The correlation between the phenolic composition and biological activities of two varieties of Brazilian propolis (G6 and G12)

Biological assays that have been performed on different types of Brazilian propolis have shown that type 6 propolis (G6) has a strong antimicrobial activity and a low flavonoid content. This study aimed to evaluate the correlation between the phenolic composition and the biological activities displayed by propolis G6 from the state of Bahia and green propolis, also known as type 12 (G12). The values of the flavonoids and the total phenolics in propolis G6 were different than those in propolis G12. Although the G12 variety presented greater antioxidant activity, propolis G6 proved to have greater antimicrobial and cytotoxic activities. The results showed that the phenolic compounds may not be the only compounds responsible for the biological activity. More detailed studies of the chemical composition and an assessment of the biological activity are required to establish the quality of propolis.

Ensaios biológicos realizados com diferentes tipos de própolis brasileira têm mostrado que a própolis do tipo 6 (G6) tem forte atividade antimicrobiana e menor teor de flavonóides. Este trabalho teve como objetivo avaliar a correlação entre a composição fenólica e atividades biológicas apresentadas pela própolis G6, do Estado da Bahia, e a própolis verde, do tipo 12 (G12). Os teores de flavonóides e fenólicos totais na própolis G6 foram diferentes dos teores da própolis G12. Apesar da G12 apresentar maior atividade antioxidante, a própolis G6 apresenta maior atividade antimicrobiana e citotóxica. Os resultados mostraram que os compostos fenólicos não são os únicos compostos responsáveis pela atividade biológica da própolis. Estudos mais específicos da composição química, em adição à avaliação das atividades biológicas, são requeridos para determinar a qualidade da própolis.

Biological activities of the fermentation extract of the endophytic fungus alternaria alternata isolated from coffea arabica L / Atividades biológicas do extrato da fermentação do fungo endofítico alternaria alternata isoladas de coffea arabica L

A total of 22 endophytic fungi isolated from coffee (Coffea arabica L.) were cultivated in vitro and their crude extracts tested. The screening was carried out using the agar diffusion method against Staphylococcus aureus, Escherichia coli and Candida albicans. The most effective isolate was Alternaria alternata, and subsequently, its extract was assayed. The total phenolic content was 3.44 μg GAE/mg of the crude extract. For the antibacterial and antifungal activity assays, minimum inhibitory concentrations (MIC) and minimum bactericidal and fungicidal concentrations (MBC and MFC) were determined. The ranges of MIC values were 50-100 μg/mL for S. aureus and 400-800 μg/mL for E. coli. The extract did not show activity in the tested concentrations for C. albicans. The fungal crude extract was assayed for antioxidant activities. Its ability to scavenge DPPH radicals and antioxidant activity by β-carotene/linoleic acid system oxidation was not significant. In addition, antitumor activity was studied using the MTT assay. At a dilution of 400 μg/mL, the extract displayed a cytotoxic activity of approximately 50 percent towards HeLa cells in vitro. The results indicate that endophytic fungi could be a promising source of bioactive compounds and warrant further study.

Total de 22 fungos endofíticos isolados de café (Coffea arabica L.) foi cultivado in vitro e seus extratos testados. A triagem foi conduzida pelo método de difusão em agar contra bactérias Gram-positiva, Gram-negativa e uma levedura. O isolado mais efetivo foi Alternaria alternata e, subsequentemente, seu extrato foi analisado. O conteúdo de fenólicos totais do extrato bruto foi de 3,44 μg EAG/mg de extrato. Para os testes de atividade antimicrobiana, a concentração inibitória mínima (CIM) e concentração bactericida e fungicida mínima (CBM e CFM) contra Staphylococcus aureus, Escherichia coli e Candida albicans foram determinadas. Resultados da CIM variaram entre 50-100 μg/mL para S. aureus e 400-800 μg/mL para E. coli. O extrato bruto não apresentou atividade nas concentrações testadas para C. albicans. Foram analisadas as atividades antioxidantes do extrato bruto. Sua habilidade para seqüestrar radicais DPPH e a atividade antioxidante pela oxidação do sistema β-caroteno/ácido linoléico não foram significativas. Além disso, a atividade antitumoral foi estudada pelo teste do MTT. À diluição de 400 μg/mL, o extrato apresentou atividade de aproximadamente 50 por cento sobre as células HeLa in vitro. Os resultados indicam que fungos endófitos poderiam ser uma fonte promissora de compostos bioativos necessitando de estudos futuros.

The "in vitro" antifungal activity evaluation of propolis G12 ethanol extract on Cryptococcus neoformans

Cryptococcosis is a worldwide disease caused by the etiological agent Cryptococcus neoformans. It affects mainly immunocompromised humans. It is relatively rare in animals only affecting those that have received prolonged antibiotic therapy. The propolis is a resin that can present several biological properties, including antibacterial, antifungal and antiviral activities. The standard strain C. neoformans ATTC 90112 was used to the antifungal evaluation. The tests were realized with propolis ethanol extract (PEE) G12 in concentrations from 0.1 to 1.6 mg mL-1. The evaluation of MIC and MFC were done according to DUARTE (2002)5. The inhibitory effect of PEE G12 on the fungal growing was seen at the concentration of 0.2 mg mL-1 and 1.6 mg mL-1 was considered a fungicidal one.

Criptococose, doença cosmopolita, causada pelo agente etiológico Cryptococcus neoformans, está associada, principalmente, a indivíduos imunocomprometidos. O acometimento de animais é relativamente raro, exceto, nos casos associados à prolongada antibioticoterapia. A própolis é uma resina que pode apresentar diversas propriedades biológicas, incluindo atividades antibacterianas, antifúngicas e antivirais. Amostra padrão de C. neoformans foi utilizada no teste de atividade antifúngica do extrato etanólico de própolis (EEP) G12 nas concentrações de 0,1 a 1,6 mg.mL-1. As avaliações da Concentração Inibitória Mínima (CIM) e Concentração Fungicida Mínima (CFM) foram realizadas conforme DUARTE5. O efeito inibitório do EEP G12 sobre o crescimento fúngico foi observado na concentração de 0,2 mg.mL-1. A concentração de 1,6 mg.mL-1 foi considerada fungicida.

Enzymatic resolution of (R, S)-ibuprofen and (R, S)-ketoprofen by microbial lipases from native and commercial sources

The enantioselectivity (E) of native lipases from Aspergillus niger, Aspergillus terreus, Fusarium oxysporum, Mucor javanicus, Penicillium solitum and Rhizopus javanicus in the resolution of (R,S)-ibuprofen and (R,S)-ketoprofenenantiomers by esterification reaction with 1-propanol in isooctane was compared with known commercial Candida rugosa (Sigma) and Candida antarctica (Novozym®435) lipases. In the resolution of (R,S)-ibuprofen, C. rugosa lipase showed good selectivity (E = 12) while Novozym®435 (E = 6.7) and A. niger (E = 4.8) lipases had intermediate selectivities. Other enzymes were much less selective (E around 2.3 and 1.5), under tested conditions. After preliminary optimization of reaction conditions (water content, enzyme concentration and presence of additives) the enantioselectivity of native A. niger lipase could be enhanced substantially (E = 15). All tested lipases showed low selectivity in the resolution of (R,S)-ketoprofen because poor ester yields and low enantiomeric excess of the acid remaining were achieved.

A enantioseletividade (E) das lipases nativas de Aspergillus niger, Aspergillus terreus, Fusarium oxysporum, Mucor javanicus, Penicillium solitum e Rhizopus javanicus na resolução dos enantiômeros do (R,S)-ibuprofeno e (R,S)-cetoprofeno na reação de esterificação com 1-propanol em isoctano foi comparada com as lipases comerciais de Candida rugosa (Sigma) e Candida antarctica (Novozym®435). A lipase de C. rugosa mostrou boa enantioseletividade (E = 12) comparada com as da Novozym®435 (E = 6.7), de A. niger (E=4.8) e com as outras lipases que foram muito menos seletivas (E por volta de 2.3 e 1.5) na resolução do (R,S)-ibuprofeno, dentro das condições testadas. Após uma otimização preliminar das condições da reação (conteúdo de água, concentração da enzima e presença de aditivos) a enantioseletividade da lipase de A. niger pôde ser substancialmente aumentada (E = 15). Todas as lipases testadas mostraram baixa seletividade na resolução de (R,S)-cetoprofeno, resultando baixos rendimentos de éster e de excesso enantiomérico do ácido não esterificado.

Comparison of the flavonoid aglycone contents of Apis mellifera propolis from various regions of Brazil

Forty-six specimens of propolis which were collected by Apis mellifera were obtained from various regions of Brazil and extracted with 80 per cent aqueous ethanol(ethanolic extract of propolis, EEP). The extracts were analysed by using determination of total flavonoid concentrations using the aluminum nitrate method, UV-spectrophotometry, reversed phase-high performance thin layer chromatography (HPTLC), and reversed phase-HPLC. Six samples of EEP, which contained high total flavonoid concentrations, were selected for futher investigation. HPTLC indicated that the quality of flavonoid aglycones of EEP from the States of Minas Gerais and Säo Paulo (Southeastern Brazil), Goias and Mato Grosso do Sul (closely to Southeastern) were similar, but were different compared to those of EEP's from Paraná and Rio Grande do Sul, which are located in Southern Brazil. Reversed Phase-HPLC analysis of EEP's from Southern Brazil identified 7 flavonoid aglycones, whereas there were 9 from Säo Paulo and Minas Gerais and 7 from Goiás and Mato Grosso do Sul. These results indicate that the plant ecology of Southeastern and Southern Brazil are different. It was also observed that all samples of EEP's demonstrated inhibition of growth of Staphylococcus aureus coagulase positive, whereas Escherichia coli was not inhibited