Deep eutectic solvents for separation and purification applications in critical metal metallurgy:Recent advances and perspectives

Solvent extraction,a separation and purification technology,is crucial in critical metal metallurgy.Organic solvents commonly used in solvent extraction exhibit disadvantages,such as high volatility,high toxicity,and flammability,causing a spectrum of hazards to human health and environmental safety.Neoteric solvents have been recognized as potential alternatives to these harmful organic solvents.In the past two decades,several neoteric solvents have been proposed,including ionic liquids(ILs)and deep eutectic solvents(DESs).DESs have gradually become the focus of green solvents owing to several advantages,namely,low toxicity,degradability,and low cost.In this critical review,their classification,formation mechanisms,preparation methods,characterization technologies,and special physicochemical properties based on the most recent advancements in research have been systematically described.Subsequently,the major separation and purification applications of DESs in critical metal metallurgy were comprehensively summarized.Finally,future opportunities and challenges of DESs were explored in the current research area.In conclusion,this review provides valuable insights for improving our overall understanding of DESs,and it holds important potential for expanding separation and purification applications in critical metal metallurgy.

A Simple Method for the Isolation and Purification of 2,4-Dihydroxy-7-Methoxy-2H-1,4-Benzoxazin-3(4H)-One (DIMBOA) from Maize (Zea mays L.) Seedlings

2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3（4H）-one （DIMBOA）, the dominant benzoxazinoid hydroxamic acid in maize （Zea Mays L.）, serves as important factors of resistance against insects and microbial diseases, allelochemicals used in competition with other plants. In this paper, a novel and simple method for the isolation and purification of DIMBOA from maize seedlings was developed. Frozen shoots from 7-d-old maize seedlings （1 000×g） were firstly defrosted and then were directly homogenized and extracted with ethyl acetate. The macerate was allowed to stand at room temperature （25±2）°C for 1 h to allow enzymatic release of DIMBOA from DIMBOA-glucoside. Then the ethyl acetate phase was filtered, dried and evaporated to dryness. The resulting light-tan, semicrystalline residue was stored at -20°C for 24 h. Upon recrystallization from acetone-hexane, a relative higher yield （0.58 g） of pure DIMBOA crystals was obtained compared with the yield afforded by Woodward methodology （0.26 g）.

Isolation and Purification of Anthocyanins from Blood Oranges by Column Chromatography

In this study, isolation and purification of anthocyanins from blood oranges by column chromatography were investigated, and then the anthocyanins of blood orange were identified. The behaviors of static adsorption and desorption, dynamic adsorption and desorption of 12 kinds of resins were compared. The results indicated that NKA-9 macroporous resin was optimum for isolation of blood orange anthocyanins, and the optimal elution reagent was 50% ethanol with citric acid （pH 2.5）. Toyopearl TSK HW-40S column was employed to separate and purify the anthocyanin extracts from blood orange. The best separation of Toyopearl TSK HW-40S column was obtained using a mobile phase of 35% methanol with 2% formic acid at a flow-rate of 0.6 mL min-~. Three kinds of anthocyanins were purified from blood orange. Then, the anthocyanins of blood orange were identified by HPLC-ESUMS analysis. The results showed that cyanidin-3-glucoside （35.2%） and cyaniding-3-（6＂-malonyl） glucoside （42.9%） were the major anthocyanins of blood orange. Furthermore, cyanidin-3-（3＂-malonyl） glucoside, cyanidin 3-（6＂-dioxalyl） glucoside and cyanidin-3-glucoside adduct：4-vinylcatechol were identified in blood orange. The combination of NKA-9 macroporous resin and Toyopearl TSK HW-40S column chromatography for isolation and purification of blood orange anthocyanins was an effective method, and HPLC-ESI/MS analysis was a convenient, rapid and effective method for identification of anthocyanins from blood orange.

Isolation,Purification and Bioactivities of Polysaccharides from Irpex lacteus

Irpex lacteus has been widely used for treating chronic glomerulonephritis as a traditional Chinese medicine.Seven water-soluble polysaccharide fractions（ILN I,ILN II,ILN III,ILA I,ILA II,ILB I and ILB II） were isolated and purified from Irpex lacteus by hot-water extraction,deproteinization,decolorization,dicthy laminoethyl（DEAE）-cellulose ion exchange and sephadex G100 chromatographies,respectively.The average molecular weights and monosaccharide composition of these polysaccharide fractions greatly differed from each other.The antitumor and antinephritis activities of the seven polysaccharide fractions were evaluated.It was found that ILN III displayed significant inhibition effects on both humar hepatocellular liver carcinoma（HepG2） and hentietta lacks（HeLa） tumor cells with IC 50 values of 60.95 and 99.95 μg/mL,respectively.ILA I exhibited significant inhibition effects on murine mesangial cells（HBZT-1） with an IC 50 value of 185.06 μg/mL.The inhibition effects of other polysaccharide fractions on these three cells were significantly different.These results suggest that the polysaccharide fractions isolated from Irpex lacteus have potential antitumor and antinephritis activities.

A simple method for the isolation and purification of resveratrol from Polygonum cuspidatum

Resveratrol, a polyphenol compound with strong biological activity, has been widely used in medicine, health products and cosmetic industries. It is also the main active component of Polygonurn cuspidatum, a well-known traditional Chinese medicine. We developed a simple and effective method for the preparation of resveratrol from P. cuspidatum. The whole preparative process consisted of reflux extraction, filtering, hydrolyzing, liquid-liquid extraction and eluting. Filtering is to remove non polar or less polar compounds and debris fragments from the extract. Hydrolyzing is to transform polydatin to resveratrol to improve the yield of resveratrol. Eluting is to remove impurities including strong acidic and water-soluble compounds. By acid hydrolysis of glycoside （polydatin）, the yield of resveratrol increased about 4-fold. The extraction recovery in different stages was high, and the content of resveratrol in the final product was over 73.8%. Compared with other methods reported, this technology is eco-friendly, easier to perform, and also has a lower cost.

Isolation, Purification and Cryopreservation of Cells from Neonatal Bovine Testis

The development and application of spermatogonial stem cell technology have an important significance in animal cloning, preservation of endangered species and spermatogenesis research. In this study, the seminiferous epithlium cells were isolated and purified, the ceils were cryopreserved after identification, and the effects of different purification and cyopreservation methods on bovine testicular cells were studied. The results showed that there were spermatogonial stem cells and sertoli cells in the neonatal bovine seminiferous tubules, differential adherent selection methods could effectively separate these two cell types. Spermatogonial stem cells were positive after AKP, C-kit, and OCT-4 identification; sertoli ceils were positive after oil red O and vimentin identification. Frozen stock solution supplemented with 10% DMSO had the best effect in spermatogonial stem cell cryopreservation, while fxozen stock solution supplemented with 10% of ethylene glycol and 0.1 mmol. L^-1 trehalose had the best effect in sertoli cells crvooreservation.

Isolation and Purification of Unstable Iridoid Glucosides from Traditional Chinese Medicine by Preparative High Performance Liquid Chromatography Coupled with Solid-phase Extraction

An efficient preparative method was successfully developed for isolation and purification of unstable components from medicinal plant extracts, using a combined method of preparative high performance liquid chro-matography(HPLC) and solid-phase extraction(SPE). The aim of this study was to obtain an effective method with high preparative efficiency and importantly to avoid the transformation of unstable compounds. The preparative HPLC system was based on an LC/MS controlled four-channel autopurification system. The SPE method was performed with a C18 packing material to trap the target compounds and to remove the acidic additive derived from the mobile phase. Using this method, the unstable iridoid glucosides(IGs) as model compounds were successfully isolated and purified from the extract of Hedyotis diffusa Willd. Six IGs(including one new minor IG) and one nucleotide compound were simultaneously obtained, each with a purity of 91% as determined by HPLC. The structures of the isolated compounds were identified by UPLC/Q-TOF MS, UV, 1D and/or 2D NMR. It was demonstrated that the combination of preparative HPLC with SPE is a versatile tool for preparative purification of unstable compounds from complex natural products.

Isolation and Purification of Myxobacteria in Chengdu

[ Objective] To lay the basis for further studying bioactive substances in myxobacteria. [ Method] A total of 35 samples including fresh water, mud, rabbit dung, sheep dung, weathered rock and rotten wood were collected from districts and counties of Chengdu. After pretreatment, the myxobacteria were isolated and purified using different methods. Vegetative cells, myxospores, fruiting body and colony morphology of these myxobacteria strains were observed. E ResultJ Forty-two myxobacteda strains were isolated and purified. They were classified into seven genera including Myxococcus, Angiococcus, Chondromyces, Sorangium, Melittangium, Stigmatella and Archangium. The plating efficiency of myxobacteria was highest in the fresh water samples. [ Conclusion] Abundant myxobacteria resource is found in fresh water.

Isolation and Preparative Purification for Ginkgolides A and B

In this paper a simple preparative method for isolation and purification of ginkgolides A and B was developed,As starting material,a commercially available standardized ginkgo extract (EGb761,containing 24% flavonoid and 6% terpene trilactones) was used,After a pretreatment step,optimized by the uniform design method ,the concentrated intermediate extract with high content of GA and gb(+90%) was separated into the individual terpenes by preparative liquid chromatography eluted with petroleum ether-ethylacetate,Analysis of products was carried out by means of HPLC-ELSD(evaporative light -scattering detector),The results show that ginkgolides A and B are obtained in higher yield and better purity.

STUDIES ON THE ISOLATION PURIFICATION AND CHARACTERIZATION OF THE FUCOIDAN-GALACTOSAN SULFATE (FGS) FROM LAMINARIA JAPONICA

FGS, isolated from the water solution of enzymolyzed laminaria japonica, is a mixture of acid heteroglycans. Four fractions F1, F2, F3, and F4 were obtained from FGS by ion exchange chromatography. After further purified by gel filtration chromatography on a sepharose 2B and 6B column, we obtained F9, F10, F11, and F12. They showed single band when identified by electrophoresis. The molecular weight of F9, F10, F11, and F12 was estimated to be 216, 120, 138 and 140KD respectively. They containedа-glucosidic bond by IR and 1H-NMR analysis. The typical absorption peaks of these polysaccharides were showed in UV and IR spectra. These polysaccharides contained rha, fuc, man, gal, and uronate when identified by paper chromatography (p.c) and gas chromatography (GC). The molar ratio of these sugars was also assayed.

The Isolation, Purification and Identification of Fumitremorgin B Produced by Aspergillus fumigatus

Twenty-six strains of Aspergillus fumigaius were screened for toxigenicity for fumitremorgins A and B. Twenty-three of 26 strains can produce fumitremorgin B in rice medium determined by TLC and HPLC, and no fumitremorgin A was detected. The strains of no.C4104 and no. 3656 were inoculated onto 5 kg of rice media and incubated in a modified procedure. Finally, 4.0 g of fumitremorgin B was obtained after extraction and purification by modified methods, and was confirmed by TLC, HPLC, spectral analysis together with other physicochemical analysis. This is the first report of the preparation of fumitremorgin B in China.

Isolation,Purification and Immunomodifying Activity of Polysaccharides from Phellinus igniarius

Phellinus igniarius polysaccharides were obtained by hot water extraction of mushroom fruit bodies followed by ethanol precipitation,and further purified by anion exchange and gel filtration chromatography.Immuno-enhancing activity was evaluated by determining the effect of different polysaccharide fractions on mouse spleen lymphocyte proliferation in vitro.Three crude polysaccharide preparations,designated PIP30,PIP60 and PIP80 according to the percentage concentration of ethanol required for precipitation from hot aqueous extracts,promoted lymphocyte proliferation to varying degrees.Purification of polysaccharide present in PIP30 and PIP60 was carried out using anion exchange chromatography.Proliferation rates in samples treated with 200 μg/mL of fractions P30U,P30W and P30S1(obtained following anion exchange chromatography of PIP30) were approximately 5-,4-,and 3.5-fold higher,respectively compared with negative controls.Similarly,marked increases(3.4-and 2.8-fold) in cell proliferation rates compared with negative controls were observed with 200 μg/mL concentrations of P60W and P60S2(obtained following anion exchange chromatography of PIP60),respectively.Two purified polysaccharide preparations,P60W1-1 and P60S1-1,were obtained following gel filtation chromatography of fractions P60W1 and P0S1,respectively.Fraction P60W1-1(10-100 g/mL) enhanced splenocyte proliferation 0.5-1.4-fold compared with negative controls,whereas no effects were observed with P60S1-1.

Isolation and Purification of Bovine Colostrum sIgA and IgG

To further utilize bioactive substance such as bovine colostrum sIgA and IgG, sIgA and IgG were isolated and purified simultaneously by salting out, ultrafiltration and gel chromatography, etc. The analysis of results were showed quantitatively by nonhydrogenized SDS-PAGE, and quanlities of sIgA and IgG were respectively detected by Western Blot. The results showed that the purity and yield of bovine colostrum sIgA were 85.3% and 42.8%, respectively, while the purity and yield of bovine colostrum IgG were respectively 97.2% and 64.4%. This preparative method provides theoretical and experimental foundation for sIgA industrial production.

Isolation and Purification of Antibacterial Peptides from Mussel

[ Objective ] This study aimed to extract antibacterial peptides from mussel. [ Method ] Blue mussels were used as raw materials for direct extraction of antibacterial peptides by using O. 5 % acetic acid, and the antibacterial peptides were isolated and purified by Sephacryl S-100 polyacrylamide gel chromatography. The fractions were collected for measurement of antibacterial activity and minimum inhibitory concentration for a variety of bacterial species by filter paper diffusion assay. Molecular weight of the antibacterial peptides was determined by SDS-PAGE. Variation of antibacterial activity of antibacterial peptides was measured at 100 ~C under conditions of different processing time and different pH. [ Result] The O. 5% acetic acid was used for crude extraction of antibacterial peptides as extrac- tion solution and led to relatively high extraction efficiency. By using Sephacryl S-100, the antibacterial peptides could be purified as a single substance. The isola- ted and purified antibacterial peptides of mussel had relatively strong antibacterial properties with molecular weight of 5 908, showing heat-resistance acid-alkaline resistance. [ Conclusion] This study laid the theoretical foundation for large-scale production of antibacterial peotides.

Isolation and Purification of Enzymatic Hydrolysates of Yam(Dioscorea opposita Thunb.)Proteins

Using yam （Dioscorea opposita Thunb. ） as the experimental material, enzymatic hydrolysates of yam proteins were prepared with alkaline protease, which were then isolated and purified by cellulose DE-52 anion exchange chromatography Sephadex G-50 gel chromatography. According to the results, four absorp- tion peaks were obtained by cellulose DE-52 anion exchange chromatography, and fractions at each absorption peak were collected. Specifically, the reducing ability of four peaks demonstrated a descending order of peak 2 （P2） 〉 peak I （ P1 ） 〉 peak 3 （P3） 〉 peak 4 （P4）. By Sephadex G-50 gel chmmatography, P1 and P2 were isolated and purified with distilled water and Tris-HC1 buffer, and two absorption peaks were obtained, respectively.

AN EFFICIENT METHOD FOR ISOLATION AND PURIFICATION OF THE PANCREATIC ISLETS

On the base of the one step, operator independent method which was set up by Christophe A.E., the pancreas was infused with cold University of Wisconsin(UW) solution for the preservation, digested by the collagenase P, circuited with HBSS+5%fetal calf serum(FCS)+10mmol/L Hepes solution, and separated with the stainless steel mesh. The number of the collected islets were 400000～1800000 per pancreas, i.e. about 12150/g pancreas. After purification, the recovery was 350000～1700000 per pancreas, i.e. about 10250/g pancreas, the recovery rate was above 80%, and the purity of the final preparation was above 95%. The insulin secretion in the response to the high concentration glucose (22 mmol/L) stimulation was apparently different on the 1,3,5 day of the cultural islets, which the high level of insulin was three times the low level (5.5 mmol/L) on the 5th day, and the insulin level of the double stimulation under perfusion conditions is apparently higher than low glucose. The result demonstrated that the purified islets were functionally alive. Histological studies also show that the shape of islets are complete, and the β cell was specially stained by the dithizone (DTZ). The Trypan Blue staining had shown the living cell was above 90%. In conclusion, the new method was highly practical and yielded higher concentration of active pancreatic islets.

Isolation,culture,and purification of olfactory mucosa-derived olfactory ensheathing cells using modified differential attachment with low concentration serum

BACKGROUND：Studies have demonstrated that olfactory mucosa can promote the regeneration and formation of axonal medullary sheath of injured neurons. To date, olfactory ensheathing cells （OECs） utilized in basic and clinical research arise primarily from the olfactory bulb mucosa. However, little is known regarding culture, purification, and biological properties of OECs . OBJECTIVE： To isolate and culture OECs utilized modified, differential attachment in combination with neurotrophic factor 3 （NT3） and low concentration serum to explore an optimal in vitro culture method for OECs.DESIGN, TIME AND SETTING： Single-sample observation was performed at the Medical Experimental Center of Stomatology College, Xi＇an Jiaotong University between March 2006 and December 2007. MATERIALS： Twelve samples from aborted embryos, 4-6 months, were used to isolate OECs; rabbit-anti-human p75NTR and glial fibrillary acidic protein （GFAP） antibody were provided by Sigma, USA. METHODS： The differential time was six hours. This was repeated twice, based on Nash＇s differential attachment. Attached OECs were cultured in DMEM-F12 culture medium containing 10% fetal bovine serum （FBS） or 2.5% FBS and NT3. MAIN OUTCOME MEASURES： OEC morphology was observed, and p75NTR and GFAP immunocyto-chemistry was used for identification and purity detection. RESULTS： Some cells attached after three days in culture. Several cells possessed short neurites with good refractivity. Some shuttle-shaped fibroblasts could be seen. On day six, more cells attached, exhibiting a three-dimensional appearance. Many cells appeared dipolar or tripolar, with slender neurites, and fibroblasts were clustered. On day nine, the number of dipolar or tripolar cell bodies with slender neurites was increased, and fibroblasts were clustered. On day 15, fibroblasts occupied the majority of the bottom of the culture bottle, with several OECs surviving at the upper layer. OECs were positive for P75NTR and GFAP expression, as identified by an immunocytologically stained brown cell body and neurites. However, fibroblasts were P75NTR and GFAP-negative. On day 9, OEC purity reached 81%, and the number of proliferating fibroblasts significantly increased. By the end of day 12, OEC purity was reduced to 56%. CONCLUSION： Modified differential attachment, in combination with low concentration serum and NT3, removes fibroblasts and reduces OEC loss. This is an appropriate method for the isolation and culture of human fetal olfactory mucosa-derived OECs.

Isolation and Purification of Rat Testicular Lactate Dehydrogenase C_4

The lactate dehydrogenase isoenzyme C4 ofrat testicle was purified with a yield of 1 2.3% anda raise of specific activity to 784-fold.The purified product was PAGE homogeneous and migrated afterLDH3 during electrophoresis.

ISOLATION AND PURIFICATION OF METHANE IVf ONOOXYGENASE FROM METHYLOMONAS SPECIES GYJ3

A three—component enzyme system that catalyzes in vivo the oxidation of CH_4 to CH_3OH has been purified with high specific activity from an unusual type I methanotroph through the use of stabilizing reagents.

A Review on the Isolation and Purification of D-allulose

D-allulose has very little content in nature,and it needs to be synthesized artificially and meet the purity requirements of industrial grade.The basic physical and chemical properties of D-allulose,its preparation methods and many different ways of isolation and purification were described.In order to achieve the goal of industrial production of D-allulose as soon as possible,the research progress of D-allulose isolation and purification technologies at home and abroad in recent years was classified and discussed,so as to provide useful reference for the practical improvement of D-allulose isolation and purification process technologies.