The present study aimed to evaluate the chemical composition, antioxidant potential, and the cytotoxic and antimicrobial activity of the essential oil of the plant species Tithonia diversifolia (Hemsl) A. Gray. The essential oil obtained was used to identify the chemical compounds present through the techniques of GC-MS and NMR. The antioxidant potential was calculated by the sequestration method of 2,2-diphenyl-1-picrylhydrazyl. For cytotoxic activity, the larval mortality of Artemia salina was evaluated. The main chemical constituents identified are αpinene (9.9%), Limonene (5.40%), (Z)-β-ocimene (4.02%), p-cymen-8-ol (3.0%), Piperitone (11.72%), (E)-nerolidol (3.78%) and Spathulenol (10.8%). In the evaluation of the antimicrobial activity, bacterial strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were used. The results showed that the bacterium E. coli were more susceptible to the presence of the essential oil, presenting minimal inhibitory concentration at the concentrations that were exposed. The essential oil presented antioxidant activity of 54.6% at the concentration of 5 mg·mL⁻¹ and provided a CI₅₀ of 4.30. It was observed that the essential oil of this species was highly toxic against A. salina lavas, as its cytotoxic activity showed an LC₅₀ of 3.11. Thus, it is concluded that T. diversifolia oils are effective in inhibiting bacterial growth and reducing oxidative stress.

This work aimed to prepare a nanoemulsion containing the essential oil of the Protium heptaphyllum resin and evaluate its biocidal activities against the different stages of development of the Aedes aegypti mosquito. Ovicide, pupicide, adulticide and repellency assays were performed. The main constituents were p-cymene (27.70%) and α-pinene (22.31%). The developed nanoemulsion showed kinetic stability and monomodal distribution at a hydrophilic–lipophilic balance of 14 with a droplet size of 115.56 ± 1.68 nn and a zeta potential of −29.63 ± 3.46 mV. The nanoemulsion showed insecticidal action with LC₅₀ 0.404 µg·mL⁻¹ for the ovicidal effect. In the pupicidal test, at the concentration of 160 µg·mL⁻¹, 100% mortality was reached after 24 h. For adulticidal activity, a diagnostic concentration of 200 µg·mL⁻¹ (120 min) was determined. In the repellency test, a concentration of 200 µg·mL⁻¹ during the 180 min of the test showed a protection index of 77.67%. In conclusion, the nanobiotechnological product derived from the essential oil of P. heptaphyllum resin can be considered as a promising colloid that can be used to control infectious disease vectors through a wide range of possible modes of applications, probably as this bioactive delivery system may allow the optimal effect of the P. heptaphyllum terpenes in aqueous media and may also induce satisfactory delivery to air interfaces.

This study evaluated the larvicidal activity of O. majorana essential oil, identified the chemical composition, evaluated the antimicrobial, cytotoxic and antioxidant potential. The larvicidal activity was evaluated against larvae of the third stage of Aedes aegypti , whereas the chemical composition was identified by gas chromatography coupled to mass spectrometer, the antimicrobial activity was carried out against the bacteria Pseudomonas aeruginosa, Escherichia coli and Staphylococcus auereus , the antioxidant activity was evaluated from of 2.2-diphenyl-1-picryl-hydrazila sequestration and Artemia salina cytotoxicity. Regarding to the results, the larvicidal activity showed that O. majorana essential oil caused high mortality in A. aegypti larvae. In the chromatographic analysis, the main component found in O. majorana essential oil was pulegone (57.05%), followed by the other components verbenone (16.92%), trans-p-menthan-2-one (8.57%), iso-menthone (5.58%), piperitone (2.83%), 3-octanol (2.35%) and isopulegol (1.47%). The antimicrobial activity showed that E. coli and P. aeruginosa bacteria were more sensitive to oil than S. aureus , which was resistant at all concentrations. Essential oil did not present antioxidant activity, but it has high cytotoxic activity against A. salina .

Ayapana triplinervis is a plant species used in traditional medicine and in mystical-religious rituals by traditional communities in the Amazon. The aim of this study is to evaluate the larvicidal activity against A. aegypti of nano-emulsions containing essential oils from A. triplinervis morphotypes, and acute oral toxicity in non-target organism. Essential oils were identified and nano-emulsions were prepared using the low energy method. The mortality test of A. aegypti larvae was performed according to the protocol recommended by the World Health Organization, and toxicity in non-target mammals was performed according to the OECD. Phytochemical analyses indicated the major compounds (E)-Caryophyllene (45.93%) and Thymohydroquinone Dimethyl Ether (32.93%) in morphotype A, and in morphotype B, Thymohydroquinone Dimethyl Ether (84.53%) was found. Morphotype A essential oil nano-emulsion showed a particle size of 101.400 ± 0.971 nm (PdI = 0.124 ± 0.009 and ZP = −19,300 ± 0.787 mV). Morphotype B essential oil nano-emulsion had a particle size of 104.567 ± 0.416 nm (PdI = 0.168 ± 0.016 and ZP = −27,700 ± 1,307 mV). Histomorphological analyses showed the presence of inflammatory cells in the liver of animals treated with morphotype A essential oil nano-emulsion (MAEON) and morphotype B essential oil nano-emulsion (MBEON). Congestion and the presence of transudate with leukocyte infiltration in the lung of animals treated with MAEON were observed. The nano-emulsions containing essential oils of A. triplinervis morphotypes showed an effective nanobiotechnological product in the chemical control of A. aegypti larvae and safe for non-target mammals.

Objective: In this work, we evaluated the chemical composition by chromatography coupled to mass spectrometry, antimicrobial and insecticidal activity of essential oils (TrEO) and nanoeffu-sion (NTrEO) of oil from Tetradenia riparia leaves. We also evaluated the acute toxicity in Mus musculus. The results showed that S. aureus showed greater susceptibility to TrEO, with a minimum inhibitory concentration (MIC) of 125 µg.mL-1, when compared to P. aeruginosa, E. coli, which presented a MIC of 250 µg.mL-1. There was a greater toxic effect on TrEO (LC50 = 630.29 µg.mL-1) and NTrEO (LC50 = 713.68 µg.mL-1) larvae, effect on pupae (LC50 = 630.29 µg.mL-1) and NTrEO (LC50 = 713.68 µg.mL-1) and ovicide (LC50 = 631.184 µg.mL-1) and NTrEO (LC50 = 146.701 µg.mL-1) of Ae. aegypti after 24 h of exposure, when compared to other exposure periods. Chemical analysis re-vealed 20 components, aromadendrene oxide (23.47%) being the main component. Female and male mice were used to assess toxicity and oral administration of NTrEO to mice did not result in acute toxicity. Thus, the essential oil of T. riparia and its nanoemulsion have insecticidal and an-timicrobial potential for Ae. aegypti, S. aureus, E. coli, P. aeruginosa, and has a high toxicological safety threshold at the concentrations evaluated in this study.

O presente estudo tem como objetivo caracterizar os impactos ambientais associados à implantação e operação da rodovia BR-156/210, especificamente no trecho que liga Macapá à localidade de Cupixi, no município de Laranjal do Jari, no Amapá. A caracterização considera os efeitos diretos e indiretos da obra sobre os componentes físicos, bióticos e socioeconômicos da região, propondo medidas mitigadoras e compensatórias para minimizar os danos ambientais gerados. A construção civil, tradicionalmente associada a externalidades negativas, tem buscado evoluir através da adoção de práticas sustentáveis, especialmente em obras de infraestrutura viária como esta, que são fundamentais para o escoamento de produtos e a integração regional. A área de estudo compreende a porção sudeste do estado do Amapá, abrangendo os municípios de Macapá, Santana e Mazagão. Trata-se de uma região ecologicamente rica, marcada por elevados índices pluviométricos, clima tropical úmido (Amw), vegetação diversificada e solos pertencentes ao período Quaternário. A implantação da rodovia atravessa áreas sensíveis que abrigam ecossistemas diversos, como florestas equatoriais, campos cerrados e manguezais, cuja conservação é vital para a manutenção da biodiversidade regional. Durante a fase que antecede a implantação, observou-se que os principais impactos incidem sobre a cobertura vegetal e a fauna silvestre. A supressão da vegetação para abertura da via causa fragmentação de habitats, perda de nichos ecológicos e desequilíbrio nos ecossistemas locais, comprometendo também as cadeias tróficas e as relações ecológicas entre as espécies. Além disso, a presença de canteiros de obras e o uso de áreas de empréstimo contribuem para a degradação ambiental, enquanto as queimadas aumentam a emissão de poluentes e reduzem a resiliência ecológica. Diante desse cenário, foram propostas medidas mitigadoras voltadas ao controle dos impactos sobre solo, ar, água, flora, fauna e ruídos. Entre as ações recomendadas estão a instalação de cercas ecológicas, programas de monitoramento ambiental, supressão vegetal controlada, umectação de vias para controle de poeira, barreiras acústicas e proibição de queimadas. Tais práticas visam garantir o equilíbrio ambiental e reduzir os efeitos negativos da obra, preservando os ecossistemas adjacentes. Por fim, a Tabela 1 resume os impactos identificados, indicando sua relevância e intensidade, reafirmando a necessidade de planejamento ambiental criterioso em empreendimentos viários na Amazônia.