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1.
A method is described for the preparation of (1) the heavy population of bovine adrenal chromaffin granules ( in 0.25 M sucrose) essentially free from contamination with mitochondria and other organelles, and (2) a subpopulation of this heavy population which is highly enriched in noradrenalin ( of the total catecholamine is noradrenalin). The method is based on isopycnic gradient centrifugation using a self-generating gradient of polyvinylpyrrolidone-coated colloidal silica particles (Percoll) in 0.5 M sucrose medium.The isolated population of noradrenalin granules appeared highly electron dense in transmission electron microscopy and revealed a rather narrow size distribution. The specific content of amine and adenine nucleotides (with reference to total granule protein) was markedly higher than for the total population of heavy chromaffin granules. The molar ratio of amines to adenine nucleotides was, however, lower in the noradrenalin granules, i.e. 4.8 vs. 11.9. 相似文献
2.
The role of the target cell in determining the structures and the amounts of hydrocarbon-DNA adducts formed after hydrocarbon activation by an exogenous metabolic ativation system was investigated by exposing intact cells of the Chinese hamster lung cell line V79, V79 cell nuclei and calf thymus DNA to benzo[a]pyrene (B[a]P) in the presenceof a rat liver homogenate activation system (S9). The DNA was isolated, enzymatically degraded to deoxyribonucleosides and the B[a]P-deoxyribonucleoside adducts analyzed by high-performance liquid chromatography. Two major adducts were present in all samples; one formed by reaction of r-7, t-8-dihydroxy-t-9, 10-epoxy-7, 8, 9, 10-tetrahydro-B[a]P (anti-B[a]PDE) with the 2-amino group of deoxyguanosine, the other formed by reaction of a metabolite of 9-hydroxybenzo[a]pyrene (9-OH-B[a]P) with an unidentified deoxyribonucleoside. The ratios of the anti-B[a]PDE-DNA adduct to the 9-OH-B[a]P-DNA adduct were: calf thymus DNA, 3 to 1: DNA from V79 nuclei, 8 to 1; DNA from intact V79 cells, 11 to 1. Similar several-fold increases in the proportion of anti-B[a]PDE-DNA adducts in V79 cells over those in calf thymus DNA were observed for a dose range of 1–10 μg B[a]P per ml. The relative extent of binding of the activated metabolite of 9-OH-B[a]P to DNA was also much lower in intact V79 cells than in calf thymus DNA after exposure to 9-OH-B[a]P in the presence of the S9 activation system.These results demonstrate that the relative abilities of various reactive bbenzo[a]pyrene metabolites formed by an exogenous activation system to reach DNA differ substantially. Therefore, assessment of the biological activity of hydrocarbons in mutation assays using exogenous activation systems must take into account not only the amounts of different reactive hydrocarbon metabolites formed but also the relative abilities of these metabolites to reach the DNA of the target cell. 相似文献
3.
The disposition of venlafaxine enantiomers in dogs, rats, and humans receiving venlafaxine. 总被引:4,自引:0,他引:4
A stereospecific high-performance liquid chromatographic (HPLC) method was developed for the quantitation of the enantiomers of venlafaxine, an antidepressant, in dog, rat, and human plasma. The procedure involves derivatization of venlafaxine with the chiral reagent, (+)-S-naproxen chloride, and a postderivatization procedure. The method was linear in the range of 50 to 5,000 ng of each enantiomer per ml of plasma. No interference by endogenous substances or known metabolites of venlafaxine occurred. Studies to characterize the disposition of the enantiomers of venlafaxine were conducted in dog, rat, and human, following oral administration of venlafaxine. The Cmax, area under the curve (AUC) and (S)/(R) concentration ratios of the (R)- and (S)-enantiomers were compared. In rats, the mean plasma ratio of (S)-venlafaxine to that of (R)-venlafaxine over 0.5 to 6.0 h varied from 2.97 to 8.50 with a mean value of 5.51 +/- 2.45. The Cmax, AUC0-infinity, and t 1/2 values of the (R)- and (S)-enantiomers in dogs were not significantly different from one another (P greater than 0.1). The mean ratios [(S)/(R)] of enantiomers of venlafaxine in human over a 2 to 6 h interval ranged from 1.33 to 1.35 with an overall ratio of 1.34 +/- 0.26 (n = 12). These ratios of the enantiomers [(S)/(R)] were not statistically different from unity (P greater than 0.1) indicating that the disposition of venlafaxine enantiomers in humans is not stereoselective and is more similar to that in dogs than that in rats. 相似文献
4.
Taxonomical properties of an actinomycete, strain No. 289, a potent producer of viral-neuraminidase inhibitor, and culture conditions for the production of the inhibitor have been studied. It belongs to the genus Streptomyces and is characterized mainly by spiral formation, smooth spore surface, Gray color-series and chromogenicity. A high yield of the inhibitor was achieved when it was cultured in a medium containing lactose, peptone and yeast extract at 27° under aerobic condition; the inhibitory activity of the broth reached as high as 24 deHAI units/ml at the fifth day of the main culture. 相似文献
5.
6.
Samantha M. Desmarais Carolina Tropini Amanda Miguel Felipe Cava Russell D. Monds Miguel A. de Pedro Kerwyn Casey Huang 《The Journal of biological chemistry》2015,290(52):31090-31100
The bacterial cell wall is a network of glycan strands cross-linked by short peptides (peptidoglycan); it is responsible for the mechanical integrity of the cell and shape determination. Liquid chromatography can be used to measure the abundance of the muropeptide subunits composing the cell wall. Characteristics such as the degree of cross-linking and average glycan strand length are known to vary across species. However, a systematic comparison among strains of a given species has yet to be undertaken, making it difficult to assess the origins of variability in peptidoglycan composition. We present a protocol for muropeptide analysis using ultra performance liquid chromatography (UPLC) and demonstrate that UPLC achieves resolution comparable with that of HPLC while requiring orders of magnitude less injection volume and a fraction of the elution time. We also developed a software platform to automate the identification and quantification of chromatographic peaks, which we demonstrate has improved accuracy relative to other software. This combined experimental and computational methodology revealed that peptidoglycan composition was approximately maintained across strains from three Gram-negative species despite taxonomical and morphological differences. Peptidoglycan composition and density were maintained after we systematically altered cell size in Escherichia coli using the antibiotic A22, indicating that cell shape is largely decoupled from the biochemistry of peptidoglycan synthesis. High-throughput, sensitive UPLC combined with our automated software for chromatographic analysis will accelerate the discovery of peptidoglycan composition and the molecular mechanisms of cell wall structure determination. 相似文献
7.
芦荟苷A、B以及异芦荟色苷D的同时分离纯化 总被引:2,自引:0,他引:2
首次采用反相中压制备色谱从芦荟中一次分离制备得到芦荟苷A、B以及异芦荟色苷D。以库拉索芦荟丙酮粗提物为原料,采用中压制备色谱系统:SCO色谱柱(40 cm×26 cm,30~50μm),流动相甲醇-0.5%乙酸水(33∶67,V/V),流速20 mL/min,等度洗脱方式,柱温室温,检测波长254 nm,收集波长356 nm对芦荟样品进行分离制备,得到三种化合物单体。经高效液相色谱、紫外、红外、质谱及核磁共振等方法分析表明所得到的三种化合物分别是异芦荟色苷D、芦荟苷A和芦荟苷B,其纯度分别达到了98.0%,96.0%和98.9%。该方法简便,产品质量高,一次制备可以得到多种单体,为芦荟成分的测定与药理活性的研究提供了条件。 相似文献
8.
S B Mortensen L Sottrup-Jensen H F Hansen T E Petersen S Magnusson 《FEBS letters》1981,135(2):295-300
9.
BACKGROUND AND AIMS: Once human skin contacts stinging hairs of Urtica spp. (stinging nettles), the irritant is released and produces pain, wheals or a stinging sensation which may last for >12 h. However, the existence of pain-inducing toxins in the stinging hairs of Urtica thunbergiana has never been systematically demonstrated. Experiments were therefore conducted to identify the persistent pain-inducing agents in the stinging hairs of U. thunbergiana. METHODS: The stinging hairs of U. thunbergiana were removed and immersed in deionized water. After centrifugation, the clear supernatants were then subjected to high-performance liquid chromatography (HPLC), enzymatic analysis and/or behavioural bioassays. KEY RESULTS: The HPLC results showed that the major constituents in the stinging hairs of U. thunbergiana were histamine, oxalic acid and tartaric acid. However, the well-recognized pain-inducing agents, serotonin and formic acid, existed at a low concentration as estimated by HPLC and/or enzymatic analyses. The behavioural tests showed that 2% oxalic acid and 10% tartaric acid dramatically elicited persistent pain sensations in rats. In contrast, 10% formic acid and 2% serotonin only elicited moderate pain sensation in the first 10 min. Moreover, no significant pain-related behavioural response was observed after injecting 10% acetylcholine and histamine in rats. CONCLUSIONS: Oxalic acid and tartaric acid were identified, for the first time, as major long-lasting pain-inducing toxins in the stinging hairs of U. thunbergiana. The general view that formic acid, histamine and serotonin are the pain-inducing agents in the stinging hairs of U. dioica may require updating, since their concentrations in U. thunbergiana were too low to induce significant pain sensation in behavioural bioassays. 相似文献
10.
Thomas R. Londo Terry Kehoe Steven A. Kates Susan Hantman Neal F. Gordon 《Letters in Peptide Science》1998,5(4):285-297
Methods for peptide assembly consist of techniques that allow for construction of complex sequences. The advantage of solid-phase methodologies is automation of the repetitive processes of deprotecting, washing, and coupling protected amino acids (acylation). However, for difficult sequences the crude product contains a variety of side products that must be removed to provide the desired target peptide in sufficient concentration and purity. This paper illustrates that high efficiency purification method-development can be achieved by combining purification and analysis on a single platform. Incorporation of fast LC-based assays using polystyrene-based POROS® Perfusion Chromatography media permitted rapid overall processing times from crude peptide purification through fraction pooling and product verification. Application of these technologies to the purification of peptides at scales of 100 mg is demonstrated. 相似文献
11.
AbstractEnvironmental and biological monitoring was carried out in the winter season of 2004 for 30 gasoline station workers (study subjects) and 30 office workers (controls) of Bangalore city, India. Personal air sampling was carried out in the breathing zone of workers using an Anasorb CSC sorbent tube (SKC 226-01) fitted to the low-flow personal samplers (PCXR4 and pocket pump Model No. 210-1002) at a flow rate of 200 ml min?1 during the shift work of 8 h. The benzene content adsorbed in the sorbent tube (SKC 226-01) was desorbed with 1 ml of benzene-free carbon disulfide on a developing vibrator and later analysed by Trace GC fitted with MXT-624 column and flame ionization detector. The mean time weighted average benzene concentration found among study and controls was 1.10±1.08 and 0.070±0.035 mg m?3, respectively. Biological monitoring for benzene exposure was performed by measuring trans,trans muconic acid (t,t-MA) in the end shift urine samples using HPLC-UV technique. End-shift urine samples (1 ml) were adjusted to pH 7–9 with phosphate buffer pH 7.4 passed through the preconditioned Q-SAX anion-exchange cartridge and the (t,t-MA) is extracted with 10% acetic acid and later analysed by HPLC-UV detection The mean t,t-MA found among study and controls were 563.16±281.81 and 266.88±110.65 µg g?1 creatinine. About 50% of the study subjects (15) have higher t,t-MA values than the biological exposure index of the American Conference of Government Industrial Hygienist (ACGIH). Correlation is significant at 5% level (p<0.05) between personal air benzene concentration and urinary t,t-MA in the study group. Based on these findings, the t,t-MA can be used as a biomarker for benzene exposure. 相似文献
12.
N. Chekroun-Bechlaghem L. Belyagoubi A. Gismondi V. Nanni G. Di Marco 《Plant biosystems》2013,147(6):843-852
AbstractExtracts and fractions using six solvents of increasing polarities from Northwest Algeria (Tamarix africana, Arthrocnemum macrostachyum and Suaeda fruticosa) were studied for phytochemical analysis and in vitro antioxidant properties. Methanol and water fractions were found to be the more suitable solvents used for extraction of polyphenolic compounds. Aqueous leaf fraction of T. africana showed the highest content of phenolics (61.06?±?0.40?mg GAE/g DW) and condensed tannins (118.43?±?11.79?mg CE/g DW). Dichloromethane stem fraction of T. africana had the highest 2,2-diphenyl-1-picrylhydrazil radical scavenging ability (0.34?±?0.00?mg/ml). Methanol leaf fraction of the same plant exhibited the highest antioxidant power against the inhibition of β-carotene bleaching, while the maximum total antioxidant capacity was recorded in the leaf extract of S. fruticosa. Phenolic content was not influenced by the species but very affected by the extraction solvent, while antioxidant activities were not influenced by these two parameters. High-performance liquid chromatography with a diode-array detector analysis of methanol and aqueous leaf fractions of T. africana revealed the presence of six phenolic acids; chlorogenic and gallic acids were predominant and 10 flavonoid compounds among which rutin and quercetin-3-O-arabonoside were the major constituents. These findings suggest that these species may be considered as an interesting source of antioxidants. 相似文献
13.
Each year in the USA approximately 7-8 million patients with non-traumatic chest pain come to hospital emergency rooms. It is estimated that approximately 2-5% of these patients are experiencing cardiac ischaemia, but due to the shortcomings of the available testing methods they are incorrectly diagnosed and discharged without appropriate therapy having been provided. Preliminary data with a globally ischaemic mouse heart model has demonstrated that endogenous inosine might be a potential biomarker of initial cardiac ischaemia before cardiac tissue necrosis. A high-performance liquid chromatographic diode array detection (HPLC-DAD) method was utilized for the detection and quantification of inosine in Krebs-Henseleit (Krebs) buffer solution perfusing from surgically removed and isolated mouse hearts undergoing global cardiac ischaemia. A C18 column at a flow rate of 0.6 ml min-1 with an aqueous mobile phase of trifluoroacetic acid (0.05% trifluoroacetic acid in deionized water, pH 2.2, v/v) and methanol gradient was used for component separation. The assay detection limit for inosine in Krebs buffer solution was 500 ng ml-1 using a 100-µl neat injection. The HPLC results were used to determine total cardiac effluxed inosine into the Krebs effluent for each mouse during oxidative stress and compared with the per cent cardiac ventricular functional recovery rate to determine if a relationship exists amongst this cardiovascular parameter during periods of cardiac oxidative stress. 相似文献
14.
AbstractEach year in the USA approximately 7–8 million patients with non-traumatic chest pain come to hospital emergency rooms. It is estimated that approximately 2–5% of these patients are experiencing cardiac ischaemia, but due to the shortcomings of the available testing methods they are incorrectly diagnosed and discharged without appropriate therapy having been provided. Preliminary data with a globally ischaemic mouse heart model has demonstrated that endogenous inosine might be a potential biomarker of initial cardiac ischaemia before cardiac tissue necrosis. A high-performance liquid chromatographic diode array detection (HPLC-DAD) method was utilized for the detection and quantification of inosine in Krebs–Henseleit (Krebs) buffer solution perfusing from surgically removed and isolated mouse hearts undergoing global cardiac ischaemia. A C18 column at a flow rate of 0.6 ml min?1 with an aqueous mobile phase of trifluoroacetic acid (0.05% trifluoroacetic acid in deionized water, pH 2.2, v/v) and methanol gradient was used for component separation. The assay detection limit for inosine in Krebs buffer solution was 500 ng ml?1 using a 100-µl neat injection. The HPLC results were used to determine total cardiac effluxed inosine into the Krebs effluent for each mouse during oxidative stress and compared with the per cent cardiac ventricular functional recovery rate to determine if a relationship exists amongst this cardiovascular parameter during periods of cardiac oxidative stress. 相似文献
15.
L—山梨糖脱氢酶的纯化及性质的研究 总被引:10,自引:2,他引:10
从5L罐发酵L-山梨糖的Gluconibacter oxydans SCB329和Bacillus thuringiensis SCB933混合菌株中差速离心收集SCB329菌体,破碎,离心获得无细胞抽提液,硫酸铵分级沉淀蛋白后依次经DEAE Cellulose 52和Q Sepharose FF柱层析分得到了L-册梨糖脱氢酶(SDH),它能将L-册梨糖脱氢氧化为L-册梨酮,SDS-PAGE电泳测 相似文献
16.
Ryoko Ikeda Tatsuto Yamamoto Masaru Funatsu 《Bioscience, biotechnology, and biochemistry》2013,77(5):1153-1159
A cellulase preparation which exhibits the highest activity at a lower pH range, 2.3 to 2.5, was purified from a commercial cellulase preparation from a culture filtrate of Asp. niger and referred to as acid-cellulase.The purification involves ammonium sulfate fractionation, gel filtration and ion-exchange and adsorption chromatographies. The purified enzyme was revealed to be homogenous in ultracentrifugation and disc as well as ampholine electrophoreses and to be an acidic protein of which isoelectric point lied at pH 3.3. The sedimentation coefficient and molecular weight were determined to be 3.27 S and 46,000, respectively. The optical properties were also studied. 相似文献
17.
A comparative study on gossypol content of various genetic types of pigment glands of cotton varieties was conducted through
an optimized high-performance liquid chromatography (HPLC) on a C18 column (4.6 mm x 250 mm, 5 Μm particle) with methanol-0.5%
acetic acid aqueous solution, 90 : 10 (v/v), as mobile phase, at a flow rate of 0.8 ml/min and UV detection at 254 nm. The
method was shown to be highly reproducible, with precision [as relative standard deviation (RSD)] and accuracy [as relative
mean error (RME)] < 10%, both intra-day and inter-day. Absolute recoveries were > 94%. The results revealed major differences
among the different gland varieties or species of cotton, including the special and ordinary glandless and glandedGossypium hirsutum, G. barbadense, and displayed the precious resources of different glands of extraordinary cotton 相似文献
18.
Erik Widerlöv Peter W. Kalivas Mark H. Lewis Arthur J. Prange George R. Breese 《Regulatory peptides》1983,6(2):99-109
Dopamine (DA) and cholecystokinin octapeptide carboxy-terminal (CCK-8) have been found to coexist in some mesolimbic neurons. The present investigation was undertaken in order to study the biochemical and behavioral interactions between CCK-8 and some central monoaminergic pathways. The action of the sulfated form of CCK-8 (10 micrograms/10 microliter intracerebroventricularly) on DA turnover in nucleus accumbens, olfactory tubercles and corpus striatum of the rat was determined after DA synthesis inhibition with alpha-methyl-p-tyrosine (250 mg/kg i.p.). Also, CCK-8 action (1-30 micrograms intracisternally) on DA synthesis was assessed by measuring accumulation of dihydroxyphenylalanine (DOPA) after DOPA-decarboxylase inhibition with NSD-1015 (m-hydroxybenzylhydrazine, 100 mg/kg i.p.). The contents of DA and its main metabolites, dihydroxyphenylacetic acid and homovanillic acid, together with serotonin and its main metabolite, 5-hydroxyindoleacetic acid (5-HIAA), were measured in different brain areas after direct injection of CCK-8 into the ventral tegmental area (A10) or nucleus accumbens. Further, the effect of CCK-8 on amphetamine-induced locomotion and apomorphine-induced stereotypies was studied along with changes in spontaneous locomotion and rearing after CCK-8 injection into the ventral tegmental area and nucleus accumbens. No consistent statistically significant effects of CCK-8 on biochemical or behavioral assessments on measures of DA function were observed. However, injection of high doses of CCK-8 into the ventral tegmental area significantly decreased levels of 5-HIAA in the nucleus accumbens, olfactory tubercles and striatum. 相似文献
19.
Salvia L.(family Lamiaceae),a large genus of over 1000 species,is widely distributed throughout tropical and temperate regions of the world.Eight-four species are native to China.However,there are many taxonomic uncertainties at the sub-generic level.Diterpenoids are a class of secondary metabolites with a large variety of structures that have been used as chemotaxonomic markers at infra-and suprageneric levels.For the sake of further chemotaxonomic understanding of Salvia,the present study investigated the... 相似文献
20.
建立白刺链霉菌(Streptomyces albospinus)CT205代谢产环己酰亚胺含量的检测方法,为菌株CT205的开发利用提供技术支持。采用高效液相色谱法(HPLC)、生物活性法和分光光度法等三种检测手段分别测定菌株CT205发酵上清液及粗提物中活性物质环己酰亚胺(Cycloheximide)的含量。三种方法测定环己酰亚胺标准品均具有较好的线性关系,其中相关系数R2HPLC法(0.999 2)>R2生物活性法(0.993 7)≈R2分光光度法(0.996 5)。HPLC法及生物活性法分别测定CT205发酵液及粗提物中活性物质含量分别为72.87、1 555.70及66.15、1 259.00μg/mL,HPLC法与生物活性法测定的发酵上清液中活性物质含量误差在+6.72 μg/mL。HPLC检测方法的准确性及灵敏度均高于生物活性法,适用于样品含量的准确测定,生物活性法适用于菌株诱变筛选及条件优化实验产生的大批量样品的测定及比较,分光光度法不适用检测杂质含量较多的样品。 相似文献