Luciana Medeiros Bertini

LARVICIDAL ACTIVITY OF ESSENTIAL OILS FROM BRAZILIAN CROTON SPECIES AGAINST AEDES AEGYPTI L

ABSTRACT Aedes aegypti is the major vector of dengue fever, an endemic disease in Brazil. In an effort to find effective and affordable ways of controlling this mosquito, the larvicidal activities of essential oils from Croton species widely found in northeastern Brazil were analyzed. The essential oils were extracted by steam distillation, and their chemical composition was determined by gas liquid-chromatography coupled with mass spectroscopy. The main components were methyleugenol and α-copaene for C. nepetaefolius (LC50 of 84 ppm); α-pinene and β-pinene for C. argyrophyloides (LC50 of 102 ppm); and α-pinene, β-phelandrene, and transcaryophyllene for C. sonderianus (LC50 of 104 ppm). Croton zenhtneri exhibited higher larvicidal activity with LC50of 28 ppm, and the main active constituent was identified as anethole, a phenylpropanoid compound.

Chemical composition, toxicity and larvicidal and antifungal activities of Persea americana (avocado) seed extracts

The present study had the aim of testing the hexane and methanol extracts of avocado seeds, in order to determine their toxicity towards Artemia salina, evaluate their larvicidal activity towards Aedes aegypti and investigate their in vitro antifungal potential against strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis through the microdilution technique. In toxicity tests on Artemia salina, the hexane and methanol extracts from avocado seeds showed LC50 values of 2.37 and 24.13 mg mL-1 respectively. Against Aedes aegypti larvae, the LC50 results obtained were 16.7 mg mL-1 for hexane extract and 8.87 mg mL-1 for methanol extract from avocado seeds. The extracts tested were also active against all the yeast strains tested in vitro, with differing results such that the minimum inhibitory concentration of the hexane extract ranged from 0.625 to 1.25mg L-(1), from 0.312 to 0.625 mg mL-1 and from 0.031 to 0.625 mg mL-1, for the strains of Candida spp, Cryptococcus neoformans and Malassezia pachydermatis, respectively. The minimal inhibitory concentration for the methanol extract ranged from 0.125 to 0.625 mg mL-1, from 0.08 to 0.156 mg mL-1 and from 0.312 to 0.625 mg mL-1, for the strains of Candida spp., Cryptococcus neoformans and Malassezia pachydermatis, respectively.O presente estudo teve como objetivo testar os extratos hexânico e metanolico das sementes do abacate, a fim de determinar sua toxicidade em Artemia salina, avaliar a atividade larvicida frente ao Aedes aegypti, bem como verificar o potencial antifungico in vitro contra cepas de Candida spp, Cryptococcus neoformans e Malassezia pachydermatis, atraves da tecnica de microdiluicao. Os extratos hexânico e metanolico das sementes de abacate apresentaram no teste de toxicidade frente a Artemia salina, valores de LC50 2,37 e 24,13mg L-1, respectivamente; contra as larvas do Aedes aegypti os resultados obtidos foram LC50 16,7mg L-1 para o extrato hexânico e 8,87mg L-1 para o extrato metanolico das sementes do abacate. Os extratos testados tambem foram ativos contra todas as cepas de leveduras, testadas in vitro, apresentando diferentes resultados, onde o MIC do extrato hexânico variou de 0,625 a 1,25mg mL-1, de 0,312 a 0,625mg mL-1 e de 0,031 a 0,625mg mL-1 para as cepas de Candida spp., Cryptococcus neoformans e Malassezia pachydermatis, respectivamente. O intervalo de MIC para o extrato metanolico foi de 0,125 a 0,625mg mL-1, 0,08 a 0,156mg mL-1 e de 0,312 a 0,625mg mL-1, para as exemplares de Candida spp., Cryptococcus neoformans e Malassezia pachydermatis, respectivamente.

Soybean (Glycine max) as a versatile biocatalyst for organic synthesis.

A series of aliphatic and aromatic aldehydes and ketones were reduced using plant cell preparations of Glycine max seeds (soybean). The biotransformation of five aromatic aldehydes in water, at room temperature afforded the corresponding alcohols in excellent yields varying from 89 to 100%. Two prochiral aromatic ketones yielded the alcohol in very low conversion, 1% and to 4%; however with good enantiomeric excess (ee) of 99 and 79%, respectively. Additionally, three prochiral and one cyclic aliphatic ketones produced the corresponding alcohols in moderate yields varying from 10 to 58% and ee varying from 73 to 99%. Hydrolysis of two aromatic esters yielded the expected carboxylic acids in 49 and 66%. Most of the obtained alcohols have commercial value as cosmetic fragrances. Although, the enzymes present in soybean (reductase/lipase) has not been defined, the reaction is an important route for the preparation of pure alcohols and carboxylic acid, with low cost and environmental impact. Keywords: Glycine max , biocatalysis, bioreduction, aldehydes and ketones, ester hydrolysis

Zingiber officinale (GENGIBRE) COMO FONTE ENZIMÁTICA NA REDUÇÃO DE COMPOSTOS CARBONÍLICOS

Various vegetables as biological catalysts were evaluated in enantioselective reduction of carbonyl compounds. The stereoselectivity of the process was in agreement with Prelogs rule for twelve of the vegetables, whereas okra and green peppers formed anti-Prelog products. Zingiber officinale exhibited the best results with 30% conversion and 89% ee. The parameters of the reaction such as time, solvent and other substrates investigated, as well as the specie, showed good chemo- and enantioselectivity.

Prospecção fitoquímica e avaliação do potencial antioxidante de Cnidoscolus phyllacanthus (müll. Arg.) Pax & k.hoffm. Oriundo de apodi – RN

As principais propriedades encontradas nas plantas com beneficios a saude sao, muitas vezes, resultados dos metabolitos secundarios encontrados em seus extratos. A especie Cnidoscolus phyllacanthus, popularmente conhecida como faveleira ou favela, conta com diversos relatos na medicina popular, tais como: cicatrizante, analgesico, anti-inflamatorio, antibiotico e diuretico. O objetivo deste trabalho foi avaliar de forma qualitativa e quantitativa os metabolitos secundarios presentes nos extratos da especie C. phyllacanthus oriunda do Nordeste Brasileiro bem como avaliar a atividade antioxidante de seus extratos. Diversos grupos de metabolitos foram determinados em seus galhos, raizes e folhas, tais como: taninos, antocianinas e alcaloides. Em relacao a atividade antioxidante, as folhas da faveleira tiveram destaque, apresentado CI50 de 58,3 ppm, semelhante ao da vitamina C (43,0 ppm) utilizado como padrao positivo. O estudo serve como aporte inicial sobre o conhecimento da viabilidade de utilizacao dessa planta para fins medicinais.