[Show abstract][Hide abstract] ABSTRACT: A sensitive method for simultaneous quantification of 13 phenolics was developed and validated by UPLC–ESI-MS/MS.•Different quality controls were applied for testing the method.•The method was applied for buriti fruits.
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to chemically and nutritionally characterize the commercial chia seeds and oil from Chile and investigate their antioxidant potential by different in vitro methods. The chia seed presented a good source of protein (25.32 g/100 g), oil (30.22 g/100 g) and total dietary fiber (37.50 g/100 g), with predominant insoluble fiber (35.07 g/100 g). The main fatty acids, ranked order of abundance, were α-linolenic acid > linoleic acid > palmitic acid ∼ oleic acid > stearic acid. The triacylglycerols (TAG) in chia oil were identified by direct mass spectrometry using the easy ambient sonic-spray ionization (EASI-MS) technique and linolenic acid (Ln) was present in the most TAG found. The oil also presented a low peroxide index value (2.56 mEq peroxide/kg). The samples exhibited a high antioxidant activity by the various in vitro methods evaluated; it is due to the presence of phenolic compounds in the seed or oil, which were, mainly, myricetin, quercetin, kaempferol, chlorogenic acid and 3,4-dihydroxyphenylethanol-elenolic acid dialdehyde (3,4-DHPEA-EDA). Our results therefore suggest that Chilean chia seeds and oil should be considered as functional ingredients with high antioxidant potential in food products with commercial applications.
[Show abstract][Hide abstract] ABSTRACT: This paper reports the antioxidant activity of a tropical fruit juice and its antiproliferative and antimutagenic effects. The antioxidant activity was determined by several different methods, such as ORAC, ABTS, PSC (peroxyl radical scavenging capacity) and CAA (cellular antioxidant activity). The total of phenolics and flavonoids were determined, and the phenolic compounds were identified by LC-DAD-ESI-MS. The juice showed high total phenolic and flavonoid contents (838.44 ± 30.27 g GAE/100 g and 219.45 ± 12.27 mg CE/100 g DW, respectively). According to the PSC, CAA, ABTS and ORAC assays, the tropical fruit juice showed a high antioxidant value of 308.39 ± 3.10 μM AEE/100 g, 26.76 ± 4.47 μM QE/100 g, 167.17 ± 4.10 μM TE/g DW and 235.90 ± 11.90 μM TE/g DW, respectively. The proliferation of HepG2 was significantly inhibited, in a dose-dependent manner, by exposure to the tropical fruit juice. Antimutagenic activity was investigated by micronucleous test in mice, and all doses evaluated (30, 100 and 300 mg/kg b.w.) showed beneficial effects. As a consequence, these results encourage further studies on the pharmacological and functional properties of this tropical fruit juice, in order to evaluate its use as a functional food, due to its beneficial health properties.
[Show abstract][Hide abstract] ABSTRACT: Using a desorption/ionization technique, easy ambient sonic-spray ionization coupled to mass spectrometry (EASI-MS), documents related to the 2nd generation of Brazilian Real currency (R$) were screened in the positive ion mode for authenticity based on chemical profiles obtained directly from the banknote surface. Characteristic profiles were observed for authentic, seized suspect counterfeit and counterfeited homemade banknotes from inkjet and laserjet printers. The chemicals in the authentic banknotes' surface were detected via a few minor sets of ions, namely from the plasticizers bis(2-ethylhexyl)phthalate (DEHP) and dibutyl phthalate (DBP), most likely related to the official offset printing process, and other common quaternary ammonium cations, presenting a similar chemical profile to 1st-generation R$. The seized suspect counterfeit banknotes, however, displayed abundant diagnostic ions in the m/z 400–800 range due to the presence of oligomers. High-accuracy FT-ICR MS analysis enabled molecular formula assignment for each ion. The ions were separated by 44 m/z, which enabled their characterization as Surfynol® 4XX (S4XX, XX = 40, 65, and 85), wherein increasing XX values indicate increasing amounts of ethoxylation on a backbone of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (Surfynol® 104). Sodiated triethylene glycol monobutyl ether (TBG) of m/z 229 (C10H22O4Na) was also identified in the seized counterfeit banknotes via EASI(+) FT-ICR MS. Surfynol® and TBG are constituents of inks used for inkjet printing.
[Show abstract][Hide abstract] ABSTRACT: In desorption electrospray ionization mass spectrometry (DESI-MS), the type of surface in addition to low gas and solvent ﬂow rates help avoid the 'splashing of solvent' or 'washing effect' where samples are promptly removed from the surface by the spray. These effects operate on smooth surfaces and generally result in unstable signals as the spray moves over the spot. The aim of this work is to investigate the performance of functionalized porous silicon surfaces (pSi) for small molecules analysis with regard to the sensitivity and stability of the signal observed in DESI-MS. The results shown that functional groups like 1-decene and Heptadecafluoro-1,1,2,2-Tetrahydrodecyl trimethoxysilane on pSi surfaces provides a good alternative for dried spot analysis by DESI-MS, increasing the sensitivity and improving stability of the signal. This is possible because the dual process containing the weak sample-surface interactions of the hydrophobic characteristic of the functional groups and trapping of ions inside the pores of the film. It provides a bigger surface area interaction between the sample and the thin solvent film created by the DESI spray, resulting in more effective dissolution of the analyte in the spray solvent without fast removal of the sample.
[Show abstract][Hide abstract] ABSTRACT: The plasma levels of corticosteroids and sex steroids during pregnancy are key indicators of mammalian placental function and the onset of parturition. Steroid hormones are believed to be disturbed in pregnancies produced using assisted reproductive technologies (ARTs) due to placental dysfunction and the frequently observed lack of parturition signals. To elucidate the plasma steroid dynamics, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and used to determine the levels of corticosteroids (corticosterone, 11-deoxicortisol, and cortisol) and their direct precursors (progesterone and 17-α-OH-progesterone) as well as sex steroids (androstenedione, estrone, estrone-sulfate, testosterone, and 17-β-estradiol) in bovine plasma. The levels of these ten steroids in recipient cows carrying naturally conceived (CTRL), in vitro fertilized (IVF) or cloned (SCNT) conceptuses were compared during late-term pregnancy (30 days prior to parturition; D-30), during near-term pregnancy (1 day prior to parturition; D-1), and on the day of parturition (D0). Significant differences were observed among the corticosteroid levels: higher levels of corticosterone, 11-deoxycortisol and cortisol were detected in cloned pregnancies at D-30, lower levels of corticosterone were observed in ART-derived pregnancies at D-1 and D0, and estrone and estradiol levels were higher in IVF-pregnancies throughout the final development. These results suggested an upregulation of the P450C11 and P450C21 enzymes thirty days prior to parturition in SCNT pregnancies, and an overactivation of the aromatase enzyme in IVF pregnancies. Taken together, the monitoring of multiple steroid hormones revealed that the pregnancies obtained using ART exhibited plasma steroid concentration dynamics compatible with the dysregulation of steroidogenic tissues.
[Show abstract][Hide abstract] ABSTRACT: Buriti (Mauritia flexuosa L. f.) is a palm widely distributed in the Amazon Rain Forest of Brazil. Oil is extracted from buriti fruit and popularly used as a food resource and for medicinal purposes. Herein we report the use of an integrative approach based on mass spectrometry (MS) techniques comprising gas chromatography coupled to electron ionization mass spectrometry (GC-MS) and easy ambient sonic-spray ionization mass spectrometry (EASI-MS) with the objective to provide comprehensive lipid characterization of buriti oil. GC-MS analysis revealed the presence of many fatty acids (oleic, palmitic and linoleic), sterols beyond α- and β-tocopherol in buriti oil. EASI-MS allowed the characterization of fatty acids and many triaclyglycerides (TAG) in the negative and positive ion mode, respectively. Additionally, the antioxidant capacity (AC) was measured by the oxygen radical absorbance capacity assay (ORAC); this test was carried with the lipophilic and hydrophilic fractions of the buriti oil. Results revealed a lypophilic antioxidant capacity (LAC) of 1.8 ± 0.01 and hydrophilic antioxidant capacity (HAC) of 8.3 ± 0.01 µmol Trolox equivalents (TE) g−1 indicating that the buriti oil comprises a reliable source of antioxidant compounds that can be more explored for food purposes.
Journal of the Brazilian Chemical Society 10/2014; 00:1-7. · 1.28 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Melia azedarach L. is a plant with wide use in folk medicine since it contains many bioactive compounds of interest. The present study aimed to extract bioactive compounds from M. azedarach fruits by a sequential process in fixed bed using various solvent mixtures. Extractions were performed at 50 °C and 300 bar in four sequential steps using supercritical CO2 (scCO2), scCO2/ethanol, pure ethanol, and ethanol/water mixture as solvents, respectively. The efficacy of the extraction process was evaluated by extraction yield and kinetics, and analysis of extracts by: (1) thin layer chromatography (TLC), (2) phenolics content, (3) reduction of surface tension of water, (4) gas chromatography (GC–MS), (5) electrospray ionization mass spectrometry (ESI–MS) and (6) antiviral activity. The overall extraction yield reached 45% and TLC analysis showed extracts with different composition. extract obtained from CO2/ethanol mixture (SCEE) exhibited the greatest ability to reduce surface tension of water from 72.4 mN m−1  of pure water to 26.9 mN m−1 of an aqueous solution of 40 g L−1. The highest phenolics contents were observed in both the hydroalcoholic extract and scCO2/ethanolic extract. Volatile oils were not detected in the supercritical extracts by GC–MS. MS analyses identified the fatty acids: linoleic, palmitic and myristic acid in the supercritical extract (SCE), and the phenolics: caffeic acid and malic acid in the other extracts. In addition, SCE and SCEE extracts showed significant inhibition percentage against Herpes Simplex Virus Type 1. The extraction process proposed in the present study produced extracts with significant potential for application in food and pharmaceutical industries.
Journal of Supercritical Fluids The 09/2014; · 2.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Several organic acids such as malic, tartaric and citric acids are key grape and wine constituents. They greatly contribute to the organoleptic properties of grapes and wines and are responsible for their acidity, a crucial wine property that is known to considerably vary as a function of grape variety, environmental conditions and viticulture, as well as during wine maturation. A rapid and simple method, requiring minimum sample pre-treatment and no chromatographic separation, based on direct infusion electrospray ionization mass spectrometry (ESI-MS) was developed and validated to quantitate organic acids in wine and grapes. The method was also demonstrated to be able to monitor a common wine adulteration procedure, that is, addition of citric acid for pH adjustment. ESI-MS data when treated via principal component analysis (PCA) was also found to group wine samples based on the profiles and concentrations of organic acids.
[Show abstract][Hide abstract] ABSTRACT: We describe herein a general method for the controlled Heck arylation of allylated malonates. Both electron-rich and electron-poor aryldiazonium salts were readily employed as the aryl-transfer agents in good yields and in high chemo-, regio-, and stereoselectivity without formation of decarboxylated byproducts. Reaction monitoring via ESI-MS was used to support the formation of chelated Pd species through the catalytic cycle. Additionally, some Heck adducts were successfully used in the total synthesis of pharmacologically active γ-lactones.
[Show abstract][Hide abstract] ABSTRACT: Summary This study aimed to evaluate the impact of vitrification on membrane lipid profile obtained by mass spectrometry (MS) of in vitro-produced bovine embryos. Matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) has been used to obtain individual embryo membrane lipid profiles. Due to conditions of analysis, mainly membrane lipids, most favorably phosphatidylcholines (PCs) and sphingomyelins (SMs) have been detected. The following ions described by their mass-to-charge ratio (m/z) and respective attribution presented increased relative abundance (1.2-20×) in the vitrified group: 703.5 [SM (16:0) + H]+; 722.5 [PC (40:3) + Na]+; 758.5 [PC (34:2) + H]+; 762.5 [PC (34:0) + H]+; 790.5 [PC (36:0) + H]+ and 810.5 [PC (38:4) + H]+ and/or [PC (36:1) + Na]+. The ion with a m/z 744.5 [PCp (34:1) and/or PCe (34:2)] was 3.4-fold more abundant in the fresh group. Interestingly, ions with m/z 722.5 or 744.5 indicate the presence of lipid species, which are more resistant to enzymatic degradation as they contain fatty acyl residues linked through ether type bonds (alkyl ether or plasmalogens, indicated by the lowercase 'e' and 'p', respectively) to the glycerol structure. The results indicate that cryopreservation impacts the membrane lipid profile, and that these alterations can be properly monitored by MALDI-MS. Membrane lipids can therefore be evaluated by MALDI-MS to monitor the effect of cryopreservation on membrane lipids, and to investigate changes in lipid profile that may reflect the metabolic response to the cryopreservation stress or changes in the environmental conditions.
[Show abstract][Hide abstract] ABSTRACT: This paper evaluates the effect of additives (NaCl and ethanol) on the solution properties of rhamnolipids. The properties are the surface activity, aggregate formations and emulsifying activity as well as the synergistic effects of additives and pH variations on the physical properties of rhamnolipids. Additionally, analysis of fatty acids and rhamnolipid homologues produced using different carbon sources was performed by mass spectrometry. The results indicate that this biosurfactant maintain its properties in the presence of additives. NaCl decreases the size and number of aggregates formed in solutions without pH control, while ethanol to rhamnolipid solutions reduces critical micelle concentration and favors aggregation of monomers. The profiles of fatty acids produced by P. aeruginosa LBI 2A1 varied according to the carbon source used, however for rhamnolipids there was no difference.
[Show abstract][Hide abstract] ABSTRACT: A novel strategy for the ESI-MS monitoring of reaction solutions involving the alternate use of permanently charge-tagged reagents has been used for comprehensive mass spectrometry monitoring of the multicomponent Hantzsch 1,4-dihydropyridine reaction. By placing a charge tag on either, or both, of the two key reactants, ion suppression effects for ESI were eliminated or minimized, and comprehensive detection of charge-tagged intermediates was achieved. The strategy allowed the trapping and characterization of the important intermediates in the mechanism for 1,4-dihydropyridine formation.
Chemistry (Weinheim an der Bergstrasse, Germany). 09/2014;
[Show abstract][Hide abstract] ABSTRACT: Changes in protein levels and lipid compositions in algal cells indicate the severity of stress related to toxic concentrations of heavy metals. In this study, the effects of exposure to cadmium and copper on Chlorella vulgaris and its capacity to remove metals were evaluated. The data revealed ion removal activity by microalgae under all treatments and different levels of protein expression after 48 h of exposure. Furthermore, we analyzed lipids contents to characterize them.
Bulletin of Environmental Contamination and Toxicology 08/2014; · 1.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Carapa guianensis is a cultivable tree used by traditional health practitioners in the Amazon region to treat several diseases and particularly symptoms related to malaria. Abundant residual pressed seed material (RPSM) results as a by-product of carapa or andiroba oil production. The objective of this study was to evaluate the in vitro and in vivo anti-malarial activity and cytotoxicity of limonoids isolated from C. guaianensis RPSM.