Estudo fitoquímico do decocto das folhas de Maytenus truncata Reissek e avaliação das atividades antinociceptiva, antiedematogênica e antiulcerogênica de extratos do decocto

The present paper describes the phytochemical investigation and biological activities of the chloroform, ethyl acetate and methanol extracts of leaf decocts of M. truncata Reiss (Celastraceae). Our studies afforded two flavonoid glycosides, quercetin-3-O-rhamnopyranosyl-O-glucopyranosyl- O-rhamnopyranosyl-O-galactopyranoside (1) and kampferol-3-O-rhamnopyranosyl-O-glucopyranosyl- O-rhamnopyranosyl-O-galactopyranoside (2) from the methanolic extract and dulcitol (3) from the ethyl acetate extract. Ethyl acetate and methanol extracts exhibited considerable antiulcerogenic and analgesic activities. The results of the phytochemical studies suggest that the healing activity of methanol extracts can be related to the presence of glycosyl flavonoids.

Ácido 15-desmetilisoplumierídeo, um novo iridóide isolado das cascas de Plumeria rubra e do látex de Himatanthus sucuuba

Himatanthus sucuuba and Plumeria rubra are used in folk medicine in Brazil to treat various ailments. The isolation of the new iridoid 15-demethylisoplumieride from the bark of Plumeria rubra L. var. acutifolia (Ait) Woodson and latex of Himatanthus sucuuba (Spruce) Woodson is reported. Other iridoid glycosides were obtained from both plants. The structures of these substances were elucidated by spectral analysis and comparison with data already reported.

Influência da temperatura de secagem sobre o rendimento e a composição química do óleo essencial de Tanaecium nocturnum (barb. Rodr.) bur. & K. Shum

The yields and chemical compositions of the essential oils obtained by steam distillation of the fresh and dried (30 and 40 ºC) leaves, stems and roots of Tanaecium nocturnum are reported. The identification and quantification of the volatile constituents were accomplished by GC/MS and GC/FID, respectively. The essential oils obtained from the various parts of the plant were constituted mainly of benzaldehyde. Large losses and variations in the quantities of the components during the drying process were observed. The presence of mandelonitrile in higher concentration in the stem and roots indicates that this species produces cyanogenic glycosides.

Descoloração redutiva de corantes azo e o efeito de mediadores redox na presença do aceptor de elétrons sulfato

We investigated the impact of sulphate and the redox mediator Anthraquinone-2,6-disulfonate (AQDS) on the decolorization of the azo dyes Congo Red (CR) and Reactive Black 5 (RB5). In anaerobic reactors free of extra sulphate dosage, the color removal efficiency decreased drastically when the external electron donor ethanol was removed. In presence of an extra dosage of sulphate, CR decolourisations were 47.8% (free of AQDS) and 96.5% (supplemented with AQDS). The decolourisations achieved in both reactors with RB5 were lower than the ones found with CR. Finally, the biogenic sulphide contribution on azo dye reduction was negligiable.

Antioxidant activities of isolated compounds from stems of Mimosa invisa Mart. ex Colla

This work describes the phytochemical study of stems of Mimosa invisa (Mimosaceae) and the evaluation of the antioxidant potential of isolated compounds. Cromatografic techniques were employed to isolate salicifoliol, pinoresinol, quercetin, quercetin-3-O-rhamnopyranosyl, quercetin-3-O-arabinofuranosyl lupeol, β-amyrin, sitosterol, p-hydroxy coumaric acid, 4-hydroxy-3-methoxy benzaldehyde (vanillin), 4-hydroxy-3,5-dimethoxy benzaldehyde, 4-hydroxy-3-methoxy benzoic acid and 4',6,7- trimethoxy flavonol. The latter had been previously described but the spectrometric data shown indicated the structure required review. The antioxidant activity of the compounds was evaluated by the DPPH test and capability of NBT reduction by superoxide radicals. Quercetin glycosides showed lower antioxidant potential than quercetin and, salicifoliol was found to be more active than pinoresinol.

Flavonoids and a neolignan glucoside from Guarea macrophylla (Meliaceae)

This work describes the phytochemical study of the methanol extract obtained from leaves of Guarea macrophylla, leading to the isolation and identification of three flavonoid glycosides (quercetin 3-O-β-D-glucopyranoside, quercetin 3-O-b-D-galactopyranoside, kaempferol 7-O-β-D-glucopyranoside) and a neolignan glucoside, dehydrodiconiferyl alcohol-4-β-D-glucoside. All compounds were identified by a combination of spectroscopic methods (¹H, 1D, 2D NMR, 13C and UV), ESI-MS and comparison with the literature data. This is the first report of flavonoids in the genus Guarea and of a neolignan glucoside in the Meliaceae family.

Utilização de detecção por espalhamento de luz evaporativo para a análise de produtos naturais

The interest in the use of evaporative light scattering detector (ELSD) for the analysis of different classes of natural products has grown over the years. This is because this detector has become an excellent alternative compared to other types of detectors, such as the refractive index detector and the ultraviolet (UV) detector. This review describes the basic principles of ELSD functioning and discusses the advantages and disadvantages in using an ELSD for the analysis of organic compounds. Additionaly, an overview, covering the last 23 years, of ELSD applications in natural products analysis (saponins, terpenes, carbohydrates, glycosides, alkaloids, steroids, flavonoids, peptides, polyketides, coumarins and iridoids) is presented and discussed.

Estudo fitoquímico e avaliação da atividade anti-inflamatória de Aeschynomene fluminensis vell. (Fabaceae)

Phytochemical investigation of Aeschynomene fluminensis leaves and branches led to isolation of the flavonoid glycosides kaempferol 3,7-di-O-α-L-rhamnopyranoside, kaempferol 7-O-α-L-rhamnopyranoside, kaempferol 3-O-apiofuranosil-7-O- rhamnopyranoside, quercitin 3-O-α-L-rhamnopyranoside, quercitin 3-O-arabinofuranoside, 8-β-D-glucopyranosyl 4',5,7-trihydroxyflavanone, the isoflavonoid 4',7-di-hydroxy-isoflavone, the dimer epicatechin-(2β→7, 4β→8)- epicatechin, the polyol 3-O-methyl-chiro-inositol and two steroids in sitosterol and stigmasterol mixture. These compounds were identified by NMR ¹H and 13C and compared with literature data. Anti-inflammatory activity of the crude methanolic extract and its fractions was evaluated.

Flavonoides glicosilados de Erythroxylum pulchrum a. st.-hil. (Erythroxylaceae)

The phytochemical investigation of Erythroxylum pulchrum St. Hil. (Erythroxylaceae) led to the isolation of three known flavonoid glycosides quercetin-3-O-α-L-rhaminoside, ombuin-3-ruthinoside and ombuin-3-ruthinoside-5-glucoside. These flavonoids are being described for the first time in this E. pulchrum. The structures of the compounds were determined by analysis of IR, MS and NMR data, as well as by comparison with literature data. The methanolic extract of leaves from E. pulchrum inhibited the growth of the Bacillus subtilis CCT 0516, Escherichia coli ATCC 2536, Pseudomonas aeruginosa ATCC 8027, P. aeruginosa ATCC 25619, Staphylococcus aureus ATCC 6538, S. aureus ATCC 25925, Streptococcus sanguinis ATCC 15300, S. salivarius ATCC 7073, S. mutans ATCC 25175 and Streptococcus ATCC. S. aureus ATCC 25925 was the most sensitive among the other S. sanguinis while S. salivarius proved the most resistant.

CHEMICAL COMPOSITION VARIABILITY IN THE Uncaria tomentosa (cat’s claw) WILD POPULATION

Uncaria tomentosa (cat's claw) is a vine widely distributed throughout the South-American rainforest. Many studies investigating the chemical composition of cat's claw have focused on the pentacyclic (POA) and tetracyclic oxindole alkaloids (TOA), quinovic acid glycosides (QAG), and polyphenols (PPH). Nevertheless, it is still uncertain how environmental factors affect chemical groups. The aim of this work was to better understand the influence of environmental factors (geographic origin, altitude, and season) on cat's claw chemical composition. Stem bark, branches and leaf samples were extracted and analyzed by HPLC-PDA. The data obtained were explored by multivariate analysis (HCA and PCA). Higher amounts of oxindole alkaloids and PPH were found in leaves, followed by stem bark and branches. No clear relationship was verified among geographic origin or altitude and chemical composition, which remained unchanged regardless of season (dry or rainy). However, three oxindole alkaloid chemotypes were clearly recognized: chemotype I (POA with cis D/E ring junction); chemotype II (POA with trans D/E ring junction); and chemotype III (TOA). Thus, environmental factors appear to have only a minor influence on the chemical heterogeneity of the cat's claw wild population. Nevertheless, the occurrence of different chemotypes based on alkaloid profiles seems to be clear.

Poisoning by Poiretia punctata in cattle and sheep

Poiretia punctata (Willd.) Desv. was associated with cattle and sheep poisoning on nine farms in the State of Sergipe, northeastern Brazil. The animals were found dead or died later after showing clinical signs for up to 18 hours. Two sheep that ingested 40g/kg body weight (g/kg) of fresh P. punctata died three and eight hours after ingestion, respectively. Another sheep that ingested 40g/kg five days after plant collection showed mild clinical signs and recovered after 24 hours. Two sheep that received 20g/kg and another that ingested three daily doses of 20g/kg showed clinical signs, but recovered. Two cattle that ingested 20g/kg of the fresh plant exhibited clinical signs and recovered. The clinical observations of poisoning were depression, ataxia, loss of equilibrium, broad-based stance, head down, falls, mandibular trismus, opisthotonous, nystagmus, and recumbence. Significant gross and histologic lesions were not observed. Samples of P. punctata were analyzed for nitrates, cyanogenic glycosides, and sodium monofluouracetate with negative results. It is concluded that P. punctata is a toxic plant that caused death in cattle and sheep in the State of Sergipe.

Comparative uptake and metabolism of 2-[14C]-2,4-dichlorophenoxyacetic acid in callus cultures of monocot (Dioscorea spp.) and dicot (Nicotiana tabacum L.) plants

(Comparative uptake and metabolism of 2-[14C]-2,4-dichlorophenoxyacetic acid in callus cultures of monocot (Dioscorea spp.) and dicot (Nicotiana tabacum L.) plants). The uptake and metabolism of 2-[14C]-2,4-dichlorophenoxyacetic acid (2,4-D) were investigated in leaf calluses of Nicotiana tabacum, tuber calluses of Dioscorea opposita and calluses derived from zygotic embryos, leaves and petioles of Dioscorea composita. Striking similarities were evident in the patterns of 2,4-D metabolites and their chemical characteristics in the three callus types of D. composita compared, but significant differences were detected among the patterns of rnetabolites in the three species studied. Preliminary investigations on the stability of various metabolites (separated using TLC) by hydrolysis showed that sugar esters appeared to be the major metabolites in tobacco whilst in yams (D. opposita) glycosides were shown to be the main ones, which indicated a similarity between plants of Gramineae and Dioscoreaceae in terms of 2,4-D metabolism. Release of 2,4-D from tobacco callus cells upon their transfer to 2,4-D-free medium was detected and the implications of this are discussed in relation to the cultural conditions necessary to induce morphogenesis in vitro.

Foliar flavonoids of nine species of Bauhinia

Foliar flavonoids of nine species of Bauhinia were isolated and identified. All the compounds correspond to glycosides derived from kaempferol, quercetin, isorhamnetin and myricetin. Derivatives of the latter aglyconhe seem to be rare in Bauhinia. Derivatives of isorhamnetin are commonly found in species of subgenus Bauhinia and were not detected in the two species of subgenus Phanera. Flavonoid patterns of species of the former subgenus are in general more complex than those of the latter.

Rhein induces apoptosis of human gastric cancer SGC-7901 cells via an intrinsic mitochondrial pathway

Rhein is a primary anthraquinone found in the roots of a traditional Chinese herb, rhubarb, and has been shown to have some anticancer effects. The aim of the present study was to investigate the effect of rhein on the apoptosis of the human gastric cancer line SGC-7901 and to identify the mechanism involved. SGC-7901 cells were cultured and treated with rhein (0, 50, 100, 150, and 200 µM) for 24, 48, or 72 h. Relative cell viability assessed by the MTT assay after treatment was 100, 99, 85, 79, 63% for 24 h; 100, 98, 80, 51, 37% for 48 h, and 100, 97, 60, 36, 15% for 72 h, respectively. Cell apoptosis was detected with TUNEL staining and quantified with flow cytometry using annexin FITC-PI staining at 48 h after 100, 200 and 300 µm rhein. The percentage of apoptotic cells was 7.3, 21.9, 43.5%, respectively. We also measured the mRNA levels of caspase-3 and -9 using real-time PCR. Treatment with 100 µM rhein for 48 h significantly increased mRNA expression of caspase-3 and -9. The levels of apoptosis-related proteins including Bcl-2, Bax, Bcl-xL, and pro-caspase-3 were evaluated in rhein-treated cells. Rhein increased the Bax:Bcl-2 ratio but decreased the protein levels of Bcl-xL and pro-caspase-3. Moreover, rhein significantly increased the expression of cytochrome c and apoptotic protease activating factor 1, two critical components involved in mitochondrial pathway-mediated apoptosis. We conclude that rhein inhibits SGC-7901 proliferation by inducing apoptosis and this antitumor effect of rhein is mediated in part by an intrinsic mitochondrial pathway.