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Mimosa tenuiflora extract has been used in food industry as an additive and in textile and leather industry as a colorant. Two types of fabrics, ready to be dyed white and indigo dyed fabrics, were dyed with M. tenuiflora extract. The fabrics were mordanted after dyeing with six different metal salts. Colorimetric evaluations of fabrics were carried out by spectrophotometer. Colour fastness to washing, rubbing and light were performed. Colour strength of fabrics was calculated from Kubelka–Munk formula. Highest vividness (C1) values were obtained by Ni mordant. Moderate fastness values were observed. However poor wet rubbing fastness values were observed in the case of indigo dyed fabrics due to lack of good wet rubbing fastness of indigo itself.  相似文献   

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Recently many people have shown great interest in traditional indigenous practices and popular medicine, involving the ingestion of natural psychotropic drugs. We received a request to analyze and determine the nature of a dark green liquid with a dark brown plant sediment, which the police had seized at an airport and inside the home of a person belonging to the 'Santo Daime' religious movement. Gas chromatography/mass spectrometry analysis of the extract identified N,N-dimethyltryptamine, a potent hallucinogen, and the beta-carboline alkaloids harmine and harmaline, revealing monoamine oxidase A-inhibiting properties. These substances are typical components of Ayahuasca, a South American psychotropic beverage obtained by boiling the bark of the liana Banisteriopsis caapi together with the leaves of various admixture plants, principally Psychotria viridis.  相似文献   

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确定含羞草中总黄酮的最佳提取部位,并对其初步分离纯化。通过正交试验,分别筛选含羞草根部、茎叶及种子中总黄酮的最优提取条件,比较三者黄酮总含量,最终确定提取部位为茎叶,最佳提取条件:以70%乙醇为溶剂,按照1∶8配料比,在55~58℃下超声50 min。提取液依次用石油醚、乙酸乙酯液液萃取,蒸干上样,用乙醇水溶液以4 m L/min梯度洗脱Diaion HP–20大孔树脂,收集洗脱液并用液相色谱监测每个梯度洗脱液的总黄酮含量,得到分离纯化过的黄酮类物质。当40%乙醇洗脱部位总黄酮含量最高,达57.7%。该工艺确定了含羞草中茎叶部位总黄酮含量最高,大孔树脂初步纯化黄酮类物质有效,为含羞草中黄酮类物质的应用提供了依据。  相似文献   

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This work shows the results obtained to determine the noise in the baseline of a specially designed Tian Calvet-Type adsorption microcalorimeter. The results show that noise levels vary from 0.5 to 10 μV, which were evaluated varying the electrical work and the micro calorimeter surrounding temperature. Relationships can be seen between the variables employed in the observation of stability, temperature, potency levels and generated noise.  相似文献   

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Sesbania cell cultures grown in the presence of different concentrations of Pb (0-1000 mg/L) and Cu (0-500 mg/L) were assayed for growth, metal accumulations and activities of antioxidative enzymes: superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (GPX). These cultures tolerated Pb up to a concentration of 500 mg/L, registering a fresh weight growth of 500% in 3 weeks. At the same time, cultures registered a growth of 200% in 3 weeks at a Cu concentration of 100 mg/L showing less tolerance than Pb. However, Sesbania cells accumulated more Cu than Pb, as determined by ICP-MS, at all the treatments tested. Cu accumulation reached 3000 mg/kg (dry weight) at a Cu treatment of 100 mg/L, while Pb accumulation was only over 150 mg/kg (dry weight) at 500 mg Pb/L. Metal accumulations were positively correlated with induction of SOD and CAT activities in both the metal treatments. SOD activity of callus was 105 U/mg (fresh weight) at a Pb treatment of 500 mg/L and the corresponding Pb accumulation of 160 mg/kg (dry weight), while the activity rose to 300 U/mg (fresh weight) at a Cu treatment of 100 mg/L and the corresponding Cu accumulation of 3000 mg/kg (dry weight). The pattern of GPX activities was, however, different, particularly in Pb treatments where activities declined with increasing concentrations of Pb in the cells as well as growth medium. This study shows how Sesbania cells withstand heavy metal stress by induction of antioxidative enzyme activities.  相似文献   

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The aim of this work was to characterize the in vitro behavior of N4- and N3S-RGDS-derivative peptides labeled with 99mTc. Peptides AGGG-Abu-GRGDSPK-NH2 (F22) and C(acm)-GGG-Abu-GRGDSPK-NH2 (SMA1) were synthesized by solid phase. The stability of 99mTc-labeled peptides was assessed in a 30-fold molar excess of cysteine and in plasma. The affinity for plasma proteins was also evaluated. Labeling yield was >95% for both peptides. 99mTc-F22 was not stable in presence of cysteine, but 63% of 99mTc remained chelated to SMA1 up to 24 hours. Both peptides showed low affinity to plasma proteins. N3S-RGDS-derivative peptide (SMA1) showed more stable coordination binding with 99mTc and a higher stability in plasma with regard to N4-RGDS-derivative peptide (F22).  相似文献   

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Large old trees are the dominant primary producers of native pine forest, but their influence on spatial patterns of soil properties and potential feedback to tree regeneration in their neighbourhood is poorly understood. We measured stable isotopes of carbon (delta(13)C) and nitrogen (delta(15)N) in soil and litter taken from three zones of influence (inner, middle and outer zone) around the trunk of freestanding old Scots pine (Pinus sylvestris L.) trees, to determine the trees' influence on below-ground properties. We also measured delta(15)N and delta(13)C in wood cores extracted from the old trees and from regenerating trees growing within their three zones of influence. We found a significant and positive gradient in soil delta(15)N from the inner zone, nearest to the tree centre, to the outer zone beyond the tree crown. This was probably caused by the higher input of (15)N-depleted litter below the tree crown. In contrast, the soil delta(13)C did not change along the gradient of tree influence. Distance-related trends, although weak, were visible in the wood delta(15)N and delta(13)C of regenerating trees. Moreover, the wood delta(15)N of small trees showed a weak negative relationship with soil N content in the relevant zone of influence. Our results indicate that large old trees control below-ground conditions in their immediate surroundings, and that stable isotopes might act as markers for the spatial and temporal extent of these below-ground effects.  相似文献   

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Navjeet Kaur 《合成通讯》2013,43(15):1711-1742
The development of new strategies for the synthesis of small-sized heterocycles has remained a highly attractive but challenging proposition. An overview of the application of microwave irradiation to the synthesis of five-membered heterocyclic compounds containing three and four nitrogen atoms is presented, focusing on the developments in the past 5–10 years. This contribution covers the literature concerning the total synthesis of N,N,N- and N,N,N,N-heterocycles. The literature data are summarized based on the size and type of cycles.  相似文献   

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A new diamide N,N,N′,N′-tetrahexylmalonamide (THMA) was synthesized, characterized and used in the extraction of U(VI) from nitric acid solutions. N,N,N′,N′-tetrabutylmalonamide (TBMA) was also studied to test the steric hindrance. Factors affecting this extraction system, the concentration of the extractant, aqueous nitric acid and NaNO3 and the temperature were investigated. The IR spectral study was also made of the extracted species.  相似文献   

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The extraction of adenosine phosphates with hydrophobic cyclic diammonium or alkyl diammonium salts is described. The selectivity of these compounds is governed by two factors, the length of the spacer arm between the two ammonium nitrogens and the pH of the system. The cyclic compound exhibits less selectivity than the similar noncyclic alkyl compounds. It is shown that several of the compounds are fairly selective for adenosine 5′-triphosphate (ATP). The best of these, N,N,N′-tetramethyl-N,N′-dioctadecyldiammoniumethane, is tested for assay of ATP in spiked urines.  相似文献   

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The isomers of the nitrogen-substituted fullerenes (azafullerenes) C19N, C59N, C69N, and C75N are examined using all-electron Gaussian atomic orbital basis density functional theory, to determine the doublet radical geometries and hyperfine coupling constants. We find that the inaccuracy of previously calculated hyperfine coupling constants of C59N resulted from a poor treatment of the geometry optimization. We find that UB3LYP minimization of the radical geometry in the 6-31G basis, followed by single-point evaluation of the hyperfine constants in which an expanded basis is used on the atomic sites of interest, forms an efficient compromise between computational cost and accuracy with respect to experimental hyperfine constants. Using this approach, we assign the hyperfine signals observed in experiments on the C69N radical by calculating the hyperfine coupling constants for all five of the isomers and examine the electron spin density distribution. Finally, we present predicted hyperfine coupling constants for the isomers of C19N and C75N for use in the interpretation of future experiments.  相似文献   

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Aprotic N,N-dimethylpropionamide (DMPA) and N,N,N′,N′-tetramethylurea (TMU) are both strong donor solvents and coordinate to metal ions through the carbonyl oxygen atom. These solvents show a different conformational aspect in the bulk phase, i.e., DMPA exists as either a planar cis or a nonplanar staggered conformer, while TMU exists in a single planar cis conformer. It has been established that the manganese(II) ion is solvated by five molecules in both solvents. Interestingly, although the planar cis conformer of DMPA is more favorable than the nonplanar staggered one in the bulk phase, the reverse is the case in the coordination sphere of the metal ion, i.e., a conformational change occurs upon solvation. To reveal the thermodynamic aspect of this conformational change, the complexation of Mn(II) with bromide ions in DMPA and TMU has been studied by titration calorimetry at 298 K. It was found that the Mn(II) ion forms mono-, di- and tri-bromo complexes in both solvents, and their formation constants, enthalpies and entropies were obtained. The Δ H1 value for MnBr+ strongly depends on the solvent, i.e., it is positive (19.4 kJ-mol−1) in DMPA and negative (−8.7 kJ-mol−1) in TMU, whereas the Δ H^∘2 and Δ H3 values for the stepwise formation of MnBr2 and MnBr3 are both small and negative. The enthalpy of transfer ΔtH from DMPA to TMU, which is evaluated on the basis of the extrathermodynamic TATB assumption, is 25.5 kJ-mol−1 for Mn2+ and −3.6 kJ-mol−1 for MnBr+. These values indicate that the difference between the formation enthalpy of MnBr+ in the two solvents, Δ H^∘1 (DMPA) – Δ H1 (TMU), is mainly ascribed to the value of ΔtH(Mn2+). It is found that the metal ion is also five-coordinated in the monobromo complex, MnBr(DMPA)4+ . The enthalpy for the conformational change of DMPA from its planar cis to the nonplanar staggered form is evaluated to be −11 and −5.5 kJ-mol−1 for Mn(DMPA)52 + and MnBr(DMPA)4+, respectively. Note that these values are significantly smaller than the corresponding value (5.0 kJ-mol−1) in the bulk phase. We thus conclude that, although steric hindrance among solvent molecules is reduced by replacing one DMPA of Mn(DMPA)52 + with the relatively small bromide ion, DMPA molecules are still sterically hindered in the MnBr(DMPA)4+ complex.  相似文献   

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