No abstract available

[en] Earlier 5-arylidene N,N-dimethylbarbiturates 1-24 were reported by our group as novel antioxidant, nevertheless, urease inhibitory activity of these compounds has not been investigated at all. In the present study, compounds 1-24 were synthesized by the reaction of N,N-dimethylbarbituric acid with different aromatic aldehydes, and screened for their in vitro urease inhibitory effects. Compound 7, was found to be most active urease inhibitor in the series. Nonetheless, compounds 11, 12, and 19 were also active against urease enzyme. (author)

[en] Highlights: • The first time to investigate the mechanism of AGEs-associated impaired vasodilation. • AGEs impair endothelial-dependent but not endothelial-independent vasodilation. • AGEs inhibited eNOS mediated NO production and down-regulated eNOS expression. • Arginase overexpression by AGEs plays important role in the impaired vasodilation. • NADPH oxidase stimulation also mediates AGEs impaired vasodilation. Advanced glycation endproducts (AGEs) play a major role in the development of many vascular complications that are mediated by endothelial dysfunction. The present work aimed to investigate the mechanism by which AGEs impair vasodilation.

[en] The activity of the enzyme urease is known to be inhibited by the heavy metal cadmium. The binding of cadmium to urease and the consequent changes of the enzyme structure are the basis of the surface plasmon resonance (SPR) biosensing system reported herein. To facilitate the formation of a self-assembled monolayer (SAM) of the urease on gold-coated glass SPR sensor disks, the enzyme has been modified with N-succinimidyl 3-(2-pyridyldithiol) propionate (SPDP). The urease monolayer was exposed to trace levels of cadmium ions and monitored by SPR. From circular dichroism (CD) data, it is believed that the conformation of the active nickel site of the urease changes upon binding of the cadmium ions. It is this change of the enzyme monolayer, measured by SPR, which has been related to the cadmium ion concentration in the range of 0-10 mg l^-1. These data are the first report of a SPR biosensor capable of detecting metal ions

[en] Eight compounds have been isolated for the first time from Vernonia cinerascens namely, 2-hydroxy-3-methoxy-5-(2-propenyl)-phenol (1), vanillic acid (2), isoferulic acid (3), caffeic acid (4), methyl gallate (5), uridine (6), 3'-methylquercetin (7) and quercetin (8), respectively. Their structures have been elucidated based on EI-MS, HREI-MS, FAB-MS, HRFAB-MS, /sup 1/H-, /sup 13/C-NMR spectroscopic data and in comparison with the reported data. All these compounds exhibited promising antioxidant and significant urease inhibitory activities. (author)

No abstract available

[en] This study determined (a) the activity of the selected enzymes of C (invertase and cellulase), N (urease), P (acid phosphatase, AcP and alkaline phosphatase, AlkP) cycling, as well as soil microbial biomass carbon (SMBC) in the rhizosphere of Agave angustifolia Haw. (maguey espadin) cultivated in valley, hill and mountain soils in Tlacolula, Oaxaca (Mexico), and (b) changes in selected biochemical soil properties associated with seasonality and plant age. Three maguey espadin plantations with two replicates per topography were selected. Rhizosphere soil sampling was carried out for one year. AcP and urease activities were highest in mountain sites. AlkP and cellulase activities were highest in hill and mountain sites. Invertase activity and SMBC were not different among sites. Phosphatase activity showed no temporal changes. Cellulase and invertase activities were highest in December; maximum urease activity was in October and February. SMBC was highest in August. AcP activity was highest in 0-2 years old plants. AlkP activity and SMBC were highest in 2.1-4 years old plants. Urease, cellulase and invertase activity was not affected by plant age. Significant effects for the site*seasonality*plant age interaction suggest that biochemical soil properties were influenced by site. Mountain soils displayed the highest enzyme activity, which can accelerate soil organic matter turnover and contribute to the longterm sustainability of maguey espadin cropping under rainfed conditions. (author)

[en] The effects of Typha latifolia L. on the remediation of cadmium (Cd) in wetland soil were studied using greenhouse pot culture, with soil Cd concentrations of 0, 1, and 30 mg/kg. The T. latifolia showed excellent tolerance to the low and high concentrations of Cd in soil. A higher bioaccumulation of Cd was observed in roots, with bioconcentration factor values of 51.6 and 9.30 at 1 and 30 mg/kg of Cd stress, respectively; Cd concentration in T. latifolia was 77.0 and 410.7 mg/kg, and Cd content was 0.11 and 0.22 mg/plant at the end of the test period. The soil enzyme activities (urease, alkaline phosphatase, and dehydrogenase) exposed to 0, 1, and 30 mg/kg Cd were measured after 0-, 30-, 60-, and 90-day cultivation period and showed an increasing trend with exposure time. Metabolite changes were analyzed using liquid chromatography-mass spectrometry, combined with principal component analysis and orthogonal partial least squares discrimination analysis. Among 102 metabolites, 21 compounds were found and identified, in response to treatment of T. latifolia with different Cd concentrations. The results showed that T. latifolia had a good remedial effect on Cd-contaminated soil. The metabolites of T. latifolia changed with different Cd concentration exposures, as a result of metabolic response of plants to Cd-contaminated soils. Analysis of metabolites could better reveal the pollution remediation mechanism involved in different Cd uptake and accumulate properties.

[en] Carriers modified by synergistic radiation grafting are used as affinity media for the separation of a lectin from a mistletoe extract. The grafted supports show distinctly superior properties when compared to conventional affinity media. The application of these carriers as urease immobilization support incorporated in a conductimetric bioreactor for urea analysis as potential diagnostic device in renal diseases is also described. (author)

[en] Changes in urease and catalase enzyme activities were investigated in the soils of plants grown under different shade conditions to reveal how the shade conditions and sapling species affect the urease and catalase enzyme activities in the soil. In this study, four different plant species were grown under five different shade conditions during one vegetation period, and soil analyses were performed to investigate the change in urease and catalase enzyme activities. As a result, it was determined that, of the soil characteristics considered, urease, EC, lime, OM, P, and K differed significantly according to the plant species, while catalase, urease, EC, and OM differed significantly according to the amount of light. In addition, it was found that soil characteristics showed different levels of variation depending on the light in the areas where different plant species were grown. The amount of light was linearly correlated with EC and with OM, while catalase and urease were in a linear relationship with each other. EC was statistically significantly correlated with all the characteristics except urease; this relationship was negative with light, P, and K. The strongest relationship was between lime (CaOH) and OM.