大孔吸附树脂法去除淫羊藿多糖中蛋白的研究

从4种大孔吸附树脂中筛选出ADS-7, 考察了其对淫羊藿多糖中蛋白的去除作用, 并讨论了pH值、 鞣酸、 上样量等对树脂去蛋白效率的影响. 结果表明, 该方法对淫羊藿粗多糖中的蛋白具有较高的去除效率, 淫羊藿粗多糖中的蛋白含量由1.2%下降到0.035%.     

Capillary-assembled microchip as an on-line deproteinization device for capillary electrophoresis

A capillary-assembled microchip (CAs-CHIP), prepared by simply embedding square capillaries in a lattice polydimethylsiloxane (PDMS) channel plate with the same channel dimensions as the outer dimensions of the square capillaries, has been used as a diffusion-based pretreatment attachment in capillary electrophoresis (CE). Because the CAs-CHIPs employ square-section channels, diffusion-based separation of small molecules from sample solutions containing proteins is possible by using the multilayer flow formed in the square section channel. When a solution containing high-molecular-weight and low-molecular-weight species makes contact with a buffer solution, the low-molecular-weight species, which have larger diffusion coefficients than the high-molecular-weight species, can be collected in a buffer-solution phase. The collected solution containing the low-molecular-weight species is introduced into the separation capillary to be analyzed by CE. This type of system can be used for CE analysis in which pretreatment is required to remove proteins. In this work a fluorescently labeled protein and rhodamine-based molecules were chosen as model species and a feasibility study was performed.      

Ultrasound in the deproteinization process for chitin and chitosan production

Recently, chitin and chitosan are widely investigated for food preservation and active packaging applications. Chemical, as well as biological methods, are usually adopted for the production of these biopolymers. In this study, modification to a chemical method of chitin synthesis from shrimp shells has been proposed through the application of high-frequency ultrasound. The impact of sonication time on the deproteinization step of chitin and chitosan preparation was examined. The chemical identities of chitin and chitosan were verified using infrared spectroscopy. The influence of ultrasound on the deacetylation degree, molecular weight and particle size of the biopolymer products was analysed. The microscopic characteristics, crystallinity and the colour characteristics of the as-obtained biopolymers were investigated. Application of ultrasound for the production of biopolymers reduced the protein content as well as the particle size of chitin. Chitosan of high deacetylation degree and medium molecular weight was produced through ultrasound assistance. Finally, the as-derived chitosan was applied for beef preservation. High values of luminosity, chromatid and chrome were noted for the beef samples preserved using chitosan films, which were obtained by employing biopolymer subjected to sonication for 15, 25 and 40 min. Notably; these characteristics were maintained even after ten days of packaging. The molecular weight of these samples are 73.61 KDa, 86.82 KDa and 55.66 KDa, while the deacetylation degree are 80.60%, 92.86% and 94.03%, respectively; in the same order, the particle size of chitosan are 35.70 μm, 25.51 μm and 20.10 μm.     

Determination of cyclosporin A in blood and plasma by column switching-HPLC after rapid sample preparation

A method for the determination of cyclosporin A in human whole blood and plasma is described which uses liquid chromatography with step gradient elution and a column switching technique. The chromatographic conditions chosen allow simple and rapid sample preparation, so that a result can be obtained within one hour. Blood and plasma are deproteinized with diluted methanol and an aliquot of the clear supernatant is directly injected. The detection limit for cyclosporin A is about 20 ng/ml starting from a 0.5 ml sample. The method is sensitive enough for monitoring the drug in the therapeutic range.     

Rapid Non-Enzymatic DNA Deproteinization in Agarose Miniplugs

Abstract

Mini agarose plugs, containing immobilized cells, were lysed and deproteinized in 3–6 h by a non-enzymatic procedure, using 4 M urea and detergents. The performance of Saccharomyces cerevisiae miniCHEF DNA pattern was not affected by the treatment. DNA contained in the miniplugs was completely digested by restriction endonucleases in 1–2 h. This procedure saves time in comparison to the 40 h of incubation with urea used in the original procedure. It also saves reagents and permits a rapid DNA digestion without using PMSF.     

Determination of vancomycin in human plasma using high-performance liquid chromatography with fluorescence detection

A high-performance liquid chromatographic (HPLC) method with fluorescence detection for the quantification of vancomycin in human plasma was developed and validated. The method includes an extraction of vancomycin by deproteinization with acetonitrile. The analyses were carried out at 258 nm as the emission wavelength while exciting at 225 nm on a reversed-phase column (30 cm × 4 mm i.d. × 10 μm Waters Associates μBondapak C18) using a mobile phase composed of methanol and phosphate buffer at pH 6.3. Vancomycin was quantitatively recovered from human plasma samples (>96%) with high values of precision. The separation was completed within 27 min. The calibration curve was linear over the range from 5 to 1,000 ng/mL with the detection and quantification limits of 2 ng/mL and 5 ng/mL, respectively. This method is suitable for the routine assay of plasma samples. Figure The effect of the deproteinization solvent on the signal of the interference peak at retention time of 15.0 min. The peak which interferes with the peaks of Erythromycin and Vancomycin has been disappeared by using 2 mL acetonitrile as the deproteinization solvent.     

Solvent and salting effects on sample preparation for the determination of fenofibric acid in human plasma by HPLC-DAD

The solvent and salting effects induced on the sample preparation procedure applied to plasma samples containing fenofibric acid and 4-chlorophenyl-4′-hydroxyphenyl methanone (internal standard) are evaluated. Sodium chloride addition during a deproteinization step using both methanol and phosphoric acid influences the recovery of the analytes as well as the selectivity of the process. The chromatographic method allows high sample volume injection (500 μl) with the focusing of both analytes in the stationary phase. The synthesized high porosity octadecylsilica material allows a fast elution gradient at 4 ml/min flow-rate and a complete analysis within 7 min. UV-detection is made at 295 nm and quantitation limit in the 20 ng/ml concentration level can be achieved. The method can be successfully applied for bioequivalence studies on fenofibrate, administrated as prodrug (fenofibric acid represents its main active metabolite) in pharmaceutical formulations. The main parameters used in studying the retention behavior of the internal standard and FEFA were also estimated.     

海参胶囊中海参多糖的提取方法

对海参胶囊中海参多糖进行提取纯化。分别探讨了酶解法、超声波提取方法;双氧水、活性炭脱色法及乙酸钾、三氯乙酸法除蛋白方法对海参多糖的得率的影响。确定最适提取条件:1g胶囊在胰蛋白酶加酶量为8000U/g,温度为37℃,pH 8.1,酶解3h后酶解完全;醇沉得到粗多糖后,经双氧水脱色、乙酸钾除蛋白。