Separation and purification of proteinases from Gastric Mucosa of Northern Sheatfish,Silurus soldatovi

The separation and purification method for pepsin of Northern Sheatfish (Silurus soldatovi) was established by using the combination technology of salting-out,gel chromatography and gel electrophoresis,and the enzymic properties were also analyzed.The experimental results indicated that 28% and 56% (NH4)2SO4 saturation could separate the activated protease from the pepsin extract of gastric mucosa of Sheatfish (Silurus soldatovi) ;compared with the homogenate extraction,the pepsin specific activity of purified extraction by Sephadex G-75 gel chromatography system increased 598 fold,was 5 times higher than that of activated liquid,and the total production rate was 10.1%.The purified pepsin liquor at the conditions of pH3.3 0.01 M alanine-formic acid buffering solution,60 cm chromatography column,and the flowing rate of 0.8 ML/min was analyzed by SDS-PAGE,which indicated that there were two bands and the molecular weight was 34.0 kDa and 40.4 kDa,respectively.There were two peaks in the enzyme activity determination of the separated collecting liquor in gel chromatography,and the SDS-PAGE showed the concentrations of the two proteins was different,which indicated that it existed at least two pepsins in the gastric mucosa of Sheatfish (Silurus soldatovi).

Separation and Purification of GST-glycerol-3-phosphate Dehydrogenase

In order to investigate the expression of glycerol-3 -phosphate dehydrogenase by GCY1 gene in recombinant Saccharomyces cerevisiae, induction culture of the S. cerevisiaestrain was performed with SD-URA 2% galactose, 3 × YP ＋ 6% glucose, SC-URA 2% galactose, and SC-URA 2% galactose ＋ 5% NaCI glyeerol-3-phosphate dehydregenase, the cultured S. cerevisiaewas comminuted followed by full-automatic high-speed purification, and SDS-PAGE gel electrophoresis was performed for molecular weight of the GST fusion protein. The results showed that after shaking culture of the S. cerevisiae containing GCY1 at 25 ℃, the OD values of its 3 × YP ＋ 6% glucose culture and SC-URA 2% galaetose ＋ 5% NaC1 culture were 8.75 and 7.35, respectively. It was shown by purification with a Profinia low-pressure liquid chromatograph that only the S. cerevisiae cultured in SC-URA 2% galactose ＋ 5% NaC1 medium expressed glycerel-3-phosphate de- hydrogenase, the molecular weight of which was detected as 65 ku by SDS-PAGE gel electrophoresis.

Studies on Oxygen Characteristics of YBa_2Cu_3O_(7-x) and Its Applications to Air Separation and Gas Purification

Oxygen diffusion and oxygen selective adsorption properties of rare earths material YBa_2Cu_3O_(7-x) (YBCO) were investigated by thermogravimetric, oxygen static adsorption and selectivity adsorption experiments. The results show that YBCO is a very good deoxidizing material. The oxygen desorption of YBCO begins remarkably at about 400 ℃, mass loss can arrive at 1.2% of its original quantity at 800 ℃. Oxygen can be completely absorbed back into the sample again when temperature descends to 400 ℃. The oxygen adsorption selectivity, reproducibility and oxygen adsorption under very low oxygen partial pressure make the material desirable for air separation and gas purification. High purity nitrogen gas was produced with the YBCO molecular sieves in the air separation and gas purification experiments. 0.017 m^3 of high purity nitrogen (>99.9999%) can be obtained with 1 kg YBCO molecular sieve in one cycle. As a deoxidant, an obvious advantage of YBCO is that no hydrogen is needed in its applications.

Functional magnetic nanoparticles for facile viable but nonculturable bacteria separation and purification

Viable But Nonculturable （VBNC） Bacteria, which represent a unique population of microorganisms in drinking water systems, have become a potential threat to human health. Current studies on VBNC ceils usually fail to obtain pure VBNC state bacteria, which may lead to inaccurate results. We therefore introduce a novel method of VBNC cell separation and puriticatlon in this paper. PAH-coated magnetic nanoparticles （MNPs） were synthesized and found to be capable of capturing and releasing bacterial cells with high efficiency. With the aid of an additional incubation step, VBNC cells were easily isolated and purified from normal bacteria using functional MNPs. Our method represents a new technique that can be utilized in studies of VBNCs.

Purification and characterization of Al_(13) species in coagulant polyaluminum chloride

Nano-Al13 was separated and purified by four methods to investigate its characteristic, and was analyzed by Al-Ferron timed complexation spectrophotometer, ^27Al-NMR （nuclear magnetic resonance）, and transmission electron microscopy （TEM）. Coagulation efficiency of nano-Al13, polyaluminum chloride （PAC）, and AlCl3 in synthetic water were also investigated by jar test. The dynamic process and aggregation state of kaolin suspensions coagulating with nano-Al13, PAC, and AlCl3 were also investigated. The experimental results indicated that the efficiency of gel column chromatography method was the highest for separating PAC solution with low Al concentration. Ethanol and acetone method was simple and could separated PAC solution with different Al concentrations, while silicon alkylation white block column chromatography method could separate PAC solution only with low Al concentration. The SO4^2-/Ba^2＋ displacement method could separate PAC solution with high Al concentration, but extra inorganic cation and anion could be introduced into the solution during the separation. The coagulation efficiency and dynamic experimental results showed that nano- Al13 with a high positive-charged species was the main species of electric neutralization in coagulation process, and it could reduce the turbidity and increase the effective particles collision rate efficiently in coagulation process. Its coagulation speed and the particle size of coagulant formed were of greatest value in this study.

Review of Alloy Membranes/Films for Hydrogen Separation or Purification

Hydrogen separation and purification are two important chemical processes in the extensive application of hydrogen energy. Membrane technology has opened up a potential solution to the problems of separation and purification in an energy effective way. Membranes of adequate hydrogen permeability, good thermal and mechanical stability are the key to successful application of membrane technology in hydrogen separation and purification. In this paper, the relative parameters concerning hydrogen permeability, the development of different types of membranes namely: palladium composite membranes; V-based alloy membranes, specific functionality embraced alloy membranes, metal hydride (MH) thin films and fabrications, were reviewed and discussed. Pd-free membranes are found to be the ideal alternatives. Suitable MH thin films with mono- or multi-layer microstructures produced by novel fabrication techniques, is likely to be the promising candidates due to possessing properties distinct from those of bulk materials in membrane form.

Ultraselective carbon molecular sieve membrane for hydrogen purification

Hydrogen is a green clean fuel and chemical feedstock. Its separation and purification from hydrogencontaining mixtures is the key step in the production of hydrogen with high purity(>99.99%). In this work, carbon molecular sieve(CMS) membranes with ultrahigh permselectivity for hydrogen purification were fabricated by high-temperature(700–900 ℃) pyrolysis of polymeric precursor of phenolphthaleinbased cardo poly(arylene ether ketone)(PEK-C). The evolution of the microstructural texture and ultramicroporous structure and gas separation performance of the CMS membrane were characterized via TG-MS, FT-IR, XRD, TEM, CO2 sorption analysis and gas permeation measurements. CMS membranes prepared at 700 ℃ exhibited amorphous turbostratic carbon structures and high H2 permeability of 5260 Barrer with H2/CH4, H2/N2 and H2/CO selectivities of 311, 142, 75, respectively. When carbonized at900 ℃, the CMS membrane with ultrahigh H2/CH4 selectivity of 1859 was derived owing to the formation of the dense and ordered carbon structure. CMS membranes with ultrahigh permselectivity exhibit an attractive application prospect in hydrogen purification.

Research Advances in Extraction and Functions of Ginkgo Flavonoids

Ginkgo flavonoids are one of the most effective medicinal components extracted from leaves of Ginkgo biloba L.According to the physical and chemical properties of ginkgo flavonoids,they can be separated and purified by resin adsorption,supercritical extraction and solvent methods.Previous studies have proved that ginkgo flavonoids have pharmacological functions in promoting blood circulation,anti-oxidation,anti-aging,improving memory,anti-tumor and liver protection,etc.Ginkgo flavonoids have been used clinically to treat angina pectoris,coronary heart disease,myocardial ischemia,hypertension,hyperlipidemia,diabetes,alzheimer's disease,atherosclerosis,gastric cancer and ovarian malignancy and other difficult miscellaneous diseases.

Isolation and characterization of lignans from the leaves of Isatis indigotica Fortune

A phytochemical investigation of 80%EtOH exact of Isatis indigotica Fortune leaves yielded ten lignans(1-10),including six furofurans lignans(1-6),one arylnaphthalenes lignans(7)and three tetrahydrofurans lignans(8-10).Their structures were determined by HRESIMS spectroscopic data and extensive NMR analyses.Among them,compounds 6,9 and 10 were isolated from the genus oi Isatis for the first time.

Isolation and identification of chemical constituents from Elephantopus scaber Linn.

Elephantopus scaber L.,as a popular Chinese medicinal herb of the Compositae family,is widely distributed in America,Africa and Asia.In the present study,five compounds were isolated from the 70%EtOH extract of the whole herb from Elephantopus scaber L.,including two lignans and three flavones.Their chemical structures were identified based on NMR spectroscopic analysis and comparison with the data reported in literature.It is noteworthy that compounds 1-5 were isolated from Elephantopus scaber L.for the first time and their chemotaxonomic significance was discussed.

Chemical components from Crotalaria pallida Ait. and their antioxidant activities

Nine compounds were isolated from the 95%ethanol extract of the dried seeds of Crotalaria pallida.The structures of all compounds were identified through the analysis of spectral data.All compounds were isolated for the first time from Crotalaria genus.Compounds 1-5 were evaluated for their antioxidant abilities by ABTS,DPPH and FRAP assays.Results showed that compounds 1-5 had moderate antioxidant activities。

Isolation and structural elucidation of the compounds from the fruits of Camptotheca acuminate

The fruit of Camptotheca acuminate is used as a traditional Chinese medicine.Eight compounds were isolated from the fruit of Camptotheca acuminate for the first time,including(+)-(S)-abscisic acid(1),blumenol A(2),(E)-3-hydroxymegastigm-7-en-9-one(3),(-)-(3R)-3,5-dimethyl-8-methoxy-3,4-dihydroisocoumarin(4),(-)-(3R)-8-methoxy-3-methyl-3,4-dihydro-1H-isochromen-1-one(5),neocnidilide(6),(3S)-butylphthalide(7)and senkyunolide I(8).Their structures were determined by comprehensive spectroscopic methods,including HRESIMS and 1D NMR.

The Herbicidal Activity of Mutant Isolates from Botrytis cinerea

Fifteen mutant isolates were obtained by ultraviolet mutation from parent isolate Botrytis cinerea BC-4. Among them three mutant isolates, BC4-1, BC4-2, and BC4-15, showed strong herbicidal activity. BC4-1 showed maximum herbicidal activity for inhibition of germination and growth of Digitaria sanguinalis L. and Arnaranthus retroflexus L. The results also showed that herbicidal activity was influenced by differing pH of PD media, with pH value of 4.0 being the optimum. The crude toxin was extracted using chloroform, petroleum ether, and ethyl acetate, respectively, and the ethyl acetate extracts showed the strongest inhibitory activity on the germination and growth of D. sanguinalis L. and A. retroflexus L. Using HPLC, one fraction with an absorption peak at 271 nm was separated from the crude toxin. This fraction could strongly inhibit the growth of D. sanguinalis L. at a concentration of 100 mg L^-1 and could completely inhibit the seed germination of D. sanguinalis L. and A. retroflexus L. at a concentration of 50 mg L^-1 .

Development of Rare Earth Hydrometallurgy Technology in China

In this paper, the recent advance of processes for treating Baotou mixed-type rare earths concentrate, bastnasite, and ionic adsorption deposit in China was reviewed. The R & D circumstance and new progresses in separation and purification of individual and high purity RE compounds in China were introduced. Moreover, the development of RE hydrometallurgy was also predicted. So we suggest to enhance the research and development of products applying RE, especially Ce, Y, Gd, Sm etc., for keeping RE consumption equilibrium and extending applications, to increase enterprise's automatic control level for improving the stability and the consistency of the products, and to pay more attention to protection of environment.

Preparation of Conotoxin MrVIB by Genetic Engineering Technology

[ Objective] The disulfide-rich conotoxin MrV1B was produced by simple and fast genetic engineering method, to find new efficient ways for the synthesis of natural active conotoxins. [Method] Primers of conotoxin gene MrVIB were synthesized to construct expression vectors pET22b（ ＋ ）/His-Xa-MrVIB and pET32a/Trx-EK-MrV1B, which were transformed into BL21 （DE3）pLysS and expressed under induction by IPTG. Recombinant proteins were purified by affinity chromatography using Ni-NTA agarose column, and the expression of the recombinant proteins was analyzed by Tricine-SDS-PAGE electrophoresis. [ Result] The recombinant conotoxins His-Xa-MrVIB and Trx-EK-MrVIB were effectively expressed in E. coli, and purified by one-step affinity chromatography, and the purity of the recombinant conotoxins was greater than 90%. [ Conclusion] The conotoxin MrVIB was effectively secreted and expressed by genetic engineering method, which could solve the problems in chemical synthesis of conotoxins including low yield, high cost and difficult purification.

Phenolic compounds from Elephantopus scaber L.

Eight compounds,(+)-syringaresinol(1),apigenin(2),3,5-dimethoxy-4-hydxyphenylpropanol(3),3,4,5-trimethoxy benzoic acid,(4)ferulaic acid(5),trans-p-hydroxycinnamic methyl ester(6),4-hydroxy-3-methoxybenz-oic acid(7)and p-methoxy benzoic acid(8)were isolated from the 70%ethanol extract of the whole herb of Elephantopus scaber L.The structures of all compounds were identified by spectral data analysis.All compounds were obtained for the first time from Elephantopus scaber L..

Phenolic compounds from Peanut testa

Phytochemical investigation of peanut testa(the seed coat of Arachis hypogaea L.)led to the isolation of eight phenolic compounds,including caffeic acid(1),methyl caffeate(2),ethyl caffeate(3),methyl protocatechuate(4),ethyl protocatechuate(5),butyl protocatechuate(6),(E)-p-hydroxycinnamic acid methyl ester(7),and resveratrol(8).The structures of the compounds were elucidated through spectroscopic data analysis and comparison with the previously reported literature.Among them,compounds 2,3,5,and 6 were obtained from Arachis hypogaea L.for the first time.

Research progress of metal chelating peptides

Some metal elements,especially trace elements,have obvious nutritional and physiological functions on the human body,which can promote the growth and development of the body,regulate the function of the body and maintain the metabolism of the human body.Compared with the elements in the form of inorganic salts,metal chelating peptides are more easily absorbed by the human body.Metal chelating peptides efficiently provide various trace elements necessary for life activities,have antioxidant,antibacterial and other biological activities,and have broad application prospects in food,medicine,cosmetics and other fields.In this paper,the methods of preparation,separation and purification of metal chelating peptides from animals and plants were reviewed,the structure-activity relationship and antioxidant activity of metal chelating peptides were analyzed,and the development prospect of metal chelating peptides was prospected.

Separating method and dynamic processes of Nano-Al_(13)

In order to investigate the characteristics of pure Nano-Al_(13) ,Nano-Al_(13) was separated and purified from a series of poly-aluminum chloride(PAC)solutions which had the same Al_(13) percentage but different total Al concentrations,by using column chromatography,ethanol-acetone resolving and SO_(4)^(2−)/Ba^(2+)displacement.The Al_(13) species yield was characterized by Al-ferron timed complexation spectropho-tometry and 27Al-NMR(nuclear magnetic resonance).The coagulation efficiency of Nano-Al_(13) ,PAC and AlCl_(3) in synthetic water was also investigated by Jar tests.The dynamic process and aggregation state of kaolin suspensions coagulating with Nano-Al_(13) ,PAC and AlC_(13) were similarly investigated using a photometric dispersion analyzer 2000(PDA2000).The experimental results indicated that the ethanol-acetone resolving method was simple and could separate the PAC solution at different concentrations,while column chromatography could separate PAC solutions at low concentrations.The SO_(4)^(2−)/Ba^(2+)displacement method could separate PAC solutions at high concentrations.However,extra inorganic cation and anion could be added in the solution during separation.The coagulation efficiency and dynamic experimental results showed that Nano-Al_(13) with high positive-charged species was effective in removing turbidity and color.The dynamic process results showed that Nano-Al_(13) also had the best recovery capability after shearing compared with PAC and AlCl3 because the Nano-Al_(13) conformation is more effective in charge neutralization.

Recovery of platinum from spent automotive catalyst based on hydrometallurgy

Platinum(Pt)is a critical raw material for automotive catalytic converters due to its high-temperature stability,corrosion resistance and catalytic activity,whereas its limited primary resources and uneven distribution make it hard to meet the growing demand of platinum.Spent automotive catalyst(SAC)is currently the most important secondary resource of platinum,of which the platinum content is much higher than that of the primary platinum resources.The recovery process of platinum from spent automobile catalyst mainly consists of pretreatment followed by enrichment and refining,involving pyro-and hydrometallurgical techniques,among which enrichment and refining processes are extremely important for platinum recovery from spent automobile catalyst.This paper provides an overview of the technologies for platinum recovery from spent automotive catalyst.The emphasis is placed on the processes of enrichment and refining based on hydrometallurgical techniques.Future directions of research and development of platinum recovery from spent automobile catalyst are also proposed.