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In developing analytical methods for batch certification of the color additive D&C Green No. 8 (G8), the U.S. Food and Drug Administration needed the trisodium salt of 1,3,6-pyrenetrisulfonic acid (P3S) for use as a reference material. Since P3S was not commercially available, preparative quantities of it were separated from portions of a sample of G8 that contained ∼3.5% P3S. The separations were performed by pH-zone-refining counter-current chromatography using dodecylamine (DA) as the hydrophobic counterion. The added DA enabled partitioning of the polysulfonated components into the organic stationary phase of the two-phase solvent system used, 1-butanol–water (1:1). Thus, a typical separation that involved 20.3 g of G8, using sulfuric acid as the retainer acid and 20% DA in the stationary phase and 0.1 M sodium hydroxide as the mobile phase, resulted in ∼0.58 g of P3S of greater than 99% purity. The identification and characterization of the separated P3S were performed by elemental analyses, proton nuclear magnetic resonance, high-resolution mass spectrometry, ultra-violet spectra, and high-performance liquid chromatography.

An improved type-J counter-current chromatography (CCC) planet centrifuge with two spiral tube columns (volume 2×15 mL, β value 0.3-0.7, tubing 0.8 mm id) was developed and evaluated for its retention ability of four typical different solvent systems including heptane-methanol (1:1, v/v) (A), hexane-ethyl acetate-methanol-water (1:1:1:1, v/v) (B), n-butanol-acetic acid-water (4:1:5, v/v) (C), PEG1000-K(2)HPO(4)-water (12.5:12.5:75, w/w) (D) under eight different operation modes. The results indicated that the spiral tube column could significantly increase the retention of four typical solvent systems compared with a traditional multilayer coil column with similar parameters (volume 35 mL, β value 0.3-0.7, tubing 0.8 mm id). The retention of stationary phase (S(f)) for the less polar system (A) and moderately polar solvent system (B) can be increased by about 10%, and for the polar system (C) and aqueous two-phase system (ATPS) (D) by 30-40%. The preliminary applications of this spiral tube column to the separation of small molecular compounds such as moderately polar theaflavins, polar anthocyanins and dipeptides were successful. Acceptable resolution can be obtained between cytochrome c and myoglobin, lysozyme and myoglobin when it was applied on protein separation; however, it still needs to be improved with regard to its column efficiency.

High-speed countercurrent chromatography (HSCCC) and preparative high-performance liquid chromatography (prep-HPLC) were successively used for the separation of pogostone and four flavonoids from Pogostemon cablin (Blanco) Benth. An efficient HSCCC separation was achieved on a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (11:5:11:5, v/v/v/v). Three well-separated peaks were obtained in the HSCCC chromatogram. The first and the second fractions each contained two flavonoids which were further separated by preparative HPLC. Consequently, the separation yielded 11.5 mg of 4', 5-Dihydroxy-3', 7-dimethoxyflavanone at a purity of 99%, 20.3 mg of 5- Hydroxy-7, 3', 4'-trimethoxyflavanone at a purity of 98%, 18 mg of 5, 4'-Dihydroxy-3, 7, 3'-trimethoxyflavone at a purity of 96%, and 8 mg of 5-Hydroxy-3, 7, 4'-tetramethoxyflvone at a purity of 98%. The third HSCCC fraction yielded 18.5 mg of pogostone at a purity of 95%. The chemical structures of these compounds were identified by ESI-MS(n), (1)H-NMR, and (13)C-NMR.

Type-I coil planet centrifuge produces a uniformly circulating centrifugal force field to produce vortex motion of two immiscible solvent phases in a cylindrical cavity of the separation column to perform efficient countercurrent chromatography. The partition efficiency obtained from the original vortex column was substantially improved by threading the cylindrical cavity to increase the area of mass transfer between the two phases. Partition efficiency of the threaded column was evaluated by three different two-phase solvent systems with a broad range of hydrophobicity each with a set of suitable test samples. Overall results of the present studies indicated that the threaded cylindrical column substantially improves the partition efficiency in terms of theoretical plate number, peak resolution, and height equivalent of one theoretical plate. The results also indicated that higher peak resolution is produced by eluting either the upper phase in the head to tail direction or the lower phase in the reversed direction. When there is a choice in the mobile phase, a better separation is achieved by using the less viscous phase as the mobile phase. Since the present system gives extremely low column pressure, it may be a potential alternative to the conventional type-J HSCCC system for a large-scale preparative separation.

High-speed counter-current chromatography (HSCCC) was successfully applied for the preparative separation and purification of alkaloids from Corydalis bungeana Turcz. (Kudiding in Chinese) for the first time. After the measurement of partition coefficient of seven target alkaloids in the nine two-phase solvent systems composed of CHCl3‐MeOH‐(0.1 M; 0.2 M; 0.3 M) HCl (4:1.5:2; 4:2:2; 4:3:2, v/v), CHCl3‐ MeOH‐0.2 M HCl (4:2:2, v/v) and CHCl3‐MeOH‐0.3 M HCl (4:3:2, v/v) were finally selected for the HSCCC separation using the first upper phase as the stationary phase and the stepwise elution of the two lower mobile phases. Consequently, sanguinarine (10 mg), corynoline (25 mg), protopine (20 mg), corynoloxine (18 mg), and 12-hydroxycorynoline (8 mg) were obtained from 200 mg of crude alkaloid extracts with purities of 94‐99% as determined by HPLC. Their chemical structures were characterized on the basis of 1 H-NMR, 13 C-NMR, and LC-ESI-Q-TOF-MS/MS analyses.

Combined with medium-pressure liquid chromatography (MPLC) and preparative high-pressure liquid chromatography (Prep-HPLC), high-speed countercurrent chromatography (HSCCC) was successfully applied for separation and purification of isoflavonoids from the extract of belamcanda. HSCCC separation was performed on a two-phase solvent system composed of methyl tert-butyl ether -ethyl acetate - n-butyl alcohol - acetonitrile -0.1% aqueous trifluoroacetic acid at a volume radio of 1:2:1:1:5. Semi-purified peak fractions from HSCCC separation were further purified by Prep-HPLC. Nine well-separated fractions were analyzed by HPLC-UV absorption spectrometry to determine their purities and characterized with ESI-MS(n). Except for peaksland VII (unknown) seven compounds were identified as apocynin (peak II), mangiferin (peak III), 7-O-methylmangiferin (peak IV), hispidulin (peak V), 3'-hydroxyltectoridin (peak VI), iristectorin B (peak VII), isoiridin (peak IX).

Partition efficiency of the high-pitch locular multilayer coil was evaluated in countercurrent chromatographic (CCC) separation of proteins with an aqueous-aqueous polymer phase system using the small-scale cross-axis coil planet centrifuge (X-axis CPC) fabricated in our laboratory. The separation column was specially made by high-pitch (ca 5 cm) winding of 1.0 mm I.D., 2.0 mm O.D. locular tubing compressed at 2 cm intervals with a total capacity of 29.5 mL. The protein separation was performed using a set of stable proteins including cytochrome C, myoglobin, and lysozyme with the 12.5% (w/w) polyethylene glycol (PEG) 1000 and 12.5% (w/w) dibasic potassium phosphate system (pH 9.2) under 1000 rpm of column revolution. This high-pitch locular tubing yielded substantially increased stationary phase retention than the normal locular tubing for both lower and upper mobile phases. In order to demonstrate the capability of the high-pitch locular tubing, the purification of collagenase from the crude commercial sample was carried out using an aqueous-aqueous polymer phase system. Using the 16.0% (w/w) PEG 1000 – 6.3% (w/w) dibasic potassium phosphate – 6.3% (w/w) monobasic potassium phosphate system (pH 6.6), collagenase I, II, V and X derived from Clostridium hystolyticum were separated from other proteins and colored small molecular weight compounds present in the crude commercial sample, while collagenase N-2 and S-1 from Streptomyces parvulus subsp. citrinus were eluted with impurities at the solvent front with the upper phase. The collagenase from C. hystolyticum retained its enzymatic activity in the purified fractions. The overall results demonstrated that the high-pitch locular multilayer coil is effectively used for the CCC purification of bioactive compounds without loss of their enzymatic activities.

Coupled with evaporative light scattering detection, a high-speed counter-current chromatography (HSCCC) method was applied to the separation and purification of three tauro-conjugated cholic acids of taurochenodeoxycholic acid (TCDCA), taurohyodeoxycholic acid (THDCA) and taurohyocholic acid (THCA) from Pulvis Fellis Suis (Pig gallbladder bile) for the first time. The two-phase solvent system composed of chloroform-methanol-water-acetic acid (4:4:2:0.3, v/v/v/v) was selected for the one-step separation where the lower phase was used as the mobile phase in the head to tail elution mode. The revolution speed of the separation column, flow rate of the mobile phase and separation temperature were 800 rpm, 1.5 ml/min and 25°C respectively. From 100 mg of the crude extract, 10.2 mg of TCDCA, 11.8 mg of THDCA and 5.3 mg of THCA were obtained with the purity of 94.6%, 96.5% and 95.4%, respectively. in one step separation The HSCCC fractions were analyzed by high-performance liquid chromatography (HPLC) and the structures of the three tauro-conjugated cholic acids were identified by ESI-MS, (1)H NMR and (13)C NMR.

A simple, selective and sensitive reversed-phase high performance liquid chromatography method for simultaneous analysis of hydrochlorothiazide and reserpine in human urine was developed and subjected to primary pharmacokinetic study. After a simple protein precipitation using methanol and extraction with ethyl acetate, the analytes were separated on an Elite C(18) column at a flow rate of 0.8 mL min(-1). The mobile phase was composed of acetonitrile (A) and 0.2% ammonium chloride solution (B) for a gradient elution starting at A:B at 30:70, v/v for 0~6 min, linearly raising the percent of A from 30% to 50% (6~9 min) and ending at 50:50, v/v (9~25 min). The standard curves were linear over the range of 0.05-20 µg mL(-1) for hydrochlorothiazide and 0.02-5.0 µg mL(-1) for reserpine, respectively (r0.999). The limit of detection (LOD) and the limit of quantification (LOQ) were 5.5 ng mL(-1) and 18.2 ng mL(-1) for hydrochlorothiazide, and 7.1 ng mL(-1) and 23.6 ng mL(-1) for reserpine, respectively. The recoveries for both analytes were above 89.0±1.35%. The intra-day and inter-day precision for hydrochlorothiazide were less than 1.91% and 1.38%, and those for reserpine were below 1.61% and 2.64%, respectively. The method indicated good performance in terms of specificity, linearity, detection and quantification limits, precision and accuracy, and it was employed successfully for the simultaneous determination of hydrochlorothiazide and reserpine in human urine samples.

Optimal positions of coiled separation columns on the type-I centrifuge were determined for four typical two-phase solvent systems to obtain the best separation efficiency (resolution and retention of stationary phase) for each with a suitable set of test samples. A set of short coiled columns is connected in series and mounted around the holder hub in four different ways: (model A) the tail of one unit with left-handedness was connected to the head of the next unit with right-handedness (TL-HR); (model B) the tail of one unit with left-handedness was connected to the tail of the next unit with right-handedness (TL-TR); (model C) the tail of one unit with left-handedness was connected to the tail of the next unit with left-handedness (TL-TL); (model D) the tail of one unit with left-handedness was connected to the head of the next unit with left-handedness (TL-HL). The results indicated that the performance of model D was the best among the four models. High revolution speed (800. rpm) is favorable to separation using the moderately hydrophobic solvent system of hexane-ethyl acetate-methanol-0.1. M HCl (1:1:1:1, v/v) (HEMW), while lower revolution speed (600. rpm) is beneficial to the separation with polar solvent system of 1-butanol-acetic acid-water (19:1:20, v/v) (BAW).

Enantiomers of lomefloxacin hydrochloride were separated by high-speed counter-current chromatography (HSCCC) using sulfated-β-cyclodextrin as a chiral selector (CS). The separation was performed with a two-phase solvent system composed of ethyl acetate-methanol-water (10:1:10, v/v) containing CS at 0-60mmol/l in a head-to-tail elution mode, while obtained fractions were identified by polarimeter and spectropolarimeter. The results show that the concentration of the CS in the system strongly affects the peak resolution (Rs). As the concentration of CS increases, the Rs first increases reaching the maximum at 50mmol/l and then decreases. When the CS concentration is kept constant in the solvent systems, the Rs decreases as the concentration of the lomefloxacin hydrochloride increases. The overall results of our studies indicated that sulfated-β-cyclodextrin is very useful for the chiral separation by HSCCC.

An effective high-speed countercurrent chromatography (HSCCC) method was established for further separation and purification of four minor flavonols in addition to five major flavonols which were reported by our previous study from extracts of Flos Gossypii. HSCCC was performed with three two-phase solvent systems composed of n-hexane-ethyl acetate-methanol-water (7.5:15:6:7, v/v), (2.5:15:2:7, v/v) and (0:1:0:1, v/v). The separation was repeated 3 times, and 3.8 mg of 8-methoxyl-kaempferol-7-O-β-D-rhamnoside (HPLC purity 98.27%), 6.7 mg of astragalin (HPLC purity 94.18%), 3.3 mg of 4'-methoxyl-quercetin-7-O-β-D-glucoside (HPLC purity 94.30%) and 8.2 mg of hyperoside (HPLC purity 93.48%) were separated from 150 mg of the crude sample. The chemical structures of the flavonols were confirmed by MS, (1)H NMR and (13)C NMR. Meanwhile, the results indicated that the target compound with smaller K value (

The conventional toroidal coil in centrifugal countercurrent chromatography has a low level of stationary phase retention, since a half of each helical turn is entirely occupied by the mobile phase. In order to cope with this problem, several new column designs including zigzag, saw-tooth, and figure-8 patterns have been introduced, and their performance was compared in terms of retention of the stationary phase (Sf), peak resolution (Rs), theoretical plate number (N), and column pressures. Overall results of experiments indicate that the figure-8 column yields the highest Rs when the lower phase is used as the mobile phase. Since the column pressure of all these new columns are much lower than that in the traditional toroidal coil column, the separation efficiency can be improved using a long separation column without a risk of column damage by high back pressure.

A typing system forClostridium difficileusing sequencing of the surface-layer protein A encoding gene (slpA) was evaluated and used to analyse clinical isolates in Japan. A total of 160 stool specimens from symptomatic patients in Japan was examined and 87C. difficileisolates were recovered.slpAsequence typing was found to have reliable typability and discriminatory power in comparison with PCR ribotyping, and the typing results were highly reproducible and comparable.slpAsequence typing was used to typeC. difficilein DNA extracted directly from stool specimens. Among the 90 stool specimens in which direct typing results were obtained, 77 specimens were positive forC. difficileculture, and typing results from isolated strains agreed with those from direct typing in all 77 specimens. TheslpAsequence type smz was dominant at all four hospitals examined, and this endemic type was detected by culture and/or direct typing in 61 (62 %) of 99 stool specimens positive for toxic culture and/or directslpAsequence typing. Comparison of epidemic strains reported throughout the world revealed one isolate identified asslpAsequence type gc8, which was found to correspond to PCR ribotype 027 (BI/NAP1/027), whereas no isolates were found with theslpAgene identical to that of PCR ribotype 078 strain.slpAsequence typing is valuable for comparison ofC. difficilestrains epidemic in diverse areas because the typing results are reproducible and can easily be shared. In addition,slpAsequence typing could be applied to direct typing without culture.

This work concentrates on a chiral separation technology named biphasic recognition applied to resolution of α-cyclohexylmandelic acid enantiomers by high-speed counter-current chromatography (HSCCC). The biphasic chiral recognition HSCCC was performed by adding lipophilic (−)-2-ethylhexyl tartrate in the organic stationary phase and hydrophilic hydroxypropyl-β-cyclodextrin in the aqueous mobile phase, which preferentially recognized the (−)-enantiomer and (+)-enantiomer, respectively. The two-phase solvent system composed of n-hexane-methyl tert-butyl ether–water (9:1:10, v/v/v) with the above chiral selectors was selected according to the partition coefficient and separation factor of the target enantiomers. Important parameters involved in the chiral separation were investigated, namely the types of the chiral selectors (CS); the concentration of each chiral selector; pH of the mobile phase and the separation temperature. The mechanism involved in this biphasic recognition chiral separation by HSCCC was discussed. Langmuirian isotherm was employed to estimate the loading limits for a given value of chiral selectors. Under optimum separation conditions, 3.5–22.0 mg of α-cyclohexylmandelic acid racemate were separated using the analytical apparatus and 440 mg of racemate was separated using the preparative one. The purities of both of the fractions including (+)-enantiomer and (−)-enantiomer from the preparative CCC separation were over 99.5% determined by HPLC and enantiomeric excess reached 100% for the (±)-enantiomers. Recovery for the target compounds from the CCC fractions reached 85–88% yielding 186 mg of (+)-enantiomer and 190 mg of (−)-enantiomer. The overall experimental results show that the HSCCC separation of enantiomer based on biphasic recognition, in which only if the CSs involved will show affinity for opposite enantiomers of the analyte, is much more efficient than the traditional monophasic recognition chiral separation, since it utilizes the cooperation of both of lipophilic and hydrophilic chiral selectors.

The toroidal coil using an equilateral triangular core and zigzag pattern column have improved both retention of the stationary phase and peak resolution of the conventional toroidal coil in centrifugal counter-current chromatography. To further improve the retention of stationary phase and peak resolution, a novel saw tooth column was designed and the performance of the system was evaluated at various flow rates. The results indicated that both retention of the stationary phase and peak resolution were improved as the flow rate was decreased and at a flow rate of 0.005 ml/min the resolution is remarkably increased. Modification of the tubing called flat-twisted tubing further improved the peak resolution without increasing the column pressure. With a decreased column length at a capacity of about 0.2 ml, resolution of the saw tooth column was 1.02.

Preparative high-speed countercurrent chromatography (HSCCC) was successfully used for isolation and purification of caffeic acid from Eupatorium adenophorum Spreng with a solvent system composed of ethyl acetate-methanol-water at a volume ratio of 10:1:10, v/v. Using a preparative unit of the HSCCC centrifuge, about a 938 mg amount of the crude extract was separated, yielding 63.2 mg of caffeic acid at purity of 96.0%. Then, the anti-microbial and anti-virus drug caffeic acid (C(9)H(8)O(4)) was intercalated into layered double hydroxides for the first time by anion exchange under a nitrogen atmosphere. The product caffeic acid-LDH has been characterized by powder X-ray diffraction (XRD), Fourier transform-infrared (FT-IR), Scanning electron micrographs (SEM), indicating that the drug has been successfully intercalated into LDH.

The toroidal columns using an equilateral triangular core, zigzag, and saw patterns has improved step by step both for retention of the stationary phase and peak resolution of the conventional toroidal coil in centrifugal countercurrent chromatography. To further improve the retention of stationary phase and peak resolution, a novel figure 8 toroidal coil was designed and the performance of the system was evaluated at various flow rates. In the figure-8 column with a capacity of 3mL, the peak resolution of dipeptides (Val-Tyr and Trp-Tyr) was 1.63, and that of DNP-amino acids (DNP-DL-glu, DNP - ala, DNP-L-ala) were 1.92 and 1.85, respectively. The results indicated that retention of stationary phase and peak resolution were improved at lower flow rates. The Rs with lower mobile phase can be further increased by modifying the tubing to form a flat twisted configuration. With a decreased column length with a capacity of about 0.1mL, resolution of the figure-8 column was 0.71 with about 40% retention of stationary phase at a flow rate of 0.005mL/min.

We explored the possibility of the cysteinyl leukotriene receptor antagonists, pranlukast and montelukast, preventing tumor cell migration through both cerebral and peripheral capillaries. To study tumor cell migration through brain capillaries, male Fisher rats were cannulated via the cisterna magna under pentobarbital anesthesia. RCN9 cells labeled with a fluorescent marker PKH67 were intravenously administered following arachidonic acid administration into the subarachnoid space, and specimens of the central nervous system were collected every 30 min for 8 h. Arachidonic acid increased the fluid volume with elevated white blood cell and RCN9 cell counts. When given 2 h before arachidonic acid administration, pranlukast, but not montelukast, reduced the fluid volume and inhibited white blood cell and RCN9 cell extravasation through the brain capillary. In addition, a Lewis lung carcinoma metastasis model in mice was used to study the inhibitory effect of pranlu kast and montelukast against cancer cell extravasation through general capillaries. When mice were given food containing either pranlukast or montelukast, immediately after paw amputation, tumor metastasis was prevented by both drugs, and their survival was prolonged. These results show that pranlukast can inhibit tumor cell migration through both the brain and peripheral capillaries, whereas montelukast inhibits tumor cell migration only in the peripheral capillaries.

Centrifugal precipitation chromatography separates analytes according their solubility in ammonium sulfate (AS) solution and other precipitants. The separation column is made from a pair of long spiral channels partitioned with a semipermeable membrane. In a typical separation, concentrated ammonium sulfate is eluted through one channel while water is eluted through the other channel in the opposite direction. This countercurrent process forms an exponential AS concentration gradient through the water channel. Consequently, protein samples injected into the water channel is subjected to a steadily increasing AS concentration and at the critical AS concentration they are precipitated and deposited in the channel bed by the centrifugal force. Then the chromatographic separation is started by gradually reducing the AS concentration in the AS channel which lowers the AS gradient concentration in the water channel. This results in dissolution of deposited proteins which are again precipitated at an advanced critical point as they move through the channel. Consequently, proteins repeat precipitation and dissolution through a long channel and finally eluted out from the column in the order of their solubility in the AS solution. The present method has been successfully applied to a number of analytes including human serum proteins, recombinant ketosteroid isomerase, carotenoid cleavage enzymes, plasmid DNA, polysaccharide, polymerized pigments, PEG-protein conjugates, etc. The method is capable to single out the target species of proteins by affinity ligand or immunoaffinity separation.

Five anthraquinones including alizarin-1-methylether, 1,2-dimethoxy-3-hydroxyanthraquinone, 1-hydroxy-3-hydroxymethylanthraquinone, rubiadin-1-methylether and anthragallol-2-methylether were isolated and purified by high-speed counter-current chromatography (HSCCC) and followed by preparative high-performance liquid chromatography (prep-HPLC) mode from Morinda officinalis How. n-Hexane–ethyl acetate–methanol–water (6:4:5:5, v/v/v/v) was employed as the two-phase solvent system in HSCCC. Consequently, partially purified fraction “1” (90.6 mg, containing alizarin-1-methylether and 1,2-dimethoxy-3-hydroxyanthraquinone), partially purified fraction “2” (52.5 mg, containing 1-hydroxy-3-hydroxymethylanthraquinone and rubiadin-1-methylether) and 19.8 mg anthragallol-2-methylether were obtained from 300 mg of the crude extract. Then the partially purified fractions were further separated by prep-HPLC, which recovered 54.9 mg alizarin-1-methylether, 10.2 mg 1,2-dimethoxy-3-hydroxyanthraquinone, 16.4 mg 1-hydroxy-3-hydroxymethylanthraquinone and 18.2 mg rubiadin-1-methylether. The purity of each compound was over 96%, as determined by HPLC. The structures of five anthraquinones were identified by MS and 1H NMR. It is the first report of discovering 1,2-dimethoxy-3-hydroxyanthraquinone from the plant of M. officinalis How. The results demonstrated that this separation mode can integrate the advantages of HSCCC and prep-HPLC to improve separation efficiency, and adopted method was a feasible, economical and efficient technique for rapid preparative isolation of complicated natural products.

Chickpea is known as a plant that is rich in protein, carbohydrates, and nutrition, and its seeds and sprouts have been processed into various health foods. In the present study, four isoflavones were purified from the seeds and sprouts of chickpea by high speed countercurrent chromatography (HSCCC) using two biphasic solvent systems composed of n-hexane-ethyl acetate-methanol-water (5:5:5:5, v/v) and ethyl acetate-water (1:1 v/v). The results indicated that 14.2 mg of formononetin, 15.7 mg of biochanin A, 9.1 mg of ononin, 11.3 mg of biochanin A-7-O-β-D-glucoside were obtained from 150 mg of sprout extracts with the purity of 92.26%, 95.86%, 95.32%, and 96.56%, respectively. Compared with the sprouts, separation of seed extracts yielded less amounts of biochanin A-7-O-β-D-glucoside and biochanin A with lower purity. The results indicate that four main isoflavones in chickpea, i.e., isoflavones, formononetin, biochanin A, ononin, and biochanin A-7-O-β-D-glucoside, are substantially increased by biosynthesis during the seed germination.

Countercurrent chromatographic (CCC) separation of lipophilic ascorbic acid derivatives and the crude extract from Kadsura Coccinea was performed using the type-J multilayer coil planet centrifuge with a hydrophobic organic-aqueous two-phase solvent system composed of n-hexane/ethyl acetate/ethanol/aqueous 0.1% trifluoroacetic acid at the volume ratio of (5 : 5 : 6 : 2). The lipophilic ascorbic acid derivatives were separated in the order of L-ascrobyl 2,6-dibutyrate, L-ascorbyl 6-palmitate and L-ascorbyl 6-stearate by eluting the lower phase as the mobile phase, and L-ascorbyl 2,6-dipalmitate was separated by eluting the upper phase at the opposite direction. The above solvent system was then applied to the CCC separation of the extract prepared from K. coccinea. With lower phase mobile, the extract was mainly separated into two peaks corresponding to lignans and triterpenoids accordingly. The HPLC analysis of the fractions showed that the former peak contained Kadsulignan N, Schizandrin H and Neokadsuranin as lignans, and the latter peak, Micranoic acid A, Neokadsuranic acid B and beta-Sitosterol as triterpenoids. The overall results indicate that the hydrophobic organic-aqueous two-phase solvent system used in the present studies was useful for the CCC separation of lignans and triterpenoids present in the natural products.

Cordycepin is successfully isolated and purified from Cordyceps millitaris in a two-step purification by high-speed countercurrent chromatography. Two solvent systems, ethyl acetate–1-butanol–water (3:2:5, v/v/v) and trichloromethane–methanol–1-butanol–water (2:1:0.25:1, v/v/v/v), were used for the two-step purification. The purity of the prepared cordycepin was 98.1% according to the high-performance liquid chromatographic analysis.

High-speed countercurrent chromatography (HSCCC) was applied for separation and purification of flavonoids from the extract of belamcanda. High efficiency of HSCCC separation was achieved on a two-phase solvent system of n-hexane-ethyl acetate-methanol-water (4:5:5:5, v/v) by eluting the lower mobile phase at a flow-rate of 1.2mL/min and a revolution speed of 800 rpm. Three well-separated peaks were obtained in the HSCCC chromatogram and their purities were determined by HPLC-UV absorption spectrometry. These peaks were characterized by ESI-MS(n) and NMR, and the data compared with the reference standards where three peaks were identified as isorhamnetin, irigenin and hispidulin. The purities of each peak were 94, 95 and 90% respectively. In HSCCC experiment, 100 mg of the crude extract were separated yielding 10 mg of isorhamnetin, 8 mg of irigenin and 7 mg of hispidulin. HSCCC thus provides a cost-effective alternative to preparative scale HPLC for the semi-preparative scale separation and purification of flavonoids from Belamcanda.

High-speed counter-current chromatography (HSCCC) and preparative high-performance liquid chromatography (prep-HPLC) were successively used for the separation of epigallocatechin and flavonoids from Hypericum perforatum L. The two-phase solvent system composed of ethyl acetate–methanol–water (10:1:10, v/v) was used for HSCCC. About 900 mg of the crude extract was separated by HSCCC, yielding 7.8 mg of quercitrin at a purity of over 97%, 12.6 mg of quercetin at a purity of over 93%, and 38.9 mg of a mixture of hyperoside, isoquercitrin and miquelianin constituting over 97% of the fraction. A mixture of epigallocatechin and avicularin pooled from three HSCCC runs, a total amount of 54.3 mg, was further separated by prep-HPLC yielding 23.4 mg of epigallocatechin and 15.3 mg of avicularin each at a purity of over 97%.

Four positionally isomeric 2-(2-quinolinyl)-1H-indene-1,3(2H)-dionedisulfonic acids (SA) and one triSA, components of the color additive Quinoline Yellow (QY, Color Index No. 47005), were isolated from the dye mixture by affinity-ligand pH-zone-refining counter-current chromatography (CCC) through complementary use of ion-exchange and ion-pair reagents as the ligand. The added ligands facilitated the partitioning of the very polar polysulfonated components into the organic stationary phase of the two-phase solvent systems that consisted of isoamyl alcohol-methyl tert.-butyl ether-acetonitrile-water (3:5:1:7), (3:4:1:7) or (3:1:1:5). Thus, separation of a 5 g portion of QY using sulfuric acid as the retainer and dodecylamine as the ligand (an ion-exchange reagent, 20% in the stationary phase), resulted in 1.21 g of 6′,5-diSA and 1.69 g of 6′,8′,5-triSA, both of over 99% purity. A minor component, 8′,4-diSA, not previously reported was also obtained (4.8 mg of over 94% purity) through a similar separation of a different batch of QY using hydrochloric acid as the retainer and 10% dodecylamine as the ligand in the stationary phase. Two components that co-eluted (0.55 g) in the 5 g separation were separated when trifluoroacetic acid was used as the retainer and tetrabutylammonium hydroxide (an ion-pair reagent) as the ligand. The separation resulted in 20.7 mg of 6′,4-diSA, not previously reported, and 111.8 mg of 8′,5-diSA, both of over 98% purity. The isolated compounds were characterized by high-resolution mass spectrometry and proton nuclear magnetic resonance with correlated spectroscopy assignments.

Countercurrent chromatographic performance of the locular multilayer coil separation column newly designed in our laboratory was evaluated in terms of theoretical plate number, peak resolution and retention of the stationary phase in protein separation with an aqueous polymer phase system using the small-scale cross-axis coil planet centrifuge (X-axis CPC) fabricated in our laboratory. The locular column was made from 1.0 mm I.D., 2.0 mm O.D. or 1.5 mm I.D., 2.5 mm O.D. PTFE tubing compressed with a pair of hemostat at 2 or 4 cm intervals. The protein separation was performed using a set of stable proteins including cytochrome C, myoglobin and lysozyme with the 12.5% (w/w) polyethylene glycol 1000 and 12.5% (w/w) dibasic potassium phosphate system under 1000 rpm of column revolution. The 1.5 mm I.D., 2.5 mm O.D. locular tubing compressed at 2 cm intervals yielded better partition efficiencies than the non-clamped tubing using both lower and upper mobile phases with satisfactory retention of the stationary phase. The overall results suggest that the newly designed locular multilayer coil is useful to the preparative separation of proteins with aqueous-aqueous polymer phase system using our small-scale X-axis CPC.

Islet-associated protein 2 (IA-2) and IA-2β are major autoantigens in type 1 diabetes and transmembrane proteins in dense core secretory vesicles (DCV) of neuroendocrine cells. The deletion of these genes results in a decrease in insulin secretion. The present study was initiated to test the hypothesis that this deletion not only affects the secretion of insulin, but has a more global effect on neuroendocrine secretion that leads to disturbances in behavior and learning. Measurement of neurotransmitters showed that norepinephrine, dopamine and serotonin were significantly decreased in the brain of double knockout (DKO) mice (P< 0.05 to

High-speed countercurrent chromatography was successfully applied for the first time for the separation of psoralen and bergapten from Ficus carica L leaves. The crudeextract obtained by light petroleum (b.p.: 60°C-90°C) from the dried leaves of Ficus carica L. was separated with a two-phase solvent system of n-Hexane-ethyl acetate-methanol-water (1:1:1:1, v/v). Each peak fraction was analyzed by high-performance liquid chromatography. The method yielded 4.4 mg of psoralen at 99.1% purity and 2.1 mg of bergapten at 98.2% purity from 400 mg of the crude extract in a single run. The two compounds were identified by (1)H-NMR, (13)C-NMR and MS.

A spiral disk assembly composed of five single-channel units was designed for high-speed counter-current chromatography (HSCCC). The retention of different solvent systems ranging from moderately polar to polar organic–aqueous systems to aqueous two-phase systems (ATPs) was investigated under different elution modes. The results indicated that the spiral disk assembly can produce excellent retention of stationary phase for moderately polar organic–aqueous solvent systems, such as chloroform–methanol–water (4:3:2) and hexane–ethyl acetate–methanol–water (1:1:1:1) by pumping lower mobile phase from head (H) to tail (T), and upper mobile phase from tail (T) to head (H) even at a high flow-rate (8 mL/min, S f > 70%), regardless of whether the inlet is at the inner or outer terminal of the channel. This makes it possible for fast analysis of some small molecular compounds. This has been proved in the separation of mixtures of three flavones, including isorhamnetin, kaempferol, and quercetin. The spiral disk assembly can also provide satisfactory retention for polar to ATPS such as 1-butanol–acetic acid–water (4:1:5) ( S f > 70%), 12.5% poly(ethylene glycol) (PEG) 1000–12.5% K 2 HPO 4 –75% water (≤1 mL/min, S f > 70%) and 4% PEG 8000–5% Dextran T500–91% water (≤0.5 mL/min, S f > 50%) by pumping lower mobile phase from inner terminal (I) to outer terminal (O), and upper mobile phase from outer terminal (O) to inner terminal (I) at a low flow-rate, while this is not possible with the multilayer coil column. Acceptable resolutions were achieved when it was used for the separation of peptides such as Leu-Tyr and Val-Tyr, and proteins including cytochrome c and myoglobin, lysozyme and myoglobin, and fresh chicken egg-white proteins.

A novel spiral tube support is introduced which allows accommodating a multlilayer spiral column made of a long piece of fluorinated plastic tubing. Two spiral columns tested in this study consist of 1.6 mm ID and 0.85 mm ID FEP (fluorinated ethylenepropylene) and PTFE (polytetrafluoroethylene) tubing with the total capacity of 100 mL and 40 mL, respectively. Performance of these spiral columns was examined with a two phase solvent system composed of 1‐butanol/acetic acid/water at a volume ratio of 4∶1∶5 using tryptophyl‐tyrosine (try‐tyr) and valyl‐tyrosine (val‐tyr) as test samples under various revolution speeds and flow rates. Among 4 different elution modes tested, L‐I‐T (lower phase pumped from the internal head end of the spiral column) and U‐O‐H (upper phase pumped from the external tail of the spiral column) at a low flow rate produced the best results especially for both columns. The highest peak resolution (Rs) of over 3.5 was obtained from U‐O‐H at a flow rate of 1 mL/min with 74% sta...

Following an initial cleanup step on the AB-8 macroporous resin, high-speed countercurrent chromatography (HSCCC) was successfully applied for the first time to the isolation and purification of four flavonoids from Flos Gossypii. HSCCC was performed with a two-phase solvent system composed of chloroform-methanol-isopropanol-water (5:5:1:3, v/v) adding 0.4% phosphoric acid in the aqueous stationary phase. The separation yielded quercetin (5.6 mg), quercetin-3′-O-D-glucoside (7.2 mg), quercetin-3-O-β-D-glucoside (16 mg), quercetin-7-O-β-D-glucoside (8.3 mg), from 100 mg of the crude extract in a one step separation. The structure identification was made by 1H NMR, 13C NMR.

Dual counter-current chromatography (dual CCC)-tandem mass spectrometry (MS/MS) was successfully performed with a newly designed spiral column for dual CCC. The small column capacity required for directly coupling with electrospray MS/MS was accomplished by forming a rectangular spiral groove on a plastic disk and sealing it with a PTFE sheet. This novel dual CCC-MS/MS technique was successfully applied for the rapid determination of methomyl, fenobucarb and carbaryl pesticides in food. A two-phase solvent system of n-hexane-acetonitrile-0.1% formic acid (45:45:10) was suitable for both good dual CCC separation and sufficient ionization of pesticides. Recoveries of these three pesticides from mandarin orange and spinach samples fortified at 0.05 mg/kg were in the range of 93-107% with relative standard deviations of 2.4-3.8%.

Spiral countercurrent chromatography (CCC) utilizes a new separation rotor composed of 8 high density polyethylene plates with spiral flow channels, mounted in the type‐J coil planet centrifuge (CPC). Synthetic peptides were evaluated for partition coefficients in various solvent systems. Approximately 30 mg amounts were chromatographed and the fractions analyzed for peptide content and purity. The solvent systems which contained sec‐butanol or n‐butanol and the mobile phase selected produced good purification. The stationary phase was highly retained over 60%, thus the spiral separation coil is able to retain these more viscous, low interfacial tension solvents that have not been able to be used well in the multi‐layer coil for high speed CCC.

Centrifugal Precipitation Chromatography (CPC) utilizes a moving solvent gradient to separate proteins and macromolecules by repetitive steps of precipitation and dissolution in a column. Proteins fractionate at locations that depend on their solubility in differing ammonium sulfate concentrations. Prior to the current study, construction of a CPC instrument has been difficult due to the complicated design of the separation column and its connections. The current manuscript introduces an innovation that replaces the custom designed column with a commercial one. This change still results in efficient separations of human albumin and γ‐globulin in a mixture, as well as in human serum.

This review describes protein purifications from cell culture medium or cell-lysate by high speed counter-current chromatography using the cross-axis coil planet centrifuge. Purifications were performed using aqueous two phase systems composed of polyethylene glycols and dextrans.

Preparative countercurrent chromatography has been used successfully for the isolation and purification of kaempferol pyranosides including kaempferol‐3‐O‐β‐D‐glucopyranosyl (2‐1)‐a‐L‐rhamnopyranoside, kaempferol‐3‐O‐β‐D‐glucopyranoside, and kaempferol‐3‐O‐a‐L‐rhamnopyranoside from the traditional Chinese herb “Jin qian cao”‐Lysimachia christinae Hance with a two‐phase solvent system composed of ethyl acetate‐methanol‐water with a volume ratio of 50∶1∶50, v/v. The composition of the phase system was optimized using analytical high speed countercurrent chromatography (HSCCC). The crude extract in the amount of 924 mg was separated, yielding 69.8 mg of kaempferol‐3‐O‐β‐D‐glucopyranosyl (2‐1)‐a‐L‐rhamnopyranoside, 45.3 mg of kaempferol‐3‐O‐β‐D‐glucopyranoside, both at a high purity of over 97% and 8.9 mg of kaempferol‐3‐O‐a‐L‐rhamnopyranoside with the purity of 92%.

Arganines A, C, D, tieghemelin, fatty acids, and steroid alcohols were isolated and purified in a total study of the seeds of Tieghemella heckelii by diverse chromatography methods. The hexane extracts yielded nine fatty acids and sixteen steroid alcohols resolved by gas chromatography, whilst the water extract gave three relatively homogenous compounds using TLC analysis, and further studies with NMR revealed the arganines previously cited. The optimization of saponins was achieved by the HSCCC method. Aside from this, conversion of Tieghemelin to Arganine C has been fulfilled to seek for the increment of the yield of the most active compound and avoidance of separation of both saponins. Here, we report the isolation and the chemical analysis of the named constituents of the seeds.

The nonsynchronous coil planet centrifuge has a unique mode of planetary motion in that it allows a freely adjustable rotational rate of the coiled separation column at a given revolution speed. This paper describes a series of studies using the apparatus fabricated in our laboratory on the countercurrent chromatographic separation of proteins with aqueous‐aqueous polymer phase systems, experimental and theoretical analysis of the effect of planetary motion on protein separation, and application to elutriation of cells such as blood cell components and mast cells using a single‐phase physiological buffer solution.

High‐speed countercurrent chromatography (HSCCC) was employed for the first time to separate lysozyme from chicken egg‐white using a reverse micellar system with 50 mM bis‐(2‐ethylhexyl) sulfosuccinate sodium (AOT) dissolved in isooctane and aqueous buffer. Lysozyme is separated from other main proteins through one step separation, and relatively high activity recovery (over 80%) can be achieved when applied to the purification of a preseparated sample, while a low recovery problem exists when applied to separate lysozyme from crude chicken egg‐white samples due to the interference of a large amount of other proteins. However, this method has advantages over traditional reverse micellar extraction (RME) for its simple continuous elution mode and high separation efficiency, and it is promising for scale‐up.

The component of the traditional Chinese medicine (TCM) can be influenced by soils, climates, and growth stages. The quality of TCM mostly depends on the quality of the raw materials of the used herbs. A portable instrument and simple analysis method are urgently needed to be used for quality control of the raw herbs. In this study, analytical CCC (Model HS06) was applied to analyze three herbs including Fructus Arctii (Arctium lappa L.), Cortex Magnoliae Officinalis (Magnolia officinalis Rehd. et Wils.), and Fructus Psoraleae (Psoralea corylitolia L.), which were collected from different growth locations. The results showed that analytical CCC gave similar resolution as preparative CCC. In this analytical CCC operation, the crude sample is loaded directly without any pre‐treatment, and only 1–10 mg sample is used for each injection. The separation time is often shorter than 1 hour and can compete with that of HPLC. HSCCC chromatograms can be used as the comparison patterns for the content contro...

High-speed counter-current chromatography (HSCCC) using the three-phase solvent system n-hexane-methyl acetate-acetonitrile-water at a volume ratio of 4:4:3:4 was applied to the comprehensive separation of secondary metabolites in several natural product extracts. A wide variety of secondary metabolites in each natural product was effectively extracted with the three-phase solvent system, and the filtered extract was directly submitted to the HSCCC separation using the same three-phase system. In the HSCCC profiles of crude natural drugs listed in the Japanese Pharmacopoeia, several physiologically active compounds were clearly separated from other components in the extracts. The HSCCC profiles of several tea products, each manufactured by a different process, clearly showed their compositional difference in main compounds such as catechins, caffeine, and pigments. These HSCCC profiles also provide useful information about hydrophobic diversity of whole components present in each natural product.

Aqueous–aqueous two-phase (AATP) systems composed of polyethylene glycol (PEG) (molecular mass, Mr:1000–8000) and dextran (Mr:40,000) were evaluated for purification of maltose binding protein tagged-histone deacetylase (MBP-HDAC) by counter-current chromatography (CCC). CCC purification of an MBP-HDAC from Escherichia coli cell-lysate was successfully demonstrated with a 7.0% PEG 3350–10% dextran T40 system containing 10 mM potassium phosphate buffer at pH 9.0. After CCC purification, both polymers in the CCC fractions were easily removed by ultrafiltration in a short period of time. The collected fractions containing target protein were analyzed by an HPLC-based in vitro assay as well as sodium dodecyl sulfate polyacrylamide gel electrophoresis. MBP tag was digested from fusion HDAC during the CCC separation and native HDAC was purified by one-step operation with well preserved deacetyl enzyme activity.

A novel spiral disk is designed by placing barricades at 6 mm intervals in the middle of the spiral channel to divide the channel into multiple sections. Glass beads are placed in every other section so that the planetary motion produces repetitive mixing and settling of polymer phase systems. Performance of this mixer-settler spiral disk assembly was examined for separation of lysozyme and myoglobin with a polymer phase system. The best results were obtained with a spiral disk equipped with barricades with openings ranging from 1.2 to 0.4 mm on each side at a high revolution speed up to 1200 rpm.

Purification of proteins based on immunoaffinity has been performed using a solid support coated with antibody against the target proteins. The method requires immobilizing the antibody onto the solid support using protein A or G, and has a risk of adsorptive loss of target proteins onto the solid support. Centrifugal precipitation chromatography has been successfully used to purify enzymes, such as ketosteroid isomerase and hyaluronidase without the use of solid support. The purpose of this study is to demonstrate that immunoaffinity centrifugal precipitation chromatography is capable of isolating an antigen by exploiting antigen-antibody binding. The separation was initiated by filling both channels with 40% saturated ammonium sulfate (AS) of pH 4-4.5 followed by loading 20 microl of human plasma (National Institutes of Health blood bank) mixed with 2 mg of rabbit anti-HSA (human serum protein) antibody (Sigma). Then, the sample channel was eluted with water at 0.03 ml/min and AS channel with 40% AS solution of pH 4-4.5 at 1 ml/min until all non-binding components were eluted. Then, the releasing reagent (50% AS solution containing 0.5 M glycine and 10% ammonium hydroxide at pH 10) was introduced through the AS channel to release the target protein (HSA). The retained antibody was recovered by eluting the sample channel with water at 1 ml/min. A hollow fiber membrane device at the outlet (MicroKros, Spectrum, New Brunswick, NJ, USA) was provided on-line dialysis of the eluent before fractions were collected, so that the fractions could be analyzed by SDS-PAGE (sodium dodecyl sulfate - polyacrylamide gel electrophoresis) without further dialysis. The current method does not require immobilizing the antibody onto a matrix, which is used by the conventional immunoaffinity chromatography. This method ensures full recovery of the antigen and antibody, and it may be applied to purification of other proteins.

Preparative high-speed countercurrent chromatography was successfully used for isolation and purification of hyperoside and luteolin‐glucoside from Agrimonia pilosa Ledeb. The separation was performed by stepwise elution with a pair of two‐phase solvent systems composed of ethyl acetate‐methanol‐water at volume ratios of 50:1:50 and 5:1:5, which had been selected by analytical high-speed countercurrent chromatography (HSCCC). Using a preparative unit of the HSCCC centrifuge, about a 300 mg amount of the crude extract was separated, yielding 7.3 mg of hyperoside and 10.4 mg of luteolin‐glucoside at a high purity of over 97%.

A high-speed countercurrent chromatography (HSCCC) technique in a semi‐preparative scale has been applied to separate and purify anthraquinones from the extract of Cassia seeds. A high efficiency of HSCCC separation was achieved on a two‐phase solvent system of n‐hexane–ethyl acetate–methanol–water (4:1:3:2, v/v/v/v) by eluting the lower mobile phase at a flow rate of 1.5 mL/min under a revolution speed of 750 rpm. A total of five well separated peaks were obtained in the HSCCC chromatogram, and their purities were determined by HPLC‐UV absorption spectrometry. These peaks were characterized by ESI‐MSn and the data compared with the reference standards. Five peaks were identified as 1,2,6‐trihydroxy‐7, 8‐dimethoxy‐3‐methylanthraquinone (7 mg), 1,2,6,8‐tetrahydroxy‐7‐methoxy‐3‐methyl‐anthraquinone (4 mg), 2‐hydroxy‐1,6,7,8‐teramethoxy‐3‐methylanthraquinone (9 mg), 6‐dihydroxy‐1,7,8‐trimethoxy‐3‐methylanthraquinone (2 mg), and 1,2‐dihydroxy‐6,7,8‐tri‐methoxy‐3‐methylanthraquinone (3 mg) from 100 mg...