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Nonenzymatic Transglycosylation Reactions Induced by Roasting: New Insights fro...

Three mixtures containing different molar proportions of (beta 1-4)-D-mannotriose and (alpha 1 -> 5)-L-arabinotriose, oligosaccharides structurally related to coffee polysaccharides (galactomannans and arabinogalactans), were roasted at 200 degrees C for different periods. Electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (ESI-MSn) analyses of labeled (180) and unlabeled samples al...

Recent Advances on Mass Spectrometry Analysis of Nitrated Phospholipids

In recent years, there has been an increasing interest in nitro fatty acids (NO2-FA) as signaling molecules formed under nitroxidative stress. NO2-FA were detected in vivo in a free form, although it is assumed that they may also be esterified to phospholipids (PL). Nevertheless, insufficient discussion about the nature, origin, or role of nitro phospholipids (NO2-PL) was reported up to now. The aim of this stu...

Chlorogenic acid-arabinose hybrid domains in coffee melanoidins: Evidences from...

Arabinose from arabinogalactan side chains was hypothesized as a possible binding site for chlorogenic acids in coffee melanoidins. To investigate this hypothesis, a mixture of 5-O-caffeoylquinic acid (5-CQA), the most abundant chlorogenic acid in green coffee beans, and (alpha 1 -> 5)-L-arabinotriose, structurally related to arabinogalactan side chains, was submitted to dry thermal treatments. The compounds fo...

Maternal plasma phospholipids are altered in trisomy 21 cases and prior to pree...

Photodegradation of 2-mercaptobenzothiazole and 1,2,3-benzotriazole corrosion i...

The photochemical degradation of 2-mercaptobenzothiazole (MBT) and 1,2,3-benzotriazole (BTA) inhibitors was studied in the present work in aqueous and in organic solutions. The extent of photo-degradation was assessed by UV-Vis spectroscopy and the main reaction products were identified by tandem electrospray ionization mass spectrometry (ESI-MS/MS). The analysis of degradation products upon UV irradiation reve...

Neutral and acidic products derived from hydroxyl radical-induced oxidation of ...

The oxidation of -(15)-l-arabinotriose (Ara(3)), an oligosaccharide structurally related to side chains of coffee arabinogalactans, was studied in reaction with hydroxyl radicals generated under conditions of Fenton reaction (Fe2+/H2O2). The acidic and neutral oxidation products were separated by ligand exchange/size-exclusion chromatography, subsequently identified by electrospray ionisation mass spectrometry ...

Sequential microwave superheated water extraction of mannans from spent coffee ...

The feasibility of using sequential microwave superheated water extraction (MAE) for the recovery of mannans from spent coffee grounds (SCG) was studied. Due to the high contents of mannose still present in the SCG residue left after two consecutive MAE, the unextracted material was re-suspended in water and submitted to a third microwave irradiation (MAE3) at 200 degrees C for 3 min. With MAE3, mannose recover...

Effect of copper ions on the degradation of thiram in aqueous solution: Identif...

The aim of this work was to examine the effect of Cu(II) on the degradation of thiram (Thi) in aqueous solutions, since the literature focused on this effect is scarce and copper based fungicides can be applied together with thiram or during the same season to agricultural crops. The effect of Cu(II) on the degradation of thiram was followed by both UV-vis and HPLC-MS/MS. When thiram is dissolved in pure water ...

Human plasma stability during handling and storage: impact on NMR metabolomics

This work contributes to fill in some existing gaps in the knowledge of human plasma degradability during handling and storage, a paramount issue in Nuclear Magnetic Resonance (NMR) metabolomics. Regarding the comparison between heparin and EDTA anti-coagulant collection tubes, the former showed no interference of the polysaccharide, while conserving full spectral information. In relation to time/temperature co...

Gas phase reactions of beta-substituted hetero-Diels-Alder adducts of meso-tetr...

beta-Substitued-meso-tetraphenylporphyrins with 5,10-dioxobenzo[g]- or 5,6-dioxobenzo[h]chromene, pyrano[3,2-c]coumarin and benzopyran moieties and the corresponding Zn(II), Cu(II) and Ni(II) complexes were studied by electrospray mass spectrometry (ESI-MS) and tandem mass spectrometry (MS/MS). These heterocyclic moieties have well established pharmacological activities and as such the introduction of these mot...