Resumo em Inglês:

There is a growing body of research on the use of liquid fuels in fuel cells, including glycerol. The direct oxidation of glycerol in an abiotic (traditional, conventional) fuel cell can not only be used to produce electrical energy, but also to obtain high value-added products. Furthermore, recent experimental studies have employed glycerol in biological fuel cells, which could contribute to transforming the biodiesel industry. Bacterial cultures have been used to degrade glycerol to produce electricity, while enzymatic processes have also employed glycerol to produce electricity and products of interest. This way, the main aim of this review is to survey the principal factors influencing the use of conventional and biological (enzymatic and microbial) fuel cells. A summary of the reports found in the literature is provided concerning the selectivity towards adsorbed intermediates and products generated during the oxidation of glycerol in conventional fuel cells. Not only experimental but also model-based aspects are addressed. For biological fuel cells, an overview of the enzymes and microorganisms used is presented, in addition to addressing the specific electron transfer mechanisms and other relevant aspects (such as challenges and limiting parameters for function and performance).

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.

Resumo em Inglês:

The exploration of carbon steel corrosion inhibition in 0.5 mol L-1 H2SO4 using extracts from Hymenaea courbaril (HC) has resulted in significant findings. Extracts from the bark, leaves, fruit pulp, and fruit shell have all proven to be effective corrosion inhibitors, as demonstrated through surface studies and electrochemical methods. Infrared spectroscopy and high-performance liquid chromatography have identified the presence of phenolic compounds, which are known to have corrosion-inhibiting potential. UV-Vis spectroscopy has further revealed the adsorption of extract species on the steel surface. Electrochemical studies have confirmed the inhibition of corrosion, allowing to propose mechanisms of both chemisorption and physisorption. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) have provided evidence of the formation of an inhibitory layer, further supporting the inhibition of corrosion. Langmuir isotherms have indicated favorable adsorption of the extracts, while reduced surface roughness suggests improved protection of the steel surface. Activation energy calculations have demonstrated an increase in energy barriers, resulting in slower corrosion rates. These findings suggest that extracts from Hymenaea courbaril show promise as eco-friendly corrosion inhibitors, with potential industrial applications. Further research is needed to optimize the extraction process and fully understand the inhibition mechanisms.

Resumo em Inglês:

Chitosan (CS) blends with collagen (CL) and Aloe vera (AV) have gained significant attention in the biomedical field due to their biocompatibility, biodegradability, and potential for wound healing applications. In this study, we investigated the preparation and characterization of CS/CL and CS/AV blends using selective precipitation and co-precipitation techniques. The synthesis processes were analyzed for yield and 4-hydroxyproline content (in CS/CL blends). The materials were characterized using bromatological analyses, viscosity measurements, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). These eco-friendly methods effectively promoted interactions between the biopolymers, resulting in homogeneous blends with tunable properties. Besides, they are simple, fast, safe, and require minimal infrastructure. This study demonstrated that selective precipitation and co-precipitation are effective methods for producing chitosan/collagen and chitosan/Aloe vera blends. These methods foster interactions and miscibility between the biopolymers, as confirmed by FTIR, XRD, viscosity, and 4-Hy content analyses. They also align with green chemistry principles by avoiding organic solvents, reducing environmental risks, and minimizing waste. The high yields achieved, especially for CS/AV blends (exceeding 96%), make these materials compatible with lyophilization procedures. The absence of segregated phases after appropriate washing underscores their suitability for pharmaceutical formulations and other applications.

Resumo em Inglês:

We created a fast and effective thin-layer chromatography method to detect homoisoflavones in Polygonatum odoratum (Mill.) Druce (POD), demonstrating high sensitivity, specificity, and stability. Utilizing this method, we assessed the quality of 20 commercial batches of POD. Our results indicated that homoisoflavones (III, IV, and V) were present in 8 samples, absent in 7, and detected in 5. This method facilitates the effective evaluation of POD germplasm resources, laying a strong foundation for enhancing quality standards. This advancement aids in the standardization and quality control of POD, ensuring the consistency of its active ingredients and thereby supporting its therapeutic applications.

Resumo em Inglês:

We report the electrochemical potential of conductive filaments produced with recycled polylactic acid (rPLA) alongside a mixture of graphite (Gpt) and/or carbon black (CB) and castor oil to create an electrode ready-to-use. Additively-manufactured electrodes (AMEs) were compared with commercial-conductive filament composed of PLA and CB. The Gpt-CB-rPLA and CB-rPLA sensors showed lower charge-transfer resistance (Rct) and a greater heterogenous rate constant, k0, (Rct= 1040 ± 50 Ω and 1810 ± 30 Ω and k0= 6.91 (± 0.58) × 103 and 5.31 (± 0.40) × 103 cm s-1, respectively) compared to the sensor from the commercial filament (Rct = 9620 ± 280 Ω and k0 = 3.62 (± 0.38) ×10-3 cm s-1). The electrochemical response of [Fe(CN6)]3-/4- displayed a peak-to-peak separation of 180 ± 8 mV (Gpt-CB-rPLA) and 240 ± 6 mV (CB-rPLA) compared to commercial AME (740 ±10 mV), without any surface treatment. The filaments were used to create a 2,4,6-trinitrotoluene (TNT) detection platform with linear range of 5-20 and 5-100 µmol L-1 for Gpt-CB-rPLA and CB-rPLA, respectively. The collector-detector device was applied for the analysis of a blast simulation. Finally, it is worth noting that the results obtained are without electrode treatment/activation, indicating that the rough surface of the additively manufactured electrode is an additional feature of the device for collecting explosive residues, simply by rubbing the additively manufactured platform on different surfaces in crime scenarios.

Resumo em Inglês:

Food contamination is a public health problem, and the search for natural additives to increase food stability and safety is challenging. This research aimed to study nanoemulsions produced with coriander essential oil and kefiran, an exopolysaccharide extracted from kefir grains. The composition of coriander essential oil was evaluated, revealing linalool as the main component. An experimental design consisting of six trials was conducted. The NE2 formulation (0.5% kefiran and 1.5% coriander essential oil) exhibited smaller particle size, monodispersity, a lower centrifugal stability coefficient, and higher absolute zeta potential values (> 30 mV), indicating high electrical stability. Morphology, thermal stability, and toxicity tests were performed. The minimum bactericidal concentration was determined and applied to commercial cheese. Thermal stability tests demonstrated an increase in the stability of NE2 compared to its individual components, and it was also proven to be non-toxic. The concentration of 25% m v-1 was identified as the minimum bactericidal concentration and was applied to commercial cheese.

Resumo em Inglês:

This study evaluated the potential of naphthoxazoles derived from lapachol as fluorescent deoxyribonucleic acid (DNA) probes. We synthesized three 2-substituted naphthoxazoles: one with a phenyl group (LOX1), and two with 2-hydroxyphenyl (LOX2) and 4-fluorophenyl (LOX3) groups, respectively. The compounds were synthesized using the Debus-Radziszewski reaction between the lapachol and aldehydes. The quantum yield (Φf) was determined using the classical relative method with 4’,6-diamidino-2-phenylindole (DAPI) as the standard, and the fluorescence lifetime (τf) was measured with a lifetime fluorescence spectrometer. The naphthoxazoles exhibited low fluorescence emission and consequently low values of Φf in their free form, demonstrating behavior similar to that of DAPI. These compounds displayed notably large Stokes shifts (approximately 340 nm) and the τf in the nanosecond range. DNA binding studies were conducted by monitoring changes in the absorption properties of naphthoxazoles in the absence and presence of calf thymus DNA at different concentrations. The results indicated that naphthoxazoles interacted with DNA through groove binding. LOX2 exhibited a binding constant (Kb) of 2.70 × 104 M-1, indicating strong binding to the biomolecule. These findings underscore the potential of LOX1, LOX2, and LOX3 as candidates for use as fluorescent DNA probes.

Resumo em Inglês:

Considering the cytotoxic properties of Schiff base ligands, we re-synthesized a gold(III) complex with a tetradentate Schiff base ligand and investigated its cytotoxic effects using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method and sulforhodamine B staining method. The results showed that the gold(III) Schiff base complex can inhibit the growth of Chinese hamster ovary (CHO) cancer cell lines. However, unlike cisplatin, it does not induce cell death in NIH 3T3 normal cells. Real-time polymerase chain reaction (PCR) results revealed that the gold(III) Schiff base complex increased the Bak1/Bclx ratio in CHO cell line by 3.53-fold compared to the control, while cisplatin increased the anti-apoptotic Bclx gene by 31.8 times and the treatment resistance AKT1 gene by 430.8 times the control. However, cisplatin only activated the extrinsic pathway of apoptosis through the caspase-3 gene. The expression levels of TLR6 and TNF-α genes in normal cells showed that both the gold(III) Schiff base complex and cisplatin did not cause inflammation in NIH 3T3 cell lines. All the results indicate that the new complex could be a promising candidate to replace cisplatin. It has been shown that it induces apoptosis and prevents the development of resistance in cancer cells. Additionally, it does not cause inflammation in normal cells.

Resumo em Inglês:

In this study, it was investigated chitosan (CHIT) films in the presence or absence of cellulose nanofibers (CNF) and silver nanoparticles (AgNP), whose chemical interactions involving metallic surfaces were characterized by surface-enhanced Raman scattering (SERS) spectroscopy. Changes in the morphology were analyzed through atomic force microscopy (AFM) and scanning electron microscopy (SEM). SEM and AFM micrographs revealed that the incorporation of CNF significantly altered CHIT films, leading to changes in the polymer topography and surface texture due to intimal interactions between CNF and the CHIT matrix. Raman spectra of CHIT and CNF/CHIT films showed similar profiles, reflecting comparable molecular structures of both modified biopolymers. However, SERS spectra of both films, after recovering with AgNP, demonstrated distinct spectral profiles. Innovatively, density functional theory (DFT) calculations of an oligomer model for CHIT were employed to assign the vibrational modes observed in the SERS spectra, which allowed identify key interactions between CHIT moieties and AgNP surfaces. SERS results revealed that chemical adsorption of CHIT on AgNP surfaces occurs through interactions of glycosidic oxygen and amino groups. Such findings provide insights into the structural and chemical behavior of this nanocomposite, highlighting its potential for advanced biological applications.

Resumo em Inglês:

With the increase in life expectancy and the significant incidence of lesions of the musculoskeletal system, both the public and private sectors seek improvements in their products and processes in order to contribute to the health of the population. Every year tons of chicken eggshell (CES) from domestic consumption are released in environment and the present work aims the production of a synthetic ceramic bone substitute using the eggshell as a source of calcium ions. According to the methodology, 5, 10, 15 and 20 mol% of iron ions were used and the characterization assays demonstrated the formation of a double calcium iron phosphate - Ca9Fe(PO4)7. MG63 cells were cultured on test specimens to cell viability assay and to each doped group analyzed, verifying cell compatibility with the studied compounds, as well as a good adhesion profile. Scanning electron microscopy (SEM) of the cells showed that material surface favored cell adhesion and the results demonstrated that the production of the compounds were viable to Ca9Fe(PO4)7 phase. So, in the future, it will be possible to have a final comprehensive biological compatibility of the prototype for further in vitro and in vivo assays.

Resumo em Inglês:

Worldwide, millions of people suffer from neurological and psychiatric conditions, such as schizophrenia, depression, and neurodegenerative diseases. These conditions are often linked to hyperactivity of monoamine oxidase B (MAO-B) in the brain, and inhibiting this enzyme can reduce oxidative stress, stabilize neurotransmitter levels, and alleviate symptoms. In this context, a pharmacophoric model was created using PharmaGist with 31 hits extracted from BindingDB to enable a pharmacophoric-based search of potential MAO-B inhibitors in ZincPharmer’s chemical space, followed by the building of 10 conformers for each molecule in the software OMEGA, screening for structural and electrostatic similarity to safinamide using ROCS (Rapid overlay of chemical structures) and EON (Electrostatic similarity for lead-hopping), respectively. In addition, the molecular docking with Gold using the score function was performed to rank the ligands with the highest probabilities of affinity to MAO-B and then discriminate those with suitable physical chemical, pharmacokinetic, and toxicological features using the tools QikProp, SwissADME, and DEREK. Four potential ligands with selective MAO-B inhibitor properties were identified, which show promise as future therapeutic agents for MAO-B-related disorders.

Resumo em Inglês:

Citronellyl esters present broad applications in the cosmetic, pharmaceutical, and food industries due to their organoleptic and biological properties. Lipase-catalyzed acylation of citronellol has been a suitable way to obtain these natural esters on a high scale. This work describes the lipase-catalyzed acylation of citronellol through esterification and transesterification with linear acylating agents (C3-C18) using Novozym®435 as a biocatalyst. The results show that all esters achieved not less than 91% conversion from an esterification model, showing a good reaction profile. Citronellyl propionate and laurate were selected for study in a transesterification reaction model, and it resulted in a lower reaction time for ester conversions. As an example, we highlight citronellyl propionate production, which approximately 10 g L-1 of the product was obtained after 1.5 h of esterification compared to 2 min by transesterification. The final esters were purified with high purity (≥ 90%) and identified by gas chromatography-mass spectrometry (GC-MS), and their structures were elucidated by 1H and 13C nuclear magnetic resonance (NMR). Enzyme recycling was evaluated and Novozym®435 was able to be applied for at least 20 cycles. Results demonstrated the efficiency of acylation reactions catalyzed by this enzyme and showed the potential of the methodology for the production and purification of flavor esters.

Resumo em Inglês:

2,5-Diketopiperazines (2,5-DKPs) are valued in Medicinal Chemistry for their diverse properties and are considered privileged structures. The natural alkaloids class of fumiquinazolines, combining 2,5-DKP and quinazolinone cores within a pyrazino[1,2-b]quinazoline-3,6-dione framework, is known for its broad biological activity. Although few synthetic approaches to such structures have been explored, this study focuses on synthesizing novel fumiquinazolines analogs featuring a pyrazinopyrido[2,3-d]pyrimidine-5,7-dione core bearing various substituents on the pyrazine moiety (C-6 and C-9), classified into three series (A, B, and C). To investigate an efficient sequential one-pot method, we used a pyridine precursor and L-amino acids in two condensation and cyclization reactions, under controlled microwave irradiations at lower temperatures than previously reported. This approach generated protected bicyclic intermediates, particularly pyrido[2,3-d]pyrimidin-4(3H)-one derivatives, which were smoothly deprotected, allowing for final intramolecular cyclization to yield disubstituted fumiquinazoline analogs (series A) without observed epimerization. The optimized protocol revealed greater efficiency for monosubstituted analogs (series B and C), speeding up the tricyclic products synthesis without the need for intermediates isolation and deprotection. Overall, this study demonstrates the incorporation of diverse protected amino acids, featuring different electronic and structural side chains, via a rapid and effective sequential one-pot strategy, resulting in the synthesis of 19 novel fumiquinazoline analogs.

Resumo em Inglês:

Human milk (HM) is recognized as an ideal nutritional source to meet the developmental needs of babies. However, a significant portion does not meet quality standards for immediate consumption, rendering it an interesting raw material for the production of by-products. This study aimed to evaluate the lipid composition and cytokines interleukin-10 (IL-10) and transforming growth factor-beta 1 (TGF-β1) in ice cream containing HM. Three formulations were developed: F1 with 93.46% HM, F2 with 46.73% cows’ milk and 46.73% HM, and F3 with 46.73% infant formula and 46.73% HM. Fatty acids (FA) and their nutritional quality, the triacylglycerol (TAG) profile, and the concentrations of cytokines IL-10 and TGF-β1 were analyzed. F1 and F3 exhibited the highest concentrations of essential FAs (18:2n-6 and 18:3n-3) compared to F2. This trend extended to eicosapentaenoic acid + docosahexaenoic acid, with higher values in F1 (10.62 ± 0.26) and F3 (11.16 ± 0.28) versus F2 (3.67 ± 0.18). Both cytokines IL-10 and TGF-β1, present in the ice creams, experienced a decrease in concentration due to the processing of the raw materials. Therefore, ice creams produced with HM have promising potential, making them recommended for use, providing a new destination for waste, and creating a novel product that can be used as a complementary food.

Resumo em Inglês:

A simple, low-cost, and rapid analytical method for determination of the total phenolic content (TPC) in extra virgin olive oil samples (EVOOs) was developed, using digital images as an analytical tool. The method is based on an optimized Folin-Ciocalteu (F-C) colorimetric reaction, followed by digital image acquisition using a smartphone and processing with ImageJ® software to obtain red, green, and blue (RGB) values. The method was successfully validated, with recoveries between 73.11 and 112.65%, limits of detection (LOD) and quantification (LOQ) of 0.41 and 1.38 mg L-1, respectively. The TPC determined for eight EVOOs from different regions of the world were in the range of 186.38 to 378.87 mg gallic acid equivalent (GAE) kg-1, in accordance with some values reported in the literature. Statistical tests confirmed agreement between the results obtained using the digital image method and a reference method employing UV-Vis spectroscopy. The method complies with the principles of green chemistry, with reductions of cost, solvent use, and analysis time.

Resumo em Inglês:

The spread of antibiotic-resistant pathogens had motivated the search for plant-derived antimicrobial agents, such as essential oils. This work investigated the antibacterial, antifungal and antibiofilm properties of the essential oil from the inflorescence of Etlingera elatior and its major compounds. Dodecanal (42.46%) and 1-dodecanol (25.84%) were the major compounds. The oil, dodecanal and 1-dodecanol were active against Staphylococcus aureus, with minimum bactericidal concentrations of 124, 31 and 62 µg mL-1, respectively. For Pseudomonas aeruginosa, the essential oil had an inhibitory effect against a multidrug resistant isolate (minimum inhibitory concentration (MIC): 4,000 µg mL-1). Dodecanal had an MIC of 60,000 µg mL-1 for all Candida species, but fungicidal activity was only detected for Candida albicans (minimum fungicidal concentration: 60,000 µg mL-1). 1-Dodecanol (60,000 µg mL-1) exhibited fungistatic activity for C. albicans. Biofilm inhibition linked to an anti-adhesive effect of the oil and dodecanal was only detected for the standard S. aureus isolate and C. albicans, respectively. In conclusion, the essential oil from the inflorescence of E. elatior and its major components were more active against nonresistant strains S. aureus. Essential oil, dodecanol and dodecanal showed excellent activity against S. aureus, however, these same materials showed low activity against P. aeruginosa.

Resumo em Inglês:

In this study, we report the synthesis of acridone derivatives and their potential as photosystem II (PSII) inhibitors, as well as their preand post-emergence herbicidal activities through chlorophyll a fluorescence and germination assays. Among the compounds tested for PSII activity, acridin-9(10H)-one showed the most promising results, reducing the performance index on an absorption basis and decreasing the quantum yield for electron transport compared to the control. These findings suggest an inhibitory effect on PSII within the electron transport chain. Additionally, 2-chloroacridin-9(10H)-one and 9(10H)-acridone-4-carboxylic acid exhibited post-emergence herbicidal activity against Amaranthus lividus and Amaranthus viridis weeds, respectively, leading to a reduction in radicle and hypocotyl lengths. Furthermore, we applied a molecular docking approach with the D1 protein and 4-hydroxyphenylpyruvate dioxygenase to investigate the structure-activity relationships among the acridone derivatives with these enzymes. The analysis highlighted the importance of the carbonyl group and aromatic substituents on the acridone scaffold facilitating ligand interactions, especially through hydrogen bonding. Consequently, our research group aims to optimize these molecular features to develop new, potent bioactive molecular scaffolds.

Resumo em Inglês:

This work describes the synthesis of two poly(lactic acid)-b-poly(ethylene glycol) copolymers (PLA-b-PEG), one containing folic acid, a targeting ligand, and the other containing fluorescein, a marker, both important in drug delivery systems. The copolymerization was carried out using the Ugi multicomponent reaction, which is a one pot reaction that involves the condensation of four components, an aldehyde or ketone, an amine, a carboxylic acid and an isocyanide. For this, poly(lactic acid) was functionalized with an aldehyde group (PLA-CHO) and poly(ethylene glycol) with an amine (PEG-NH2) and a carboxylic acid group (PEG-COOH), to be used in the Ugi reactions. From Fourier transform infrared spectroscopy (FTIR), hydrogen nuclear magnetic resonance (1H NMR) and ultraviolet-visible (UV-Vis) analyses, it was possible to confirm the synthesis of the block copolymers, in addition to the presence of both folic acid and fluorescein in the chemical structure of the materials. The work demonstrates that the Ugi reaction is an effective method to obtaining copolymers with different functionalities, and these materials have the potential to prepare micro and nanoparticles to be used in the controlled release of drugs.