MCI Gel Column Research Articles

Identification of components in coriander (Coriandrum sativum L.) inhibiting degranulation of RBL-2H3 cells

We found that a water-soluble extract of coriander (Coriandrum sativum L.) (leaves, petioles and stems) inhibits antigen-induced degranulation of RBL-2H3 cells, a rat basophil leukemia cell line. The aim of this study was to elucidate the anti-degranulation active components in the extract. The methanol-eluate fraction obtained by fractionation of the water-soluble extract using MCI gel column chromatography had strong activity, and eight components were isolated and identified. Two of them were identified as new compounds, (3S)-3-methyl-6-hydroxyisocoumarin 8-O-β-D-glucopyranoside (compound 1) and (7S,8R)-7,8-dihydro-8-β-D-glucopyranosyloxy-4-methoxy-7-methyl-5H-fro[2,3-g][2]benzopyran-5-one (compound 2). As a result of evaluation of anti-degranulation activity of eight components, seven of them, such as tryptophan, phenylalanine, dihydroxycoumarin glucoside, quercetin glycoside, rutin, compound 1, and compound 2, had the activity. These results indicated that the water-soluble extract of coriander contains several anti-degranulation substances.

Strategy for the separation of strongly polar antioxidant compounds from Lycium barbarum L. via high-speed counter-current chromatography

In the separation of strongly polar antioxidant compounds from natural products using high-speed counter-current chromatography that is target-guided by 2,2-diphenyl-1-picrylhydrazyl high-performance liquid chromatography experimentation, low adsorption ability is encountered due to the strong polarity of the target compounds. In this study, a strategy of novel partition coefficient value calculation was proposed for overcoming this problem. The partition coefficient value was expressed as the ratio of the antioxidant activities of the upper phase and the lower phase. This strategy was used in high-speed counter-current chromatography with a hydrophilic organic/salt-containing aqueous two-phase system for bioassay-guided separation of strongly polar antioxidant compounds from Lycium barbarum L. The antioxidant activity was determined via the radical scavenging activity method using 2,2-diphenyl-1-picrylhydrazyl radicals. A hydrophilic organic/salt-containing aqueous two-phase system of 95% EtOH - sat. (NH4)2SO4 (1:1.8, v/v) was successfully used to separate Lycium barbarum L. extract. Five fractions were collected via high-speed counter-current chromatography separation. The antioxidant activity of the third fraction was the highest. Three compounds were separated via MCI gel column chromatography and Sephadex LH-20 column chromatography from the third fraction, and their antioxidant activities were determined. The antioxidant activities of the three compounds were higher than that of the third fraction. These results demonstrate that this strategy can be used to separate strongly polar antioxidant compounds from natural products.

One-step synthesis of red-emitting carbon dots via a solvothermal method and its application in the detection of methylene blue

The synthesis of carbon dots (CDs) with long wavelengths, particularly the red-emitting ones, has always been the focus of researchers, and a carbon source is critical in this process. In this study, we report the synthesis of red-emitting CDs (CD-tetra) via a one-step solvothermal method with 1,2,4,5-benzenetetramine tetrahydrochloride as a novel carbon source and ethanol as a solvent, and the quantum yield (QY) of CDs is as high as 30.2%. Middle chromatography isolated gel (MCI Gel) column was used to obtain R-CDs, O-CDs and Y-CDs with emission wavelengths at 619, 608 and 554 nm, respectively. It was discovered that these CDs exhibited great differences in their particle sizes and elemental compositions. Moreover, the fluorescence of the CD-tetra could be efficiently quenched using methylene blue (MB). Under optimal conditions, a linear relationship between the decreased fluorescence intensity of the CD-tetra and the concentration of MB was established in the range of 0.05–9.5 μM. The limit of detection (LOD) is 10 nM, suggesting a promising assay for the detection of MB.

Isolation of high-purity peptide Val-Val-Tyr-Pro from Globin Peptide using MCI gel column combined with high-speed counter-current chromatography.

Peptides have gained increased interest over the past several decades because of their therapeutics. In this research, a strategy combining MCI gel column chromatography and high-speed countercurrent chromatography was developed for the separation of high-purity peptide Val-Val-Tyr-Pro from Globin Peptide. First, the fraction of Val-Val-Tyr-Pro mixtures with a purity of 15.8% was obtained by using MCI gel column with a mixture of ethanol/water (20:80, v/v/v). Then, the high-purity Val-Val-Tyr-Pro was separated by high-speed countercurrent chromatography with a aqueous two phase systems of ethanol/acetonitrile/iso-propyl alcohol/(NH4 )2 SO4 Saturated solution /H2 O (0.5:0.5:0.25:1.5:0.7,v/v). The ammonium sulfate from high-speed countercurrent chromatography fractions was removed from target compound by MCI gel column chromatography using ethanol/water in stepwise elution mode. A 78mg of Val-Val-Tyr-Pro was successfully purified with the purities of 98.80% from 30g crude Globin Peptide. The amino acid sequence of the Val-Val-Tyr-Pro was determined by electrospray ionization high resolution tandem mass spectrometry. The method presents a practical strategy for the large-scale separation of pure peptide Val-Val-Tyr-Pro from Globin Peptide, and provides a reference method for obtaining high-purity peptide from other polypeptide mixtures.

Supercritical fluid chromatography for separation and preparation of tautomeric 7-epimeric spiro oxindole alkaloids from Uncaria macrophylla

Increasing challenge arising from configurational interconversion in aqueous solvent renders it rather difficult to isolate high-purity tautomeric reference standards and thus largely hinders the holistic quality control of traditional Chinese medicine (TCM). Spiro oxindole alkaloids (SOAs), as the markers for the medicinal Uncaria herbs, can easily isomerize in polar or aqueous solvent via a retro-Mannich reaction. In the present study, supercritical fluid chromatography (SFC) is utilized to separate and isolate two pairs of 7-epimeric SOAs, including rhynchophylline (R) and isorhynchophylline (IR), corynoxine (C) and corynoxine B (CB), from Uncaria macrophylla. Initially, the solvent that can stabilize SOA epimers was systematically screened, and acetonitrile was used to dissolve and as the modifier in SFC. Then, key parameters of ultra-high performance SFC (ultra-performance convergence chromatography, UPC2), comprising stationary phase, additive in modifier, column temperature, ABPR pressure, and flow rate, were optimized in sequence. Two isocratic UPC2 methods were developed on the achiral Torus 1-AA and Torus Diol columns, suitable for UV and MS detection, respectively. MCI gel column chromatography fractionated the U. macrophylla extract into two mixtures (R/IR and C/CB). Preparative SFC, using a Viridis Prep Silica 2-EP OBD column and acetonitrile-0.2% diethylamine in CO2 as the mobile phase, was finally employed for compound purification. As a result, the purity of four SOA compounds was all higher than 95%. Different from reversed-phase HPLC, SFC, by use of water-free mobile phase (inert CO2 and aprotic modifier), provides a solution to rapid analysis and isolation of tautomeric reference standards for quality control of TCM.

In vitro and in vivo antitumor effects of the extract of Sapindus spp.

This study evaluated the antitumor effect of some fractions extracted from Sapindus spp. on breast cancer. Four water-extracted fractions (I, II, III, IV) were isolated from the pericarp of Sapindus spp. using X-5 and AB-8 macroporous resin columns and MCI gel column. The in vitro effect was determined using the MTT assay. Our results indicated that fractions I-IV did not exhibit significant cytotoxic effects towards the normal cell MDA-kb2; Fraction II and IV inhibited the growth of MCF-7 (estrogen receptor positive), MDA-MB-231 (estrogen receptor negative), and MDA-MB-435s human breast cancer cell lines; of these, MDA-MB-435s cell line was the most sensitive, and the IC50 of Fraction II and IV against this cell line were 33.11 and 30.06µg/mL, respectively. In the in vivo experiment, Fraction II and IV showed a strong antitumor effect at a dose of 162.5mg/kg/d, with inhibition rate of 40.43% and 38.77%. Fraction II and IV also induced apoptosis of tumor cells, activations of Bax (Fraction II) and inhibition of Bcl-2 (Fraction II and IV). Our results underscore the pharmacological potential of Sapindus spp. extracts.

Inhibitory Activity against Helicobacter pylori of Isolated Compounds from Pinus koraiensis Siebold et Zucc Leaves

A phenol substance was extracted from Pinus koraiensis Siebold et Zucc leaf extracts and its biological efficacy was measured. The highest content of the phenol substance contained in Pinus koraiensis Siebold et Zucc leaves was 13.5 mg/g, which was obtained when it was extracted with 80% ethanol. At a concentration of 200 mg/mL, the phenolic substances extracted with 80% ethanol and water showed antimicrobial activities against Helicobacter pylori, producing clear zones of 10 and 12 mm diameter, respectively. Pinus koraiensis Siebold et Zucc. leaf extracts were separated using a Sephadex LH-20 column and 4 fractions were obtained (fractions A-D). Fractions C and D showed the greatest inhibitory activity against Helicobacter pylori producing 10.1 and 12.3 mm clear zones, respectively. These two fractions were purified using a Sephadex LH-20 and MCI-gel column (H2O→100% ethanol). Purified compounds A and B were identified as syringic acid and compound C was identified as p-coumaric acid based on 1 H-nuclear magnetic resonance (NMR), 13 C-NMR, and fast atom bombardment mass spectrometry spectra. When two or more purified compounds were mixed, a synergistic effect of anti-Helicobacter pylori activity was evident. This result indicates that extracts of Pinus koraiensis Siebold et Zucc leaves could be considered a functional food because of their high antimicrobial properties.

Antibacterial Activity of Lotus Leaves (<i>Nelumbo Nucifera</i>) Against Food-Borne Pathogens

The antibacterial activity of different solvent extracts from lotus leaves against four food-borne bacteria (Escherichiacoli, Salmonellatyphimurium, Staphyloccocusaureus, Bacillussubtilis) was analyzed by agar diffusion method and the ethanol extract of the plant was found to have the highest antimicrobial activity with the diameter of inhibition zones ranging from 17.2 to 17.8 mm. Then the ethanol extract of lotus leaves were further separated by MCI-gel column and the antibacterial activity were investigated viamacrodilution broth method. Furthermore, preliminary phytochemical test were also carried out. Fraction 3 eluted from MCI-gel was found to have highest antibacterial activity with the minimum inhibitory concentration and minimum bactericide concentration values in the ranges of 0.0313~0.125 g mL-1 and 0.0626~0.25 g mL-1, respectively. Antifungal activity analysis showed that ethanol extract of lotus leaves had a low inhibitory activity against all fungi. The result of the phytochemical analysis of the extract showed the presence of phenolic compounds, flavones and alkaloids which may be responsible for its antibacterial activity. Furthermore, lotus leaves extract was observed to have a better antiseptic capacity than sodium benzoate in apple juice (preservative used in food). Therefore, lotus leaves may be used as a botanical natural food preservative against food-borne pathogens.

α-Glucosidase inhibitory activity by the flower buds of Lonicera japonica Thunb

In the present study, the methanol extract from the flower buds of Lonicera japonica Thunb. was investigated on rat intestinal α-glucosidase inhibitory activity. This extract enriched in polyphenols, showed a potent α-glucosidase inhibitory activity with maltose as a substrate in enzyme assay. The extract was then applied to MCI-gel column chromatography with a water–methanol gradient to give three fractions: fraction 1 (F-1, water), fraction 2 (F-2, 80% methanol in water), and fraction 3 (F-3, 100% methanol). F-2 showed the highest maltase inhibitory activity compared with F-1 and F-3, and down-regulated α-glucosidase activity for the maltose hydrolysis in Caco-2 monolayer. In maltose-loaded SD-rats, F-2 significantly reduced postprandial blood glucose level. 3,5-Dicaffeoylquinic acid was found to be the potent maltase inhibitor, whereas chlorogenic acid and rutin showed a weak inhibitory activity against maltase. This is the first report on the mammalian α-glucosdiase inhibition of L. japonica. The result presented here suggests a use of the extract of L. japonica for antidiabetes.

Rapid chemical profiling of saponins in the flower buds of Panax notoginseng by integrating MCI gel column chromatography and liquid chromatography/mass spectrometry analysis

The flower buds of Panax notoginseng (Notoginseng flower, FBP) are used as the traditional Chinese medicine San-Qi-Hua. In this study, we conducted column chromatography fractionation and liquid chromatography/mass spectrometry (LC/MS) analysis to comprehensively profile bioactive notoginseng saponins (ginsenosides) in FBP. MCI gel column chromatography allowed separation and enrichment of minor saponins. Electrospray ionization tandem mass spectrometry of [M−H]− and [M+Na]+ precursor ions of the saponins provided reliable structural information for the sapogenin, and sequence of sugar chains. Confirmed by high-accuracy Q-TOF analysis, 170 notoginseng saponins were characterized from FBP, and 91 of them were reported from Panax species for the first time. The new ginsenosides contain acyl groups on α-chain, malonyl group at 20-OH, or di-malonyl groups. This study also indicated that the flower buds of P. notoginseng contained more protopanaxadiol-type but less protopanaxatriol-type ginsenosides than the roots.

FAST ISOLATION OF GINSENOSIDES Re AND Rg1 FROM THE ROOTS OF PANAX GINSENG BY HSCCC-ELSD COMBINED WITH MCI GEL CC GUIDED BY HPLC-MS

Ginsenosides Re and Rg1, the main bioactive components of Panax ginseng, have been preparatively isolated and purified using high-speed counter-current chromatography (HSCCC) combined with MCI gel column chromatography (MCI gel CC). Guided by HPLC-MS, the crude extracts from the roots of P. ginseng were pre-separated on an MCI gel column to obtain mixtures of ginsenosides Re and Rg1. Then, a 200 mg volume of enriched sample was separated by HSCCC with a two-phase solvent system composed of ethyl acetate–n-butanol–water (4: 1: 6, v/v/v), yielding 52.6 mg of Rg1 and 37.2 mg of Re with the purities of 99.3% and 98.2%, respectively. The total recovery of Rg1 and Re was 82.4% and 84.4%, respectively, in the two-step separation. This study introduces a fast and efficient method for purification of ginsenosides Re and Rg1 from P. ginseng.