Publications by authors named "Francesca Perri"

Aims: The purpose of the study was to evaluate the impact of the lockdown established by the Italian government to limit the spread of Coronavirus disease (COVID-19) on glycemic control in a large sample of patients with type 1 diabetes (T1D) based on age, type of insulin therapy, number of telemedicine visits and physical activity.

Material And Methods: We retrospectively evaluated glycemic control in young T1D patients using the DexcomG6 system before the Italian lockdown (February 10-23, 2020-Time 0) and during lockdown (April 17-30, 2020-Time 1). Data on age, type of insulin therapy, number of telemedicine visits and physical activity of 202 patients with T1D and a median age of 18.

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The acid-catalyzed dehydration is one of the most important processes, which transforms 3-hydroxy steroids into their corresponding unsaturated derivatives. This reaction is of great importance because it can produce molecules that play a key role in the understanding of the natural metabolism of steroids. Sterol dehydration is generally performed with aqueous acidic systems, and the treatment often affords low yields of the desired compounds and/or complex mixtures of by-products.

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The methylation reaction of N(beta)-nosyl hydrazides of N-nosyl protected alpha-amino acids by using diazomethane shows a controlled regiochemical trend and makes it possible to obtain the corresponding products methylated at specific positions depending on the amount of diazomethane used. The observed selectivity is closely connected with the different acidity of sulfonyl hydrazide, sulfonamide, and acyl hydrazine protons present in the analyzed substrates. The reactivity order of these three diverse reactive sites is supported by theoretical calculations.

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In this paper we describe a simple and efficient solution-phase synthesis of N-methyl-N-nosyl-alpha-amino acids and N-Fmoc-N-methyl-alpha-amino acids. This represents a very important application in peptide synthesis to obtain N-methylated peptides in both solution and solid phase. The developed methodology involves the use of N-nosyl-alpha-amino acids with the carboxyl function protected as a phenacyl ester and the methylating reagent diazomethane.

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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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A study of the methylation of N-nosyl-alpha-amino acids and derivatives with trimethylsilyldiazomethane is here reported. Trimethylsilyldiazomethane allows the chemo-specific methylation of the carboxyl function of N-nosyl-alpha-amino acids in high yields and purity. This method provides a practical route to N-methyl-alpha-amino acids avoiding the use of the more toxic and explosive diazomethane.

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A convenient route for the synthesis of lipophilic N-Fmoc-N-methyl-alpha-amino acids and N-nosyl-N-methyl-alpha-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-alpha-amino acids and on the subsequent methylation of the N-nosyl-alpha-amino acid benzhydryl esters with diazomethane.

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The vacuum distillation of bergamot peels furnishes a high-quality essential oil that is totally bergapten-free. This oil was compared with that produced by distillation of cold-pressed oils and those commercially available. The oil obtained by vacuum distillation of the bergamot vegetable matrix shows a composition quite similar to that of the cold-pressed oil.

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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 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.

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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 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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Synthetic corticosteroids are widely used as anti-inflammatory agents. Mechanisms of their degradation continue to be studied. D-ring homoannulation is a well-known metabolic pathway for steroids in vivo.

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Treatment of Delta 4-3-ketosteroids with m-chloroperbenzoic acid at 0 degrees C produced the corresponding steroidal seven-membered A-ring epoxy lactones. The adopted procedure allowed for efficient recovery and separation of the products with definite stereochemistry.

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In this paper we describe an analytical method for the determination of p-phenylenediamine (PPDA) in hair dyes. In the adopted methodology the analyte is transformed into the corresponding imine derivative by treatment with benzaldehyde, and then analyzed by gas chromatography (GC) combined to mass spectrometry (MS), operating in SIM conditions. The direct and simultaneous chemical derivatization of the two amino functions of the analyte with benzaldehyde enhances the instrumental responses enabling the use of a sensitive and accurate method.

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