Analysis of tomato glycoalkaloids by liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

Steroidal glycoalkaloids (SGAs) extracted from tomato leaves and berries (Lycopersicon esculentum Mill.) were separated and identified using optimized reversed-phase liquid chromatography with electrospray ionization (ESI) and ion trap mass spectrometry (ITMS). The ESI source polarity and chromatographic conditions were evaluated. The ESI spectra contain valuable information, which includes the mass of SGAs, the mass of the aglycones, and several characteristic fragment ions. Cleavage at the interglycosidic bonds proximal to the aglycones is the most prominent process in the ESI process. A protonated molecule, [M+H]+, accompanied by a mixed adduct ion, [M+H+Na]2+, was observed for a-tomatine (i.e., m/z 1034.7 and 528.9) and dehydrotomatine (i.e., m/z 1032.6 and 527.9) in positive ion mode spectra. The structures of these tomato glycoalkaloids were confirmed using tandem mass spectrometry. The identification of a new a-tomatine isomer glycoalkaloid, named filotomatine (MW 1033), which shares a common tetrasaccharide structure (i.e., lycotretraose) with a-tomatine and dehydrotomatine, and soladulcidine as an aglycone, is described for the first time. It occurs in significant amounts in the extracts of wild tomato foliage. Multistage mass spectrometry both of the protonated molecules and of the doubly charged ions was used for detailed structural elucidation of SGAs. Key fragmentations and regularities in fragmentation pathways are described and the fragmentation mechanisms involved are propose

The mechanism of the amine-catalysed isomerizationof dialkyl maleate: A computational study

DFT at B3LYP/6-31G (d,p) level calculation results for the amine-catalysed isomerization of dimethyl maleate revealed that the mechanism proceeds via foursteps: (1) a concerted proton transfer from one amine molecule to another which subsequently enhances the addition of the adduct thus formed to the C-C double bond to yield INT1. (2) Abstraction of a proton from the -carbon of INT1 by a second amine molecule to give intermediate INT2. (3) Rotation about the C-C single bond followed by proton abstraction by an amine molecule to yield unstable INT3, and (4) an elimination of an amine molecule to yield the trans isomer, dimethyl fumarate. Furthermore, it was found that step 1 is the rate limiting step. However, the activation energy difference between steps 1 and 2 was significantly low and its value depends on the amine catalyst used. The activation energy was found to be lower in water when compared to that calculated in the gas phase. In addition, linear correlation was found between the amine-catalysed isomerization experimental rate and the pKa of the amine catalyst on one hand and the enthalpic and free activation energies on the other hand. The calculations also confirmed that the reaction is first order in dimethyl maleate, second order in the amine catalyst and overall third order. This study disproves three of the four different intermediates that were previously suggested to explain the amine catalysed isomerization of dialkyl maleates. The study verifies the intermediate suggested by Rappopor

Establishing the occurrence of major and minorglucosinolates in Brassicaceae by LC-ESI-hybrid linearion-trap and Fourier-transform ion cyclotron resonancemass spectrometry

Glucosinolates (GLSs) are sulfur-rich plant secondary metabolites which occur in a variety of cruciferous vegetables and among various classes of them, genus Brassica exhibits a rich family of these phytochemicals at high, medium and low abundances. Liquid chromatography (LC) with electrospray ionization in negative ion mode (ESI-) coupled to a hybrid quadrupole lineariontrap (LTQ) and Fouriertransformioncyclotronresonancemass spectrometer (FTICRMS) was employed for the selective and sensitive determination of intact GLSs in crude sample extracts of broccoli (Brassica oleracea L. Var. italica), cauliflower (B. oleracea L. Var. Botrytis) and rocket salad (Eruca sativa L.) with a wide range of contents. When LTQ and FTICR mass analyzers are compared, the magnitude of the limit of detection was ca. 5/6-fold lower with the FTICR MS. In addition, the separation and detection by LC–ESI-FTICR MS provides a highly selective assay platform for unambiguous identification of GLSs, which can be extended to lower abundance (minor) GLSs without significant interferences of other compounds in the sample extracts. The analysis of Brassicaceae species emphasized the presence of eight minor GLSs, viz. 1-methylpropyl-GLS, 2-methylpropyl-GLS, 2-methylbutyl-GLS, 3-methylbutyl-GLS, n-pentyl-GLS, 3-methylpentyl-GLS, 4-methylpentyl-GLS and n-hexyl-GLS. The occurrence of these GLSs belonging to the saturated aliphatic side chain families C4, C5 and C6, presumably formed by chain elongation of leucine, homoleucine and dihomoleucine as primary amino acid precursors, is described. Based on their retention behavior and tandem MS spectra, all these minor compounds occurring in plant extracts of B. oleracea L. Var. italica, B. oleracea L. Var. Botrytis and E. sativa L. were tentatively identified

Removal of Dexamethasone Sodium Phosphate (DSP) in liquid phase by Using Advanced Oxidation Processes (AOPs)

The occurrence and the fate of pharmaceuticals residues in wastewater treatment and in the environment has attracted an increasing interest during the last decade and have posed a new challenge to professionals for wastewater recovery as well as to the pharmaceutical industry. The removal of many of pharmaceutical compounds, during municipal wastewater treatment, has showed to be incomplete and unsuitable. As a result, residues of these compounds have been detected in surface waters in concentrations ranging from the ng L-1 up to the mg L-1 level. Advanced Oxidation Processes (AOP) are commonly designed to produce hydroxyl radicals (HO•) that react efficiently with most organic compounds present in the water. Photo-catalysis has emerged as viable alternative for removing micro-pollutants and other organic contaminants from surface, ground and wastewater. The catalyst used in this study was the semiconductor titanium dioxide (TiO2) chosen for its properties: high resistance to corrosion, low toxicity and low costs. The aim of this work was the application of photo-catalysis for the degradation of dexamethasone sodium phosphate (9-fluoro-11β,17-dihydroxy-16α-methyl-21-(phosphonooxy) pregna- 1,4-diene-3,20-dione disodium salt). This pharmaceutical compound is one of the most potent corticosteroids with anti- inflammatory and immunosuppressive properties. It has been widely used to treat inflammation, allergy and diseases related to adrenal cortex insufficiency. DSP is also known to reduce neointimal hyperplasia in arteries and has been used for coating drug- eluting stents for local drug delivery to prevent restenosis. Photochemical reactions were carried out by using a solar simulator and kinetic parameters were determined. Identification of the photoproducts was performed by liquid chromatography system coupled to a hybrid linear quadrupole ion trap (LTQ) – Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. The standard solution used as control in the darkness did not show any significant degradation during the experimental time. Data of the DSP degradation fitted well a pseudo first order kinetic curve and the half-life was 30 min. Four photoproducts have been successfully identified

Hemp chemotype definition by cannabinoids characterization using lc-esi(+)-ltq-fticr ms and infrared multiphoton dissociation

The development and application of advanced analytical methods for a comprehensive analysis of Cannabis sativa L. extracts plays a pivotal role in order to have a reliable evaluation of their chemotype definition to guarantee the efficacy and safety in pharmaceutical use. This paper deals with the qualitative and quantitative determination of cannabidiol (CBD), tetrahydro-cannabinol (THC), cannabinol (CBN), tetrahydrocannabivarin (THCV), cannabidivarin (CBDV), and cannabigerol (CBG) based on a liquid chromategraphy-mass spectrometry (LC-MS) method using electrospray ionization in positive mode (ESI+), coupled with a hybrid quadrupole linear ion trap (LTQ) and Fourier transform ion cyclotron resonance mass spectrometer (FTICR-MS). For the first time, structural information of phytocannabinoids is available upon precursor ions’ isolation within the FTICR trapping cell and subsequent fragmentation induced by infrared multiphoton dissociation (IRMPD). Such fragmentation and accurate mass measurement of product ions, alongside collision-induced dissociation (CID) within LTQ, was advantageous to propose a reliable fragmentation pattern for each compound. Then, the proposed LC-ESI(+)-LTQ-FTICR MS method was successfully applied to the hemp chemotype definition of three registered Italian accessions of hemp C. sativa plants (Carmagnola C.S., Carmagnola, and Eletta Campana), thus resulting in the Eletta Campana accession being the best one for cannabis product manufacturing

The role of the innate immune response in HPV-related oral and oropharyngeal cancer

Introduction. During the last 20 years, the incidence of HPV-associated oropharyngeal cancer is increased. Principal actors of the innate immune response against HPV are represented by the TLRs (Toll like receptors). On the other hand different studies have reported that HPV can directly inhibit the functions of the TLRs pathway through interferons (IFNs). There are very few preliminary studies on the role of TLRs mediated HPV clearance in human oncology. Our study aim has been to evaluate whether TLR4 identifies HR-HPV integration state in OSCC. Methods. Protein levels of TLR4 in OSCC were assessed using Immunohistochemistry (IHC). In situ hybridization (ISH) for HPV-DNA detection in morphological context and Pyro-sequencing method have been performed in order to detect viral integration or episomic status. The relationship between TLR expression with or without HPV infection has been elucidated. Results. ISH HPV positive samples have reported lower TLR4 intensity than negative samples and it has confirmed by statistically significant difference (p = .002). There is no statistical correlation between TLR4 intensity and PCR HPV results (p > 0.05). Point-biserial correlation coefficient revealed statistically significant association between TLR4 expression and HR-HPV integration status (p = .0001) and between TLR4 expression index and HR-HPV infection (p = .001). Conclusions. We retain that TLR4 down-regulation is not associated to the histological tumoral grade but rather to HPV-16 infection and to its integration state into the host DNA

Damage of calcarenite stone in archaeological site: relationship between wheathering, pollution and biological agents

For thousand of years, when magnificence and beauty were the goals of architecture, stones were the most widely used durable materials. The deterioration of building stones causes irreparable damages to our cultural heritage, not only as loss of architecture and ancient art, but especially as loss of symbols of human cultural identity and continuity. Sun, frost, wind, rain, pollution etc. contribute to a gradual process of weathering. Biological activity also plays a role and its association with physico-chemical phenomena should be considered essential for understanding long term deterioration. In this contest appear necessary to understand the weight of each single environmental parameter in order to assess and to plan not only a suitable restoration project and a preventive maintenance but also to test natural products (specific biocides) to be used to limit the degradation caused by bio deterioration agents We studied the influence and synergistic effects of climatic parameters (temperature, light irradiation, wind intensity, humidity), pollution (SO2, CO, NO2, Ozone and heavy metals), and biological attacks on a building placed between an archaeological site of Lavello, a little town located in the Basilicata Region, and the industrial area surrounding this town. Moreover, X-ray diffraction, X-ray induced photoelectron spectroscopy (XPS), X-ray fluorescence spectrometry (XRF), ground penetrating radar and geo-electrical measurements (GPR and MGE), Fourier Transform Infrared spectroscopy (FT-IR) and biological investigations were carried out on powdered calcarenite and on stones samples. Preliminary results show that climatic parameters and pollution undermine the structure and the compactness of stones (i.e. micro-fractures, increase of salts’ concentration) favouring the biological colonization (bacteria, mushrooms and lichens) especially in south–east direction of prevailing winds

Study of the photodegradation of tribenuron-methyl in aqueous solution of two Moroccan soils

Photodegradation of Tribenuron-methyl [methyl 2-(((((4-methoxy-6-methyl-1,3,5-triazin-2- yl)methylamino)carbonyl)amino)sulfonyl)benzoate] was carried out in aqueous solution under UV light. The research of the structures of the photoproducts highlighted by follow-up CLHP was carried out by coupling CLHP/SM. The results of this study allowed concluding that the transformation of the tribenuron-methyl depends on the pH of the medium and the light of irradiation. With this intention, the study of the retention, the mineralization of the tribenuron-methyl in two Moroccan soils of the area of Gharb (Northwest of Morocco) called Tirs and Dehs was carried out using the molecule labelled on carbon ureic and in controlled conditions. The adsorption and desorption of the tribenuron-methyl by the two grounds were carried out by the method of Batch balancing. The adsorption of the active matter follows a nonlinear isotherm. The ground Dehs has a more important affinity for the molecule the tribenuron-methyl than the ground Tirs. The desorption of the tribenuron-methyl is more important starting from the ground Dehs. The mineralization of the molecule by biological way is more important starting from the ground Tirs. The contribution of nitrogen seems to inhibit the process of mineralization starting from this ground

The water we would like

Water is needed for our health: it maintains the health and integrity of every cell in the body, keeps the bloodstream liquid enough to flow through blood vessels, helps eliminate the by-products of the body’s metabolism, aids digestion, and other exceptional properties. High-quality water is needed to preserve health. Unfortunately, the environment and all its sectors are differently contaminated. This dangerous state is closely linked to increased anthropic activities (industrial and agricultural) and the use of harmful substances released without control. Old contaminants (pesticides and substances deriving from industrial activities) and new contaminants, called "emerging" (drugs, phytotoxins, body care products), can arrive in rivers, in surface and deep water, and the sea if they are not removed from the wastewater. These substances are harmful to human health because they enter the environment in quantities exceeding the natural self capacity purification of the ecosystems. We can be exposed to water-derived contaminants in different ways. For example, people can ingest small amounts of pollutants by drinking water; they can absorb pollutants through the skin while bathing or showering and during recreational activities, such as swimming, windsurfing, and water skiing; they can inhale droplets suspended in the air or vapors while taking a shower. They can also ingest foods that have been contaminated with water-borne pollutants.Wastewater treatment plants (WWTPs) cannot altogether remove most of these substances, which can easily reach the drinking water supplies, causing health problems for adults and children. Although drinking water quality is regulated and monitored in many countries, today’s increased knowledge suggests reviewing standards and guidelines on a near-permanent basis for both held and newly identified contaminants and adopting technologies as tertiary treatment processes, which could promote the easy degradation of recalcitrant compounds. It will be necessary to verify that the degradation products are less dangerous than the original molecules and that no dangerous aggregation products are formed. This communication reports some of the degradation studies carried out by our Research Teams in collaboration with foreign researchers using Advanced Oxidation Processes (AOPs) on pesticides and pharmaceuticals present in actual water samples. Photolysis and heterogeneous photocatalysis under simulated solar irradiation using two forms of TiO2 (suspended or immobilized on the surface of thin glass plates) have been investigated to assess the suitability of different oxidation processes to promote mineralization of recalcitrant substances. Transformation products (TPs) have been identified by an LC system coupled to a hybrid LTQ-FTICR (7-T) mass spectrometer (MS). To evaluate the treatment methods' effectiveness, the treated solutions' measurements have been performed using the “Microtox® Toxicity Test” that reports the luminescence inhibition of the marine bacteria Vibrio fischeri. During the degradation process, the temporary formation of toxic fragments was observed, which rapidly degraded to complete mineralization. Samples collected during the degradation process showed the temporary toxicity of the water. The rate of decomposition was highly dependent on the method used. Advanced oxidation processes such as TiO2/Xe-arc system, lead to a rapid decrease of the biorecalcitrant chemical concentrations in aqueous solutions, while photolysis and TiO2-coated glass are less effective. These promising results push us to continue and improver experimental trials. What is the future prospect? The creation of prototypes to be used by farmers and artisans to start with the virtuous path of water recycle

Removal of imidacloprid from polluted water using adsorption and membrane separation technologies

In this work, the stability of imidacloprid in fresh water and sludge was studied. The results revealed that the pesticide is unstable in both media. In freshwater, it underwent hydrolysis whereas a degradation to several metabolites has been observed in sludge. The rate constants for the hydrolysis and degradation at 25°C were 0.0.0067 and 0.0.0099 d–1, respectively. Monitoring the degradation of imidacloprid in sludge by high-pressure liquid chromatography-mass spectrometry (HPLC-MS) revealed that five metabolites have emerged during the study. These metabolites include imidacloprid urea, imidacloprid-guanidine, 6-hydroxynicotinic acid, an olefin, and 5-hydroxy, 1-(6-chloro-3-pyridylmethyl)-2-(nitroimino)-imidazolidin-5-ol. The efficiency of Al-Quds University Wastewater Treatment Plant towards the removal of imidacloprid indicates that the ultrafiltration-hollow fiber unit was insufficient, whereas the ultrafiltration-spiral wound, activated carbon, and reverse osmosis units were efficient for complete removal of the pesticide. Adsorption experiments of imidacloprid using either activated charcoal or micelle-clay complex were found to fit Langmuir isotherms better than Freundlich isotherm. The data demonstrate a higher Langmuir Qmax value for the activated charcoal (126.6 mg g–1) when compared to the micelle-clay complex (11.76 mg g–1). Filtration column experiments, conducted with mixed micelle-clay complex and sand (using a ratio of 1/50 by mass) at a flow rate of 2 mL min–1 and influent concentration of 50 mg L–1, revealed that a sufficient removal of imidacloprid was achieved in the first fraction of 100 mL elution. These findings indicate that the adsorption technology using the micelle-clay complex provides efficient removal of imidacloprid in continuous flow mode