Resumo em Inglês:

Circular chemistry (CC) is an approach for establishing chemical processes to become truly circular and sustainable. It adopts the principles of circular economy (CE), employing life cycle approaches and systems thinking, which help to understand and address the sustainability issues of chemical processes and products. Within this whole context, it is possible to identify some problems of the current lifestyle, such as plastic waste disposal, CO2 emission, e-waste, among others, which need to be addressed accordingly. The reuse provided, well-structured within the context of circular chemistry, can bring benefits in all spheres: social, environmental and economic. Thus, the purpose of this revision is to present CE and CC as the pillars for a sustainable development, bringing discussions about: CE and CC systems; sustainable chemistry; and chemistry 4.0, which embeds digitization, sustainability, and circular economy in industrial chemical processes. Through the knowledge of chemistry, both CC and CE can contribute with innovative methods and processes which maximize benefits, eliminating, or, at least, reducing adverse impacts, thus contributing to construct a mutually beneficial relationship between science and society, its surroundings, and the environment. Therefore, implementing this new model is an opportunity that challenges the human imagination in building a better world.

Resumo em Inglês:

The genus Bacillus is Gram-positive, anaerobic or aerobic facultative bacteria, often described to be associated with the mangrove rhizosphere. Secondary products of their metabolism, coming from places affected by pollution and environmental stresses, such as mangroves, have been attracting interest from the biotechnological point of view. In view of this scenario, this work analyzed the ethyl acetate extracts of the cultured Bacillus species, previously isolated from mangroves located in the state of Sergipe, Brazil. Chromatographic profiles of seven bacterial isolates collected from two different mangroves were analyzed using gas chromatography/mass spectrometry (GC-MS) and many important compounds of biotechnological interests, mainly those derived from azo-aromatic compounds such as pyrazines, pyrrolo-pyrazines, and piperazinediones, were detected. This study is one of the first, in our knowledge, prospecting volatile or semi volatile organic compounds from ethyl acetate extracts produced by bacteria isolated from the mangroves, and intents to increase the interest in this coastal ecosystem as a source of compounds with biotechnological applications.

Resumo em Inglês:

Genus Maytenus (Celastraceae) has proved to be a good source of new bioactive sesquiterpene pyridine alkaloids. Maytenus royleanus is a medicinal plant used in folk medicine for different ailments in a variety of ways around the world. Investigation of the roots of M. royleanus resulted in the isolation of an undescribed antitumor sesquiterpene pyridine alkaloid: Royleanine A (1). Its structure was established by analysis of spectroscopic data and comparison with reported data. Royleanine A (1) was evaluated for its antitumor potential against several cancer cell lines and was found to be significantly active against OVC-5 cells (ovarian cancer cell line) with half maximal inhibitory concentration (IC50) 28.9 µg mL-1, cervical (Hela) IC50 0.064 µg mL-1 and prostate (PC 3) cancer lines with 0.034 µg mL-1.

Resumo em Inglês:

We addressed some physicochemical and biological differences in commercial turmeric, acquired from both handling pharmacies and stores selling natural products for quality assessment. For this, it was determined the melting point, antioxidant activity by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), antimicrobial activity via the agar disk-diffusion assay, metallic contaminants by X-ray fluorescence with energy dispersion (EDXRF), spectral behaviors by Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) and determination of curcumin concentration by UV-Vis. The results obtained of the several commercial turmeric samples were not homogeneous, showing in fact significant differences regarding melting points, UV-Vis spectral scan profiles, and FTIR spectra, presenting toxic metals and quite low curcumin contents. This sheds light on the urge to implement adequate quality control in this type of raw material for human safe use of curcumin. Particularly, contamination with heavy metals, such as mercury, is a serious health problem, due to its high toxicity and accumulative power in the body.

Resumo em Inglês:

Biochar from slow pyrolysis under controlled conditions is favorable in the transformation of waste into materials that serve as soil conditioners, and/or environmental remediation. Thus, this work aimed to produce and characterize biochar from cassava waste under different temperature conditions and evaluate interactions with Ca2+ and Pb2+ for agricultural and environmental applications. To investigate the efficiency of the interaction of biochar with nutrients (Ca) and contaminants (Pb), the influence of pH and contact time were evaluated. There was an increase in pH, pHzpc (zero point charge), and condensed aromatic structures in BC, due to the increase in pyrolysis temperature. Also, biochar demonstrated a Pb2+ adsorbed amount of 2.03 to 2.37 mg g-1 and a Ca2+ release capacity of 0.655 to 0.765 mg g-1. In this way, biochar produced from residues of cassava waste can be a viable strategy to enhance agricultural production and reduce environmental contaminants.

Resumo em Inglês:

This study evaluated the chemical composition, antioxidant and anticholinesterase activities, and the toxicity of hydroethanolic extracts of the Parkia platycephala Benth. Hot extraction with 70% hydroethanolic solution was used to obtain crude extracts of the leaf (LE), bark (BE), flower (FE), and seed (SE). Separation and identification of the compounds were performed by liquid chromatography with diode array detection and gas chromatography coupled with mass spectrometry. Antioxidant and anticholinesterase activities were performed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and Ellman methods, respectively, and the preliminary toxicity by the method with Artemia salina. Chromatography analysis indicated naringin, kaempferol, stigmasterol, and β-sitosterol in all extracts. Gallic acid is prominent in the LE and FE, while ferulic acid is abundant in the BE and lupeol and lupeol acetate are prominent in the SE. The BE antioxidant activity (lethal concentration of 50% (IC50) = 14.72 ± 0.13 µg mL-1) is equivalent to the standard rutin (IC50 = 15.85 ± 0.08 µg mL-1). The SE had the best acetylcholinesterase inhibition potential (IC50 = 5.73 ± 0.68 µg mL-1). Aside from the SE, which is not toxic, the other extracts had low (LE, FE) and moderate (BE) toxicity. The extracts of P. platycephala have potential antioxidant and therapeutic uses, especially against Alzheimer’s disease.

Resumo em Inglês:

Black mold, a disease caused by the fungus Pilgeriella anacardii Arx & Müller, affects cashews (Anacardium occidentale). Some cashew clones are more resistant to the pathogen; however, little is known about the chemical profile responsible for this trait. The investigation of volatile organic compounds (VOCs) from leaves of dwarf cashew clones resistant (BRS 226 and BRS 265) and susceptible (CCP 76 and BRS 189) to the pathogen was carried out. Leaves were collected during the months of disease incidence and decline (March to July 2019, Brazil), and VOCs were analyzed by gas chromatography-mass spectrometry (GC-MS) combined with chemometric tools. The GC-MS analysis tentatively identified 96 compounds. Partial least squares discriminant analysis (PLS-DA), orthogonal partial least squares discriminant analysis (OPLS DA), hierarchical cluster analysis (HCA), and ROC curves analysis were useful in dividing VOCs into distinct resistance and associated chemical susceptibility groups for different clones. The VOCs in the leaves of the resistant clones were identified as alcohols and aldehydes containing six carbons: (E)-hex-2-enal, hex-3-en-1-ol, (Z)-hex-2-en-1-ol, (E)-hex-2-en-1-ol, and hexan-1-ol. Moreover, α-pinene, pseudolimonene, α-phellandrene, β-myrcene, sylvestrene, β-cis-ocimene, methyl salicylate, myrtenol, α-copaene, γ-muurolene, germacrene D, valencene, and germacrene B were also detected in these samples and may be candidate chemical biomarkers for cashew resistance to P. anacardii.

Resumo em Inglês:

In this study, we evaluated the catalytic properties of hydroxyapatite (HA) nanoparticles (NPs) doped with Fe3O4/γ-Fe2O3 for the degradation of methylene blue (MB) dye using a photo-Fenton process at pH 2.5, 7.0, and 9.0. The HA NPs were characterized using X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectrometry, Raman spectroscopy, thermogravimetric analysis, fluorescence spectrometry, and point of zero charge experiments. Upon using unmodified HA NPs, 1.33 mL of H2O2 30% (v/v), and ultraviolet radiation (125 W Hg lamp), the discoloration values achieved at pH 2.5, 7.0, and 9.0 were 88.4, 44.8, and 58.1%, respectively. For the HA NPs modified with Fe3O4/γ-Fe2O3, the composition Ca2.5FeII2.5FeIII5(PO4)6(OH)2 yielded the best results during the photo-Fenton-based process, and discolorations of 100, 100, and 95.2% were achieved at pH 2.5, 7.0, and 9.0, respectively. To confirm the effectiveness of the Ca2.5FeII2.5FeIII5(PO4)6(OH)2 NPs, the total organic carbon (TOC) and toxicity effects on Lactuca sativa L. were evaluated, and reproducibility tests were performed. The TOC removal of the Ca2.5FeII2.5FeIII5(PO4)6(OH)2 NPs was ca. 90% and the toxicity of the MB dye was eliminated after 120 min of reaction; moreover, the NPs retained their physical stability and activity and were reused for 11 consecutive degradation experiments.

Resumo em Inglês:

Passion fruit woodiness disease, caused by the Cowpea aphid-borne mosaic virus (CABMV), is one of the leading phytosanitary challenges of passion fruit production. Passiflora cincinnata has been recognized for its potential in genetic improvement due to its highest resistance to CABMV and other phytopathogens. Metabolomic and histological alterations of P. cincinnata infected with CABMV were evaluated and searched for differential responses during the asymptomatic or symptomatic infection phases to correlate them with the mechanisms of metabolic defense. The metabolites of infected plants were analyzed by liquid chromatography-mass spectrometry. Based on the metabolomic profile, the times of infection were grouped into early or late infection phases. The metabolites related to CABMV infection were classified as alkaloids, saponins, phospholipids and acids. This study can assist agricultural institutions or farms in the early diagnosis and correct management of CABMV infection and contribute to the genetic improvement of the Passiflora genus against this disease.

Resumo em Inglês:

Silicon oxycarbide (SiCO) ceramics obtained from polymer pyrolysis and with varied carbon contents were prepared and evaluated as new electrodic materials for sensing of tert butylhydroquinone (TBHQ) and butylated hydroxyanisole (BHA) antioxidants. Three polymers were synthesized varying molecular architecture and aromatic carbon groups, followed by pyrolysis at 1000 and 1500 °C to obtain SiCO ceramics. Graphitization and crystallization processes were evidenced, in different extent, according to precursor chemistry. SiCO at 1500 °C with intermediary carbon content provided slight improvement in the peak anodic separation of TBHQ and BHA and higher peak current compared with glassy carbon electrode (GCE). Higher acidic sites concentration together with more ordered residual carbon phase produced in situ contributed to great electrochemical performance of SiCO towards phenolic compounds detection. Therefore, the ceramic herein prepared exhibits highly efficient features as a new SiCO composited electrode for simultaneous determination of antioxidant phenolic compounds bearing in mind further analytical applications.