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.

Abstract Lignocellulosic waste is a valuable source of energy, fuels, and raw materials for the chemical industry. In this study, the potential of cupuaçu husks, derivative from a typical fruit of the Brazilian Amazon, was evaluated. Therefore, biomass was submitted to acid hydrolysis and pyrolysis, and the contents of sugars, by-products, bio-oil compounds, and bio-oil theoretical energy potential were determined. X-ray diffraction, High performance liquid chromatography, Fourier-transform infrared and Gas chromatography mass spectrometry analyzes were used. The hydrolysate has considerable sugar levels (31.7%) and presence of relevant by-products including furfural, levulinic acid and hydroxymethylfurfural. Bio-oil contained a variety of phenolic compounds, and its theoretical energy potential suggested usability of cupuaçu husks for energy generation. Economic analysis showed that commercialization of bioproducts obtained by biomass hydrolysis and pyrolysis could be highly profitable. These outcomes indicate a range of applications for cupuaçu husks in biorefinery processes and potential to promote sustainability and social development.

This work uses new waste feedstock, essential to increase the range of new biomasses, demonstrating experimentally and numerically the economic potential of coconut husk residues to produce renewable biofuels (pyrolytic oil and biochar) through slow pyrolysis. The samples were submitted to a pyrolysis process (500 ºC for 30 min, with a heating rate of 20 ºC min-1, using water vapor as carrier gas), where the biochar and bio-oil yields reached were 31 and 30%, respectively. The main components found in bio-oil were furfural (29.23%), phenol (22.18%), and isoeugenol (10.26%). The surface area values (Brunauer-Emmett-Teller (BET) and Langmuir) found for biochar were greater than 300 m2 g-1 and a micropore volume of 0.11 cm3 g-1. The estimated theoretical energy potential of biochar and bio-oil were 208,107,180 MJ and 190,205,438 MJ, equivalent to 3,729,518.4 tons of coconut husks. Thus, this study brings as a novelty a new feedstock associated with bioprocess technological models that will pave sustainable avenues for the development of biorefineries, offering a sustainable green option to produce bioproducts and bioenergy. In the proposed model, the wastes are valorized using various processes addressing economy.

Cupuaçu husk (CH) is the waste of a common fruit from a native species of the Brazilian Legal Amazon. The current study investigated the influence of ultrasound (US) combined with aqueous, acid, alkaline, and ionic liquid (IL) pretreatments on the chemical and physical aspects of CH and the yield of chemical platforms production, 5-hydroxymethylfurfural (HMF) and furfural (FF), using IL. Scanning electron microscopy, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy were used to feature the raw and pretreated biomass. The highest levels of glucose (9.90 g L-1) were observed in the liquid fraction resulting from the acid + US pretreatment followed by acid hydrolysis. The IL + US pretreatment recorded the best performance in removing lignin. Based on XRD analyses, ultrasound increased crystallinity of all pretreated samples as a result of the removal of cellulose’s amorphous fraction. However, it promoted accessibility to adopted reagents by increasing biomass exposure due to cavitation. The best yields of HMF and FF were recorded from hydrolysis of the solid fraction resulting from the acid + US (12.94%) and alkaline + US (48.84%) pretreatment, respectively. These results indicate satisfactory performance of ultrasound assisted pretreatments to the simplified and economic conversion of biomass into value-added products.

In the current search for renewable energy sources, residual biomass has gained ground in the concept of biorefinery. Furanic compounds such as 5-hydroxymethylfurfural (HMF), furfural (FF) and derivatives such as levulinic acid (LA), obtained from biomass, have emerged as important industrial chemical platforms. In this sense, this work aimed to use pequi bark, typical biomass and abundant in the Brazilian cerrado, in the production of HMF, FF and LA using the ionic liquid 1-n-butyl-3-methyl-imidazole bromide ([BMIM][Br]). The analysis of chemical composition of pequi bark showed that it has potential for use in the production of bioproducts, FF, HMF and LA, with yields of 65, 3 and 23.7%, respectively. High glucose conversion rates were found (> 90%). The analysis of variance (ANOVA) was applied to obtain the mathematical model with α = 0.05, verifying the significance of the second order model established for HMF (F = 0.00167) and FF (0.004494). The model fit is satisfactory, obtaining the coefficient of determination (R2) for the HMF and for the FF of 0.9599 and 0.08422, respectively. From the results obtained, it can be concluded that pequi bark has good precursor capacity for use in biorefinery processes.

Abstract In the current search for renewable energy sources, residual biomass has been highlighted as a potential source of chemical compounds that are currently obtained from petroleum. Among the derivatives obtained from this, 5-hydroxymethylfurfural and furfural are considered key parts in this process as they are key compounds in the fine chemical industry. This work aims at the use of the rice husks and soybean peel for the synthesis of 5-hydroxymethylfurfural and furfural using the ionic liquid [BMIM][Br]. The physical pre-treatment of biomasses was carried out followed by acid hydrolysis. For the synthesis of the furanic compounds, different temperatures and reaction times were used. The products obtained in each step were analyzed by infrared spectrophotometry and by high performance liquid chromatography. The best yields for rice husks was obtained with 4 hours of reaction at 120 °C (34%) and for soy peel with 3 hours of reaction at 120 °C (59%), for furfural production. For 5-hydroxymethylfurfural production the yields were 8.7% and 3.4% for rice and soy husks, respectively. It was found that glucose was the main group related to bio-products obtaining.

The aims of the current study are to investigate the composition of biomass from baru processing and to explore the feasibility of valuing it through the development of bioproducts such as fermentable sugars, furanics and biochar. Baru (Dipteryx alata Vog.) waste (endocarp and mesocarp) has great energetic potential to produce bioproducts due to its chemical composition. Proximate analyses applied to such waste have found low favorable moisture and ash content in it. Bioproduct characterizations after acid hydrolysis have shown that baru endocarp and mesocarp biomass can enable a range of value-added products in biorefinery concepts such as furfural and 5-hydroximetylfurfural (20.0 and 1.5% yield, respectively), and high sugar content (approximately 19.15 and 38.40%, respectively). Pyrolysis processes also present high biochar content (ca. 48%), with satisfactory characteristics to be used as fuel, as well as calorific value higher than 30 kJ g-1.

Este trabalho descreve a reação de ciclocondensação de 3-amino-5-metil-1H-pirazol com 1,1,1-tricloro-4-alcóxi-3-alquen-2-onas [CCl3C(O)CH=C(R¹)OR, onde R¹/R = H/Me, Me/Et, Et/Me, Pr/Et, Bu/Me, iso-Bu/Me] e β-dimetilaminovinil cetonas [R²C(O)CH=CHNMe2, onde R² = Ph, Ph-4-Me, Ph-4-F, Ph-4-Cl, Ph-4-Br, Ph-4-NO2, fur-2-il, tien-2-il, pirrol-2-il, pyrid-2-il], em refluxo de ácido acético para a obtenção de uma série de catorze pirazolo[1,5-a]pirimidinas. Os produtos foram obtidos em bons rendimentos (65-98%). Este trabalho apresenta ainda uma metodologia simples e seletiva para a obtenção de 3-bromo-pirazolo[1,5-a]pirimidinas, com rendimentos de 70-98%.

The reaction of 3-amino-5-methyl-1H-pyrazole with 1,1,1-trichloro-4-alkoxy-3-alken-2-ones [CCl3C(O)CH=C(R¹)OR, where R¹/R = H/Me, Me/Et, Et/Me, Pr/Et, Bu/Me, iso-Bu/Me] or β-dimethylaminovinyl ketones [R²C(O)CH=CHNMe2, where R² = Ph, Ph-4-Me, Ph-4-F, Ph-4-Cl, Ph-4-Br, Ph-4-NO2, fur-2-yl, thien-2-yl, pyrrol-2-yl, pyrid-2-yl], in acetic acid under reflux for 16 hours, furnished highly regioselective the halomethylated pyrazolo[1,5-a]pyrimidines and aryl[heteroaryl]pyrazolo[1,5-a]pyrimidines, respectively. A protocol for the bromination reaction at the 3-position pyrazolo[1,5-a]pyrimidines also was investigated.