Antibacterial evaluation of Styrax pohlii and isolated compounds

The antibacterial activity of the compounds egonol (1) and homoegonol (2), of the crude ethanolic extract of Styrax pohlii (Styracaceae) aerial parts (EE), and of its n-hexane (HF), EtOAc (EF), n-BuOH (BF), and hydromethanolic (HMF) fractions was evaluated against the following microorganisms: Streptococcus pneumoniae (ATCC 6305), S. pyogenes (ATCC 19615), Haemophilus influenzae (ATCC 10211), Pseudomonas aeruginosa (ATCC 27853), and Klebsiella pneumoniae (ATCC 10031). The broth microdilution method was used for determination of the minimum inhibitory concentration (MIC) during preliminary evaluation of antibacterial activity. The EE yielded MIC values of 400 µg/mL for S. pneumoniae and P. aeruginosa and 300 µg/mL for H. influenzae. The HF and EF fractions exhibited enhanced antibacterial activity, with MIC values of 200 µg/mL against S. pneumoniae, but only EF displayed activity against H. influenzae (MIC 200 µg/mL). The best MIC value with compounds 1 and 2 (400 µg/mL) was obtained for (1) against S. pneumoniae and P. aeruginosa. Therefore, 1 exhibited weak antibacterial activity against these standard strains.As atividades antimicrobianas das substâncias egonol (1) e homoegonol (2), do extrato etanólico das partes aéreas de Styrax pohlii (Styracaceae) (EE), bem como das frações n-hexano (HF), AcOEt (EF), n-BuOH (BF) e hidrometanólica (HMF) foram avaliadas frente aos seguintes microorganismos: Streptococcus pneumoniae (ATCC 6305), S. pyogenes (ATCC 19615), Haemophilus influenzae (ATCC 10211), Pseudomonas aeruginosa (ATCC 27853) e Klebsiella pneumoniae (ATCC 10031). O método de microdiluição em caldo foi utilizado para a determinação da concentração inibitória mínima (CIM) na avaliação preliminar da atividade antimicrobiana. EE mostrou valores de CIM de 400 µg/mL para S. pneumoniae e P. aeruginosa, e 300 µg/mL para H. influenzae. As frações HF e EF apresentaram melhora na atividade antimicrobiana, com valores de CIM de 200 µg/mL frente S. pneumoniae, mas apenas EF apresentou ação contra H. influenzae (200 µg/mL). Em relação às substâncias 1 e 2, o melhor valor de CIM (400 µg/mL) foi obtido por 1 frente a S. pneumoniae e P. aeruginosa, que exibiu fraca atividade antimicrobiana contra estas cepas padrões

Schistosomicidal evaluation of flavonoids from two species of Styrax against Schistosoma mansoni adult worms

Context: Schistosomiasis is a major health problem worldwide. Thus, the search for new schistosomicidal agents from natural sources can provide prototypes for drug discovery. Objective: The present study investigated the chemical composition of the EtOAc fractions of Styrax pohlii Pohl (Styracaceae) (EF-SP) aerial parts and S. camporum A. DC. leaves (EF-SC), as well as schistosomicidal activities against Schistosoma mansoni adult worms, which have not yet been studied. Materials and methods: The crude ethanol extracts of S. camporum leaves and S. pohlii aerial parts (EE-SC and EE-SP) were partitioned with n-hexane, EtOAc, and n-BuOH. The EtOAc fractions were purified by preparative HPLC. The crude extracts, EtOAc fractions and pure compounds were tested against S. mansoni adult worms in vitro. Results: The purification procedure resulted in the isolation of kaempferol-3-O-(2 '',4 ''-di-O-(E)-p-coumaroyl)-beta-D-glucopyranoside (1), kaempferol-3-O-(2 '',6 ''-di-O-(E)-p-coumaroyl)-beta-D-glucopyranoside (2), quercetin (3), and kaempferol (4). The bioassay results indicated that EE-SC, EF-SC, EF-SP, and compounds 2 and 4 are able to separate coupled S. mansoni adult worms. Additionally, EE-SC, EF-SP, and compound 4 killed the adult schistosomes in vitro at 100 mu g/mL and 100 mu M. Discussion and conclusion: This is the first time that the presence of compounds 1-2 in S. pohlii and 3-4 in S. camporum has been reported. Additionally, biological results indicated that S. pohlii and S. camporum have great potential as a source of active compounds.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2008/10.283-1]Coordenadoria de Aperfeicoamento de Pessoal do Ensino Superior (CAPES)Coordenadoria de Aperfeicoamento de Pessoal do Ensino Superior (CAPES)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq