-dithia[3.3]cyclophane 2,11-dioxides with planar and central chirality were synthesized in high yields, starting from 2,5-dimethyl-1,4-benzenedimethanethiol, through the formation of suitable transient sulfenic functions that add to the triple bonds of disubstituted benzenes. Experimental observations allowed mechanistic and stereochemical insights into the key step of the synthetic pathway, and NMR experiments were diagnostic for the structure assignments of the cage-like compounds. The stereochemical characteristics of the new dithiacyclophane S,S′-dioxides synthesized may be applicable in the field of organocatalysis.
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A simple and efficient synthesis of a solid-supported thiol has been developed. Mercaptoacetic acid was first protected by the dimethoxytrityl group and then anchored to Wang resin through an ester bond. Deprotection of the thiol function... more
A simple and efficient synthesis of a solid-supported thiol has
been developed. Mercaptoacetic acid was first protected by
the dimethoxytrityl group and then anchored to Wang resin
through an ester bond. Deprotection of the thiol function led
to resin-supported mercaptoacetic acid, a useful supported
Introduction
The deprotection of amino functions of N-nosyl-α-amino
acids is generally performed by using sulfur nucleophiles by
nucleophilic aromatic substitution.[1] The reaction is often
complicated because of the difficult separation of the deprotected
products from the adduct formed by the nucleophile
and the aromatic derivative. For this reason the use of
solid-supported thiols is important in the deprotection of
the amino function of N-nosyl-protected amino acids.
However, only one example of a resin-bound thiol used as
a nucleophilic reagent for the deprotection of nitrobenzenesulfonamides
has been reported.[2]
Solid-supported reagents and scavengers have been used
in organic synthesis for many years, and the prominence of
parallel synthesis has led to renewed interest in this group
of reagents. In particular, polymer-supported thiols are used
as scavengers for electrophilic reagents such as benzyl and
allyl halides, aldehydes and ketones. The deprotection of
Fmoc-protected amines has been realized successfully by
using catalytic DBU in the presence of N-(2-mercaptoethyl)-
aminomethylpolystyrene, which functions as a solid-supported
scavenger to trap the released dibenzofulvene
(DBF).[3]
Ion-exchange resins containing thiol groups directly
bonded to aromatic ring resins have also been used to remove
small quantities of mercury from waste water.[4]
Moreover, thiolated polymers have been employed in the
development of controlled drug-release systems.[5] In aqueous
solutions these modified polymers are capable of form-
[a] Dipartimento di Scienze Farmaceutiche, Università della
Calabria,
Via P. Bucci cubo 15/C, 87036 Arcavacata di Rende (CS), Italy
Fax: +39-0984-492855
E-mail: A.Liguori@unical.it
Eur. J. Org. Chem. 2009, 3795–3800 © 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 3795
thiol reagent that can be used in the polymer-assisted solution-
phase removal of nosyl (Ns) groups from the amino function
of α-amino acids in peptide synthesis.
been developed. Mercaptoacetic acid was first protected by
the dimethoxytrityl group and then anchored to Wang resin
through an ester bond. Deprotection of the thiol function led
to resin-supported mercaptoacetic acid, a useful supported
Introduction
The deprotection of amino functions of N-nosyl-α-amino
acids is generally performed by using sulfur nucleophiles by
nucleophilic aromatic substitution.[1] The reaction is often
complicated because of the difficult separation of the deprotected
products from the adduct formed by the nucleophile
and the aromatic derivative. For this reason the use of
solid-supported thiols is important in the deprotection of
the amino function of N-nosyl-protected amino acids.
However, only one example of a resin-bound thiol used as
a nucleophilic reagent for the deprotection of nitrobenzenesulfonamides
has been reported.[2]
Solid-supported reagents and scavengers have been used
in organic synthesis for many years, and the prominence of
parallel synthesis has led to renewed interest in this group
of reagents. In particular, polymer-supported thiols are used
as scavengers for electrophilic reagents such as benzyl and
allyl halides, aldehydes and ketones. The deprotection of
Fmoc-protected amines has been realized successfully by
using catalytic DBU in the presence of N-(2-mercaptoethyl)-
aminomethylpolystyrene, which functions as a solid-supported
scavenger to trap the released dibenzofulvene
(DBF).[3]
Ion-exchange resins containing thiol groups directly
bonded to aromatic ring resins have also been used to remove
small quantities of mercury from waste water.[4]
Moreover, thiolated polymers have been employed in the
development of controlled drug-release systems.[5] In aqueous
solutions these modified polymers are capable of form-
[a] Dipartimento di Scienze Farmaceutiche, Università della
Calabria,
Via P. Bucci cubo 15/C, 87036 Arcavacata di Rende (CS), Italy
Fax: +39-0984-492855
E-mail: A.Liguori@unical.it
Eur. J. Org. Chem. 2009, 3795–3800 © 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 3795
thiol reagent that can be used in the polymer-assisted solution-
phase removal of nosyl (Ns) groups from the amino function
of α-amino acids in peptide synthesis.
In this paper we report a method based on solid-phase extraction (SPE) and subsequent analysis by gas chromatography combined with mass spectrometry for determination of chloroform in potable water. The affinity of chloroform for the... more
In this paper we report a method based on solid-phase extraction (SPE) and subsequent
analysis by gas chromatography combined with mass spectrometry for determination of
chloroform in potable water. The affinity of chloroform for the resin enables almost complete
recovery of the analyte. The analytical method proposed enables evaluation of chloroform
levels down to 0.295 lg L)1. The procedure is characterized by lack of interferences, in fact the
GC–MS analysis reveals the presence of only one peak, that of chloroform. Use of CDCl3 as
labelled internal standard also makes the procedure suitable for use as a reference analytical
method for quantification of chloroform in drinking water.
analysis by gas chromatography combined with mass spectrometry for determination of
chloroform in potable water. The affinity of chloroform for the resin enables almost complete
recovery of the analyte. The analytical method proposed enables evaluation of chloroform
levels down to 0.295 lg L)1. The procedure is characterized by lack of interferences, in fact the
GC–MS analysis reveals the presence of only one peak, that of chloroform. Use of CDCl3 as
labelled internal standard also makes the procedure suitable for use as a reference analytical
method for quantification of chloroform in drinking water.
Sulfamoylation of the l-ornithine methyl ester side-chain generates a non-natural arginine isostere which can be coupled with N-Fmoc-l-proline to synthesize analogues which maintain the structural characteristics of the biologically... more
Sulfamoylation of the l-ornithine methyl ester side-chain generates a non-natural arginine isostere which can be coupled with N-Fmoc-l-proline to synthesize analogues which maintain the structural characteristics of the biologically important Pro-Arg dipeptide sequence. As a probe of its biological importance, the sulfamoylated amino acid derivative was also incorporated as P1 residue in tripeptide structures matching the C-terminal subsequence of fibrinogen. The reported results demonstrate that the functionalization of l-ornithine side-chain with a neutral sulfamoyl group can generate an arginine bioisostere which can be used for the synthesis of prototypes of a new class of human thrombin inhibitors.
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N-Methyl-beta(3)-amino acids are important building blocks in the synthesis of biologically active molecules. A very simple and efficient approach to transform natural alpha-amino acids into their corresponding N-methyl-beta(3)-amino... more
N-Methyl-beta(3)-amino acids are important building blocks in the synthesis of biologically active molecules. A very simple and efficient approach to transform natural alpha-amino acids into their corresponding N-methyl-beta(3)-amino acids is here presented. In the method, the key intermediates N-methyl-N-nosyl-alpha-aminoacyldiazomethanes are prepared in only one step, by a simple treatment of the corresponding N-nosyl-alpha-aminoacyl chlorides with diazomethane. The synthetic route takes advantage from the use of the nosyl group. This N-masking moiety activates the NH function, and the N-methylation can directly occur during the acylation step of diazomethane, rendering useless a second step that instead is shown to be necessary in all the classical procedures already reported for the preparation of N-methyl-beta(3)-amino acids. The Wolff rearrangement of N-methyl-N-nosyl-alpha-aminoacyldiazomethanes provides the corresponding N-methyl-N-nosyl-beta(3)-amino acids with total retention of the chiral configuration of the starting alpha-amino acids. No epimerization of the chiral carbon atom is observed also when N-methyl-N-nosyl-beta(3)-amino acids are transformed into chlorides and coupled with alpha-amino acid methyl esters to achieve model scaffolds for biologically important modified peptides.
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A highly efficient and practical synthesis of peptides in solution phase has been developed. The procedure is based on the use of p-nitrobenzenesulfonyl (nosyl) group for the protection of the amino function of α-amino acids. Every step... more
A highly efficient and practical synthesis of peptides in solution phase has been developed. The procedure is based on the use of p-nitrobenzenesulfonyl (nosyl) group for the protection of the amino function of α-amino acids. Every step of the procedure, protection of the amino function by the nosyl group, formation of the peptide bond, and removal of the sulfonamide group,
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ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full... more
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
An efficient one-pot preparation of N-ethyl-N-4-nitrophenylsulfonyl (nosyl) amino acid methyl esters was accomplished by a simple N-ethylation reaction by using triethyloxonium tetrafluoroborate in the presence of... more
An efficient one-pot preparation of N-ethyl-N-4-nitrophenylsulfonyl (nosyl) amino acid methyl esters was accomplished by a simple N-ethylation reaction by using triethyloxonium tetrafluoroborate in the presence of N,N-diisopropylethylamine. The N-ethylated amino acid methyl esters are obtained with total retention of stereochemistry at the original chiral centers. To further broaden the scope of this methodology, the N-ethylated nosyl-protected compounds are easily converted in the more practical fluorenylmethyloxycarbonyl (Fmoc)-protected derivatives. The cleavage of methyl ester by using a mild and neutral method enables the preparation of N-ethyl amino acids that are building blocks suitable for introduction into a peptide chain. The methodology works well with both nosyl- and Fmoc-based solution-phase peptide synthesis.
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Sulfurous waters are certainly a substantial asset of the Calabria Region of Italy. They can be regarded as worth developing because of their human health implications and, if thermal tourism is promoted, their importance to the local... more
Sulfurous waters are certainly a substantial asset of the Calabria Region of Italy. They can be regarded as worth developing because of their human health implications and, if thermal tourism is promoted, their importance to the local economy. Because the effects of thermal waters on human health are not yet completely known and understood, it would be of interest to identify organic compounds responsible for their biological activity. This manuscript reports results from analysis of thermal waters in Calabria. Molecular clusters of sulfur atoms were detected in the waters and polysulfide ions were identified after conversion to the corresponding dimethyl derivatives. The occurrence of C16 and C18 unsaturated fatty acids can probably be attributed to the algae present in the water.
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We report here a convenient and simple solid-phase synthesis of N-nosyl-N-methyl-alpha-amino acids and N-Fmoc-N-methyl-alpha-amino acids, important building blocks for the synthesis of conformationally restricted and protease-resistant... more
We report here a convenient and simple solid-phase synthesis of N-nosyl-N-methyl-alpha-amino acids and N-Fmoc-N-methyl-alpha-amino acids, important building blocks for the synthesis of conformationally restricted and protease-resistant natural peptides and peptide analogues. The methodology involves the use of 2-chlorotrityl chloride resin to temporarily protect the carboxylic group of alpha-amino acids and of diazomethane as the reagent to methylate the sulfonamidic function. The approach developed is particularly efficient also with alpha-amino acids bearing appropriately protected functionalized side chains.
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Research Interests: Engineering, Technology, Mass Spectrometry, Magnetic Resonance Spectroscopy, Biological Sciences, and 9 morePlant Physiology, Gas Chromatography, CHEMICAL SCIENCES, Analytical Method, Gas Chromatography/mass Spectrometry, Reproducibility of Results, Correlation coefficient, Sensitivity and Specificity, and Acetic Anhydrides
In this paper we report a method based on solid-phase extraction (SPE) and subsequent analysis by gas chromatography combined with mass spectrometry for determination of chloroform in potable water. The affinity of chloroform for the... more
In this paper we report a method based on solid-phase extraction (SPE) and subsequent analysis by gas chromatography combined with mass spectrometry for determination of chloroform in potable water. The affinity of chloroform for the resin enables almost complete recovery of the analyte. The analytical method proposed enables evaluation of chloroform levels down to 0.295 μg L−1. The procedure is characterized by lack of interferences, in fact the GC–MS analysis reveals the presence of only one peak, that of chloroform. Use of CDCl3 as labelled internal standard also makes the procedure suitable for use as a reference analytical method for quantification of chloroform in drinking water.
Research Interests:
A convenient route for the synthesis of lipophilic N-Fmoc-N-methyl-α-amino acids and N-nosyl-N-methyl-α-amino acids, interesting building blocks to be used for the preparation of N-methylated peptides, is presented. Both nosyl- and... more
A convenient route for the synthesis of lipophilic N-Fmoc-N-methyl-α-amino acids and N-nosyl-N-methyl-α-amino acids, interesting building blocks to be used for the preparation of N-methylated peptides, is presented. Both nosyl- and Fmoc-protected monomers are accessible, so these compounds can be used in solution as well as in solid phase peptide synthesis. The methodology is based on the use of benzhydryl group to protect temporarily the carboxyl function of N-nosyl-α-amino acids and on the subsequent methylation of the N-nosyl-α-amino acid benzhydryl esters with diazomethane. The benzhydryl esters offer several beneficial features such as simple preparation, stability to methylation and selective deprotection under mild conditions. The overall procedure is highly efficient in that the adopted conditions keep the chiral integrity of amino acid precursors and the process does not require chromatographic purification of the methylated products.
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[reactions: see text] An efficient and general solution-phase method for the site-specific N-methylation of peptides has been developed. This novel procedure involves synthesis of N-nosyl protected peptides and their subsequent... more
[reactions: see text] An efficient and general solution-phase method for the site-specific N-methylation of peptides has been developed. This novel procedure involves synthesis of N-nosyl protected peptides and their subsequent N-methylation with diazomethane. Its efficiency was proved by the successful synthesis of various hindered oligopeptides containing N-methyl amino acid residues with excellent yield and purity. The method is particularly attractive in that the adopted conditions do not cause any detectable racemization of the peptide stereocenters and the process does not require chromatographic purification of the methylated products. A further advantage is the compatibility of this methodology with Fmoc solution-phase peptide synthesis.
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... Reduction of N-Methoxy-N-Methylamides to the Corresponding Amines with AlCl 3 /LiAlH 4 . Maria Luisa Di Gioia,; Antonella Leggio,; Adolfo Le Pera,; Angelo Liguori,; Francesca Perri,; Maria Caterina Viscomi. Article first published... more
... Reduction of N-Methoxy-N-Methylamides to the Corresponding Amines with AlCl 3 /LiAlH 4 . Maria Luisa Di Gioia,; Antonella Leggio,; Adolfo Le Pera,; Angelo Liguori,; Francesca Perri,; Maria Caterina Viscomi. Article first published online: 21 NOV 2006. ...
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For Abstract see ChemInform Abstract in Full Text.
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Abstract In this work is presented a synthetic procedure for the preparation of chiral nitrones from N‐Fmoc protected amino acids and dipeptides. The nitrone functional group can replace the carboxyl unit of amino acid and peptide systems... more
Abstract In this work is presented a synthetic procedure for the preparation of chiral nitrones from N‐Fmoc protected amino acids and dipeptides. The nitrone functional group can replace the carboxyl unit of amino acid and peptide systems and can be inserted into the ...
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ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full... more
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
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Xenoestrogens are chemically distinct industrial products potentially able to disrupt the endocrine system by mimicking the action of endogenous steroid hormones. Among such compounds, the ubiquitous environmental contaminants bisphenol A... more
Xenoestrogens are chemically distinct industrial products potentially able to disrupt the endocrine system by mimicking the action of endogenous steroid hormones. Among such compounds, the ubiquitous environmental contaminants bisphenol A (BPA) and 4-nonylphenol (NPH) may promote adverse effects in humans triggering estrogenic signals in target tissues. Following a research program on human exposure to endocrine disruptors, we found contamination of fresh food by BPA and NPH. More important, these contaminants were found to display estrogen-like activity using as a model system the estrogen-dependent MCF7 breast cancer cells (MCF7wt); its variant named MCF7SH, which is hormone-independent but still ERα-positive, and the steroid receptor-negative human cervical carcinoma HeLa cells. In transfection experiments BPA and NPH activated in a direct manner the endogenous ERα in MCF7 wt and MCF7SH cells, as the antiestrogen hydroxytamoxifen was able to reverse both responses. Moreover, only the hormone-binding domains of ERα and ERβ expressed by chimeric proteins in HeLa cells were sufficient to elicit the transcriptional activity upon BPA and NPH treatments. Transfecting the same cell line with ERα mutants, both contaminants triggered an estrogen-like response. These transactivation properties were interestingly supported in MCF7wt cells by the autoregulation of ERα which was assessed by RT-PCR for the mRNA evaluation and by immunoblotting and immunocytochemistry for the determination of protein levels. The ability of BPA and NPH to modulate gene expression was further confirmed by the upregulation of an estrogen target gene like pS2. As a biological counterpart, concentrations of xenoestrogens eliciting transcriptional activity were able to stimulate the proliferation of MCF7wt and MCFSH cells. Only NPH at a dose likely too high to be of any physiological relevance induced a severe cytotoxicity in an ERα-independent manner as ascertained in HeLa cells. The estrogenic effects of such industrial agents together with an increasing widespread human exposure should be taken into account for the potential influence also on hormone-dependent breast cancer disease.
Research Interests: Breast Cancer, Immunohistochemistry, Gene expression, Western blotting, Cell Division, and 16 moreEstrogen Receptor, Cell line, Humans, bisphenol A, Female, Endocrine, Nonylphenol, Clinical Sciences, Phenols, Model System, Food Contamination, Transfection, Industrial Production, Environmental Pollutants, Breast Cancer Cells, and Estrogen receptor alpha
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A novel procedure for the deprotection of the carboxyl group of amino acid methyl esters is presented. The process is carried out by the reagent system aluminium trichloride/N,N-dimethylaniline that can successfully be applied to unblock... more
A novel procedure for the deprotection of the carboxyl group of amino acid methyl esters is presented. The process is carried out by the reagent system aluminium trichloride/N,N-dimethylaniline that can successfully be applied to unblock the carboxyl moiety either of N-Fmoc-protected amino acid methyl esters and N-Fmoc-protected short dipeptide methyl esters. The chiralities of the optically pure amino acid or peptide precursors are maintained totally unchanged.
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A simple and efficient synthesis of a solid-supported thiol has been developed. Mercaptoacetic acid was first protected by the dimethoxytrityl group and then anchored to Wang resin through an ester bond. Deprotection of the thiol function... more
A simple and efficient synthesis of a solid-supported thiol has been developed. Mercaptoacetic acid was first protected by the dimethoxytrityl group and then anchored to Wang resin through an ester bond. Deprotection of the thiol function led to resin-supported mercaptoacetic acid, a useful supported thiol reagent that can be used in the polymer-assisted solution-phase removal of nosyl (Ns) groups from the amino function of α-amino acids in peptide synthesis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
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In this article we describe a versatile and straightforward preparative approach to chiral aryl α-amino ketones via a Friedel-Crafts-type reaction of stable and enantiomerically pure N-Fmoc protected l-amino acid chlorides with toluene in... more
In this article we describe a versatile and straightforward preparative approach to chiral aryl α-amino ketones via a Friedel-Crafts-type reaction of stable and enantiomerically pure N-Fmoc protected l-amino acid chlorides with toluene in the presence of aluminum ...
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ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
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For Abstract see ChemInform Abstract in Full Text.
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For Abstract see ChemInform Abstract in Full Text.
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For Abstract see ChemInform Abstract in Full Text.