787 resultados para Euphorbia hirta


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A copper-containing amine oxidase from the latex of Euphorbia characias was purified to homogeneity and the copper-free enzyme obtained by a ligand-exchange procedure. The interactions of highly purified apo- and holoenzyme with several substrates, carbonyl reagents, and copper ligands were investigated by optical spectroscopy under both aerobic and anaerobic conditions. The extinction coefficients at 278 and 490 nm were determined as 3.78 × 105 m−1 cm−1 and 6000 m−1 cm−1, respectively. Active-site titration of highly purified enzyme with substrates and carbonyl reagents showed the presence of one cofactor at each enzyme subunit. In anaerobiosis the native enzyme oxidized one equivalent substrate and released one equivalent aldehyde per enzyme subunit. The apoenzyme gave exactly the same 1:1:1 stoichiometry in anaerobiosis and in aerobiosis. These findings demonstrate unequivocally that copper-free amine oxidase can oxidize substrates with a single half-catalytic cycle. The DNA-derived protein sequence shows a characteristic hexapeptide present in most 6-hydroxydopa quinone-containing amine oxidases. This hexapeptide contains the tyrosinyl residue that can be modified into the cofactor 6-hydroxydopa quinone.

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Leonardo da Vinci; 7 51/64 in.x 6 19/64 in.; pen, ink and red chalk on paper

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Also published in Linné's Amoenitates academicae, v. 3, ed. 1, 1756; ed. 2, 1764; ed. 3, 1787, p. 100-131. cf. Hulth, Bibl. Linn. (1907) p. 85.

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Of late, decrease in mineral oil supplies has stimulated research on use of biomass as an alternative energy source. Climate change has brought problems such as increased drought and erratic rains. This, together with a rise in land degeneration problems with concomitant loss in soil fertility has inspired the scientific world to look for alternative bio-energy species. Euphorbia tirucalli L., a tree with C3/CAM metabolism in leaves/stem, can be cultivated on marginal, arid land and could be a good alternative source of biofuel. We analyzed a broad variety of E. tirucalli plants collected from different countries for their genetic diversity using AFLP. Physiological responses to induced drought stress were determined in a number of genotypes by monitoring growth parameters and influence on photosynthesis. For future breeding of economically interesting genotypes, rubber content and biogas production were quantified. Cluster analysis shows that the studied genotypes are divided into two groups, African and mostly non-African genotypes. Different genotypes respond significantly different to various levels of water. Malate measurement indicates that there is induction of CAM in leaves following drought stress. Rubber content varies strongly between genotypes. An investigation of the biogas production capacities of six E. tirucalli genotypes reveals biogas yields higher than from rapeseed but lower than maize silage.

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This study aimed to assess the genetic inheritance, determine the better DNA isolation protocol for this species and to identify molecular markers associated with the Wild Poinsettia (Euphorbia heterophylla L.) resistance ALS- and PROTOX- inhibiting herbicides and. The genetic inheritance of resistance was determined from crosses between E. heterophylla biotypes susceptible (S) and resistant (R), backcrosses and F2 generation. The complete dominance of resistance was confirmed with dose response curves. Ten adjusted methods for DNA isolation described in the literature were tested. The specific primers for ALS and PROTOX genes were designed from the consensus DNA sequence of these genes, obtained by aligning the gene sequences of the species Manihot esculenta and Ricinus communis L. Additionally, it was assessed the transferability of twenty SSR (simple sequence repeat) markers designed for Manihot esculenta, because among the species of Euphorbiaceae with more developed SSRs markers, because it is the closest relative phylogenetic species of E. heterophylla. Regarding genetic inheritance, the frequencies observed in the F1, F2, RCs and RCr did not differ significantly from the expected frequencies for a trait controlled by two dominant genes for multiple resistance and a single dominant gene for simple resistance to ALS- and PROTOX-inhibiting herbicides. The similar levels of resistance to dosage up to 2000 g i.a. ha-1 of fomesafen and dosage up to 800 g i.a. ha-1 of imazethapyr observed in F1 (heterozygous) and homozygous R biotype confirm the complete dominance of resistance to PROTOX- and ALS-inhibiting herbicides, respectively. The 0.2%BME protocol allowed the isolation of 7,083 ng μL-1 DNA, significantly (P=0.05) higher than other methods. Co-isolation of phenolic compounds was observed in FENOL and 3%BME+TB methods, but the addition of polyvinylpyrrolidone (PVP40) in the protocol extraction buffer 3%BME+TA solved this problem. The primers designed for ALS and PROTOX genes amplified but not showed no visible polymorphism in agarose gel between the S and R biotypes of E. heterophylla. Regarding the SSR transferability, ten markers were transferred to E. heterophylla, however, these six primers showed polymorphism among S and R biotypes.

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Purpose: This study was aimed to evaluate the antioxidant activity of the methanol extract of Euphorbia spinidens (Euphorbiaceae) and its effect on Herpes simplex virus type-1 (HSV-1) replication. Methods: The methanol extract of aerial parts of E. spinidens collected from Khorasan State in North- Eastern part of Iran was used in this study. Total phenolic, flavonoid contents and the antioxidant activity were evaluated using Folin-Ciocalteu method, aluminum chloride colorimetric method and β- carotene-linoleate model system, respectively. Both the cytotoxic and antiviral effects of the crude extract on Vero cell line were determined by quantifying the viability of Vero cells using 3-(4,5- dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)2H-tetrazolium (MTS) assay. Results: Total phenolic and flavonoid contents of E.spinidens were 70 ± 1 mg of gallic acid equivalent/g of dry extract (mg GAE/g extract) and 49.66 ± 1.00 mg rutin equivalent/g of dry extract (mg RTN/g extract), respectively. Antioxidant activity was 44 ± 1 % compared with the standard, buthylated hydroxytuloene (BHT). The 50 % cytotoxic concentration (CC50) of the extract on Vero cells was 5.072 ± 0.063 mg/ml and its antiviral concentration of 50 % effectiveness (EC50) value was 0.34 ± 0.003 mg/ml. Conclusion: The findings of this study show that the methanol extract of E. spinidens has high content of phenolic and flavonoid compounds with good antioxidant activity. Furthermore, this extract has significant antiviral effect on HSV-1 probably due to the inhibition of viral replication.

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Este trabalho foi desenvolvido com a finalidade de apresentar algumas considerações sobre a biologia reprodutiva de Clidemia Iurta, Conclui-se que: I ) A ântese tem início em torno das 18:00 h e termina por volta das 09:00 h do dia seguinte; 2) Esta é uma espécie preferencialmente alógama, porém não apresenta auto-incompatibilidade genética; 3) A polinização parece depender de agentes polinizadores, principalmente abelhas das famílias Apidae (Bambus, Melipona, Euglossa, Trigona) e Halictidae.

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Natural products have widespread biological activities, including inhibition of mitochondrial enzyme systems. Some of these activities, for example cytotoxicity, may be the result of alteration of cellular bioenergetics. Based on previous computer-aided drug design (CADD) studies and considering reported data on structure-activity relationships (SAR), an assumption regarding the mechanism of action of natural products against parasitic infections involves the NADH-oxidase inhibition. In this study, chemometric tools, such as: Principal Component Analysis (PCA), Consensus PCA (CPCA), and partial least squares regression (PLS), were applied to a set of forty natural compounds, acting as NADH-oxidase inhibitors. The calculations were performed using the VolSurf+ program. The formalisms employed generated good exploratory and predictive results. The independent variables or descriptors having a hydrophobic profile were strongly correlated to the biological data.

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Aim of the study: Alcoholic or hydroalcoholic preparations of the plant Solidago chilensis Meyen (Asteraceae) are employed in popular medicines to treat inflammation. The anti-inflammatory effects of the hydroalcoholic extract of aerial parts of the plant (93% ethanol) were investigated and the main components of the extract were identified. Materials and methods: Ear oedema was induced in male Wistar rats by topical application of the chloroform fraction of latex-extract from Euphorbia milii. Leukocyte mobilisation was quantified after air-pouch inflammation evoked by oyster glycogen. Leukocyte-endothelial interactions and mast cell degranulation were quantified by intravital microscopy. The extract itself was characterised via HPLC-DAD-MS and HPLC-MS/MS. Results: Topical (12.5-50 mg/kg) or intraperitoneal (25 or 50 mg/kg) administrations of the extract reduced ear oedema formation (>25% reduction). Intraperitoneal applications of 25 mg/kg of extract inhibited the migration of polymorphonuclear cells into the inflamed cavity (about 50%). In addition, the rolling behaviour and adherence of circulating leukocytes to postcapillary venules of the mesentery network was diminished (50%), but the mast cell degranulation in the perivascular area was not affected. The major components of the extract were identified as caffeoylquinic acid derivatives and the flavonoid rutin. Conclusions: The data presented herein show local and systemic anti-inflammatory effects of the hydroalcoholic extract of aerial parts of Solidago chilensis, and implicate the inhibition of leukocyte-endothelial interactions as an important mechanism of the extract`s action. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

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Estudou-se em laboratório a atividade moluscicida de 68 extratos de 23 plantas brasileiras. As soluções em água desclorada dos extratos hexânicos e etanólico, nas concentrações de 1, 10 e 100 ppm, foram testadas sobre caramujos adultos e desovas de Biomphalaria glabrata, criados em laboratório. As plantas que demonstraram ação moluscicida na concentração de 100 ppm foram: Arthemisia verlotorum Lamotte, Caesalpinia peltophoroides Benth, Cassia rugosa G.Don., Eclipta alba Hassk, Euphorbia pulcherrima Willd, Euphorbia splendens Bojer, Joannesia princeps Vell, Leonorus sibiricus L.,Macrosiphonia guaranitica Muell,Nerium oleander L., Palicourea nicotianaefolia Cham, e Schlech., Panicum maximum M., Rumex crispus L., Ruta graveolens L., e Stryphnodendron barbatiman M.