Dalva Trevisan Ferreira

Chemical constituents from roots of Pyrostegia venusta and considerations about its medicinal importance

This paper describes the chemical constituents isolated from roots of Pyrostegia venusta. From ethanol extract of the roots allantoin, b-sitosterol, 3b-O-b-D-glupyranosylsitosterol and hesperedin were isolated. The structures of these natural products were identified on the basis of spectral data, including 2D NMR of the peracetyl derivative of hesperidin.

Synthesis of the naturally occurring naphtho-z.sfnc;2,3-bz.sfnc;pyran-5,10-quinones α-caryopterone,dihydro-α-caryopterone and their isomers 6-hydroxy-dehydro-α-lapachone and 6-hydroxy-α-lapachone

Abstract Isomeric 6- and 9-hydroxy-naphtho-z.sfnc;2,3-bz.sfnc;pyran-5,10-quinones were synthesised by alkylation-cyclisation of 2- and 3-hydroxyjuglone in a single step and can be distinguished by UV-visible spectra in the presence of additives and 1 HNMR.

Diterpenos, triterpenos e esteróides das flores de Wedelia paludosa

Phytochemical investigation of the flowers of Wedelia paludosa afforded two diterpenes, ent-kaur-16-en-19-oic acid and ent-kaur-9(11),16-dien-19-oic acid, three acylated triterpenes, 3b-O-hexa-decanoylolean-12-en-28-oic acid, 3b-O-pentadecanoylolean-12-en-28-oic acid and 3b-O-tetradecanoylolean-12-en-28-oic acid, and three steroids, stigmasterol, 3b-O-b-D-glycopyranosyl sitosterol and 3b-O-b-D-glycopyrano-sylstigmasterol. The substances were identified by their spectral data.

Antimicrobial activity and chemical investigation of Brazilian Drosera

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.

Eudesmanolide Lactones from Wedelia paludosa

Abstract Two new eudesmanolide lactones (1 and 2) were isolated from the flowers of Wedelia paludosa. The structures of these sesquiterpenoids were elucidated from spectral data.

Phytochemical and antifungal activity of anthraquinones and root and leaf extracts of Coccoloba mollis on phytopathogens

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%.

Free radical scavenging activity of Pfaffia glomerata (Spreng.) Pederson (Amaranthaceae)

OBJECTIVE : To evaluate the free radical scavenging and cytotoxic activities of the butanolic (BuOH) extract, methanolic (MeOH) extract and 20-hydroxyecdysone extracted from the roots of Pfaffia glomerata . MATERIALS AND METHODS : Pfaffia glomerata roots were collected, powdered and extracted with methanol by maceration at room temperature. The extract was concentrated under vacuum, yielding a residue, followed by a butanol extraction. The 20-hydroxyecdysone (EC) was obtained by chromatographic separation of the BuOH fraction. An amount of 10 mg of each dry extract and EC was dissolved in 0.1% dimethyl sulphoxide-phosphate-buffered-saline solution (DMSO-PBS) and screened for their capabilities on scavenging thiobarbiturate reactive substances (TBARS). The antioxidant activity of each extract was determined in vitro by measuring malonyldialdehyde (MDA) and 4-hydroxynonenal (4-HNE) in erythrocyte ghosts treated with ferric-ascorbate. The investigation has also included the cytotoxicity measurement by Trypan blue exclusion test and tetrazolium reduction assay in mice peritoneal macrophages. RESULTS : The free radical scavenging activity of EC was higher than that present in the BuOH fraction. The MeOH extract showed a remarkable pro-oxidant activity. The EC-free radical reaction-inhibition was almost twice of that of the control a-Tocopherol (aT). The Trypan blue exclusion assay confirmed toxicity of the MeOH extract, whose lethality surpassed 80% of the treated macrophages after 1 h of 0.01 mg exposure per 106 cells. CONCLUSIONS : The present study shows the antioxidant effect of the Brazilian Ginseng. The scavenging effect was evidenced for EC as well the BuOH fraction. The MeOH extract showed cytotoxicity on mice peritoneal macrophages. Such toxicity is probably due to ginsenosides present in this latter fraction and warrants further toxicological evaluation of the Brazilian Ginseng roots.

In vitro evaluation of the genotoxic activity and apoptosis induction of the extracts of roots and leaves from the medicinal plant Coccoloba mollis (Polygonaceae).

Coccoloba mollis (Family Polygonaceae) is a medicinal plant popularly used in cases of memory loss, stress, insomnia, anemia, impaired vision, and sexual impotence, but the scientific literature, to date, lacks studies on the biological effects of this species, particularly with regard to cytotoxicity and induction of DNA damage. The aim of the present study was to assess in vitro (in hepatic HTC cells) ethanolic extracts of the roots and leaves of C. mollis for cytotoxicity, genotoxicity, and induction of apoptosis. For these evaluations the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay, comet assay, micronucleus test with cytokinesis block, and an in situ test for detection of apoptotic cells with acridine orange staining were used. The results showed that the extract obtained from the roots of C. mollis is more cytotoxic than that obtained from the leaves and that the reduction in cell viability observed in the MTT assay was a result, at least in part, from the induction of apoptosis. Both extracts induced DNA damage at a concentration of 20 microg/mL in the comet assay, but no genotoxicity was detected with any of the treatments carried out in the micronucleus test.

Alcalóides de flores e folhas de Erythrina speciosa Andrews

In vitro bioassays with leave extracts of Erythrina speciosa showed promising activity against Trypanosoma cruzi. From the flowers of E. speciosa two alkaloids were isolated: erysotrine and erythartine. The leaves furnished one alkaloid, nororientaline. The structures were determined on the basis of spectroscopic evidence. This is the first report about the investigation of alkaloids in flowers and leaves of this species, as well the first report of nororientaline occurrence in this plant.

Phytotoxin produced by Bipolaris euphorbiae in-vitro is effective against the weed Euphorbia heterophylla

Four virulent strain isolates of the fungus, Bipolaris euphorbiae (previously identified as a Helminthosporium sp.), isolated from host plants in four states within Brazil were screened for the production of phytotoxins that promoted wilting and defoliation of the Brazilian weed, Euphorbia heterophylla, commonly found growing among soyabean crops. Only one isolate, B. euphorbiae Strain I (EUPH petropar from Mato Grosso state), produced phytotoxin in-vitro when grown in stationary culture for 7 d at 28 ° C on minimum salts medium supplemented with 1.5 % glucose as the sole carbon source. Phytotoxin was also produced when the fungal strain was grown on fructose, galactose, mannose, xylose and sucrose. The addition of nitrogen source (yeast extract, peptone or malt extract) to the culture medium did not influence phytotoxin production. The phytotoxin produced by Strain I was most active at pH 6.0, stable between pH 3-9, and was highly thermostable, remaining fully active when heated at 90 ° C for 1 h.