Giovanni Sindona

Statin-like Principles of Bergamot Fruit (Citrus bergamia): Isolation of 3-Hydroxymethylglutaryl Flavonoid Glycosides

The 3-hydroxy-3-methylglutaryl neohesperidosides of hesperetin (brutieridin, 1) and naringenin (melitidin, 2) were isolated and detected from the fruits of bergamot (Citrus bergamia). The structures of these compounds were determined by spectroscopic and chemical methods.

Tandem mass spectrometry in food safety assessment: The determination of phthalates in olive oil

A gas chromatography-tandem mass spectrometry (GC-MS/MS) method for the detection of six phthalates in olive oil was developed. A gel permeation chromatography (GPC) clean-up step with cyclohexane:dichoromethane 7:3 as mobile phase was employed to remove the high-molecular mass species present in oil. Two ionization methodologies, i.e. electron (EI) and isobutane-chemical ionization (CI), were compared, in MS/MS mode, to achieve better analytical performances. An overall evaluation of all analytical parameters shows that the EI-MS/MS approach provides satisfactory results and is to be preferred to CI-MS/MS, at least in the case of the examined analytes. The observed accuracies, ranging from 71.7% to 112.2%, and the RSD values less than 9.7%, confirm the effectiveness of the proposed method in the assay of phthalate content in such a complex matrix as olive oil. The proposed protocol for the identification and assay of phthalates in olive oil might be of interest for the implementation of the QS (quality assurance scheme) for residue monitoring in food safety assessment.

Direct olive oil analysis by low-temperature plasma (LTP) ambient ionization mass spectrometry

A fast, reagentless, and direct method is presented for the mass spectrometric analysis of olive oil without any sample pretreatment whatsoever. An ambient ionization technique, the low-temperature plasma (LTP) probe, based on dielectric barrier discharge, is used to detect both minor and trace components (free fatty acids, phenolics and volatiles) in raw untreated olive oil. The method allows the measurement of free fatty acids (the main quality control parameter used to grade olive oil according to quality classes), selected bioactive phenolic compounds, and volatiles. The advantages and limitations of the direct analysis of extremely complex mixtures by the ambient ionization/tandem mass spectrometry combination are discussed and illustrated. The data presage the possible large-scale application of direct mass spectrometric analysis methods in the characterization of olive oil and other foodstuffs.

Virtual freezing of the hemiacetal–aldehyde equilibrium of the aglycones of oleuropein and ligstroside present in olive oils from Carolea and Coratina cultivars by ionspray ionization tandem mass spectrometry

The composition of the equilibrium between aldehydes and hemiacetals was evaluated by ionspray ionization tandem mass spectrometry. The methanolic extracts of virgin olive oil from Carolea and Coratina cultivars contain a complex mixture of hydroxytyrosol (3) and tyrosol (4) derivatives (5, 6) characterized by the presence of aldehyde moieties in equilibrium with their hydrated form (8) or with the corresponding methanol hemiacetals 9 and 10. The equilibrium was frozen by droplet evaporation, thus allowing the structure determination of each component. The formation of the decarboxylated species 11-14, reported previously, was not observed.

Direct Identification of Phenolic Glucosides from Olive Leaf Extracts by Atmospheric Pressure Ionization Tandem Mass Spectrometry

Pneumatically assisted electrospray (or ionspray) coupled with liquid chromatography was applied to the identification of the phenolic glucoside content of olive leaf directly from the crude extracts. The mass spectra of the positive ions provide insights into the composition of the phenolic constituents. Oleuropein, ligstroside and a disaccharide containing the hydroxytyrosol moiety were found in olive leaf of Olea europea L. cv. Cassanese and their structures were thoroughly determined by tandem mass spectrometry.

Synthesis, biological evaluation, and molecular modeling of oleuropein and its semisynthetic derivatives as cyclooxygenase inhibitors.

Oleuropein, the main phenolic compound in virgin olive oil, and several of its derivatives such as oleuropein aglycone, hydroxytyrosol, and their respective acetylated lipophilic forms were obtained by simple and environmentally friendly semisynthetic protocols. The same molecules were then tested in vitro and in vivo, comparing their intriguing anti-COX-1 and anti-COX-2 properties to those of well-known anti-inflammatory drugs such as ibuprofen and celecoxib. Finally, molecular modeling experiments displaying the most probable binding modes within the classical binding clefts of the enzymes suggest the heme moiety as a potential alternative target.

Characterization of cassanese olive cultivar through the identification of new trace components by ionspray tandem mass spectrometry

Pneumatically assisted electrospray (ionspray) coupled with liquid chromatography was applied in the identification of antioxidants present in traces in the leaves of Olea europea L. cv. Cassanese, a typical olive tree from the northeastern part of Calabria region in Italy. The structures of these potential biomarkers were evaluated with reference to established mass spectrometric rules or, in one case, by matching the tandem mass spectrum of the unknown with that of an authentic sample obtained by synthesis. Copyright

Synthesis of 4′-aza analogues of 2′,3′-dideoxythymidine by 1,3-dipolar cycloadditions of nitrones to 1-N-vinyl-thymine

Abstract The title compounds have been obtained by 1,3-dipolar cycloadditions of methylene nitrones, prepared in situ from suitably protected hydroxylamines, to 1- N -vinyl-thymine. The 4′- aza -2′,3′-dideoxyerythrofuranoside ( 4 ), an analogue of 2′,3′-dideoxythymidine, might exhibit antiviral activity.

Review: multistage mass spectrometry in quality, safety and origin of foods.

Quality and safety control and the validation of origin are hot issues in the production of food and its distribution, and are of primary concern to food and agriculture organization. Modern mass spectrometry (MS) provides unique, reliable and affordable methodologies to approach with a high degree of scientificity any problem which may be posed in this field. In this review the contribution of mass spectrometry to food analysis is presented aiming at providing clues on the fundamental role of the basic principles of gas-phase ion chemistry in applied research fields. Applications in proteomics, allergonomics, glycomics, metabolomics, lipidomics, food safety and traceability have been surveyed. The high level of specificity and sensitivity of the MS approach allows the characterization of food components and contaminants present at ultra-trace levels, providing a distinctive and safe validation of the products.

High-throughput determination of Sudan Azo-dyes within powdered chili pepper by paper spray mass spectrometry.

A high-throughput mass spectrometric method is presented for the simultaneous detection of Sudan I, II, III, IV and Para-Red azo-dyes in foodstuff. The method is based on the use of paper spray mass spectrometry (MS) and deuterium-labeled internal standards on a triple-quadrupole instrument. A detailed assay of each azo-dye was performed by the isotope dilution method, through the precursor ion scan approach, using deuterium-labeled internal standards. The gas-phase breakdown pattern of each labeled and unlabeled analogue displays the naphthoic moiety as a common fragment. Sudan dyes can be determined above the threshold of 1 ppm. Paper spray allows for a wide range of analytes and samples to be investigated by MS in the open air and without sample preparation and bypassing chromatography.