Resumo em Inglês:

Mangroves are highly productive ecosystems that support a diverse range of plant, animal, and microorganism species, especially fungi. This ecosystem is characterized as a transition zone between sea and land which is interesting because this environment can be considered an extreme environment due to the peculiar characteristics that it can exhibit, which is interesting for the establishment of diverse fungal species with great biotechnological potential, these habitats are relevant for the bioprospecting of interesting secondary-metabolite-producing fungi. Fungi play an essential role in maintaining this environment and also represent a rich source of structurally diverse antimicrobial compounds. This review summarizes antibacterial, antifungal, and antiviral chemicals produced by soil/sediment-derived mangrove fungi from 1990 to 2022.

Resumo em Inglês:

The reactivity and steric hindrance of optically active tertiary alcohols limit the development of more direct enantioselective methodologies for their synthesis, such as kinetic resolution (KR). In this work, we optimized the reaction conditions of an enzymatic KR of two tertiary benzyl bicyclic alcohols using readily available reagents and biocatalyst. Studies were conducted with 1-methyl-1,2,3,4-tetrahydronaphthalen-1-ol and 1-methyl-2,3-dihydro-1 H-inden-1-ol as substrates and commercial lipase A from Candida antarctica (CAL-A) as biocatalyst for the enantioselective transesterification of these racemic tertiary alcohols. After varying the reaction parameters, such as acyl donor, solvent, and enzyme/substrate ratio, the (R)-esters were obtained with high conversions (44-45%) and excellent enantiomeric excess (96-99%) in only 4-5 h, to our knowledge being the best result for KR of the evaluated tertiary alcohols in terms of reaction rate, conversion, and enantioselectivity reported so far.

Resumo em Inglês:

This study investigates the potential of Morita-Baylis-Hillman adducts derived from carvacrol as anticancer agents. The synthesis process, involving the reaction of aromatic aldehydes with carvacrol acrylate as a Michael acceptor, resulted in stable adducts with impressive yields ranging from 60 to 92%, achieved within a maximum reaction time of 24 h. Through a screening process utilizing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, compound 6, identified as the acrylate/2-naphthyl adduct, emerged as the most active within the series among twelve compounds tested. Specifically, compound 6 exhibited a remarkably potent impact on neuroblastoma cell lines, particularly SH-SY5Y cells, with half-maximal inhibitory concentration (IC50) of 8.7 µM after 72 h (42 times more potent than carvacrol, IC50 = 374.1 μM). The exploration of the selectivity index (SI) against normal cell lines demonstrated an outstanding SI of 4.28 compared to other compounds. Mechanistic studies on SH-SY5Y cells revealed a concentration-dependent apoptotic effect attributed to caspase 3/7 activation. In silico modeling showcased favorable pharmacokinetic properties for compound 6, including effective absorption after oral administration. Assessment of toxicity of compound 6 profile using brine shrimp and the Irwin test indicated low toxicity, highlighting its potential for future anticancer agent development.

Resumo em Inglês:

As one of the most important types of evidence at the scene of the crime, the rapid identification of the human bloodstain is of great significance to solve the criminal case. In this paper, the spectral data of different species of bloodstain samples including human, chicken and pig were acquired by using a hand-held near-infrared spectrometer. Then, the training models were established via convolutional neural network-support vector machine algorithm. Meanwhile, the traditional support vector machine, genetic algorithm-back propagation and random forest classification algorithms were also compared. The results showed that the prediction accuracy of convolutional neural network-support vector machine algorithm was the highest and the overall performance of the model was the best. The rapid detection method based on a handheld near-infrared spectrometer and convolutional neural network-support vector machine algorithm could identify the species of bloodstain efficiently, non-destructively, quickly and accurately and it provided a new technical reference for bloodstains detection and identification.

Resumo em Inglês:

New therapeutic options against leishmaniasis are necessary, especially those of natural origin, like licarin A, a neolignan with activity against Leishmania major. The effect of licarin A (DL01) and its derivatives (DL03, DL10, DL17 and DL21) was evaluated against Leishmania amazonensis promastigotes and intracellular amastigotes. Promastigote forms were assayed in different incubation periods and the 50% effective concentration (EC50) was determined. Cytotoxicity was assessed in murine peritoneal macrophages by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay to determine the 50.0% cytotoxicity concentrations (CC50). Anti-amastigote activity was evaluated through the effective concentration to amastigotes (EC50ama and EC90ama), and selectivity indexes (SI) were calculated. Lipophilicity (LogP) and mitochondrial membrane potential (∆Ψ) were analyzed. DL21 showed a significant anti-promastigote (EC50pro: 4.68 μM) and anti-amastigote (EC50ama and EC90ama: 0.42 and 15.91 μM, respectively) activity, and substantial SI (94.73) to amastigotes and an adequate Log P (5.54), while not changing ∆Ψ. DL21 is a promising drug candidate and further studies are necessary for better understanding licarin A mechanisms of action.

Resumo em Inglês:

This study investigates the interaction between calcium ions and glucosamine molecules (GlcN) gas-phase and the interaction of calcium ion with GlcN in the microsolvation environments using Car Parrinello molecular dynamics and density functional theory. Our findings reveal stable complexation between GlcN and calcium ions at various molecular sites in gas-phase and in the microsolvation environments. Furthermore, the Quantum Theory of Atoms in Molecules (QTAIM) analyses indicate a predominantly ionic character for all interactions in both gas-phase and microsolvation systems. The Natural Bond Orbital analyses demonstrate that the calcium ion serves as an electron acceptor, receiving lone pairs of electrons from oxygen and nitrogen atoms for its vacant orbitais. A comprehensive understanding of GlcN-calcium-water interactions at the molecular level can contribute to new research directions and applications for chitosan and its monomer, glucosamine, in the pharmacological domain.

Resumo em Inglês:

The extensive use of pesticides promoted the need for bioremediation methods, including for pyrethroids. Therefore, biodegradation of gamma-cyhalothrin by fungi from a Brazilian cave known as Gruta do Catão (São Desidério, Bahia, Brazil) was investigated. Experiments were conducted with Aspergillus ustus CBMAI 1894, Talaromyces brunneus CBMAI 1895, and Aspergillus sp. CBMAI 1926 in 2% malt liquid medium with 300 mg L-1 gamma-cyhalothrin (25 °C, 130 rpm, 21 days, pH 7.0). All strains biodegraded this insecticide, and the most efficient biocatalyst was A. ustus CBMAI 1894 with 50% biodegradation, even though reduced mycelial mass was observed in the presence of gamma-cyhalothrin. A three factor Box-Behnken design was carried out. Temperature and pesticide concentration influenced biodegradation, whereas pH was non-significant. In conclusion, cave fungi can be explored for bioremediation, and future studies should focus on understanding the enzymatic apparatus, physiology, and genetics behind these microorganisms, which can present unique properties for biotechnological applications.

Resumo em Inglês:

In this study, we describe a light-driven photocatalytic decarboxylation of palmitic acid and related fatty acids using Chlorella variabilis fatty acid photodecarboxylase (CvFAP). By utilizing violet light emitting diode (LED) light (50 W; 397 nm), we achieved a remarkable conversion efficiency of 99% within just 4 min, surpassing the previous 79% conversion achieved in 60 min using blue LED light (300 W; 439 nm). Importantly, the use of 50 W violet LED light also resulted in a lower enzyme photoinactivation rate when compared to 300 W blue LED. Comparing the whole-cell biocatalyst with the enzymatic extract, we found that the former demonstrated superior catalytic performance and reduced susceptibility to photoinactivation. Furthermore, whole-cell biocatalyst reuse was demonstrated after five sequential batches. Employing this approach, we successfully synthesized 26 mmol L-1 h-1 of pentadecane, showcasing a promising strategy to improve productivity. These findings represent a significant advancement in CvFAP photodecarboxylation processes compared to the literature, utilizing an alternative light source, with potential implications to the biofuel sector.

Resumo em Inglês:

Laser flash photolysis studies (λ = 355 nm) on the characterization and reactivity for the triplet excited state of 2-methoxythioxanthone, 2-benzyloxythioxanthone, and 2-(n-propoxy) thioxanthone revealed that the transients generated in their excitation, in acetonitrile, have absorption bands with maxima at 310 and 620 nm. These transients decayed by a mixed 1st and 2nd order kinetics, with a lifetime of 5.3 μs for 2-methoxythioxanthone and benzyloxythioxanthone and 3.9 μs for 2-(n-propoxy) thioxanthone. In methanol, ethanol, and 2-propanol, a new absorption at 430-460 nm was observed, which was attributed to their corresponding ketyl radical (the second-order quenching rate constant (kq) is ca. 105 L mol-1 s-1). The energy transfer rate constants for trans-stilbene, 1-methylnaphthalene, and 1,3-cyclohexadiene were diffusion-controlled, indicating a triplet energy for these alkoxy thioxanthones higher than 61 kcal mol-1. The quenching rate constant observed for 1,4-cyclohexadiene (ca.109 L mol-1 s-1) suggests that the lowest energy triplet excited state for these thioxanthones must have nπ* character. For phenols and indole (kq ca. 109 L mol-1 s-1), the reaction mechanism must involve the initial formation of a triplet exciplex, followed by a coupled electron/proton transfer. For triethylamine and 1,4-diazabicyclo[2.2.2]octane (kq ca. 109 L mol-1 s-1) it was observed the formation of the radical anion of the alkoxy thioxanthones formed from electron transfer (λ = 410 nm).

Resumo em Inglês:

This research explores the concentration of black carbon (BC) in particulate matter (PM10 and PM2.5) from ten monitoring stations in the Metropolitan Region of Rio de Janeiro (MRRJ), Bonsucesso (BS), Botafogo (BOT), Copacabana (COP), Gavea (GAV), Gericino (GER), Lagoa (LAG), Recreio dos Bandeirantes (REC), Santa Cruz (SC), Castelo (CAS) and Urca (URC), covering a range of pollution sources (vehicular, industrial, and residential). PM samples were collected using filter units every week from January 2018 to December 2019. Results revealed high concentrations of PM10 in BS (86 ± 22 µg m3) and PM2.5 in REC (30 ± 11 µg m3). Likewise, both monitoring stations exceeded the international limits. In 2019, BC in PM10 decreased in the following order: BS > CAS > GER > BOT > SC > GAV. For 2018, BC in PM2.5 decreased as follows REC > LAG > SC, while 2019 REC > GAV > LAG > COP > URC. REC and BS have industrial and commercial activities and intense vehicular traffic. During the period of study, average BC concentrations in PM10 and PM2.5 were 3.3 ± 1.5 and 1.9 ± 0.70 µg m3, respectively. These findings indicate that BC concentrations should be monitored and regulated in locations with high levels of traffic-related air pollution for offering new insights and guiding efforts to minimize emissions and enhance public health.

Resumo em Inglês:

Short-chain chiral esters are important constituents in natural fruit flavors, as well as in food and pharmaceutical industries. Different chemical and bio-catalytic routes are used for their synthesis, but the use of simultaneous techniques has not been much explored, as combinatorial synthesis and bio-catalysis in continuous-flow systems. Here, the objective was to synthesize chiral esters typically found in fruit flavors, to obtain chemical libraries with high conversion and enantiomeric excess, using combinations of these three techniques. Combinatorial synthesis in continuous-flow coil-type reactors with fix bed was used in the esterification of the secondary alcohols 2-butanol (1a), 2-pentanol (1b), 3-hexanol (1c), 2-heptanol (1d) and 2-octanol (1e) with acetic (2) and propanoic (3) acids. A surface-response method was applied to optimize the reaction conditions. Conversions were above 88% after 60 min for the reaction with chemical catalysts in continuous-flow reactors compared to 85%, but after 120 min, when conventional batch processes were used. By applying a biocatalyst, a chemical library of R acetates was prepared, with conversions over 48% after 48 h for batch and 40% after only 70 min for continuous flow reactions. It was observed that both enzymatic and homogeneous chemical catalysis showed to be viable for the chiral esters.

Resumo em Inglês:

This research aimed to compare the composition profiles of roasted Coffea canephora varieties (conilon, robusta, and intervarietal hybrids) grown in the Western Amazon. Ten coffees of each variety were evaluated. No difference in the contents of caffeine (1427 to 3364 mg 100 g 1) and kahweol (absence to 25.7 mg 100 g 1) was observed. Hybrid coffees were discriminated from traditional varieties (conilon and robusta) and stood out for their higher content of trigonelline, chlorogenic acids, and total diterpenes (mean values of 613,3791, and 471 mg 100 g 1, respectively), higher cafestol/kahweol ratio (7.6 to 15.0), and higher frequency of kahweol presence. Traditional varieties only differed in cafestol and 16-O-methylcafestol contents. Robusta coffees stood out for their lower cafestol content (116 mg 100 g 1), and conilon for their lower 16-O-methylcafestol content (139 mg 100 g 1). Differences between the traditional varieties are smaller than that observed among them and the intervarietal hybrid coffees.

Resumo em Inglês:

Schinus terebinthifolius Raddi (Anacardiaceae), commonly known as “pimenta rosa”, “aroeira da praia”, “aroeira”, “aroeirinha”, and “cabuí” is frequently used in traditional medicine to address various conditions, including skin wounds, ulcers, tumors, diarrhea, arthritis, as well as urinary and respiratory tract infections. This study aimed to develop and validate an analytical method using high-performance liquid chromatography with diode array detector (HPLC-DAD) for quantifying gallic acid (GA) in methanolic extracts of S. terebinthifolius leaves, branches, and fruits. The chromatographic separations utilized a reversed-phase Zorbax Eclipse XDB-C18 column with an isocratic elution mode of acetonitrile/methanol/water acidified with 0.2% formic acid. The flow rate was 0.8 mL min-1, and detection occurred at 254 nm. The developed HPLC-DAD method demonstrated selectivity, with a GA retention time of 5.263 min and absorption maxima at 220 and 271 nm. The method exhibited high linearity (coefficient of 0.9996), precision (relative standard deviation (RSD) values < 5%), and robustness. Accuracy ranged from 100.28 to 111.71%, with an average recovery of 105.41% and an average RSD of 3.46%. These validated results play a crucial role in assessing and standardizing raw materials containing S. terebinthifolius, emphasizing the reliability of the developed HPLC-DAD method for GA quantification in different plant parts.

Resumo em Inglês:

Annona tomentosa, popularly known as “araticum marolo”, is an Annonaceae with little scientific evidence regarding its phytochemistry and biological activities. Based on this, the present study carried out the chemical characterization of the methanolic extract and fractions of ethyl acetate and alkaloid of the stem bark of A. tomentosa, in addition to evaluating their influence on the viability, proliferation and migration of breast (MCF-7) cells in a three-dimensional (3D) model. The samples were analyzed by liquid chromatography tandem mass spectrometry (LC MS/MS), and the Global Natural Products Social Networking (GNPS) platform was used to construct a molecular network. 21 compounds were identified, of which 16 belong to the alkaloid class. Multicellular spheroids (MCTS) growth was reduced after 216 h of treatment, as well as their viability (ca. 50% for the extract and ca. 25% for the alkaloid fraction). The extract and the alkaloid fraction showed greater antiproliferative (at a concentration of 100 µg mL-1 after 216 h, ca. 48% for the extract and ca. 20% for the fraction) and antimigratory (at concentrations 50-500 µg mL-1 for the extract and 100-250 µg mL-1 for the fraction) effects. This study is pioneering in demonstrating the antitumor effects in a 3D culture model, also revealing its potential for the isolation of alkaloids.

Resumo em Inglês:

The structure of costunolide was modified before conducting the Cope rearrangement under thermal conditions. This modification was undertaken to block the highly reactive Michael acceptor α-methylene-γ-lactone, thus preventing side reactions at high temperatures. In this work, the reaction was performed under heating or microwave irradiation using costunolide, not its modified version. Rates of Cope reactions catalyzed by palladium(II) assisted by microwave were substantially enhanced. The rearrangements of costunolide to elemanolide, eudesmanolides, and germacranolide were catalyzed by palladium acetate, bis(benzonitrile)palladium dichloride, and a mixture of both organometallics. Rates of microwave promoted rearrangements of costunolide were six times faster than the reactions assisted by heating. The best success rate for elemanolide (7) was obtained using a mixture of Pd(OAc)2 and (NCPh)2PdCl2. In this case, compound 7 was obtained in a yield of 34%, while the other sesquiterpene lactones were formed only in trace amounts. The reaction products were isolated using semi-preparative high performance liquid chromatography and further purified through sequential analytical high performance liquid chromatography. Bioactivity profiles that used etiolated wheat coleoptiles were conducted for compounds 6, 7, and 9: The tested compounds presented very high phytotoxicity, with inhibition up to 97%.

Resumo em Inglês:

Accurate nanoparticle characterization is essential since it can significantly affect its physicochemical and biological properties. Among physicochemical properties used to characterize nanomaterials, size and size distribution are essential and should be assessed before surveying poisonousness or biocompatibility. Several methods are suitable to evaluate these characteristics including the dynamic light scattering. The aims of the present paper were to propose a methodology to measure nanoparticle size and present the estimation of the particle size uncertainty using the dynamic light scattering technique. The reliability of measurements was ensured by a series of handling precautions and quality criteria for good measurements to be applied for methodology validation using reference material polyvinylpyrrolidone coated silver nanoparticles. The identification and quantification of input quantities to the measurement uncertainties were estimated. The uncertainty concerning the equipment was 1.2% while the repeatability obtained was 1.4%, within the range of values stipulated in the reference standard (less than 5%). The relative standard uncertainties of trueness and repeatability were below the thresholds defined by the International Organization for Standardization. The result of the expanded uncertainty was 3.9% with 95% coverage probability for the reference material.

Resumo em Inglês:

Gamma radiation is an effective method for microbial decontamination of plant materials. However, this treatment can induce changes in the chemical structure of plant constituents. Stem barks of Luehea ochrophylla were exposed to different doses of gamma radiation to evaluate decontamination efficiency and changes in chemical composition of plant material including phenolic fraction. The major microbial contaminants of non-irradiated samples were isolated and identified as the fungal species Eurotium chevalieri L. Mangin and Lecythophora decumbens. The dose of 5.0 kGy was effective to achieve total decontamination of the stem barks of L. ochrophylla. The formation of free radicals was verified in the plant material using electron paramagnetic resonance spectroscopy, and was supposed to be related to the trans-aconitic acid, a plant constituent. It was the only secondary metabolite to have its concentration significantly altered with radiation in phenolic fraction, as observed by liquid chromatography with diode array detector coupled to mass spectroscopy (LC-DAD-MS). The trans-aconitic acid was isolated and exposed to gamma radiation in aqueous medium. Its concentration decreased after exposition to a dose of 3.0 kGy, corroborating the supposition of its degradation. Citric acid was the main radiolytic product formed by irradiation of trans-aconitic acid in the presence of water.

Resumo em Inglês:

Macroalgae contains micro and macromolecules of great interest for various sectors, for example, food, cosmetics, and pharmaceuticals. These compounds can be obtained through different extraction methods, among them the use of organic solvents with varying polarities. In this study, materials were characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy, infrared spectrometry, X-ray diffraction and differential scanning calorimetry in the seaweed biomasses before and after an extraction process with organic solvents. The red macroalgae Crassiphycus birdiae, cultivated on the northeast coast of Brazil, appeared, after extraction, as an amorphous material with some porosity. Its composition includes the elements carbon, oxygen, sodium, magnesium, sulfur, chlorine, potassium, aluminum, silicon, calcium, and iron. The presence of the agar polysaccharide was also verified by infrared spectroscopy. The decomposition of this polysaccharide was observed using differential scanning calorimetry.