• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1318-1323
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• 2004

This study describes the purification and characterization of a novel antihypertensive angiotensin 1­converting enzyme (ACE) inhibitory peptide from Saccharomyces cerevisiae. Maximal production of the ACE inhibitor from Saccharomyces cerevisiae was obtained from 24 h of cultivation at $30^{\circ}C$ and its ACE inhibitory activity was increased by about 1.5 times after treatment of the cell-free extract with pepsin. After the purification of ACE inhibitory peptides with ultrafiltration, Sephadex G-25 column chromatography, and reverse-phase HPLC, an active fraction with an $IC_{50}$ of 0.07 mg and $3.5\%$ yield was obtained. The purified peptide was a novel decapeptide, showing very low similarity to other ACE inhibitory peptide sequences, and its amino acid sequence was Tyr-Asp-Gly-Gly-Val-Phe-Arg-Val-Tyr-Thr. The purified inhibitor competitively inhibited ACE and also showed a clear antihypertensive effect in spontaneously hypertensive rats (SHR) at a dosage of 1 mg/kg body weight.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.5
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• pp.337-340
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• 2001

A galactooligosaccharide(GalOS)-producing yeast, OE-20 was selected from forty seven strains of yeast growing in Korean traditional Meju (cooked soybean) and the yeast was tentatively identified as Kluyveromyces maxianus var lactis by its morphology and fermentation profile. A maximum yield of 25.1%(w/w) GalOS, which corresponds to 25.1 g of GalOS per liter, was obtained from the reaction of 100 g per liter of lactose solution at 3$0^{\circ}C$, pH 7.0 for 18 h with an intracellular crude $\beta$-galactosidase. Glucose and galactosidase were found to inhibit GalOS formation. The GalOS that were purified by active carbon and celite 545 column chromatography were supplemented in MRS media and a stimulated growth was observed of some intestinal bacteria. In particular the growth rate of Bifidobacterium infantis in the GalOS containing MRS broth increased up to 12.5% compared to that of the MRS-glucose broth during a 48h incubation period.

• Korean Journal of Agricultural Science
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• v.38 no.3
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• pp.533-540
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• 2011

This study is to develop a mulit-layer glued columns for construction of Korean-style houses by using domestic small diameter logs. Dried small square lumber glued each other to develop a multi-layer glued columns and evaluated its performance of strength. Then, predicted the design load of multi-layer glued columns and make a comparison between actual load and design load of multi-layer glued columns. In the results, allowable load by allowable stress of multi-layer glued columns was measured one-third of actual columns load and prediction load was measured less than 10~30% of the actual load. Therefore, muilt-layer glued member has a standard allowable stress of compressive of 13 MPa (Larix leptolepis) and 19 MPa (Chamaecyparis obtusa) when used as columns. Also, using compression strength of small diameter square logs could calculate maximum loads of multi-layer glued member as column.

• BMB Reports
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• v.37 no.5
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• pp.597-602
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• 2004

N-terminal His-tagged recombinant $\beta$-1,4-galactosyltransferase from Neisseria meningitidis was expressed and purified to homogeneity by column chromatography using Ni-NTA resin. Mutations were introduced to investigate the roles of, Ser68, His69, Glu88, Asp90, and Tyr156, which are components of a highly conserved region in recombinant $\beta$-1,4 galactosyltransferase. Also, the functions of three other cysteine residues, Cys65, Cys139, and Cys205, were investigated using site-directed mutagenesis to determine the location of the disulfide bond and the role of the sulfhydryl groups. Purified mutant galactosyltransferases, His69Phe, Glu88Gln and Asp90Asn completely shut down wild-type galactosyltransferase activity (1-3%). Also, Ser68Ala showed much lower activity than wild-type galactosyltransferase (19%). However, only the substitution of Tyr156Phe resulted in a slight reduction in galactosyltransferase activity (90%). The enzyme was found to remain active when the cysteine residues at positions 139 and 205 were replaced separately with serine. However, enzyme reactivity was found to be markedly reduced when Cys65 was replaced with serine (27%). These results indicate that conserved amino acids such as Cys65, Ser68, His69, Glu88, and Asp90 may be involved in the binding of substrates or in the catalysis of the galactosyltransferase reaction.

• Korean Journal of Environmental Agriculture
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• v.34 no.3
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• pp.196-203
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• 2015

BACKGROUND: Purpose of this research is HPLC analysis method development of lycopene in tomato. And then, three components of carotenoid in four kinds of tomatoes (general tomato, cherry tomato, red and orange date tomato) were compared with each other. METHODS AND RESULTS: Lycopene in tomato was extracted with hexane likes other carotenoid components using 500 mg of dried powder sample. HPLC analysis conditions were column temperature ($40^{\circ}C$), detection wavelength (454 nm), flow rate (1.0 mL/min) and injection volume ($20.0{\mu}L$). Lycopene was analyzed by the gradient elution ($60{\rightarrow}100%$) of the mobile phase solvents A[water: methanol=25: 75 (v/v)] and B[ethyl acetate]. CONCLUSION: Three components of carotenoids (lutein, ${\beta}$-carotene, lycopene) were observed in tomatoes. The total carotenoid contents was the highest in red date tomato (662.0 mg/kg dry wt.) and the lowest in orange date tomato (111.3 mg/kg dry wt.). Lycopene contents in tomatoes was the highest percentage (93%) among all the carotenoids.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.276.1-276.1
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• 2003

This study describes a simple and sensitive semi-micro HPLC method with UV detection and direct deproteinization. The plasma protein was precipitated using perchloric acid (60％) and the supernatant was directly injected onto the semi-micro HPLC system. The separation was achieved on a C18 (25 mm ${\times}$ 2.0 mm I.D) analytical column with a mobile phase of sodium acetate buffer (pH 3.5, 50 mmol) - acetonitrile (60:40, V/V). (omitted)

• Korean Journal of Medicinal Crop Science
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• v.15 no.4
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• pp.296-303
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• 2007

Acer tegmentosum (Acereaceae) has been used a source of traditional medicines for the treatment of hepatic disorders in Korea. This research was conducted to determine biofunctional activities of A. tegmentosum stem extract and to identify its bioactive components. Methanolic extract from A. tegmentosum stem was partitioned by using organic solvents, including n-hexane, ethyl acetate, n-butanol, and water. Two compounds were isolated by using an ODS column chromatography from ethyl acetate soluble fraction shown to the strongest antioxidant activity ($RC_{50}=3.15\;{\mu}g/m{\ell}$) among the fractions. The isolated compounds were analyzed by $^1H$ and $^{13}C$ NMR, IR, UV/VIS, MS spectrum data and identified as catechin, ${\rho}-Hydroxyphenethyl$ alcohol $1-O-{\beta}-_D-(6'-O-galloyl)-glucopyranoside$. The compounds have shown strong antioxidant activity, with similar activity to BHA ($RC_{50}=2\;{\mu}g/m{\ell}$). Especially, ${\rho}-Hydroxyphenethyl$ alcohol 1-O-{\beta}-_D-(6'-O-galloyl)-glucopyranoside$ was shown strong anti-lipid peroxidative activity. However, the compounds were not shown antimicrobial activities. In antimicrobial activity assays, ethyl acetate soluble fraction was effective to bacterial inhibition, such as Escherichia coli and Klebsiella pneumonia, with minimum inhibitory concentrations in $125\;{\mu}g/m{\ell}$. Otherwise, antifungal activity against Candida albicans was shown in n-hexane soluble fraction exhibiting $63\;{\mu}g/m{\ell}$ of minimum inhibitory concentration. In anticomplementary activity assays, water soluble fraction was the most effective exhibiting 24% inhibitory activity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.3
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• pp.161-168
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• 1988

The Stability of PSP extracted from the intoxicated sea mussel, Mytilus edulis was evaluated by the thange of heating conditions and pH of the PSP solution. Also the composition of the PSP extracted from the cultured sea mussel collected at Chungmu, Korea on March 12, 1986 was analyzed. The extracted PSP was stable over the range of pH 2.0 to 4.0, but it was unstable above pH 4.5. For example. the toxicity of extracted PSP of pH 3.0 was only decreased less than $20\%$ by the treatment at $121^{\circ}C$ for 15min or at 100 for 2 hours, but it was decreased more than $80\%$ by the same treatment when the pH of the PSP solution was adjusted to 6.0. The toxin was purified from the ethanolic extract of the digestive glands of the sampled sea mussel by Bio-gel P-2 and Bio-Rex 70 column chromatography. The toxic fractions obtained were analyzed by cellulose acetate membrane electrophoresis, TLC and HPLC. The compositional analytical results of the PSP, most of the toxins were certified as $GTX_{1-4}$, while the toxicity of STX was only about 1/40 of that of $GTX_s$.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.266-271
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• 2023

The antioxidant capacity of the Psidium guajava leaf extracted with EtOH and their MeOH fractions using column chromatography were evaluated by 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging assays, total phenolic and flavonoid content, and Superoxide dismutase (SOD) assay. To determine its utility as a functional material, the crude extract was fractionated by flash column chromatography on ODS using a stepwise elution with combinations of MeOH/H₂O and then all the fractions were also investigated. In the results of antioxidant activities, the 40% and 60% MeOH fractions show the meaningful values, and then the two fractions were selected to examine the isolation and identification of the major constituents via HPLC and nuclear magnetic resonance. Further purification led to isolation of two quercetin derivatives; quercitrin (1) and isoquercetin (2). Through SOD assay, some methanol fractions via column chromatography and isolated compounds showed improved antioxidant activities compared to the extract.

• Korean Journal of Medicinal Crop Science
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• v.15 no.3
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• pp.215-219
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• 2007

This study was conducted to analyze not only for the quality guaranteed of red ginseng but also for the minor ginsenosides. Although several studies have reported to analyze ginseng saponins, those were focused to major saponins, including 6 to 7 ginsenosides. As increase of interest in medicinal effect of ginseng products, anasis of various ginsenosides in both red and white ginseng are strongly demanded. To perform optital condition of 12 ginsenoside analysis, We controlled HPLC conditions, such as the gradient elution of the mobile phase. We found the adequate separation method for 12 ginse-nosides. The optimum condition was as following : H$_2$O/CH$_3$CN ratios were 82/18, 70/30, 55/45 and 50/50, respectively. Sol-vent flow rate was 1.00 ma/min. Column temperature was kept to 35$^{\circ}$C. UV detector was set to 203 nm.