Resumo em Inglês:

The present study analyzed the chemical composition and phytotoxic activity of Artemisia lancea essential oil (EO). Gas chromatography-mass spectrometry (GC-MS) results showed the presence of 55 compounds, representing 82.36% of the entire EO, with eucalyptol (18.7%) being the most abundant constituent. Phytotoxic bioassay results indicated that the EO (concentration ranging from 0.25-5 mg mL−1) inhibited the growth of Amaranthus retroflexus and Setaria viridis. Root length of A. retroflexus and S. viridis were reduced with the increasing concentration of the EO, especially when the EO was applied at 1-5 mg mL−1. When treated with 1-5 mg mL−1 EO, shoot length of A. retroflexus and S. viridis were also significantly suppressed. The half maximal inhibitory concentration (IC50) values for inhibiting root and shoot growth of A. retroflexus by the EO were 0.284 and 0.246 mg mL−1; for S. viridis, the EO showed IC50 values of 0.44 and 0.262 mg mL−1 for root and shoot inhibition, respectively. The most promising findings were observed when A. lancea EO concentration reached 1 mg mL−1 and higher, which completely inhibited seed germination of A. retroflexus and S. viridis. These findings suggest A. lancea EO has potential as an eco-friendly bioherbicide for agricultural weed control.

Resumo em Inglês:

The rapid advance of nanotechnology has led to the proliferation of a wide range of water-soluble nanomaterials and therefore, a profound impact on the environment, underscoring the need to devise effective methods for isolating and confining these nanomaterials. This study presents the development of a highly effective system capable of removing and storing gold nanoparticles in solution using modified resins with different linking groups, such as tris(2-aminoethyl) amine, 3-mercaptopropionic acid, 11-mercaptoundecanoic acid, and L-cysteine. The catalytic properties of the resins functionalized with the thiol group containing gold nanoparticles were evaluated, using the reduction of the nitro compounds (3,5-dinitrosalicylic acid, 4-nitroguaiacol and 4-nitroaniline) as model reaction. Solid-phase organic synthesis was employed to prepare the modified resins and their interaction with gold nanoparticles was characterized using infrared spectroscopy, thermogravimetric analysis, field emission scanning electron microscopy-energy dispersive spectroscopy, and X-ray photoelectron spectroscopy. The removal capacity of the resins was evaluated using ultraviolet-visible optical emission spectroscopy and inductively coupled plasma techniques. Ultraviolet-visible technique was suitable to assess the catalytic properties of the functionalized resins containing gold nanoparticles. It was determined that the functionalized resins showed remarkable capacity for complex gold nanoparticles, removing them from the solution. The most significant removal was with 11-mercaptoundecanoic acid.

Resumo em Inglês:

In order to extract hesperidin from Citrus aurantium L. through green and efficient ways, a novel method based on deep eutectic solvent (DES) assisted extraction has been developed. Compared to known alkali extraction and acid precipitation or organic solvent (ethanol, methanol) extraction, this new DES system of choline chloride/diethanolamine (DES-14) method exhibited excellent extraction efficiency for hesperidin. Under optimal conditions, the extraction yield of hesperidin reached 6.26 ± 0.05%. Further studies with infrared spectroscopy, 1H nuclear magnetic resonance, and density functional theory showed the DES-14 was formed mainly through the interaction of H-bond and van der Waals forces. In addition, scanning electron microscopy and density functional theory revealed the strong dissolving capacity, and the H-bond formation between DES-14 and hesperidin, as well as van der Waals forces all contributed to efficient extraction of hesperidin. The results provide a new strategy for efficient extraction and utilization of hesperidin in Citrus.

Resumo em Inglês:

Acetic acid bacteria (AAB) are versatile organisms that catalyze the conversion of a wide range of carbon sources into biomolecules of great industrial interest. In this study, we exploited the ability of Gluconobacter spp. to synthesize levans. Among the isolated strains, Gluconobacter cerinus UELBM11 produced approximately 14.0 g L−1 of levan under non-optimized conditions. Gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared spectroscopy (FTIR), and nuclear magnetic resonance (NMR) analyses confirmed that levan obtained from G. cerinus UELBM11 consisted of a β-(2→6)-D-fructose backbone with some β-(2→1) ramifications. The average molecular weight (Mw) of the purified levan was 8.78 × 105 Da. Thermogravimetric/differential thermogravimetric (TGA/DTG) analysis indicated high thermal stability, with the maximum decomposition rate observed at 227.44 °C. Scanning electron microscopy (SEM) revealed a microporous morphology, and the antioxidant activity assays demonstrated that levan had a high scavenging capacity of 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and hydroxyl radicals. Therefore, it has been demonstrated the levan produced by G. cerinus UELBM11 is a promising natural antioxidant and, owing to its microporosity and excellent thermal properties and stability, is a potential candidate as an additive in cosmetics, pharmaceuticals, and food products.

Resumo em Inglês:

Novel nanocomposites synthesized with pollen grain, as a precursor, were tested for CO2 adsorption performance. The pollen-derived carbons were obtained by direct calcination (PC), calcination followed by KOH-chemical activation (PCKOH), and MgO incorporation using high-energy ball-milling (PC-MgO and PCKOH-MgO). All the as-prepared materials were texturally, morphologically and structurally characterized by N2 physisorption, scanning electron microscopy (SEM-EDS) and X-ray diffraction (XRD); CO2 adsorption/desorption was measured by thermogravimetry. The four materials were able to adsorb CO2 at 30 ºC and 1 bar, but PCKOH-MgO, with the high surface area (12.4 m2 g-1), total pore volume of (0.13 cm3 g-1) and microporosity, was the best (2.06 mmol g-1 and percentage of adsorption (Qad) = 9.06%, at 1 bar). This result is due to the synergic effect of both synthesis methods. Neither temperature (from 30 to 100 ºC), nor pressure (from 1 to 15 bar), improved the adsorption process of PCKOH-MgO. CO2 desorption times at 300 ºC were 47 min for PCKOH-MgO and 30 min for the other adsorbents, showing the possibility of cycling. Based on the obtained results, the PCKOH-MgO activated carbon nanocomposite stands as a promising adsorbent to be potentially used for industrial CO2 capture applications and to contribute to long-term solutions to avoid dangerous climate-change and reduce CO2 emissions.

Resumo em Inglês:

Lisdexamfetamine is a prodrug that is converted to d-amphetamine in the body, mainly used to treat attention deficit hyperactivity disorder in children and adults. Its mechanism involves the enhancement of neurotransmitters such as norepinephrine and dopamine, which are critical for attention and behavioral regulation. With the upcoming patent expiration of Vyvanse®, bioanalytical methods for the quantification of lisdexamfetamine in plasma are needed for use in pharmacokinetic studies. In this work, we developed and validated a sensitive bioanalytical method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for lisdexamfetamine quantification in human plasma. The method developed was performed for 4 min per sample and using the concentration range of 0.3-100 ng mL-1. Intra-batch, inter-batch and instrument reproducibility, the precision was lower than 10%. The results demonstrated that the method is rapid, sensitive, robust, and suitable for pharmacokinetic studies.

Resumo em Inglês:

This study expands and shows the versatility of applications in hydrophilic interaction chromatography coupled with triple quadrupole mass spectrometry (HILIC-MS/MS) using a FRULIC-N column to determine 31 phenolic compounds in beverage industry residues (coffee, apple juice, beer, and wine). Optimization, via Doehlert design, determined the acetonitrile proportion (50-90%) and pH (3.0-7.0) in the mobile phase (MP). A 22 factorial design assessed the concentration of ammonium acetate (10-110 mmol L-1) in the MP and column temperature (20-60 °C). Injection volume (5-45 µL) was univariately optimized. Separations at 60 °C reduced chromatographic run time to less than 11 min. Gradient elution (500 µL min-1) employed an MP comprising acetonitrile and ammonium acetate (110 mmol L-1, pH 7). Validation demonstrated average coefficient of determination (R2) 0.9707, limit of detection 0.001-0.503 mg L-1 and quantification 0.004-1.524 mg L-1, precision < 12.2%, recovery 92.4-110.8%. The method was applied to five residues, indicating its viability for determining phenolics in beverage production residues.