• Analytical Science and Technology
• /
• v.26 no.1
• /
• pp.34-41
• /
• 2013

Split-flow thin cell (SPLITT) fractionation (SF) is a rapid separation technique capable of separating colloidal particles or macromolecules into two or more fractions. SF allows fractionations in a preparative scale as sample is fed continuously. Generally SF uses a thin ribbon-like channel equipped with two flow stream splitters at the inlet and outlet of the channel. Thus there exist two flow inlets and two flow outlets at the top and bottom of the inlet and outlet of the channel, respectively. There are two operating modes in SF, conventional mode and full-feed mode (FFD). Although the resolution in the FFD mode is lower than that in the conventional mode, FFD mode has some merits. The design of the channel and operation are simpler in the FFD mode, as it does not require the feeding of the solvent. Thus there is no flow stream splitter at the channel inlet, and only one pump is needed, unlike the conventional mode, where two pumps are required for the feedings of the sample and the solvent separately. Also the sample is not diluted in the FFD mode as there is no solvent feeding, which is important for fractionation samples with low colloidal concentrations such as environmental samples. For some of environmental samples, pre-concentration is often required. In this study, a new large-scale splitter-less FFD-SF channel was implemented, where there is no splitter at the outlet as well as at the inlet of the channel. It was possible to build the channel in a much larger dimension than conventional ones, allowing much higher sample throughput (TP). The new channel was tested and optimized with polyurethane (PU) latex beads, and then applied to large-scale separation of Polyacrylate (PA).

• Korean journal of food and cookery science
• /
• v.12 no.1
• /
• pp.115-121
• /
• 1996

Ixeris dentata Nakai (Compositae) is a perennial herb and the young shoots when prepared properly are edible as a bitter appetizing vegetable in the early spring. The whole plant has been used as a folk medicine in treating diabetes in Korea. As a part of our studies on bitter substances, we have investigated the bitterness of the plant through a taste-guided fractionation method. Bitter substances were extracted by the solvent fractionation and the bitterness was evaluated by 10 trained panelists consisted with graduate students of Dept. of Foods and Nutrition. It has been revealed that the bitter compounds were distributed throughout the extracting fractions and the higher intensity of the bitterness was seen in the n-BuOH fractions. The bitter compounds were subfractionated by the silica gel column chromatography and the bitterness was evaluated by the trained panelists. The subfractions which were indicated as the bitter compounds will be further studied to isolate the compounds. The H$_2$O fractions were grouped according to the molecular weight through the ultrafiltration and the group with 1,000 < m.w. < 30,000 was evaluated as the most intense bitter subfraction.

• Korean Journal of Food Science and Technology
• /
• v.29 no.2
• /
• pp.204-210
• /
• 1997

The ethyl acetate (EtOAc) extracts from needles of Pinus densiflora were showed antimicrobial activities against bacteria, yeast and fungi. The antimicrobial active substance of EtOAc extracts were successively purified with solvent fractionation, silica gel adsorption column chromatography and Sephadex LH-20 column chromatography. The purified active substance was isolated as crystals and identified as benzoic acid by $MS,\;^{1}H-NMR\;and\;^{13}C-NMR$. The amount of benzoic acid was 0.608 mg per gram of fresh needle of Pinus densiflora.

• Korean Journal of Food Science and Technology
• /
• v.31 no.5
• /
• pp.1386-1391
• /
• 1999

The methanol extract of Gardenia jasminoides Ellis showed antimicrobial activity against bacteria and yeasts. The extract was successively purified with solvent fractionation, silica gel adsorption column chromatography, Sephadex LH-20 column chromatography, octadecylsilane column chromatography. The purified active substance was isolated by high performance liquid chromatography. The isolated compound was 3,4-dihydroxybenzoic acid which was determined by mass spectrometer, gas chromatograph-mass spectrometer, $^{1}H-nuclear$ magnetic resonance, $^{13}C-nuclear$ magnetic resonance and two-dimensional nuclear magnetic resonance. The content of 3,4-dihydroxybenzoic acid was $32.7\;{\mu}g/g$ in dried fruits of Gardenia jasminoides Ellis.

• Applied Biological Chemistry
• /
• v.41 no.2
• /
• pp.191-196
• /
• 1998

The MeOH extract from root of Pulsatilla koreana was showed antimicrobial activities against bacteria and yeast. The antimicrobial active substances of MeOH extract were successfully purified with solvent fractionation, silica gel adsorption column chromatography and Sephadex LH-20 column chromatography. The purified two active substances were isolated by HPLC and identified as 4-hydroxy-3-methoxycinnamic acid and 3,4-dihydroxycinnamic acid by MS, $^{1}H-NMR$ and $^{13}C-NMR$.

• Korean Journal of Food Science and Technology
• /
• v.29 no.4
• /
• pp.823-826
• /
• 1997

The EtOAc extracts from needles of Pinus densiflora showed antimicrobial activities against bacteria, yeast and fungi. The antimicrobial principle was successively purified by solvent fractionation, silica gel adsorption column chromatography and Sephadex LH-20 column chromatography. The active substance was further purified by HPLC using $C_{18}$ column. The active substance was identified as trans-cinnamic acid by MS, $^{1}H-NMR\;and\;^{13}C-NMR$. The amount of cinnamic acid was $9.27\;{\mu}g$ Per gram of fresh needle of Pinus densiflora.

• Natural Product Sciences
• /
• v.10 no.5
• /
• pp.223-227
• /
• 2004

This study was carried out to investigate inhibitory effect of extracts from the root of Paeonia lactiflora on postprandial hyperglycemia. Organic solvent (hexane, ethyl acetate, butanol, aqueous) extracts from the crude drug were fractionated by high performance liquid chromatography. These fractions were examined to evaluate ${\alpha}-glucosidase$ (EC 3. 2. 1. 20) inhibition by microplate colorimetric assay. Among the fractions examined, the ethyl acetate fraction from the roots of Paeonia lactiflora showed potent inhibitory effects on ${\alpha}-glucosidase$. Therefore, further fractionation of the fraction was carried out to isolate the active principles. Finally, we isolated and Purified 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG) as a active principle by activity-guided fractionation. These results suggest that the extract from the root of Paeonia lactiflora can be used as a new nutraceutial for inhibition on postprandial hyperglycemia and PGG might be a candidate for developing an ${\alpha}-glucosidase$ inhibitor.

• Bulletin of the Korean Chemical Society
• /
• v.21 no.1
• /
• pp.69-74
• /
• 2000

Applicability of Thermal field flow fractionation (ThFFF) was investigated for the analysis of masticated natural rubber (NR) adhesives produced bya hot melt mastication process. An optimum ThFFF condition for NR analysis was found by using tetrahydrofuran (THF) as a solvent/carrier and a field-programming. Low flowrate (0.3 mL/min) was used to avoid stopping the flow for the sample relaxation. Measured molecular weight distribution was used to monitor degradation of rubber during the mastication process. Rubber samples collected at three different stages of the mastication process and were analyzed by ThFFF. It was found that in an anaerobic process rubber degradation occurs at the resin-mixing (compounding) zone as well as in the initial break-down zone, while in an aerobic process most of degradation occurs at the initial breakdown zone. It was also found that E-beam radiation on NR causes a slight increase in the NR molecular weight due to the formation of a branched structure.

• The Korean Journal of Food And Nutrition
• /
• v.28 no.1
• /
• pp.1-8
• /
• 2015

This study was designed to determine the antioxidant activity of solvent fractions of broccoli sprouts grown by controlling the growing environment at the plant factory system. Fractionation was achieved with chloroform, n-hexane, ethyl acetate, butanol, water by 70% EtOH extract of the broccoli sprouts. Each solvent fraction was put through TLC and HPLC to separate active components. Higher antioxidant activities were observed for the butanol and ethyl acetate layers. Further evaluation of each of the 5 layers (LH1 to LH5) of the butanol fraction showed that the refined LH3 extract had a high antioxidant effect. Components with similar Rf values from TLC had the same retention times and peaks in the HPLC analysis. It was also determined that the sulforaphane content was high at the chloroform and butanol layers and the sulforaphane was responsible for, the high antioxidant activity. Thus, to use for functional materials, the butanol extract/layer of broccoli sprouts is recommended as the most effective.

• Food Science and Preservation
• /
• v.9 no.1
• /
• pp.97-101
• /
• 2002

Antimicrobial and antioxidative activities of various solvent extracts from different parts of the loquat were investigated to process it as the functional food. The extraction yield showed higher in butanol fraction of 4.95% in peel and 4.42% in seed than others, but water fraction showed high extraction yield of 3.89% in leafs 23.6% in the seedless fruit and 21.1% in fresh, In the antimicrobial activity test, ethyl acetate fraction that leaf and fruit excluded seed inhibited higher 19, 15 mm and 16, 15 m in clear zone far Staphylococcus aureus and Escherichia coli in each. Ethyl acetate fraction that extracted from a series of polar and nonpolar solvent fractionation of methanol extracts showed better results in the hydrogen donating activity of 82% in leaf, 74% in seedless fruit, 68% in seed, 52% in peel and 30% in fresh.