Anticariogenic and Antimycobacterial Activities of the Essential Oil of Siparuna guianensis Aublet (Siparunaceae)

Siparuna guianensis is a Brazilian plant with extensive ethnobotanical indication and identified as one of the priority species that should be preserved in the Brazilian Cerrado. This work aimed to investigate the chemical composition and the antibacterial effects of the essential oil from leaves of S. guianensis (SG-EO) grown in southeastern Brazil against a representative panel of oral pathogens and mycobacteria. Anticariogenic and antimycobacterial activities of SG-EO were evaluated in terms of their minimum inhibitory concentrations (MICs). The essential oil from leaves of S. guianensis was analyzed by gas chromatography coupled to mass spectrometry (GC-MS). Forty one compounds were identified, accounting for 92.7 % of the SG-EO composition. E,E-farnesol (18.0 %), β-myrcene (16.0 %), germacrene-D (10.0 %) and siparunone (14.6 %) were the major SG-EO constituents. SG-EO showed the strongest anticariogenic activity against the aerobic bacterium Streptococcus mutans (MIC of 50 µg/mL). SG-EO was also evaluated for its antimycobacterial activity, and showed MIC values of 250 µg/mL against Mycobacterium avium and 500 µg/mL against M. tuberculosis and M. kansasii. These results imply that S. guianensis may be a new alternative source of substances of medicinal interest. This is the first report of anticariogenic and antimycobacterial activities of essential oil of S. guianensis. DOI: http://dx.doi.org/10.17807/orbital.v0i0.93

Anticariogenic and Antimycobacterial Activities of the Essential Oil of Siparuna guianensis Aublet (Siparunaceae)

Siparuna guianensis is a Brazilian plant with extensive ethnobotanical indication and identified as one of the priority species that should be preserved in the Brazilian Cerrado. This work aimed to investigate the chemical composition and the antibacterial effects of the essential oil from leaves of S. guianensis (SG-EO) grown in southeastern Brazil against a representative panel of oral pathogens and mycobacteria. Anticariogenic and antimycobacterial activities of SG-EO were evaluated in terms of their minimum inhibitory concentrations (MICs). The essential oil from leaves of S. guianensis was analyzed by gas chromatography coupled to mass spectrometry (GC-MS). Forty one compounds were identified, accounting for 92.7 % of the SG-EO composition. E,E-farnesol (18.0 %), β-myrcene (16.0 %), germacrene-D (10.0 %) and siparunone (14.6 %) were the major SG-EO constituents. SG-EO showed the strongest anticariogenic activity against the aerobic bacterium Streptococcus mutans (MIC of 50 µg/mL). SG-EO was also evaluated for its antimycobacterial activity, and showed MIC values of 250 µg/mL against Mycobacterium avium and 500 µg/mL against M. tuberculosis and M. kansasii. These results imply that S. guianensis may be a new alternative source of substances of medicinal interest. This is the first report of anticariogenic and antimycobacterial activities of essential oil of S. guianensis. DOI: http://dx.doi.org/10.17807/orbital.v0i0.93

Methods of carboxyl and carbonyl groups quantification in pulp of bleached kraft cellulose

A qualidade da polpa branqueada é avaliada por intermédio de vários parâmetros, mas a alvura é um dos mais significantes. Entretanto, a exposição da polpa branqueada a luz, calor, umidade, produtos químicos e oxigênio pode provocar escurecimento ou amarelecimento da polpa, fenômeno este conhecido como reversão de alvura. As causas da reversão de alvura ainda não estão completamente elucidadas, contudo, grupos carbonílicos e carboxílicos presentes na polpa contribuem para os processos envolvidos no seu amarelecimento. Assim, a determinação quantitativa desses grupos é uma importante ferramenta para avaliar a qualidade da polpa branqueada. Neste trabalho são discutidos e comparados os diferentes métodos para determinação de grupos carbonílicos e carboxílicos em polpa kraft branqueada. Os grupos carboxílicos foram determinados por meio de uma nova metodologia, desenvolvida a partir da titulação potenciométrica direta, em que o método de titulação TAPPI (T 237 om-93) foi utilizado para validação do método desenvolvido. Já os grupos carbonílicos foram determinados pelos métodos de oximação e número de cobre (TAPPI T 430 om-94). No método de oximação foram otimizadas as condições de pH, concentração de cloridrato de hidroxilamina (NH2OH.HCl) e tempo de reação. Foram utilizadas amostras de polpa kraft branqueada industriais e polpas oxidadas com ozônio (O3), periodato de sódio (NaIO4) e NaIO4/clorito de sódio (NaClO2). A análise por espectroscopia FT-IR também foi investigada como uma ferramenta qualitativa para caracterização das amostras de polpa de celulose empregadas. Excelente correlação (r = 0,9956) foi observada entre os teores de grupos carboxílicos obtidos pelos métodos da titulação potenciométrica direta e TAPPI (T 237 om-93), contudo, os resultados encontrados para o método de titulação potenciométrica foram, em média, 22% maiores que os detectados no método TAPPI. A titulação potenciométrica mostrou ser o método mais viável, considerando-se a facilidade de execução, tempo de análise, custo de reagentes e precisão dos resultados. O método de oximação foi inadequado para análise quantitativa de grupos carbonílicos em polpa kraft branqueada, sendo os melhores resultados alcançados em pH 5, 48 h de reação sob agitação, e concentração de 0,1 mol de NH2OH.HCl/2 g de polpa. As amostras oxidadas com periodato de sódio foram mais reativas frente à oximação, em relação às amostras de polpa oxidada com ozônio, em função da natureza das carbonilas formadas. A espectroscopia no infravermelho não se mostrou uma ferramenta útil na determinação de grupos carbonílicos em amostras de celulose branqueada comercial. A identificação do grupo carbonílico no espectro no infravermelho de amostras oxidadas com NaIO4 foi mais difícil em comparação às amostras oxidadas com O3. Observa-se, pelos resultados que o método de oximação não deve ser utilizado na determinação do teor de grupos carbonílicos; já o método de titulação potenciométrica direta mostrou-se uma técnica promissora na determinação quantitativa de grupos carboxílicos em amostras de polpa kraft branqueada.Bleached pulp quality is evaluated by many parameters but brightness is by for one of the most significant ones. However, exposure of bleached pulp to light, heat, humidity, chemicals and oxygen can causes darkening or yellowing of the pulp, a process also known as brightness reversion. The reasons why brightness reversion occur are not yet well defined. Carbonyl and carboxyl groups present in pulp may contribute to the yellowing processes. Thus, the quantitative determination of these groups is important to evaluate the quality of bleached pulp. This work aimed at evaluating different methods for carbonyl and carboxyl groups determination in bleached kraft pulp. Carboxyl groups were measured by new methodology using the direct potentiometric titration, where the method TAPPI (T 237 om-93) was used for validation of developed method. Carbonyl groups determination carbonyl groups was made by the oximation and copper number (TAPPI T 430 om-94) methods. In the oximation method the conditions for pulp oximation reaction were optimized, incluing pH, hydroxylamine hydrochloride (NH2OH.HCl) concentration and reaction time. Pulp samples of kraft bleached industrial and oxidized with ozone (O3), sodium periodate (NaIO4) and NaIO4/sodium chlorite (NaClO2) were used. The analysis for FT-IR spectroscopy was also investigated as a qualitative tool for characterization of samples of cellulose pulp bleached industrial and oxidized with O3 and NaIO4/NaClO2. Excellent correlation (r = 0.9956) was observed between the adapted potentiometric titration and TAPPI T 237 om-93 methods; however, the results found for the potentiometric titration method were 22% larger than found them in the TAPPI method. The potentiometric titration was elected the most viable considering execution easiness, analysis time, reagents cost and accuracy. The oximation method was not showed adequate for quantitative analysis of carbonyl groups in bleached kraft pulp. The optimal conditions for oximation reaction were pH 5.0, 48 h of reaction under agitation and 0.1 mol of NH2OH.HCl/2 g of pulp. Pulps oxidized with sodium periodate (NaIO4) were more reactive towards oximation than pulp oxidized with ozone, due the nature of formed carbonyl. The FT-IR spectroscopy was not showed an useful qualitative tool for determination of carbonyl groups in cellulose bleached commercial. The identification of carbonyl groups in the infrared spectrum of samples oxidized with NaIO4 was more difficult in relation to the samples oxidized with O3. Taken together, the results showed that the oximation method should not be used for determination of carboxyl groups content; although, the direct potentiometric titration method showed a promising technique for quantitative determination of carboxyl groups in bleached kraft pulp samples.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Polymeric nanoparticles for the control of eafcutting ants and search for novel natural substances with antitumor activities

PART I: Polymeric nanoparticles and bioassay-guided phytochemical investigation of Trichilia elegans e Trichilia catigua (Meliaceae) for the control of leaf-cutting ants Leaf-cutting ants are known as severe agricultural pests. Several compounds have been proposed for their control such as organophosphorus, pyrethroids and sulfluramid insecticides. However, non-target animals and environmental contamination are common problems and therefore new strategies to control these pests have been requested. In this context, this work involved the bioassay-guided study of T. elegans e T. catigua (Meliaceae) and also the development and characterization of three different nanoparticles, containing either ricinine, xanthyletin or rauianin for the control of leaf-cutting ants. Phytochemical investigations from active extracts and fractions have allowed to isolate 23 compounds (3 new), including sterols, coumarins, phenolic compounds, oxazol derivative, flavonoids and limonoids. The compound 3-(4'-hydroxyphenyl)-2-propenoic acid (4''-carboxyl)-phenyl ester (14), from T. elegans, showed high biologic activity against leaf-cutting ants. Additionally, the limonoid cedrelone, from T. catigua, was active against the symbiotic fungus of leaf-cutting ants (L. Leucoagaricus gongylophorus). The solvent displacement technique adopted here showed to be very efficient for the preparation of nanoparticle formulations containing either xanthyletin or rauianin. In addition, a novel method was developed for the encapsulation of ricinine. These natural insecticides were nanoencapsulated for the first time and the results observed here showed a better activity, more water dispersivity and stabilization of nanoparticles if compared to free compounds.Financiadora de Estudos e ProjetosPARTE I: Nanopartículas poliméricas e estudo fitoquímico biomonitorado de Trichilia elegans e Trichilia catigua (Meliaceae) associados ao controle de formigas cortadeiras. As formigas cortadeiras são conhecidas por serem uma séria praga para a agricultura e vários compostos diferentes têm sido propostos para o controle destas, tais como, organofosforados, piretróides e sulfluramidas. No entanto, problemas com animais não-alvo e contaminações ambientais são extremamente comuns e assim novas estratégias de controle desses insetos se fazem necessárias. Nesse contexto, este trabalho envolveu o estudo biomonitorado de Trichilia elegans e T. catigua (Meliaceae) e também o desenvolvimento e caracterização de nanopartículas poliméricas, contendo ricinina, xantiletina ou rauianina para o controle de formigas cortadeiras. O estudo fitoquímico dos extratos e frações ativas permitiu o isolamento de 23 compostos (3 inéditos), incluindo esteróides, cumarinas, compostos fenólicos, derivado de oxazole, flavonóides e limonóides. O composto 3-(4'-hidroxifenil)-2- propenoato de 4''-carboxilfenil (14), isolado de Trichilia elegans apresentou alta atividade contra formigas cortadeiras. O limonóide cedrelona isolado de T. catigua foi ativo contra fungo simbionte (L. gongylophorus Leucoagaricus) da formiga cortadeira. O método de nanoprecipitação se mostrou eficiente para encapsulção de xantiletina e rauianina. Em adição um método novo, aqui denominado deposição interfacial/deslocamento do solvente, foi desenvolvido visando à encapsulação de ricinina. Estes formicidas naturais foram encapsulados pela primeira vez e os resultados aqui observados demonstraram maior atividade, dispersão em meio aquoso e estabilidade das nanopartículas em comparação aos compostos livres

Chemical composition of the volatile oil of Cardiopetalum calophyllum collected in the Cerrado area

ABSTRACT: The Annonaceae family consists of ~135 genera with diverse species and a large number of chemical compounds arising from the secondary metabolism. However, the chemical composition of the essential oil of several species of the family such as Cardiopetalum calophyllum has not been completely determined. In this study, the essential oils extracted from the leaves, flowers, and fruits of C. calophyllum, collected in typical areas of the Cerrado of Goiás, were characterized. The essential oil was extracted by hydrodistillation for 4h using a Clevenger apparatus. The chemical analysis was carried out by gas chromatography-mass spectrometry (GC-MS), and the constituents were identified by comparing the spectra and retention index obtained with those available in the literature. Twenty three compounds were identified in the essential oil of leaves; the oxygenated sesquiterpene, spathulenol (28.78%), was the major compound. Twenty five compounds were identified in the flowers, mainly comprising sesquiterpene hydrocarbons, germacrene-D (37.03%) and germacrene-B (13.72%). Seventeen compounds were reported in fruits, mainly comprising sesquiterpene hydrocarbons, germacrene-D (28.19%) and germacrene-B (20.90%), and an oxygenated sesquiterpene, spathulenol (11.53%). This is the first report on the chemical composition of the essential oils from leaves, flowers, and fruits of C. calophyllum

Development and validation of a RP-HPLC method to determine the xanthyletin content in biodegradable polymeric nanoparticles

Xanthyletin is used as an inhibitor of the symbiotic fungus (Leucoagaricus gongylophorus) of the leaf-cutting ant (Atta sexdens rubropilosa), one of the most significant agricultural plague insects. The incorporation of this compound into nanoparticles is a promising approach to effectively control leaf-cutting ants. This study presents the development and validation of a specific analytical method using high-performance liquid chromatography (HPLC) for quantification of the xanthyletin content in biodegradable polymeric nanoparticles. The analytical methodology developed was specific, linear, accurate, precise, and robust. The absolute recovery of xanthyletin in colloidal suspensions was nearly 100%. The HPLC method proved reliable for the quantification of xanthyletin content in nanoparticle formulations

Chemical composition, anti-Trypanosoma cruzi and cytotoxic activities of the essential oil from green fruits of Protium ovatum (BURSERACEAE)

Abstract Chagas disease is a major neglected tropical disease caused by Trypanosoma cruzi. It has been treated with the antiparasitic drugs nifurtimox and benzonidazole, which cause several side effects. The market for natural products has considerably grown lately and the use of plants has become an alternative to the development of novel drugs to cure the disease. Therefore, this study aimed at describing the chemical analysis of the essential oil from green fruits of Protium ovatum and evaluating their trypanocidal and cytotoxic potential. The essential oil was obtained by Clevenger hydrodistillation whereas its chemical composition was determined by gas chromatography coupled to mass spectrometry (GC-MS). The major compounds found in the essential oil from green fruits of P. ovatum were ß-myrcene (62.0 %), a-pinene (11.3 %) and limonene (7.3 %). To the best of our knowledge, this was the first time that the chemical composition of the essential oil from green fruits of P. ovatum was described. Results showed that the essential oil had strong trypanocidal activity against trypomastigote forms of theY strain of Trypanosoma cruzi (IC50 = 1.2 µg/mL). In addition, the essential oil from green fruits of P. ovatum did not display cytotoxicity against LLCMK2 adherent epithelial cell at the concentration range under analysis (CC50 = 550.3 µg/mL). As a result, it is an excellent option for the development of novel antiparasitic drugs