Gustavo Oliveira Everton Livres

P. guajava leaves and essential oil obtained by hydrodistillation technique were collected. Chemical constituents were evaluated by gas chromatography-mass spectrometry (GC/MS). The total phenolic content was quantified by the Folin-Ciocalteau spectrophotometric method. For the toxicity test, the Artemia salina bioassay was applied. The nanoemulsion (W/A) was prepared using the low energy phase inversion method. The LC50 was calculated for the action of the nanoemulsion against Aedes aegypti larvae by the Probit method. The main chemical constituent found in the essential oil of P. guajava was -pinene 34.25%. Total phenolic compounds were quantified as 210.35 mg EAT g-1. In the toxicity bioassay, the LC50 of 323.6 mg L-1 was classified as non-toxic. The nanoemulsion droplets after 30 days of handling had an average size of 120.41 ± 0.55 nm. The larvicidal activity of the nanoemulsion showed mortality at concentrations of 10 to 100 mg L-1 with an LC50 of 12.75 mg L-1.

The study focuses on the antioxidant properties of Ocimum citriodurum, revealing that rosmarinic acid is the predominant compound in its hydroalcoholic extract. Utilizing HPLC-MS, researchers identified seven chemical constituents and established an active potential of 0.547 for the extract's antioxidant activity. In vitro tests confirmed its efficacy with a 50% effective concentration of 50.53 mg/L against the DPPH method. Additionally, a Didactic Sequence was developed to teach about bioactive molecules and antioxidants, integrating findings with organic chemistry content.

The book explores the remarkable properties of essential oils from various plants, focusing on their antioxidant, anti-inflammatory, and anti-arthritic activities. It details the extraction and characterization of these oils through hydrodistillation and GC-MS analysis, identifying 48 chemical constituents, predominantly (E)-anethole. The study highlights the preparation of a low-energy phase inversion nanoemulsion, demonstrating significant efficacy in biological assays, suggesting that nanoencapsulated systems could enhance pharmacological applications.

The study explores the synthesis of silver nanoparticles (AgNPs) from Piper nigrum essential oil nanoemulsion, utilizing a phase inversion method and AgNO3 reduction. It highlights the chemical profile, with limonene as the primary component, and evaluates the antioxidant and anti-inflammatory activities of the AgNPs. Notably, the research found an IC50 value of 16.26 mg L-1 for antioxidant activity and 0.217 mg mL-1 for anti-inflammatory effects at pH 11, demonstrating the efficacy of P. nigrum AgNPs in enhancing these biological activities.

The study investigates the essential oil of Aniba rosaeodora Ducke, highlighting its primary chemical component, linalool, which constitutes 63.16% of the oil and shows promise for pharmaceutical applications. Toxicity tests indicate a non-toxic profile, with an LC50 range of 582 to 282 mg L-1. The oil exhibits effective larvicidal activity against Aedes aegypti, with an LC50 of 41.07 mg L-1, and demonstrates significant antioxidant properties. These findings suggest its potential for application in pest control and health-related fields.

The study focuses on the innovative synthesis and evaluation of silver nanoparticles (AgNPs) derived from the hydroalcoholic extract of Passiflora edulis Sims seeds. Using cold maceration and HPLC-MS for chemical profiling, the research identified Genisteins as the primary constituent. AgNPs were synthesized through Ag+ reduction and characterized via UV-Vis spectrophotometry and DLS. The antioxidant activity was assessed using the ABTS method, revealing a notable CI50 of 9.23 mg L-1 at pH 4, highlighting the effectiveness of these nanoparticles and the influence of pH on their properties.

The study investigates the essential oil of Aniba rosaeodora Ducke, highlighting its primary component, linalool, which constitutes 63.16% of the oil and shows promise for pharmaceutical applications. Toxicity tests reveal a non-toxic classification with an LC50 range of 582 to 282 mg L-1. The oil exhibits significant larvicidal activity against Aedes aegypti larvae, with an LC50 of 41.07 mg L-1, alongside notable antioxidant properties. The findings suggest its potential for effective larvicidal applications.

The study explores the growing interest in essential oils as natural alternatives to synthetic additives in food, highlighting their chemical profiles and antibacterial properties. Essential oils derived from natural condiments were found to be nontoxic to Artemia salina Leach and demonstrated significant bactericidal activity against clinically relevant bacteria. Notably, oils from O. vulgare, T. vulgaris, and C. zeylanicum showed effective results. The research emphasizes the potential of these essential oils as cost-effective, natural solutions for combating pathogenic microorganisms in food applications.

Brazil boasts an impressive diversity of plant species, estimated between 50,542 and 60,042, across six distinct biomes. These include the lush Amazon rainforest, the central Cerrado savannah, the Atlantic Mata Atlântica, the arid Caatinga, the southern Pampa grasslands, and the unique Pantanal wetlands. This rich variety highlights Brazil's status as one of the most biodiverse countries globally, showcasing its ecological significance and the importance of preserving these unique environments.

The study investigates the molluscicidal properties of essential oils from Syzygium cumini and Hymenaea courbaril, extracted through hydrodistillation and analyzed via Gas Chromatography-Mass Spectrometry. Toxicity tests using Artemia salina indicated both oils were nontoxic, with specific LC50 values for each. The molluscicidal assays revealed effective concentrations against Biomphalaria glabrata, suggesting these essential oils could serve as natural alternatives to combat schistosomiasis-carrying snails.