Giuseppina Dessì

Single-step green synthesis and characterization of gold-conjugated polyphenol nanoparticles with antioxidant and biological activities

Background Gold nanoparticles (GNPs) are likely to provide an attractive platform for combining a variety of biophysicochemical properties into a unified nanodevice with great therapeutic potential. In this study we investigated the capabilities of three different natural polyphenols, epigallocatechin-3-gallate (EGCG), resveratrol (RSV), and fisetin (FS), to allow synergistic chemical reduction of gold salts to GNPs and stabilization in a single-step green process. Moreover, antioxidant properties of the nanosystems, as well as preliminary antiproliferative activity and apoptotic process investigation of model EGCG-GNPs on stable clones of neuroblastoma SH-SY5Y cells expressing CFP-DEVD-YFP reporter, were examined. Methods The GNPs were characterized by physicochemical techniques, polyphenol content, and in vitro stability. The antioxidant activity of the GNPs was also determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) cation (ABTS) radical-scavenging assays. Stable clones of neuronal SH-SY5Y-CFP-DEVD-YFP were generated and characterized, and cell viability after treatment with EGCG-GNPs was assessed after 72 hours through a 3(4,5-dimethylthiazol-2yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay. Activation of the apoptotic pathways was also investigated by Western blot analysis. Results With a diameter in the size range of 10–25 nm, the obtained nanoparticles (NPs) were found to contain 2.71%, 3.23%, and 5.47% of EGCG, RSV, and FS, respectively. Nanoprototypes exhibited remarkable in vitro stability in various media, suggesting that NP surface coating with phytochemicals prevents aggregation in different simulated physiological conditions. The scavenging activities for DPPH and ABTS were highly correlated with EGCG, RSV, and FS content. Moreover, high correlation coefficients between the ABTS and DPPH values were found for the prepared nanosystems. EGCG-GNPs induce a dose-dependent reduction on SH-SY5Y-CFP-DEVD-YFP cell viability that is likely to involve the activation of the apoptotic pathways, similarly to free EGCG, as suggested by the processing of the CFP-DEVD-YFP reporter. Conclusion These results prompted us to propose the ecofriendly synthesized EGCG-, RSV-, and FS-based nanogold conjugates as suitable carriers for bioactive polyphenols to be used for the treatment of disorders associated with oxidative stress, including neurodegenerative disorders, cardiovascular disease, and cancer.

Determination of four thiophenethylamine designer drugs (2C-T-4, 2C-T-8, 2C-T-13, 2C-T-17) in human urine by capillary electrophoresis/mass spectrometry.

An analytical procedure for the simultaneous determination in human urine of four thiophenethylamine designer drugs (2C-T series) is reported. The quantitative analysis was performed by capillary electrophoresis with mass spectrometric detection (CE/MS), using 2,5-dimethoxy-4-methylthiophenethylamine-D(4) (2C-T-D(4)) as internal standard. In order to minimize interferences with matrix components and to preconcentrate target analytes, solid-phase extraction (SPE) was introduced in the method as a clean-up step. The method was validated according to international guidelines. The data for accuracy and precision were within required limits. Calibration curves were generated over the range from 10 to 500 ng mL(-1) and correlation coefficients always exceeded 0.997. The method was demonstrated to be specific, sensitive, and reliable for the analysis of these derivatives in urine samples.

Determination of p‐Methoxyamphetamine by Capillary Electrophoresis with Diode Array Detection from Urine and Plasma Samples

Abstract In recent years, a number of newer designer drugs have entered the illicit drug market. The amphetamine derivatives represent the largest group of designer drugs. This paper describes a method for quantifying p-methoxyamphetamine in human plasma and urine by capillary electrophoresis with a diode array detector. Using an aqueous pH 2.5 phosphate buffer, CE analysis gave peaks with good symmetry and reproducible migration time. Under these experimental conditions, the p-methoxyamphetamine was resolved in 7 min and without interferences from biological matrices. The identification using the migration time was confirmed by UV spectra recorded with a diode array detector DAD (190–350 nm). Prior to CE‐DAD analysis, a simple solid phase extraction (SPE) was used for sample cleanup. The main advantages of the present method lie in its simplicity and clean and reliable extraction from plasma and urine. The method was validated according to international guidelines.

Phototoxicity due to Cachrys libanotis.

After classification and identification of the plant, the alcoholic extract of Cachrys libanotis L. was analysed in order to identify the phototoxic agents. The substances responsible for photodermatitis were found to be 4 furocoumarins, of which 3 have been clearly identified, namely 5‐methoxy‐, 8‐methoxy‐and 5,8‐dmiethoxypsoralen. The structure of a 4th compound was not completely defined.

A RAPID METHOD FOR DETERMINATION OF FOUR THIOAMPHETAMINE DESIGNER DRUGS (ALEPH-4, ALEPH-8, ALEPH-13, ALEPH-17) IN HUMAN URINE

An analytical procedure for the simultaneous determination in human urine of four thioamphetamine designer drugs (ALEPH series) is reported. The quantitative analysis was performed by capillary electrophoresis with diode array detector (CE-DAD), using 2,5-dimethoxy-4-methylthioamphetamine-D3 (ALEPH-D3) as internal standard. In order to minimize interferences with matrix components and to preconcentrate target analytes, solid phase extraction was introduced in the method as a clean-up step. The method was validated according to international guidelines. Data for accuracy and precision were within required limits. Calibration curves were generated ranging from 1 to 500 μg mL−1 and correlation coefficients always exceeded 0.998. The method was demonstrated to be specific, simple, and reliable for the analysis of these derivatives in urine samples.