Extraction and purification of eupatilin fromArtemisia princeps PAMPAN recycling preparative HPLC

A recycling preparative HPLC was used to extract and separate the eupatilin contained inArtemisia princeps PAMPAN, and the optimum operating condition was experimentally determined. Eupatilin was extracted by ethanol solvent from the leaf and trunkof Artemisia princeps PAMPAN. The resulting solution was further partitioned with n-hexane, chloroform and ethyl acetate. The solution containing eupatilin was collected using a preparative as well as analytical column, and it was identified by LC-CE-MS. In the experiment, the mobile phase consisted of water/aceto-nitrile/TFA=50/50/0.5 (vol%), and UV wavelength measured was 370 nm. For analytical chromatography, the injection volume was 20 μL and the flow rate was fixed at 1.0 mL/min. The measured retention time for eupatilin was approximately 8.6 min in the above operating condition. For recycling preparative HPLC with commercially available GSA 310A column at 1.5 mL/min of the flow rate and 2 mL of injection volume, the purity of the eupatilin was almost 100% after recycling twice.     

非均相催化一步合成碳酸二苯酯的研究（VI）Sn 的添加量对Pd-Sn催化性能的影响

The compound metal oxide LaxPbyMnzO used as support was prepared by the sol-gel method, and the catalyst in which Pd was used as active component and Sn as co-active component for direct synthesis of diphenyl carbonate (DPC) with heterogeneous catalytic reaction was obtained by co-calcination and precipitation respectively.The catalyst was characterized by XRD, SEM and TEM respectively. The specific surface area of catalysts was measured by ChemBET3000 instrument, and the activity of the catalysts was tested by the synthesis of DPC in a pressured reactor. The results showed that when the co-active component Sn was added by co-calcination method A, its loading content was equal to 14.43% and active component Pd was loaded by precipitation, the yield and selectivity of DPC could reach 26.78% and 99% respectively.     

非均相催化一步合成碳酸二苯酯的研究(VI)Sn的添加方法及添加量对Pd-Sn催化性能的影响

The compound metal oxide Lax Pby Mnz O used as support was prepared by the sol-gel method, and the catalyst in which Pd was used as active component and Sn as co-active component for direct synthesis of diphenyl carbonate (DPC) with heterogeneous catalytic reaction was obtained by co-calcination and precipitation respectively. The catalyst was characterized by XRD, SEM and TEM respectively. The specific surface area of catalysts was measured by ChemBET3000 instrument, and the activity of the catalysts was tested by the synthesis of DPC in a pressured reactor. The results showed that when the co-active component Sn was added by co-calcination method A, its loading content was equal to 14.43% and active component Pd was loaded by precipitation, the yield and selectivity of DPC could reach 26.78% and 99% respectively.     

Stoichiometric determination of hydroperoxides in fats and oils by fourier transform infrared spectroscopy

A primary Fourier transform infrared (FTIR) spectroscopic method for the determination of peroxide value (PV) in edible oils was developed based on the stoichiometric reaction of triphenylphosphine (TPP) with hydroperoxides to produce triphenylphosphine oxide (TPPO). Accurate quantitation of the TPPO formed in this reaction by measurement of its intense absorption band at 542 cm⁻¹ provides a simple means of determining PV. A calibration was developed with TPPO as the standard; its concentration, expressed in terms of PV, covered a range of 0–15 PV. The resulting calibration was linear over the analytical range and had a standard deviation of ±0.05 PV. A standardized analytical protocol was developed, consisting of adding ∼0.2 g of a 33% (w/w) stock solution of TPP in hexanol to ∼30 g of melted fat or oil, shaking the sample, and scanning it in a 100-μm KCI IR transmission cell maintained at 80°C. The FTIR spectrometer was programmed in Visual Basic to automate scanning and quantitation, with the reaction/FTIR analysis taking about 2 min per sample. The method was validated by comparing the analytical results of the AOCS PV method to those of the automated FTIR procedure by using both oxidized oils and oils spiked with tert-butyl hydroperoxide. The two methods correlated well. The reproducibility of the FTIR method was superior (±0.18) to that of the standard chemical method (±0.89 PV). The FTIR method is a significant improvement over the standard AOCS method in terms of analytical time and effort and avoids solvent and reagent disposal problems. Based on its simple stoichiometry, rapid and complete reaction, and the singular band that characterizes the end product, the TPP/TPPO reaction coupled with a programmable FTIR spectrometer provides a rapid and efficient means of determining PV that is especially suited for routine quality control applications in the fats and oils industry.     

Identification of Anamorph Yeast of Tremella aurantialba and Optimization of Medium Composition for Production of Exopolysaccharides

A yeast-like fungus strain B1 isolated from wild fungus Tremella aurantialba was identified and initially characterized. Two phylogenetic trees were generated based on the sequences of large subunit ribosomal RNA gene D1/D2 regions and internal transcribed spacer (ITS) regions of related fungi, respectively. The analysis of D1/D2 regions and ITS sequences showed that fungus B1 was clustered together with T. aurantialba, T. aurantia and T. microspore in the phylogenetic trees. Both the morphological characteristic and phylogenetic analysis established that fungus B1 was one of the anamorph strains of T. aurantialba and belongs to Tremella genus. A fermentation medium for exopolysaccharides (EPS) production by T. aurantialba B1. Plackett-Burmen design was used to evaluate the effects of different components in the culture medium. Glucose and yeast extract have significant influence on the EPS production. The concentrations of two factors were optimized subsequently using central composite design and response surface analysis. The results showed that 49.2 g/L glucose and 10.4 g/L yeast extract could lead to the maximum production of EPS (4.99 g/L). The optimized medium led to a 1.5-fold enhancement of the production of EPS by T. aurantialba B1, as compared with that without optimization.     

高纯度共轭亚油酸的规模化制备及其异构体的鉴定

Conjugated linoleic acid(CLA)is a kind of fatty acid with physiological activities and potential appli-cation prospect ,A synthesis method of conjugated linoleic acid and a purification technology were studied .CLA was prepared and purified by urea-complexation and conjugation using safflower oil as raw material,The purity of CLA and total recovery of the product was more than 95% and 48%,respectively,The main isomers produced in alkali-catalyzed conjugation were identified by gas chromatography (GC)linked to mass spectrometry(MS) and Fourier transform infrared spectroscopy(FTIR),The total amount of the two main isomers (9cis,11trans-and 10trans,12cis-CLA) determined by GC was more than 90% of the product.     

Relationship between fluorescence and antioxidant activity of ethanol extracts of a maillard browning mixture

The relationship between the color and fluorescence of a Maillard browning mixture (0.1M glucose+0.1M glycine, heated at 100 C) and the antioxidant activity of ethnol extracts of the mixture was investigated. The activity was estimated by comparing the peroxide value development of soybean oil substrates containing the extracts with that of a control. The excitation and emission maxima of the mixture were 365 and 440 nm, and those of the extract 367 and 430 nm. The relative fluorescence (that of 1 μg quinine sulfate/mL 0.01N H₂SO₄=100) of the mixture after 16 hr browning was 450, whereas that of the corresponding extract was 175.8. The fluorescence of the mixture increased in parallel to the color (absorbance at 490 nm), which, in turn, was almost proportional to reaction time, except at the earlier stages of browning. The change of the fluorescence with the reaction time at the earlier stages was far greater than that of the absorbance at the same stages. Determination of fluorescence seems to provide a more sensitive method for tracing early browning than that of absorbance. The ethanol extracts from very early stages of the browning exhibited considerable antioxidant activity, and, unlike the absorbance of the mixture or the fluorescence of the extract, the activity of the extract changed very little with the reaction time. It appears that effective antioxidants with almost no color but with considerable fluorescence were already formed at the earlier stages of browning.     

Box-Behnken设计法优化大肠杆菌重组DsBA蛋自纯化工艺(英文)

Disulfide bond formation protein A (DsbA) is one of the important helper proteins for folding in protein synthesis in vivo. In this study, purification of recombinant DsbA was investigated by examining four important factors with Box-Behnken design method, a statistic-based design of experiments. The optimal operation conditions were obtained by adopting the effectiveness coefficient method on the multi-objective problem, which takes the protein recovery, purification efficiency and throughput of ion-exchange chromatography into account. After the optimization, protein recovery of 96.8% and purity higher than 95% DsbA was achieved, and the productivity was (377.9±1.7)mg soluble DsbA per liter broth. The purified protein was identified by peptide mass fingerprinting matching the record of gi|2624856, a mutant of DsbA. The DsbA was preliminarily applied to the refolding of denatured lysozyme in vitro.     

电化学还原硝基甲烷合成N-甲基羟胺盐酸盐的工业化试验

An industrial electrolytic cell was designed for the electrochemical synthesis of N-methylhydroxylamine hydrochloride （N-MHA）. Copper was used as the cathode, graphite as the anode, and a cation membrane as the separator. The results show that N-MHA with a high purity of 99% can be electrosynthesized directly from nitromethane in HC1 solution. Under a constant current of 1000-2500A.m^-2 in the temperature of 30-50℃, the average yield, current efficiency, and reaction selectivity were 65%, 70%, and 99%, respectively. Graphite electrode and membrane material can be used continuously in the preparative electrolysis for 5000h. Moreover, the effects of the electrode and membrane materials, current intensity, electrolyte temperature, and other associated parameters on the electrosynthesis results were investigated. The direct current power consumption was 8151.3kW-h-（1000kg N-MHA）^ -1. This method is a simple separation process with limited contamination and hence, is a new green synthesis method for the industrial production of N-MHA.     

APPLICATION OF “VAPOR-PHASE RESISTANCE METHOD” TO THE STUDY ON CONDENSATION IN HORIZONTAL TUBES

A physical model and a mathematical model were established in order to describe and improve the“vapor-phase resistance method” of Bell and Ghaly.Considering the effect of ripples at the interface onvapor-phase resistance,a correction factor v_ι was proposed.Another factor (θ/π)β which correctsthe influence of the liquid pool along the bottom of the horizontal tube on the liquid-phase heat transfercoefficient was derived and the relationship of θ and β was correlated.The heat transfer coefficient pre-dicted by Bell's method are approximately 10—15% lower than the experimental values if the effect ofripples on vapor-phase resistance has not been taken into account.The comparison of the predicted valuesof h_c from the modified vapor-phase resistance method with the experimental data showed a deviation of±10%.     

银杏内酯的提取纯化与分离

以银杏叶标准化提取物为原料 ,经乙酸乙酯提取纯化得高纯度的银杏内酯混合物 ,方法简单 ,银杏内酯含量达 95 1% ;再以其混合物经硅胶柱层析 ,得到银杏内酯A、银杏内酯B及银杏内酯C的单体化合物     

注射用银杏内酯B在比格犬体内的药代动力学研究

通过测定注射用银杏内酯B静脉给药比格犬血药代谢动力学,为指导临床安全、合理用药提供理论依据.对18只比格犬,静脉注射给药,给药后于不同时间在经前肢静脉采血2.5-3mL,用气相-质谱联用法(GC-MS)测定血药浓度,计算药代动力学参数.结果如下:比格犬静脉给予注射用银杏内酯B 0.5,1,2mg/kg,分布半衰期t1/...     

天然药物银杏内酯研究进展

本文就银杏叶药用现状,发展趋势进行了分析。对银杏内酯的化学结构、药理作用与临床应用、制备及分析方法等方面作了介绍,并讨论了它的应用开发前景。     

Separation and purification of six isoflavones from Iris tectorum Maxim by macroporous resin-based column chromatography coupled with preparative high-performance liquid chromatography

ABSTRACT

A rapid and robust preparation method of six isoflavones from ethanol aqueous extract of Iris tectorum Maxim (I. tectorum) was established by using macroporous resin column chromatography and preparative high-performance liquid chromatography (Prep-HPLC). After separation by AB-8 resins, total flavonoids content increased from 10.60% in the crude extract to 54.20% with a recovery yield of 75.12%. Subsequently, the extracts were purified by Prep-HPLC, and the purities were more than 82.2% after assessment by analytical HPLC and characterization by mass spectrometry. The established method is expected to be used for preparing available quantities of pure isoflavones from I. tectorum.     

模拟移动床色谱分离药物PG05的实验研究

用实验室自行研制组装的一套 A型三带制备型模拟移动床色谱 (简称 SMBC)系统对手性药物 PG0 5进行了分离。以普通的反相 YWG ODS为固定相 ,甲醇和水的混合液为流动相 ,从含有大量杂质的 PG0 5原料中分离得到了纯度大于 95 %的 S(-) PG0 5产品。对色谱柱的配置、切换时间、进样量、萃取液流速、柱对称性、柱体积等各种影响因素做了实验分析。实验证明 ,用 A型三带SMBC分离 PG 0 5是可行的。同时 ,与传统的批处理层析工艺比较 ,SMBC系统可大大节约溶剂消耗 ,降低成本 ,提高产品的纯度和产量。     

Synthesis of gelatin–PVA adsorbent and its application in the separation of ginkgo flavonol glycosides and terpene lactones

Spherical adsorbents derived from the glutaraldehyde cross-linked hybrid of gelatin and polyvinyl alcohol (PVA) were synthesized, and their adsorption selectivity for ginkgo flavonol glycosides and terpene lactones was also investigated in detail. An adsorbent with an appropriate gelatin content can selectively adsorb flavonol glycosides with a high adsorption capacity based mainly on hydrogen bond interactions, while showing only a fairly low adsorption capacity for terpene lactones. A much higher adsorption affinity of flavonol glycosides than that of terpene was calculated from the adsorption isotherms. Thus, a simple preparative separation procedure for ginkgo flavonol glycosides and terpene lactones from a ginkgo leaf was established. An enriched extract containing flavonol glycosides of up to 60% and terpene lactones as low as 0.2% and an extract with a terpene lactones content up to 30% was prepared by this method, respectively.     

Antioxidants from a heated histidine-glucose model system. I: Investigation of the antioxidant role of histidine and isolation of antioxidants by high-performance liquid chromatography

The radical-combining activity of Maillard reaction products [MRP_(aq)], produced by heating d-glucose and l-histidine (3:1) in a 0.1 M phosphate buffer for 10 h at 105°C (final pH 6.53), was estimated directly by means of a diphenylpicrylhydrazyl radical (DPPH^·) method. Additionally, the indirect methods of peroxide values changes (oven test), hexanal formation, and protection factors (Rancimat method) were determined on a lipid model system that consisted of sunflower seed oil/water (1:2), emulsified with 3% (w/w) Tween 40. Results from the DPPH^· method showed a potential antioxidant activity of MRP_(aq), which was confirmed by the indirect methods. Surprisingly, histidine in solution alone (heated or not) exhibited an antioxidant activity greater than or similar to the MRP_(aq) activity in the indirect methods with the lipid model system, in contrast to the results from the DPPH^· method. The suitability of various solvents for extraction of potential antioxidant compounds from freeze-dried MRP_(aq) was examined, and ethanol extracts showed the greatest activity by the DPPH^· method. Consequently, the ethanol extract of freeze-dried MRP_(aq) was separated by means of preparative reverse-phase high-performance liquid chromatography (HPLC) with a 0.05 M phosphate buffer (pH 4.4)/water/acetonitrile gradient system. The antioxidant activity of the eluate was measured through the DPPH^· method, and a fraction (Fraction A) with antiradical activity was further purified by preparative HPLC. Fraction B was collected, and its freeze-dried residue exhibited potent antiradical activity, significantly greater than that of the same level of n-propyl gallate.     

Separation and Purification of Three High-Purity Isoflavonoids from Belamcanda chinensis (L.) DC. by Supercritical Fluid Extraction and High-Speed Counter-Current Chromatography

Supercritical fluid extraction (SFE) was used to extract three isoflavonoids including irigenin, irisfloretin and dichtomitin from Belamcanda chinensis (L.) DC. The parameters including pressure, temperature, sample particle size, and flow rate of CO₂ were optimized with an orthogonal test. Under the optimized conditions of 15 MPa, 55°C, a sample particle size of 20–40 mesh and CO₂ flow rate of 40 L h^?1. The process was then scaled up by 10 times using a preparative SFE system. The yield of the crude extract from SFE was 4.1%, which contained irigenin, irisfloretin, and dichtomitin 0.71%, 0.49%, and 0.05%, respectively. To compare the extraction methods, Soxhlet Extraction (SE) was performed. The results indicated that SFE was better than SE. Irigenin, irisfloretin, and dichtomitin in the SFE extract were then separated and purified by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of petroleum ether–ethyl acetate–methanol–water (2:4:3:3, v/v). From 5.0 g of dry crude extract, 27.8 mg irigenin, 16.4 mg irisfloretin, and 2.1 mg dichtomitin were obtained at purities of 97.1%, 96.4%, and 98.0%, respectively, as determined by HPLC-PDA. These results well indicate that SFE and HSCCC are very powerful techniques for the extraction and purification of irigenin, irisfloretin, and dichtomitin from B. chinensis.     

One Step Large-Scale Separation and Purification of Rutin from Boenninghausenia sessilicarpa by Countercurrent Chromatography

In this study, a preparative countercurrent chromatography (CCC) method for isolation and purification of the bioactive component rutin directly from the ethanol extract of Boenninghausenia sessilicarpa was successfully established by using n-butanol-ethyl acetate-water as the two-phase solvent system. The upper phase of n-butanol-ethyl acetate-water (4:1:5, v/v) was used as the stationary phase of CCC. Under the optimum conditions, 112 mg of rutin at 98.6% purity was obtained from 2.0 g of the crude extract in a single CCC separation. The peak fraction of CCC was identified by negative ESI, ¹H NMR, and ¹³C NMR.