ABSTRACT
Abstract In hybrid cultivated form, Dendranthema grandiflorum (Ramat.) Kitam., Asteraceae, flowers (Chrysanthemum morifolium Ramat.) were utilized in the production of extracts, which were analyzed for larvicidal activity against Aedes aegypti third instar larvae. Methanol and dichloromethane extracts showed LC50 values of 5.02 and 5.93 ppm, respectively. Using GC–MS, phytochemical analyses of the dichloromethane extract showed the presence of triterpenoids and fatty acids, while flavonoids and caffeoylquinic acids were shown to occur in the methanol extract by ESI Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (ESI-FT-ICR-MS). Triterpenoids and fatty acids are well known insecticidal compounds. From this study, it can be concluded that D. grandiflorum grown for floriculture, as an agribusiness, can have additional applications as raw material for the production of insecticidal products.
ABSTRACT
The ethanol extract of the vegetal species Pentaclethra macroloba (Willd.) Kuntze, Fabaceae, was fractioned and the antibacterial activity was determined. The active ethyl acetate (ea) fraction showed activity against Gram-positive (Staphylococcus spp. and Enterococcus spp.) and Gram-negative (Pseudomonas aeruginosa, Acinetobacter spp. and Klebsiella pneumoniae) multiresistant bacteria. Gallic acid derivatives were identified as the main compounds in inactive subfractions from the ea fraction, while the active one afforded ellagic acid as the major constituent when submitted to acid hydrolysis reaction, which suggests the presence of hydrolysable tannins. The minimum bactericidal concentration analysis showed a bactericide mechanism of action for the tannin subfraction found. The antibacterial mechanism of action of the active tannin subfraction against S. aureus reference strains (ATCC 29213 e 33591) was proposed adopting an in vitro assay of protein synthesis inhibition. For this, bacterial cells were labeled with [35S] methionine in the presence of the subfraction. The protein synthesis inhibition was observed at 256 µg/mL of this subfraction. At this concentration it did not present cytotoxicity in eukaryotic cells by the neutral red technique, suggesting selective toxicity. The present study is the first in vitro investigation of the antibacterial properties of tannin fractions obtained from a polar extract of P. macroloba.
ABSTRACT
In order to validate the Bumelia sartorum Mart., Sapotaceae, traditional use for infection diseases, this study evaluates the antibacterial activity of the stem bark fractions against methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) Staphylococcus aureus strains by using the agar dilution method and reported as MIC (minimal inhibitory concentration). In addition, the DPPH scavenging activity of these fractions was measured and the chemical composition and acute toxicity of the active fraction were also determined. The ethyl acetate (EtOAc) extract was chemically analyzed by LC/MS, direct ionization APCI/MS, ¹H NMR and 13C-NMR. All fractions, except butanol extract, presented high antioxidant activity, especially the methanol and the EtOAc extracts, which showed EC50 values (5.67 and 5.30 µg/mL, respectively) considerably lower than the Gingko-standard EGb 761® (38.58 µg/mL). The antibacterial activity against S. aureus strains was observed in EtOAc (MIC 256-512 µg/mL), which showed a very low toxicity. The chemical study of this fraction revealed the abundant presence of polyphenolic compounds. The antibacterial and antioxidant activities reported in this paper for EtOAc extract from B. sartorum and the low toxicity of this fraction opens the possibility that it could be helpful for the developing of new antibacterial agents for treating S. aureus infections.
ABSTRACT
Echinodorus macrophyllus, commonly known as chapéu-de-couro, is a medicinal plant used in folk medicine to treat inflammation and rheumatic diseases. In this work, we used short-term bacterial assays based on the induction of SOS functions to examine the genotoxicity and mutagenicity of an aqueous extract of E. macrophyllus leaves. Whole extract and an ethyl acetate fraction showed similar genotoxicity and caused an ~70-fold increase in lysogenic induction. The extract also gave a positive result in the SOS chromotest with an increase of 12-fold in beta-Galactosidase enzymatic units. There was a strong trend towards base substitutions and frameshifts at purine sites in the mutations induced by the extract in Escherichia coli (CC103 and CC104 strains) and Salmonella typhimurium test strains (22-fold increase in histidine revertants in TA98 strain). Since reactive oxygen species may be implicated in aging process and in degenerative diseases, we used antioxidant compounds as catalase, thiourea and dipyridyl in the lysogenic induction test. All this compounds were able to reduce the induction factor observed in the treatment with chapéu-de-couro, thus suggesting that the genotoxicity and mutagenicity were attributable to the production of reactive oxygen species that targeted DNA purines.
Subject(s)
Animals , Alismataceae/genetics , Escherichia coli , Plant Extracts , Salmonella , Reactive Oxygen Species , Mutagenicity Tests , Plants, MedicinalABSTRACT
A espécie Calceolaria chelidonioides (Scrophulariaceae), até então inédita nas citações científicas, foi estudada sob o ponto de vista farmacológico buscando-se identificar possíveis atividades antimicrobiana e antioxidante em metodologia in vitro. As partes aéreas dessa espécie demonstraram atividade antioxidante em modelo usando o radical livre DPPH. As flores de C. chelidonioides mostraram grande potencial antibacteriano frente à bactéria Staphylococcus aureus resistente a meticilina MRSA, um dos principais responsáveis em casos de infecção hospitalar.
The species Calceolaria chelidonioides (Scrophulariaceae), not scientific described so for, was studied in pharmacological aspects aiming to identify some anti-microbial and antioxidant activity. The aerial parts showed antioxidant activity using in vitro DPPH model. The flowers from C. chelidonioides showed strong antibacterial potential against meticiline resistant Staphylococcus aureus (MRSA) strains the main responsible for hospital infection complications.
ABSTRACT
Do extrato butanólico de Croton campestris St. Hill. (Euphorbiaceae) foram isolados quatro flavonóides, todos O-glicosídeos da quercetina. Estas substâncias foram identificadas como 3-O-b-D-apiofuranosil-(1®2)-galactopiranosil quercetina (1), 3-O-b-D-galactopiranosil quercetina (hiperina) (2), 3-O-a-L-arabinopiranosil quercetina (guaijaverina) (3) e 3-O-a-L-ramnopiranosil quercetina (quercitrina) (4).O presente trabalho relata a presença destas substâncias pela primeira vez para esta espécie de Croton, cuja elucidação estrutural deu-se por espectroscopia em UV, EM e RMN, incluindo as técnicas bidimensionais: ¹H-¹H (2D NOESY, 2D COSY), ¹H-13C (2D HETCOR) e 13C (APT), além de comparações com os dados da literatura.
Four flavonoids were isolated from the butanolic extract of the aerial parts of Croton campestris St. Hill. (Euphorbiaceae). These compounds were identified as 3-O-b-D-apiofuranosyl-(1®2)-galactopyranoside quercetin (1), 3-O-b-D-galactopyranoside quercetin (hyperin) (2), 3-O-a-L-arabinopyranoside quercetin (guaijaverin) (3) and 3-O-a-L-ramnopyranoside quercetin (quercitrin) (4). They have been isolated for the first time from Croton campestris. Their structures were elucidated by UV, MS and NMR experiments including ¹H-¹H (2D NOESY, 2D COSY), ¹H-13C (2D HETCOR), 13C (APT) and by comparison of the spectral data with those reported in the literature.