The study of phytotherapy in dentistry holds great relevance because of the scarcity of research conducted on the treatment of oral pathologies, specifically, caries and periodontal disease. Therefore, this research aimed to analyze the chemical composition of extracts from Couroupita guianensis Aubl. leaves, evaluate their toxicity, and assess their antioxidant and antimicrobial properties against Staphylococcus aureus, Streptococcus mutans, and Candida albicans. Three extracts were prepared using assisted ultrasound and the Soxhlet apparatus, namely, Crude Ultrasound Extract (CUE), Crude Soxhlet Extract (CSE), and the Ethanol Soxhlet Extract (ESE). Flavonoids, tannins, and saponins were detected in the chemical analysis, while LC-DAD analysis revealed the presence of caffeic acid, sinapic acid, rutin, quercetin, luteolin, kaempferol, and apigenin in all extracts. GC-MS analysis identified stigmasterol and β-sitosterol in the CUE and CSE. The ESE showed higher antioxidant activity (2.98 ± 0.96 and 4.93 ± 0.90) determined by the DPPH• and ABTS•⁺ methods, respectively. In the toxicity evaluation, the CUE at 50 μg/mL and the ESE at 50 μg/mL stimulated the growth of Allium cepa roots, while all extracts inhibited root growth at 750 μg/mL. None of the extracts exhibited toxicity against Artemia salina. Antibacterial activity was observed in all extracts, particularly against the microorganisms S. aureus and S. mutans. However, no antifungal activity against C. albicans was detected. These results suggest that extracts of C. guianensis have therapeutic potential for controlling microorganisms in the oral microbiota.

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.

In this study, our objective was to conduct a comprehensive phytochemical analysis, determine toxicity levels, and assess the antioxidant and antimicrobial properties of extracts derived from the leaves of Dipteryx alata Vogel, a native species of the Brazilian cerrado flora. Three distinct extracts were prepared utilizing assisted ultrasound and the Soxhlet apparatus, namely, Ultrasound Crude Extract (UCE), Soxhlet Crude Extract (SCE), and the Soxhlet Ethanol Extract (SEE). The phytochemical analysis revealed the presence of flavonoids, tannins, phytosterols, and saponins in all extracts. Additionally, alkaloids were specifically identified in the SCE and SEE extracts. In the analysis using LC-DAD, the compounds gallic acid, rutin, quercetin, luteolin and kampefrol were determined in higher concentrations in the SCE, followed by the SEE and UCE, respectively. The GC-MS analysis revealed the presence of campesterol, stigmasterol and β-sitosterol in all extracts, with UCE and SCE showing a higher concentration of β-sitosterol. SCE showed the highest concentration of all identified compounds. In the analysis of antioxidant activity by DPPH• and ABTS•⁺, SEE showed greater efficiency (IC₅₀ = 2.98 ± 2.92 and 6.57 ± 0.89 μg/mL, respectively). In the toxicity test with Allium cepa, all extracts stimulated root growth at 50 g/mL; UCE and SEE stimulated root growth at 250 g/mL; and SEE inhibited root growth at 750 g/mL. In the Artemia salina toxicity, all extracts were non-toxic. Antibacterial activity was identified in the microorganisms S. aureus and S. mutans; however, the extracts did not show antifungal action against the strain of C. albicans. The extracts of D. alata have therapeutic potential for applicability in dentistry.