JBCS

Alkaloids, including a new aporphine alkaloid and a pyrrole alkaloid, were isolated from Acorus gramineus rhizomes. The presence of alkaloids is first reported from A. gramineus. The alkaloids showed significant anti-neuroinflammatory and antiproliferative activities.

Two new eudesmane-type sesquiterpenoids and one new mellein derivative were isolated from the cultures of the fungus Marasmiellus ramealis. The new sesquiterpenoids showed inhibitory activity against acetylcholinesterase.

Subcritical fluid extraction is an innovative technique to substitute the classical methods for lipid extraction. In this study, chemometric tools were applied to evaluate the influence of independent factors (temperature and pressure) in the determination of fatty acids in perilla oil and compare the results with the official Soxhlet methodology.

Catalytic activity of NiAl at 600 ºC. This catalyst gave the best results for GSR under the test conditions, proving stable and active throughout the 4 h reaction time.

The phytochemical study of Hyptis crassifolia led to the isolation and structure elucidation of nine diterpenes. 6α,11,12,15-Tetrahydroxy-8,11,13-abietatrien-7-one, 11,12,16-trihydroxy-17(15→16)-abeo-abieta-8,11,13-trien-7-one and 11,12,15-trihydroxy-8,11,13-abietatrien-7-one are new, and a structural revision is proposed for (16S)-12,16-epoxy-11,14-dihydroxy-17(15→16)-abeo-abieta-8,11,13-trien-7-one.

Least square regression and artificial neural network were evaluated as modeling tools in the optimization of a solid-phase extraction method for cadmium determination using flame atomic absorption spectrometry.

In the present study, a cationic surfactant with a proper alkyl group side chain is dissolved in the aqueous sample and then a proper ion-pairing agent is added. Due to the interaction between the surfactant and ion-pairing agent, very fine solid particles are formed and precipitates of analyte are adsorbed on the surface of solid particles and dissolved in HNO₃ in ethanol, and then aspirated directly into the flame of the atomic absorption spectrometer (AAS).

A new high performance liquid chromatography with diode array detection methodology was developed for glycerol analysis in sugar cane spirit and applied to selected set of cachaças. Glycerol contents in aged cachaças were about 10-fold higher than in non-aged cachaças.

In this work, we used near infrared reflectance spectroscopy and multivariate control charts based on significant principal component (PC) scores and net analytical signal (NAS) for simultaneous quality monitoring of isoniazid and rifampicin in a pharmaceutical formulation.

In this work fatty esters derived from Juglone were synthesized by modified Steglich esterification. Compounds prepared showed promising results as wax inhibitors on crude oil.

Novel highly soluble photoluminescent macromolecule having n-type conjugated segment and presenting low-lying LUMO level, ionization potential (IP) and electron affinity (EA) of 6.25 and 3.65 eV, respectively.

The structure and operating principle of the dye-sensitized solar cell (DSSC).

Method based on digital imaging and multivariate analysis for the classification of castor seeds with respect to the cultivar type.

Pyrohydrolysis is an alternative method for sample preparation and allows the vaporization of the analyte by hydrolysis under high temperature (around 1000 °C). Instrumentation required for a pyrohydrolysis analysis is very simple and minimal sample preparation is required. In this sense, pyrohydrolysis is suitable for B determination in SiC samples, due to the low limit of detection achieved and minimum interference of the matrix in the determination using plasma techniques.

The graphical abstract pictorially represents the three-step synthesis of three cyclic alkaloids (coniine, an oriental food flavor and a natural product extracted from Pinus ponderosa) prepared from commercially available starting materials. The key step was the A³-coupling reaction.

Two nitrogen-rich energetic salts were synthesized and their chemical and physical properties were also fully characterized.

Graphene for dispersive solid-phase extraction of triazine and neonicotine pesticides from environmental water.

Direct solid sampling is a fast, simple and sustainable procedure to analyze hard-to-dissolve samples. This green analytical procedure is proposed here for the determination of Pb in cosmetics by atomic absorption spectrometry.

The simultaneous determination of Na, Ca and K in biodiesel was performed by flame atomic emission spectrometry using a continuous electromagnetic radiation detector and two different sample preparation procedures: direct dilution with kerosene and emulsification using HNO₃, n-butanol and Triton X-100.

A schematic representation of the solid phase extraction of metribuzin by using hydrophilic-lipophilic balance (HLB) cartridge and recovery amounts (%) of metribuzin by different methods. The solid phase extraction method with HLB cartridge had the highest metribuzin recovery.

Chiral β-hydroxy-2-oxazolines were synthesized and evaluated as catalysts for the addition of diethylzinc to aldehydes and were effective in obtaining the addition products, with enantiomeric excess up to 78%.

An integrative approach based on GC-MS and easy ambient sonic-spray ionization mass spectrometry (EASI-MS) was employed for comprehensive characterization of lipids in buriti oil. In addition, the biologic activities were also evaluated.

Caffeine degradation was evaluated at an initial concentration of 5.2 µmol L^-1 (1000 µg L^-1) employing low iron and hydrogen peroxide concentrations. The Fenton and the Fenton-like processes were investigated. The effects of inorganic ions on caffeine degradation were evaluated, as well as chronic toxicity of the reaction condition in which there was higher caffeine degradation by Fenton's reagent.

This work explains how the size of a carbon nanotube, urea, and temperature would influence the insertion of Tretinoin, a skin anti-cancer drug, into carbon nanotubes.

Buried steel pipelines, in the presence of stray AC voltage may suffer external corrosion. Corrosion enhancement and corrosion potential shift due to the intrinsic nonlinear electrochemical properties are evaluated by digital simulations for different peak-voltages ΔE.