Fabio Mazzotti

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.

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.

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

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.

Assay of tyrosol and hydroxytyrosol in olive oil by tandem mass spectrometry and isotope dilution method

Hydroxytyrosol and tyrosol, the strong antioxidant present in large amount in virgin olive oil have been assayed by LC-MS/MS under MRM condition and isotope dilution method, using d(2)-labelled internal standards obtained by simple synthetic procedures. The assay has been performed under MRM condition monitoring two transitions for each analyte to improve the specificity. This paper deals with a modern approach for assaying the content of this polyphenols in virgin olive oil down to a limit of a few hundreds of parts per billion. Tyrosol and hydroxytyrosol ranged from 10 to 47ppm and from 5 to 25ppm in commercial olive oil, respectively. The accuracy (98-107%) and analytical parameters values confirm the reliability of the proposed approach. The method can be extended to any natural matrices, including mill wastes, after a simple step of sample preparation.

Authenticity of PGI “Clementine of Calabria” by Multielement Fingerprint

Clementine is a citrus fruit that has found a peculiar habitat in specific areas of Calabria, a region located in southern Italy. Due to its peculiar characteristics it was recently awarded with protected geographical indications (PGI) from the European Union. In this work, stepwise linear discriminant analysis (S-LDA), soft independent modeling of class analogy (SIMCA), and partial least-squares discriminant analysis (PLS-DA) were used to build chemometric models able to protect PGI Clementine from others of different origin. Accordingly, the concentration of 24-26 elements was determined in peel and juice samples, respectively, obtained from Calabrian PGI clementine and from fruits cultivated in Algeria, Tunisia, and Spain. A cross-validation procedure has shown very satisfactory values of prediction ability for both S-LDA (96.6% for juice samples and 100% for peel samples) and SIMCA (100% for both peel and juice samples). PLS-DA models also yielded satisfactory results.

Comprehensive assay of flavanones in citrus juices and beverages by UHPLC-ESI-MS/MS and derivatization chemistry.

Flavanones, a class of flavonoids present in large amounts in fruits and vegetables, have been assayed by LC-MS/MS and derivatization chemistry using d0/d3-labelled derivatized internal standards obtained by simple reaction procedures which involves d0/d3 methoxyamine. The assay method considers 13 flavanones including aglycones, neohesperidosides, rutinosides and 3-hydroxy-3-methyl glutaryl derivatives. The strengths of the method consist in a relative short analysis time (16 min) and good repeatability and reproducibility values which are in most cases under 10% (RSD%). The accuracy values range from 95.4% to 111.3% whilst the LOQ values ranges from 0.05 to 0.29 mg/L depending on the analyte.

Light and heavy dansyl reporter groups in food chemistry: amino acid assay in beverages

5-Dimethylamino-1-sulfonyl naphthalene (DNS, commonly referred as dansyl) is a functionality, bearing well-established properties in directing the fragmentation, by mass spectrometry (MS), of the corresponding ionized sulfonylated derivatives. This property is shared also by its labeled analogs. The use of d(0)/d(6) DNS derivatives is now exploited in the application of the well-established isotope dilution mass spectrometric approach in the assay of complex mixtures. A new method for the quantitation of amino acids (AAs) in beverages is therefore presented, which relies on liquid chromatographic separation of their N-dansylated derivatives followed by comparative electrospray tandem MS/MS of the d(0)/d(6) isobaric mixtures. Labeled and unlabeled DNS derivatives of the selected AAs are readily available by microwave-assisted synthetic protocols. The novelty of the method is represented by the use of heavy and light DNS-isotopologue providing suitable reporter groups. Multiple-reaction monitoring has been applied in the assay of AAs in wine, pineapple juice and bergamot juice with good-to-excellent results as proved by both relative standard deviation, lower than 15%, and by the accuracy values in the range 90-110%.

High-Throughput Assay of Oleopentanedialdheydes in Extra Virgin Olive Oil by the UHPLC-ESI-MS/MS and Isotope Dilution Methods

The quality of extra virgin olive oil is associated with the presence of microcomponents whose healing effects have been proved in some special cases. The enzymatic hydrolysis of oleuropein and ligstroside, and of their demethylated analogues, affords four different pentanedialdehydes, and for one of which, 2-(4-hydroxyphenyl)ethyl (3S,4E)-4-formyl-3-(2-oxoethyl)hex-4-enoate, also known as oleocanthal, an anti-inflammatory effect was quite recently carefully assessed. Extra virgin olive oil is now worldwide considered as a functional food whose daily intake, as for the Mediterranean diet, helps consumers in keeping a constant level of nonsteroidal anti-inflammatory drug (NSAID) in the blood. The presence of these active principles provides, therefore, olive oil with an important added value. In the framework of the actions of the recently funded Agrifood Regional Center, which should coordinate the scientific research and production worlds, an absolute analytical method was developed for the mass spectrometric detection of the two most abundant NSAIDs, Tyr-OLPD and HTyr-OLPD (oleopentanedialdehydes (OLPDs) conjugated to p-hydroxyphenylethanol and 3,4-dihydroxyphenylethanol, respectively), by UHPLC-ESI-MS/MS.

Effect of H/D isotopomerization in the assay of resveratrol by tandem mass spectrometry and isotope dilution method.

Resveratrol is a phytoalexin found in several plant tissues and present in wines, which is supplied as a nutritional supplement. Different studies have revealed its beneficial effects as anticancer, antiviral, neuroprotective, antiaging, and anti-inflammatory natural active principle. The assaying of resveratrol by mass spectrometry and isotope dilution method, using a stable [(2)H(4)] analogue, has required a full elucidation of its gas-phase H/D isotopomerization. Either selected ion monitoring (SIM) or multiple reaction monitoring (MRM) methods have been used for the evaluation of the amount of resveratrol present in wine and plasma samples in the negative ionization mode. In all instances the acquired accuracy, limit of quantitation (LOQ), and limit of detection (LOD) are fit for the intended purpose of the assay.