Fate of egg white proteins in aged painting layers by UV-induced processes: a comprehensive proteomic study.

Understanding the aging of pictorial binders is essential for preserving artworks and identifying the chemical changes that affect their stability. Among historical binders, egg tempera was widely used due to its durability, yet protein degradation over time weakens the painting layer, especially when interacting with inorganic pigments. This study simulated the natural aging of egg-based paintings by exposing non-pigmented egg white and egg white mixed with calcium carbonate (white pigment) or hematite (red pigment) to UV-Vis irradiation and 50 °C for up to 864 h.

Contamination of Wheat Flour and Processed Foodstuffs with Soybean and Mustard Allergenic Proteins.

In recent years, sustainable agricultural practices in wheat cultivation have garnered significant attention, particularly those focused on minimizing pesticide and herbicide usage to safeguard the environment. One effective approach is green manuring, which entails rotating wheat with crops such as soybean and mustard to harness their natural pesticidal and herbicidal properties. While this method presents clear environmental advantages, it also poses a risk of cross-contamination, as these globally recognized allergens may unintentionally pass through wheat-based products.

Unveiling the Secret Chemistry of Street Art by a Multitechnique Approach.

In recent years, graffiti and street art have gained recognition as legitimate art forms, deserving of the same care and attention as traditional art. As a result, conservators and restorers are now working to develop standardized guidelines for the cleaning, conservation, and restoration of these vibrant works. Our study takes a closer look at the materials used in street art, specifically the spray varnishes used by artists.

Complete Polar Lipid Profile of Kefir Beverage by Hydrophilic Interaction Liquid Chromatography with HRMS and Tandem Mass Spectrometry.

Kefir, a fermented milk product produced using kefir grains, is a symbiotic consortium of bacteria and yeasts responsible for driving the fermentation process. In this study, an in-depth analysis of kefir's lipid profile was conducted, with a focus on its phospholipid (PL) content, employing liquid chromatography with high-resolution mass spectrometry (LC-HRMS). Nearly 300 distinct polar lipids were identified through hydrophilic interaction liquid chromatography (HILIC) coupled with electrospray ionization (ESI) and Fourier-transform orbital-trap MS and linear ion-trap tandem MS/MS.

Gas-Phase Fragmentation of Coenzyme Q Radical Anion Generated by APCI: A Study by High/Low-Resolution Tandem/Sequential Mass Spectrometry.

Coenzyme Q (CoQ) and closely related compounds with varying isoprenoid tail lengths (CoQ, = 6-9) are biochemical cofactors involved in many physiological processes, playing important roles in cellular respiration and energy production. Liquid chromatography (LC) coupled with single or tandem mass spectrometry (MS) using electrospray (ESI) or atmospheric pressure chemical ionization (APCI) is considered the gold standard for the identification and quantification of CoQ in food and biological samples. However, the characteristic fragmentation exhibited by the CoQ radical anion ([M], / 862.

Leuconostoc mesenteroides strain MS4-derived bacteriocins: A potent antimicrobial arsenal for controlling Xylella fastidiosa infection.

Xylella fastidiosa subsp. pauca (Xfp) currently presents a serious threat to agriculture in Europe and in the Mediterranean, following its discovery in several countries. Addressing this bacterial plant disease with traditional agricultural practices and management strategies has proven inadequate, highlighting the urgent need for effective and environmentally safe antibacterial solutions.

Confirmation of the unexpected occurrence of bitterness-inducing cucurbitacins in edible unripe melons by a two-step workflow based on liquid chromatography with combined UV and high-resolution MS detection.

Plant metabolites known as cucurbitacins are known to impart an unpleasant bitter taste to edible fruits and even lead to severe health complications after the ingestion of relatively high amounts. In this study, an analytical method based on reversed phase liquid chromatography with combined detection by UV spectroscopy and atmospheric pressure chemical ionization high-resolution single/tandem mass spectrometry was applied to confirm the occurrence of four cucurbitacins (B, D, and R, and 23,24-dihydro cucurbitacin B) previously inferred in unexpectedly bitter-tasting fruits of an Italian variety (Scopatizzo) of unripe melon (Cucumis melo L.), known for the sweetness of its fruits.

Look but don't touch: Non-invasive chemical analysis of organic paint binders - A review.

Diagnostics on historical art samples are decisive for assessing degradation and understanding the chemical composition of supports and polychromies. These investigations help us in uncovering the artist's style and techniques and provide invaluable information for restoration, preservation and conservation. In paint formulation, the binder, also known as medium, disperses insoluble pigments and creates a homogeneous, adhesive mixture.

Tandem Mass Spectrometry in Untargeted Lipidomics: A Case Study of Peripheral Blood Mononuclear Cells.

Peripheral blood mononuclear cells (PBMCs), including lymphocytes, are important components of the human immune system. These cells contain a diverse array of lipids, primarily glycerophospholipids (GPs) and sphingolipids (SPs), which play essential roles in cellular structure, signaling, and programmed cell death. This study presents a detailed analysis of GP and SP profiles in human PBMC samples using tandem mass spectrometry (MS/MS).

Discovering the Ellagitannin Landscape of Dried Walnut Shells by Liquid Chromatography with Tandem Mass Spectrometry.

Walnut shells, often discarded as waste, hold hidden potential as a source of ellagitannins (ETs), compounds known for their promising antioxidant properties and health benefits. This study employed reversed-phase liquid chromatography (RPLC) coupled with Orbitrap-based high-resolution mass spectrometry (HRMS) via electrospray ionization (ESI) in negative polarity to investigate the ET profile in extracts of dried powdered walnut shells. Several compounds belonging to various ET families were successfully identified as deprotonated molecules ([M - H]) and characterized, including mono-, di-, tri-, tetra-, and pentagalloyl glucopyranoses, as well as ETs containing the hexahydroxydiphenoyl (HHDP) group.

Proteomics for Microalgae Extracts by High-Resolution Mass Spectrometry.

Two protocols of protein extraction from Arthrospira platensis (spirulina) microalgae to study their proteome by mass spectrometry (MS) are here presented. The first is based on an aqueous buffer solution of Tris-HCl and the second on cold acetone. The identification of proteins was carried out by a bottom-up approach, which involves enzymatic digestion of extracted proteins followed by either matrix-assisted laser desorption ionization with time-of-flight (MALDI-TOF) MS or liquid chromatography (LC) coupled with electrospray ionization (ESI) and Fourier-transform tandem MS.

Mass spectrometric characterization of aminophospholipids containing N-(2-hydroxyethyl)glycine in kombu algae extracts.

Rationale: 1,2-Diacyl-sn-glycero-3-phospho-O-[N-(2-hydroxyethyl)glycines] (PHEGs) are a class of rare aminophospholipids found specifically in brown algae, including kombu seaweed. Despite their potential importance in algal physiology, a comprehensive mass spectrometry (MS) characterization, useful to understand their biological behaviour, is still lacking.

Methods: To establish the structural regiochemical features of PHEGs, we employed hydrophilic interaction liquid chromatography (HILIC).

Development of a New Binary Matrix for the Comprehensive Analysis of Lipids and Pigments in Micro- and Macroalgae Using MALDI-ToF/ToF Mass Spectrometry.

While edible algae might seem low in fat, the lipids they contain are crucial for good health and preventing chronic diseases. This study introduces a binary matrix to analyze all the polar lipids in both macroalgae (Wakame-, Dulse-, and Nori- spp.) and microalgae (Spirulina-, and Chlorella-) using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS).

Development of super nanoantimicrobials combining AgCl, tetracycline and benzalkonium chloride.

In this work, we demonstrate that a simple argentometric titration is a scalable, fast, green and robust approach for producing AgCl/antibiotic hybrid antimicrobial materials. We titrated AgNO into tetracycline hydrochloride (TCH) aqueous solution, thus forming AgCl/TCH in a one-step procedure. Furthermore, we investigated the one-pot synthesis of triply synergistic super-nanoantimicrobials, combining an inorganic source of Ag ions (AgCl), a disinfecting agent (benzyl-dimethyl-hexadecyl-ammonium chloride, BAC) and a molecular antibiotic (tetracycline hydrochloride, TCH).

Nisin-based therapy: a realistic and eco-friendly biocontrol strategy to contrast subsp. infections .

The lack of sustainable strategies for combating () highlights the pressing need for novel practical antibacterial tools. In this study, subsp. strain ATCC 11454 (), known for its production of nisin A, was tested against subsp.

Lipidomics reveals the reshaping of the mitochondrial phospholipid profile in cells lacking OPA1 and mitofusins.

Depletion or mutations of key proteins for mitochondrial fusion, like optic atrophy 1 (OPA1) and mitofusins 1 and 2 (Mfn 1 and 2), are known to significantly impact the mitochondrial ultrastructure, suggesting alterations of their membranes' lipid profiles. In order to make an insight into this issue, we used hydrophilic interaction liquid chromatography coupled with electrospray ionization-high resolution MS to investigate the mitochondrial phospholipid (PL) profile of mouse embryonic fibroblasts knocked out for OPA1 and Mfn1/2 genes. One hundred sixty-seven different sum compositions were recognized for the four major PL classes of mitochondria, namely phosphatidylcholines (PCs, 63), phosphatidylethanolamines (55), phosphatidylinositols (21), and cardiolipins (28).

Exploration of the Lipid Profile of Edible Oleaginous Microgreens by Mass Spectrometry-Based Lipidomics.

The spreading awareness of the health benefits associated with the consumption of plant-based foods is fueling the market of innovative vegetable products, including microgreens, recognized as a promising source of bioactive compounds. To evaluate the potential of oleaginous plant microgreens as a source of bioactive fatty acids, gas chromatography-mass spectrometry was exploited to characterize the total fatty acid content of five microgreens, namely, chia, flax, soy, sunflower, and rapeseed (canola). Chia and flax microgreens appeared as interesting sources of α-linolenic acid (ALA), with total concentrations of 2.

Matrix Selection Strategies for MALDI-TOF MS/MS Characterization of Cyclic Tetrapyrroles in Blood and Food Samples.

Cyclic tetrapyrrole derivatives such as porphyrins, chlorins, corrins (compounds with a corrin core), and phthalocyanines are a family of molecules containing four pyrrole rings usually coordinating a metal ion (Mg, Cu, Fe, Zn, etc.). Here, we report the characterization of some representative cyclic tetrapyrrole derivatives by MALDI-ToF/ToF MS analyses, including heme b and c, phthalocyanines, and protoporphyrins after proper matrix selection.

Food allergen detection by mass spectrometry: From common to novel protein ingredients.

Food allergens are molecules, mainly proteins, that trigger immune responses in susceptible individuals upon consumption even when they would otherwise be harmless. Symptoms of a food allergy can range from mild to acute; this last effect is a severe and potentially life-threatening reaction. The European Union (EU) has identified 14 common food allergens, but new allergens are likely to emerge with constantly changing food habits.

The Effect of Milling on the Ethanolic Extract Composition of Dried Walnut ( L.) Shells.

This study investigates the ethanolic extract of dried walnut ( L.) shells upon hammer milling (HM) and ball milling (BM) grinding processes. Marked differences were observed in the attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectra.

Methyl carbamates of phosphatidylethanolamines and phosphatidylserines reveal bacterial contamination in mitochondrial lipid extracts of mouse embryonic fibroblasts.

The occurrence of methyl carbamates of phosphatidylethanolamines and phosphatidylserines in the lipid extract of mitochondria obtained from mouse embryonic fibroblasts was ascertained by hydrophilic interaction liquid chromatography with electrospray ionization single and multi-stage mass spectrometry, performed using sinergically a high resolution (quadrupole-Orbitrap) and a low resolution (linear ion trap) spectrometer. Two possible routes to the synthesis of methyl carbamates of phospholipids were postulated and evaluated: (i) a chemical transformation involving phosgene, occurring as a photooxidation by-product in the chloroform used for lipid extraction, and methanol, also used for the latter; (ii) an enzymatic methoxycarbonylation reaction due to an accidental bacterial contamination, that was unveiled subsequently on the murine mitochondrial sample. A specific lipid extraction performed on a couple of standard phosphatidyl-ethanolamines/-serines, based on purposely photo-oxidized chloroform and deuterated methanol, indicated route (i) as negligible in the specific case, thus highlighting the enzymatic route related to bacterial contamination as the most likely source of methyl carbamates.

Strategies for the analysis of arsenolipids in marine foods: A review.

Arsenic-containing lipids, also named arsenolipids (AsLs), are a group of organic compounds usually found in a variety of marine organisms such as fish, algae, shellfish, marine oils, and microorganisms. Numerous AsLs have been recognised so far, from simple compounds such as arsenic fatty acids (AsFAs), arsenic hydrocarbons (AsHCs), and trimethylarsenio fatty alcohols (TMAsFOHs) to more complex arsenic-containing species, of which arsenophospholipids (AsPLs) are a case in point. Mass spectrometry, both as inductively coupled plasma (ICP-MS) and liquid chromatography coupled by an electrospray source (LC-ESI-MS), was applied to organic arsenicals playing a key role in extending and refining the characterisation of arsenic-containing lipids in marine organisms.

Uncovering heterogeneity of anacardic acids from pistachio shells: A novel approach for structural characterization.

Anacardic acids (AnAs) are important secondary metabolites that occur primarily in plants of the Anacardiaceae family, such as pistachio (Pistacia vera L.). Some AnAs have been associated with health benefits, and the position of the CC double bonds is a crucial feature of these metabolites.

Oxidative NHC Catalysis: An Unconventional Tool for Macrocyclic Oligoesters Synthesis.

The application of N-heterocyclic carbene (NHC) catalysis under highly diluted oxidative condition to the polycondensation of dialdehydes and diols is herein presented as an alternative, atom-economical synthetic route to macrocyclic oligoesters (MCOs). The disclosed protocol paves the way to the straightforward access to MCOs, starting from commercial dialdehydes, avoiding the use of toxic diacyl chlorides, commonly employed in traditional MCOs synthetic processes. The method is totally metal-free, takes place in the green Me-THF solvent and requires the use of a fully recyclable quinone oxidant.

PE, or not PE, that is the question: The case of overlooked lyso-N-acylphosphatidylethanolamines.

Rationale: Lyso derivatives of N-acyl-1,2-diacylglycero-3-phosphoethanolamines (L-NAPEs) are a lipid class mostly expressed in vegetables during stress and tissue damage that is involved in the synthesis of the lipid mediator N-acylethanolamines. L-NAPEs can be challenging to distinguish from isomeric phosphatidylethanolamines (PEs), especially in extracted complex samples where they could be confused with abundant PEs.

Methods: In this study, hydrophilic interaction liquid chromatography with electrospray ionization hyphenated with (tandem) mass spectrometry (MS) was proposed to distinguish L-NAPEs and PEs as deprotonated molecules, [M - H] , using both high-resolution/accuracy Fourier transform MS and low-resolution linear ion trap (LIT) mass analyzers.