Résumé
A protocol was developed for the micropropagation of Plumbago scandens L. from the shoot tip and node explants.The best response of shoot elongation (10.18±2.01 mm) was observed on MS basal medium supplemented with 0.02 mg/L IAA – 0.02 mg/L GA3. The maximum number of root induction (10.0±2.21) and shoot elongation (8.24±3.24 mm) was observed on medium containing 0.01 mg/L IBA and 0.01 mg/L GA3. The in vitro propagated plants were transferred to soil with 80% survival rate. Profuse compact callus was induced and proliferated from several explants (cotyledons, internodes, hypocotyls and roots) cultured on MS medium supplemented with all the combinations of 2,4-D – GA3 or 2,4-D alone and combinations of IAA – BAP or IAA alone, and the highest percentage of friable callus (90%) were induced in the sections of compact callus using 2.0 mg/L IAA – 0.02 mg/L BAP – 0.5 mg/L GA3.The qualitative determination of chemical constituents in the extracts was evaluated by a gas chromatography coupled to a mass spectrometry, and it was verified the presence of plumbagin only in root extracts but not in in vitro plantlets.The antibacterial activity of root extracts against various pathogenic bacteria, and the minimum inhibitory concentrations (MICs) was determined. Chloroform extracts showed good antibacterial activity against Neisseria gonorrhoeae between 0.4 to 1.0 mg/L with 20.4 to 30.0 mm (diameter zone of inhibition); inhibition against Staphylococcus aureus was moderate, and lower against Escherichia coli. Chloroform extracts had the lowest MICs for N. gonorrhoeae (<0.1 mg/mL per disc), and the activities against S. aureus (MIC 0.2 mg/mL) and E. coli (MIC 0.4 mg/mL) were less pronounced.
Résumé
The aim of this work was to study the phytochemical and antifungal activity of anthraquinones and root and leaf extracts of Coccoloba mollis on phytopathogens. The chemical analysis of ethanolic extracts showed a mixture of long-chain hydrocarbons, carboxyl esters and 3-taraxerone in the leaf extract. Two anthraquinones (emodin and physcion) were isolated and identified from the root extract. Phytochemical screening using the pharmacognostic methods revealed the presence of flavonoids and tannins in the leaves and roots. Anthraquinones were only found in the root extract, no alkaloids, coumarins, saponins and simple phenolics were present. The antifungal activity of C. mollis extracts and anthraquinones isolated from the root of this plant against Botryospheria ribis, B. rhodina, Lasiodiplodia theobromae and Fusarium sp showed promising results for their use as fungicides, where emodin was the most active compound, which inhibited the microorganisms tested up to 44 percent.
Résumé
The common everyday use of medicinal plants is an ancient, and still very widespread practice, whereby the need for studies on their possible toxicity and mutagenic properties. The species Coccoloba mollis has been much used in phytotherapy, mainly in cases involving loss of memory and stress. In order to investigate its genotoxic and mutagenic potential, ethanolic extracts from the leaves and roots underwent Salmonella/microsome assaying (TA98 and TA100 strains, with and without exogenous metabolism - S9), besides comet and micronucleus tests in vivo.There was no significant increase in the number of revertants/plate of Salmonella strains in any of the analyzed root-extract concentrations, although the extract itself was extremely toxic to the Salmonella TA98 strain in the tests carried out with S9 (doses varying from 0.005 to 0.5 µg/plate). On the other hand, the leaf-extract induced mutations in the TA98 strain in the absence of S9 in the highest concentration evaluated, although at very low mutagenic potency (0.004 rev/µg). Furthermore, there was no statistically significant increase in the number of comets and micronuclei, in treatments involving Swiss mice. It was obvious that extracts of Coccoloba mollis, under the described experimental conditions, are not mutagenic.
Sujets)
Animaux , Microsomes , Plantes médicinales , Salmonella , Test des comètes , Tests de micronucleus , Tests de mutagénicité , PolygonaceaeRésumé
The chemical study of Spathodea campanulata (Bignoniaceae) roots peels afforded an iridoid glucoside(ajugol) and two phenolic derivatives (p-hydroxy-benzoic acid and methyl p-hydroxy-benzoate). Thecompounds were characterized upon spectral data interpretation. Bioactivities of the constituents wereevaluated against fungus Cladosporium herbarum.
O estudo químico das cascas das raízes de Spathodea campanulata (Bignoniaceae) conduziu ao isolamentode um irióide glicosilado (ajugol) e dois derivados fenólicos (ácido p-hidroxi-benzóico e p-hidroxi-benzoato demetila). Os compostos foram identificados com base na interpretação dos seus dados espectrais. A atividadebiológica destes constituintes foi avaliada contra o fungo Cladosporium herbarum
Sujets)
Bignoniaceae , Composés PhénoliquesRésumé
The antimicrobial activity of three different extracts (hexanic, ethyl acetate, methanol) obtained from Brazilian Drosera species (D. communis, D. montana var. montana, D. brevifolia, D. villosa var. graomogolensis, D. villosa var. villosa, Drosera sp. 1, and Drosera sp. 2 ) were tested against Staphylococcus aureus (ATCC 25923), Enterococcus faecium (ATCC23212), Pseudomonas aeruginosa (ATCC27853), Escherichia coli (ATCC11229), Salmonella choleraesuis (ATCC10708), Klebsiella pneumoniae (ATCC13883), and Candida albicans (a human isolate). Better antimicrobial activity was observed with D. communis and D. montana var. montana ethyl acetate extracts. Phytochemical analyses from D. communis, D. montana var. montana and D. brevifolia yielded 5-hydroxy-2-methyl-1,4-naphthoquinone (plumbagin); long chain aliphatic hydrocarbons were isolated from D. communis and from D. villosa var. villosa, a mixture of long chain aliphatic alcohols and carboxylic acids, was isolated from D. communis and 3b-O-acetylaleuritolic acid from D. villosa var. villosa.