Prediction of total acid number in distillation cuts of crude oil by ESI(-) FT-ICR MS coupled with chemometric tools

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESCompetitive adaptive reweighted sampling-partial least squares (CARS-PLS) and negative-ion mode electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI(-) FT-ICR MS) data were adopted to assess the total acid number (TAN)28918221829FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESSEM INFORMAÇÃOSEM INFORMAÇÃOSEM INFORMAÇÃOThis research was generously funded by PETROBRAS/CENPES, FAPESP, CNPq, CAPES, and FINE

Isomeric separation of cannabinoids by UPLC combined with ionic mobility mass spectrometry (TWIM-MS)-Part I

The Cannabis sativa L. plant is rich in a wide variety of cannabinoids. δ9-tetrahydrocannabinol (δ9-THC) is the main chemical compound responsible for its psychoactive effect, and it can be identified as [M+H]+ and [M-H]- ions at m/z 315 and 313, respectively, where M=C21H30O2. However, six other isomeric or isobaric forms of δ9-THC can exist, which makes its unequivocal characterization a challenge. In this work, ultra-high liquid chromatography coupled to traveling wave ion mobility mass spectrometry (UPLC-TWIM-MS) were applied to both electrospray ionization modes (ESI(±)) and used to analyze hashish, marijuana, and parts of the Cannabis Sativa L. plant (flower and leaf). The presence of a complex isomeric mixture of cannabinoids has been identified, and the mixture mainly contains δ9-THC, cannabidiol (CBN-C5 and Mw =310Da), δ9-tetrahydrocannabinolic acid A and B (δ9-THCA-C5 A/B and Mw =358Da) and their isomers. Three isomers of the ions were identified at m/z 315/313, 311, and 357 by using direct infusion ESI-TWIM-MS technique, while higher selectivity was observed in UPLC-ESI-TWIM-MS data, with the maximum isomeric separation between four and five compounds achieved when using single-ion mode (SIM) acquisition. The ions at m/z 311/309, 315/313, 345, and 357 correspond to CBN-C5, δ9-THC, cannabielsioc acid, δ9-THCA-C5 and their isomers, respectively, and they were the main species found. The calculations of collision cross sections were reported for all isomers of cannabinoids and associated with TWIM-MS results

Genetics tools for corpora allata specific gene expression in Aedes aegypti mosquitoes

Abstract Juvenile hormone (JH) is synthesized by the corpora allata (CA) and controls development and reproduction in insects. Therefore, achieving tissue-specific expression of transgenes in the CA would be beneficial for mosquito research and control. Different CA promoters have been used to drive transgene expression in Drosophila, but mosquito CA-specific promoters have not been identified. Using the CRISPR/Cas9 system, we integrated transgenes encoding the reporter green fluorescent protein (GFP) close to the transcription start site of juvenile hormone acid methyl transferase (JHAMT), a locus encoding a JH biosynthetic enzyme, specifically and highly expressed in the CA of Aedes aegypti mosquitoes. Transgenic individuals showed specific GFP expression in the CA but failed to reproduce the full pattern of jhamt spatiotemporal expression. In addition, we created GeneSwitch driver and responder mosquito lines expressing an inducible fluorescent marker, enabling the temporal regulation of the transgene via the presence or absence of an inducer drug. The use of the GeneSwitch system has not previously been reported in mosquitoes and provides a new inducible binary system that can control transgene expression in Aedes aegypti

Fractionation of asphaltenes in n-hexane and on adsorption onto CaCO3 and characterization by ESI(+)FT-ICR MS: Part I

Two methods of asphaltenes fractionation have been employed to facilitate the characterization of their respective subfractions. The methods are based on step-wise precipitation with different n-hexane/crude oil ratios, and on adsorption onto CaCO3. Three subfractions were produced for each method, being named of 3.5 V, 3.5-6 V, and 6-40 V (for the first method); and non-adsorbed (bulk), adsorbed, and irreversibly adsorbed (for the second method). The fractions were characterized by elementary analysis, nuclear magnetic resonance of proton (1H NMR) and by positive ion-mode electrospray Fourier transform ion cyclotron resonance mass spectrometry (ESI(+) FT-ICR MS). The elemental analysis, described in previous work, revealed that the C/H ratio for whole asphaltene and its sub-fractions varied between a narrow range (0.83-0.88) which means they present similar aromaticity or unsaturation. Furthermore, the elemental analysis corroborates with the 1H NMR analysis suggesting that subfraction 6-40 V presented a more aromatic profile than of remaining subfractions, while for the fractionation using CaCO3, this behavior was observed for the adsorbed subfraction. However, a more detailed molecular information was obtained from ESI(+)-FT-ICR MS data, showing that polar compounds species with lower carbon numbers were mainly found for the irreversibly adsorbed subfraction. Besides, the double bond equivalent (DBE) distribution is an important tool to associate the chemical information with solubility parameters, in which, a narrower DBE distribution was observed for irreversibly adsorbed (for fractionation onto CaCO3) and subfraction 3.5 V (fractionation in n-hexane) samples, indicating that they are less soluble in hydrocarbons. Also, solubility parameters (d) were calculated from ESI(+) FT-ICR MS data, where the results indicate that subfractions produced in n-hexane have a lower tendency to precipitate in hydrocarbons in relation to subfractions produced onto CaCO3210790802CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DO AMAPÁ - FAPEAPFUNDAÇÃO DE AMPARO À PESQUISA E INOVAÇÃO DO ESPÍRITO SANTO - FAPESsem informação23038.007083/2014-40sem informaçãosem informaçã

Asphaltenes subfractions extracted from Brazilian vacuum residue: Chemical characterization and stabilization of model water-in-oil (W/O) emulsions

Asphaltenes were obtained from a Brazilian vacuum residue (VR) by precipitation with different ratios of n-heptane/VR to give three asphaltene subfractions. The behavior of these different subfractions in relation to the stability of water-in-oil (W/O) emulsions were evaluated. The whole asphaltene subfraction (AH) was obtained with the addition of n-heptane/VR in a 40:1 ratio (v/v) followed by filtration. Two more asphaltene subfractions (A4 and A10) were obtained by precipitation with n-heptane/VR ratios of 4:1 and 10:1, respectively. The properties of the precipitated asphaltene subfractions were analyzed by atmospheric pressure photoionization (APPI) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) in positive-ion mode, ultraviolet–visible (UV–Vis) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. The FT-ICR MS results showed that the A4 subfraction exhibited a profile with a higher amount of heteroatoms, high polarity and broader molecular weight distribution (Mw). An inverse correlation was observed concerning the degree of aromaticity and solubility in heptane/toluene solutions (onset point). The AH and A10 subfractions were more aromatic than A4, as confirmed by 1H NMR analysis. Also, the asphaltene subfractions promoted greater stability of the emulsions produced. The droplet size distribution and bottle test showed similar results for the stability of the emulsions obtained with the three different subfractions. After the application of centrifugal forces, the formation of a densely packed layer emulsion was observed, containing approximately 85% of water. The stabilization was improved when the W/O interface formed a viscous layer and effectively blocked the water coalescence, which remained stable for two weeks

Brown seaweed Padina gymnospora is a prominent natural wound-care product

Seaweeds are related to anti-inflammatory, anti-bacterial and anti-noceptive effects. This work aimed to verify the potential of seaweed Padina gymnospora (Kützing) Sonder 1871 to improve wound healing in vitro. P. gymnospora was collected at a bethonic area in Espirito Santo. Methanolic extract of P. gymnospora was obtained by percolation. To determine cytotoxicity, colorimetric MTT tests were performed against normal fibroblasts (L929), macrophages (RAW 264.7) and human ovarian carcinoma (OVCAR-3) cell lines using concentration range of 12–110 μg ml−1. To evaluate in vitro wound healing, monolayer of fibroblasts L929 was seeded and artificial wounded. Cell proliferation was blocked by 5 μg ml−1 Mytomycin C. Nitric oxide inhibition was quantified with Raw 264.7 by Griess reaction. Minimal inhibitory concentration (MIC) against Staphylococcus aureus was determined. Eletrospray ionization with Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR MS) was applied to detail composition of P. gymnospora methanolic extract. No cytotoxic effect in all cell lines was detected until the maximum concentration of 110 μg ml−1. P. gymnospora promoted significantly migration at the concentration of 25 μg ml−1 (p < 0.05). A prominent inhibition of nitric oxide formation was achieved in a concentration of 20 μg ml−1 of methanolic extract of P. gymnospora (62.06 ± 1.20%). Antibacterial activity against S. aureus could be demonstrated with MIC of 500 μg ml−1. ESI-FT-ICR MS analysis indicated eleven molecules between then, linolenic, oleic and linoleic acid. P. gymnospora favored wound repair in vitro what could be related to its fatty acid composition. In addition, its antimicrobial effect, and NO inhibition activity contribute for a new approach of P. gymnospora as a promise natural product for treatment of cutaneous wound. Keywords: Padina gymnospora, Wound-healing, Nitric oxide, Staphylococcus aureus, Fatty acid

2-(4-IODO-2,5-DIMETOXIFENIL)-N-[(2-METOXIFENIL)METIL]ETAMINA OU 25I-NBOME: CARACTERIZAÇÃO QUÍMICA DE UMA DESIGNER DRUG

Drug trafficking and the introduction of new drugs onto the illicit market are one of the main challenges of the forensic community. In this study, the chemical profile of a new designer drug, 2-(4-iodine-2,5-dimethoxyphenyl)-n-[(2-methoxyphenyl)methyl]etamine or 25I-NBOMe was explored using thin layer chromatography (TLC), ultraviolet-visible spectrophotometry (UV-Vis), attenuated total reflection with Fourier transform infrared spectroscopy(ATR-FTIR), gas chromatography mass spectrometry (GC-MS) and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR MS). First, the TLC technique was effective for identifying spots related to 25C-, 25B- and 25I-NBOMe compounds, all with the same retention factor, Rf ≈ 0.50. No spot was detected for 2,5-dimethoxy-4-bromoamphetamine, 2,5-Dimethoxy-4-chloroamphetamine or lysergic acid diethylamide compounds. ATR-FTIR preserved the physical-chemical properties of the material, whereas GC-MS and ESI-MS showed better analytical selectivity. ESI(+)FT-ICR MS was used to identify the exact mass (m/z428.1706 for the [M + H]+ ion), molecular formula (M = C18H22INO3), degree of unsaturation (DBE = 8) and the chemical structure (from collision induced dissociation, CID, experiments) of the 25I-NBOMe compound. Furthermore, the ATR-FTIR and CID results suggested the presence of isomers, where a second structure is proposed as an isomer of the 25I-NBOMe molecule

Fractionation of Asphaltene by Adsorption onto Silica and Chemical Characterization by Atmospheric Pressure Photoionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, Fourier Transform Infrared Spectroscopy Coupled to Attenuated Total Reflectance, and Proton Nuclear Magnetic Resonance

Asphaltenes are defined as the petroleum fraction insoluble in <i>n</i>-alkanes and soluble in aromatic solvents, such as toluene. Such definition implies that asphaltenes are not a homogeneous material but a mixture of fractions. Asphaltenes represent one of the major contributors to several problematic issues for the petroleum industry. Destabilized asphaltenes can cause arterial clogging within pipelines and wellbores, corrosion and fouling of production equipment, reduction of catalyst activity in refining processes, and other problems. This work describes an investigation of the separation of asphaltenes into three different fractions by adsorption onto silica particles. These fractions (two adsorbed and one non-adsorbed onto silica) were characterized by elemental analysis (C, H, and N), Fourier transform infrared spectroscopy coupled to attenuated total reflectance (ATR–FTIR), proton nuclear magnetic resonance (¹H NMR) spectroscopy, and atmospheric pressure photoionization Fourier transform ion cyclotron resonance mass spectrometry (APPI–FT-ICR MS). APPI–FT-ICR MS and ATR–FTIR accessed chemical information on a molecular level [molecular formula, carbon number (CN) and double bond equivalent (DBE) distributions, and organic groups], whereas ¹H NMR and elemental analysis provided the aromaticity degree and C/H atomic ratio of the samples, respectively. The C/H atomic ratio decreases in the following the order: non-adsorbed > whole asphaltene > adsorbed > irreversibly adsorbed. The irreversible fraction adsorbed had the lowest percentage of aromatic hydrogen compared to other fractions by ¹H NMR. There was a good correlation between the results of NMR and elemental analysis. The efficiency of fractionation on silica particles was proven to be successful by the low concentration of polyaromatic hydrocabons observed for two samples adsorbed onto silica and the increasing of the aromaticity degree and C/H ratio for the non-adsorbed fraction. N₂, N₂O, and NO compound classes were selectively separated from whole asphaltene and concentrated in polar fractions (adsorbed fractions onto silica), with their CN and DBE distributions reported. Therefore, this work demonstrated the selectivity of the fractionation method onto silica to retain highly polar compounds and, moreover, extends to the study of the adsorbent surface and how the molecules of the asphaltenes will behave against this change