Search results for "leave"
showing 10 items of 372 documents
Superposing significant interaction rules (SSIR) method: a simple procedure for rapid ranking of congeneric compounds
2020
The Superposing Significant Interaction Rules (SSIR) method is revised and implemented. The method is a simple combinatorial procedure, which deals with in situ generated rules among a dichotomized congeneric molecular family, selecting the most probabilistically relevant ones. The mere counting of the number of relevant rules attached to new compounds generates a molecular ranking useful for database filtering, refinement and prediction. The algorithm only needs for a symbolic molecular representation and this allows for mining the database in a confidential manner. Third parties will not know the real compounds that are on the way to be worked out. The procedure is tested for a complete s…
Long-term effects of soil management on ecosystem services and soil loss estimation in olive grove top soils
2016
Soil management has important effects on soil properties, runoff, soil losses and soil quality. Traditional olive grove (OG) management is based on reduced tree density, canopy size shaped by pruning and weed control by ploughing. In addition, over the last several decades, herbicide use has been introduced into conventional OG management. These management strategies cause the soil surface to be almost bare and subsequently high erosion rates take place. To avoid these high erosion rates several soil management strategies can be applied. In this study, three strategies were assessed in OG with conventional tillage in three plots of 1. ha each. Soil properties were measured and soil erosion …
Pesticide analysis in coffee leaves using a quick, easy, cheap, effective, rugged and safe approach and liquid chromatography tandem mass spectrometr…
2017
An analytical method using a quick, easy, cheap, effective, rugged and safe (QuEChERS) procedure for multi-residue determination of 52 pesticides in coffee leaf extractshas been developed and validated according to SANTE/11945/2015 guidelines. Different sorbent combinations for dispersive solid phase extraction (d-SPE) clean-up as well as dispersive liquid-liquid microextraction (DLLME) were tested. The relative standard deviations (RSDs) for the recovery of 87-94% of pesticides added to coffee leaf extracts,was ≤20% for samples spiked at concentrations up to 50ng*g-1 depending on the clean-up procedures. However, samples spiked with a 100ng*g-1 pesticide mixture gave RSDs>20% for most pest…
Light-induced proton slip and proton leak at the thylakoid membrane
2005
A treatment of leaves of Spinacia oleracea L. with light or with the thiol reagent dithiothreitol in the dark led to partly uncoupled thylakoids. After induction in intact leaves, the partial uncoupling was irreversible at the level of isolated thylakoids. We distinguish between uncoupling by proton slip, which means a decrease of the H+/e(-) -ratio due to less efficient proton pumping, and proton leak as defined by enhanced kinetics of proton efflux. Proton slip and proton leak made about equal contributions to the total uncoupling. The enhanced proton efflux kinetics corresponded to reduction of subunit CF1-gamma of the ATP synthase as shown by fluorescence labeling of thylakoid proteins …
Activity of lupane triterpenoids from Maytenus species as inhibitors of nitric oxide and prostaglandin E2
2005
In the present study, we report that three new lupane triterpenes (1-3), in addition to 16 known ones (4-19), were isolated from the root bark of Maytenus cuzcoina and the leaves of Maytenus chiapensis. Their structures were elucidated by spectral analysis, including homonuclear and heteronuclear correlation NMR experiments (COSY, ROESY, HSQC, and HMBC). The natural compounds and derivatives 6a, 6b, 9a, and 9b have been tested for potential anti-inflammatory activity, and several compounds including 3-epicalenduladiol (2), 11alpha-hydroxy-glochidone (3), rigidenol (6), acetoxy-rigidenol (6a), 11alpha-acetoxy-30-chloro-3-oxo-lup-20(29)-ene (6b), betulin (9), 28-acetoxy-betulin (9a), epibetul…
Crystal structure of [Cu(N-quinolin-8-yl-p-toluenesulfonamidate)2]: study of its interaction with DNA and hydrogen peroxide
2001
A new copper complex with N-quinolin-8-yl-p-toulenesulfonamide has been prepared and characterised. The compound crystallises in the triclinic system, space group P1, with a=13.457(3), b=15.067(5), c=18.589(3) A; α=112.05(2), β=93.92(2), γ=108.30(2)° and Z=4. The geometry of the Cu(II) ion is distorted square planar. The N-quinolin-8-yl-p-toulenesulfonamidate anion behaves as a bidentate ligand through the N s u l f o n a m i d a t e and N q u i n o l i n e atoms. The complex does not cleave DNA in the presence of hydrogen peroxide.
Cytotoxic bufadienolides from the leaves of a medicinal plant Melianthus comosus collected in South Africa.
2020
Abstract From the leaves of South African medicinal plant Melianthus comosus, four previously undescribed bufadienolides, 16β-formyloxymelianthugenin (1), 2β-acetoxymelianthusigenin (2), 2β-hydroxy-3β,5β-di-O-acetylhellebrigenin (3), and 2β-acetoxy-5β-O-acetylhellebrigenin (4) were isolated together with two known bufadienolides. The structural elucidation of the compounds was based on 1D and 2D NMR spectroscopy, high-resolution mass spectrometry, and other spectroscopic methods. The relative configurations were determined by single-crystal X-ray crystallography analysis and NOESY correlations. The isolated compounds displayed strong cytotoxicity against MCF-7 breast cancer cells, sensitive…
Anti-inflammatory and antiallergic activity in vivo of lipophilic Isatis tinctoria extracts and tryptanthrin.
2006
The effects of a supercritical CO2 (SFE) extract, a dichloromethane (DCM) extract from Isatis tinctoria leaf and the alkaloidal constituent tryptanthrin were studied in acute and subchronic experimental models of inflammation. The SFE and DCM extracts showed anti-inflammatory activity in the carrageenan-induced acute mouse paw oedema (ED50 values of 78 mg/kg and 165 mg/kg P. O., respectively) and in the acute tetradecanoylphorbol acetate (TPA)-induced mouse ear oedema in oral (62% and 32% oedema reduction at 100 and 125 mg/kg, respectively) and topical application (37% and 33% reduction of oedema at 0.5 mg/ear). In contrast, tryptanthrin showed no significant anti-inflammatory effect. The D…
Current and New Insights in the Sustainable and Green Recovery of Nutritionally Valuable Compounds from Stevia rebaudiana Bertoni.
2015
International audience; The South American plant Stevia rebaudiana Bertoni is a great source of noncaloric sweeteners (steviol glycosides), mainly concentrated in its leaves, but also has important antioxidant compounds (vitamin C, polyphenols, chlorophylls, and carotenoids) and other important macro- and micronutrients such as folic acid and all of the essential amino acids except tryptophan. Traditionally, conventional methods have been used to recover nutritionally valuable compounds from plant food matrices. However, nowadays, the need for obtaining greener, sustainable, and viable processes has led both food industries and food scientists to develop new processes in full correspondence…
Short-term response to waterlogging in Quercus petraea and Quercus robur: A study of the root hydraulic responses and the transcriptional pattern of …
2015
International audience; We characterized the short-term response to waterlogging in Quercus petraea (Matt.) Liebl. and Quercus robur L. as the initial response towards their known long-term differences in tolerance to waterlogging. One-month old seedlings were subjected to hypoxic stress and leaf gas exchange, shoot water potential (Psi(s)) and root hydraulic conductivity (Lp(r)) were measured. In parallel, the expression of nine aquaporins (AQPs) along the primary root was analysed by quantitative RT-PCR. Results showed a similar reduction in net assimilation (A) and stomatal conductance (g(s)) for the two species. Notably, the response of Lpr differed temporally between the two species. Q…