• Journal of Microbiology and Biotechnology
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• v.29 no.3
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• pp.410-418
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• 2019

To investigate a novel ${\beta}$-glucosidase from Bifidobacterium breve ATCC 15700 (BbBgl) to produce compound K (CK) via ginsenoside $F_2$ by highly selective and efficient hydrolysis of the C-3 glycoside from ginsenoside Rd, the BbBgl gene was cloned and expressed in E. coli BL21. The recombinant BbBgl was purified by Ni-NTA magnetic beads to obtain an enzyme with specific activity of 37 U/mg protein using pNP-Glc as substrate. The enzyme activity was optimized at pH 5.0, $35^{\circ}C$, 2 or 6 U/ml, and its activity was enhanced by $Mn^{2+}$ significantly. Under the optimal conditions, the half-life of the BbBgl is 180 h, much longer than the characterized ${\beta}$-glycosidases, and the $K_m$ and $V_{max}$ values are 2.7 mM and $39.8{\mu}mol/mg/min$ for ginsenoside Rd. Moreover, the enzyme exhibits strong tolerance against high substrate concentration (up to 40 g/l ginsenoside Rd) with a molar biotransformation rate of 96% within 12 h. The good enzymatic properties and gram-scale conversion capacity of BbBgl provide an attractive method for large-scale production of rare ginsenoside CK using a single enzyme or a combination of enzymes.

• Korean Journal of Plant Resources
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• v.36 no.3
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• pp.225-236
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• 2023

Stomatal traits such as stomata density (SD), aperture length (APL) and width (APW), guard cell length (GCL) and width (GCW), and distance between stomata (DIS) were investigated to identify correlation with agronomic traits for 35 Korean wheat cultivars. Flag leaf width (FLW) of Korean wheat cultivars was the widest in Ol-mil, and the narrowest in Keumkang. SD tended to be higher on the adaxial side than on the abaxial side in Korean wheat cultivars. SD of adaxial and abaxial sides was classified into a cultivar with a significantly different or not. In APL, 18 wheat cultivars showed significant differences according to leaf side, and APL of adaxial was longer than APL of abaxial in 13 wheat cultivars. In APW, 15 wheat cultivars showed a significant difference, and APW of abaxial was wider than APW of adaxial among them. In GCL, 14 wheat cultivars showed a significant difference, and the GCL of abaxial was longer than the GCL of adaxial in 10 wheat cultivars. In GCW, 10 wheat cultivars showed a significant difference, GCW of adaxial was wider than GCW of abaxial and in 6 wheat cultivars. FLW of adaxial and abaxial showed a negative correlation with GCL and a positive correlation with grain number per panicle. FLW of only abaxial showed a positive correlation with DIS. The SD of the adaxial showed a negative correlation with GCL, while the SD of the abaxial showed a negative correlation with APL. APL of both sides of the leaf showed a positive correlation with GCL, and APW of only abaxial showed a negative correlation with GLC. DIS of adaxial showed a negative correlation with tiller number (TN), while DIS of abaxial showed a positive correlation with GNP.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.214-214
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• 2022

Soluble starch synthases (SSs) elongate α-glucans from ADP-Glc to the glucan nonreducing ends and play a critical role in synthesizing resistant starch in the rice. A total of 10 SSs isoforms were reported in rice, including granules-bound starch synthase I (GBSSI), GBSSII, starch synthase I (SSI), SSIIa (SSII-3), SSIIb (SSII-2), SSIIc (SSII-1), SSIIIa (SSIII-2), SSIIIb (SSIII-1), SSIVa (SSIV-1), and SSIVb (SSIV-2). SSIII proteins are involved in forming the B chain and elongating cluster filling chains in amylopectin metabolism. The functions of SSIIIb (SSIII-1) are less clear as compared to SSs. Here, we sought to shed light on the genetic diversity profiling of the SSIII-1 gene in 374 rice accessions composed of 54 wild-type accessions and 320 bred cultivars (temperate japonica, indica, tropical japonica, aus, aromatic, and admixture). In total, 17 haplotypes were identified in the SSIII-1 coding region of 320 bred cultivars, while 44 haplotypes were detected from 54 wild-type accessions. The genetic diversity indices revealed the most negative Tajima's D value in the temperate-japonica, followed by the wild type, while Tajima's D values in other ecotypes were positive, indicating balancing selection. Nucleotide diversity in the SSIII-1 region was highest in the wild group (0.0047) while lowest in temperate-japonica. Lower nucleotide diversity in the temperate-japonica is evidenced by the negative Tajima's D and suggested purifying selection. The fixation index (F_ST) revealed a very high level of gene flow (low F_ST) between the tropical-japonica and admixture groups (F_ST=-0.21) followed by admixture and wild groups (-0.04), indica and admixture groups (0.02), while low gene flow with higher F_ST estimates between the temperate-japonica and aus groups (0.72), tropical-japonica and aromatic groups (0.71), and temperate-japonica and admixture groups (0.52). Taken together, our study offers insights into haplotype diversity and evolutionary fingerprints of SSIII-1. It provides genomic information to increase the resistant starch content of cooked rice.

• The Korean Journal of Food And Nutrition
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• v.37 no.1
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• pp.17-29
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• 2024

To increase industrial applicability of Astragalus membranaceus (AM) as immunostimulating materials, hot-water extract (AME) was prepared from AM and fermented with Kimchi-lactic acid bacteria (Lactobacillus sakei & Leuconostoc mesenteroides) to prepare fermented AM-postbiotics (FAME). Although FAME prepared from AM-postbiotics did not show a significant enhancement in macrophage stimulating activity compared to non-fermented AME, crude polysaccharide (FAME-CP) fractionated by EtOH precipitation from FAME showed significantly higher macrophage stimulating activity than AME-CP. Compared to AME-CP, FAME-CP showed dramatic changes in component sugar and molecular weight distribution. FAME-CP was a polysaccharide with a major molecular weight distribution of 113.4 kDa containing Man (44.2%), Glc (19.3%), Gal (10.2%), GalA (10.2%), and Ara (7.4%) as sugar components. FAME-CP with enhanced macrophage stimulatory activity not only increased expression levels of mRNA genes encoding macrophage-activated factors (iNOS, TNF-α, MCP-1, IL-6, and COX-2), but also led the nuclear translocation of activated p65 and c-Jun. In conclusion, crude polysaccharide from AM-postbiotics fermented with lactic acid bacteria could increase industrial applicability as a functional material with enhanced immunostimulating activity than AME-CP.

• Journal of the Korean Applied Science and Technology
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• v.41 no.1
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• pp.46-57
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• 2024

In this study, the various process conditions for high-power DC Magnetron Sputtering (DCMS) on the surface roughness of carbon thin films were investigated. The optimal conditions for Si/C coating were 40min for deposition time, which does not deviate from normal plasma, to obtain the maximum deposition rate, and the conditions for the best surface roughness were -16volt bias voltage and 400watt DC power with 1.3x10-3torr chamber pressure. Under these optimal conditions, an excellent carbon thin film with a surface roughness of 1.62nm and a thickness of 724nm was obtained. As a result of XPS analysis, it was confirmed that the GLC structure (sp² bonding) was more dominant than the DLC structure (sp³ bonding) in the thin film structure of the carbon composite layer formed by DC sputtering. Except in infrequent cases of relatively plasma instability, the lower bias voltage and applied power induces smaller surface roughness value due to the cooling effect and particle densification. For the optimal conditions for Graphite/C composite layer coating, a roughness of 36.3 nm and a thickness of 711 nm was obtained under the same conditions of the optimal process conditions for Si/C coating. This layer showed a immensely low roughness value compared to the roughness of bare graphite of 242 nm which verifies that carbon coating using DC sputtering is highly effective in modifying the surface of graphite molds for glass forming.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.307-313
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• 2013

This study was carried out to investigate the residual characteristics of fungicide azoxystrobin and difenoconazole in Prunus mume fruits, and establish pre-harvest residue limits (PHRL) based on dissipation and biological half-lives of fungicide residues. The fungicides were sprayed onto the crop at recommended dosage once and 3 times in 7 days interval, respectively. The samples were harvested at 0, 1, 2, 4, 6, 8, 10, 12 and 14 days after treatment. These residual pesticides were extracted with QuEChERS method, clean-up with $NH_2$ SPE cartridge, and residues were analyzed by HPLC/DAD and GLC/ECD, respectively. Method quantitative limits (MQL) of azoxystrobin were 0.03 mg $kg^{-1}$ and of difenoconazole were 0.006 mg $kg^{-1}$. Average recovery were $93.2{\pm}2.49%$, $85.5{\pm}1.97%$ for azoxystrobin at fortification levels at 0.3 and 1.5 mg $kg^{-1}$, and $100.8{\pm}6.74%$, $87.6{\pm}9.92%$ for difenoconazole at fortification levels at 0.06 and 0.3 mg $kg^{-1}$, respectively. The biological half-lives of azoxystrobin were 5.9 and 5.2 days at recommended dosage once and 3 times in 7 days interval, respectively. The biological half-lives of difenoconazole were 9.3 and 8.0 days at recommended dosage once and 3 times in 7 days interval, respectively. The PHRL of azoxystrobin and difenoconazole were recommended as 5.32 and 1.64 mg $kg^{-1}$ for 10 days before harvest, respectively.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7179-7188
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• 2015

Cancer is a major health obstacle around the world, with hepatocellular carcinoma (HCC) and colorectal cancer (CRC) as major causes of morbidity and mortality. Nowadays, there isgrowing interest in the therapeutic use of natural products for HCC and CRC, owing to the anticancer activity of their bioactive constituents. Boswellia serrata oleo gum resin has long been used in Ayurvedic and traditional Chinese medicine to alleviate a variety of health problems such as inflammatory and arthritic diseases. The current study aimed to identify and explore the in vitro anticancer effect of B. Serrata bioactive constituents on HepG2 and HCT 116 cell lines. Phytochemical analysis of volatile oils of B. Serrata oleo gum resin was carried out using gas chromatography-mass spectrometry (GC/MS). Oleo-gum-resin of B. Serrata was then successively extracted with petroleum ether (extract 1) and methanol (extract 2). Gas-liquid chromatography (GLC) analysis of the lipoidal matter was also performed. In addition, a methanol extract of B. Serrata oleo gum resin was phytochemically studied using column chromatography (CC) and thin layer chromatography (TLC) to obtain four fractions (I, II, III and IV). Sephadex columns were used to isolate ${\beta}$-boswellic acid and identification of the pure compound was done using UV, mass spectra, $^1H$ NMR and $^{13}C$ NMR analysis. Total extracts, fractions and volatile oils of B. Serrata oleo-gum resin were subsequently applied to HCC cells (HepG2 cell line) and CRC cells (HCT 116 cell line) to assess their cytotoxic effects. GLC analysis of the lipoidal matter resulted in identification of tricosane (75.32%) as a major compound with the presence of cholesterol, stigmasterol and ${\beta}$-sitosterol. Twenty two fatty acids were identified of which saturated fatty acids represented 25.6% and unsaturated fatty acids 74.4% of the total saponifiable fraction. GC/MS analysis of three chromatographic fractions (I,II and III) of B. Serrata oleo gum resin revealed the presence of pent-2-ene-1,4-dione, 2-methyl- levulinic acid methyl ester, 3,5- dimethyl- 1-hexane, methyl-1-methylpentadecanoate, 1,1- dimethoxy cyclohexane, 1-methoxy-4-(1-propenyl)benzene and 17a-hydroxy-17a-cyano, preg-4-en-3-one. GC/MS analysis of volatile oils of B. Serrata oleo gum resin revealed the presence of sabinene (19.11%), terpinen-4-ol (14.64%) and terpinyl acetate (13.01%) as major constituents. The anti-cancer effect of two extracts (1 and 2) and four fractions (I, II, III and IV) as well as volatile oils of B. Serrata oleo gum resin on HepG2 and HCT 116 cell lines was investigated using SRB assay. Regarding HepG2 cell line, extracts 1 and 2 elicited the most pronounced cytotoxic activity with $IC_{50}$ values equal 1.58 and $5.82{\mu}g/mL$ at 48 h, respectively which were comparable to doxorubicin with an $IC_{50}$ equal $4.68{\mu}g/mL$ at 48 h. With respect to HCT 116 cells, extracts 1 and 2 exhibited the most obvious cytotoxic effect; with $IC_{50}$ values equal 0.12 and $6.59{\mu}g/mL$ at 48 h, respectively which were comparable to 5-fluorouracil with an $IC_{50}$ equal $3.43{\mu}g/mL$ at 48 h. In conclusion, total extracts, fractions and volatile oils of B. Serrata oleo gum resin proved their usefulness as cytotoxic mediators against HepG2 and HCT 116 cell lines with different potentiality (extracts > fractions > volatile oil). In the two studied cell lines the cytotoxic acivity of each of extract 1 and 2 was comparable to doxorubicin and 5-fluorouracil, respectively. Extensive in vivo research is warranted to explore the precise molecular mechanisms of these bioactive natural products in cytotoxicity against HCC and CRC cells.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.633-640
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• 2011

After Ganoderma lucidum was cultured in mushroom complete medium (MCM) supplemented with ginseng extract (GE), crude polysaccharide (GL-GE-CP) was fractionated from mycelium. Among GL-GE-CP from mycelium in MCM supplemented with 5, 10, and 15% GE (v/v ratio of MCM to GE), GL-GE-15-CP (15% GE) most significantly enhanced macrophage stimulation and intestinal immune system modulating activity compared with GL-CP in MCM without GE. When GL-GE-15-CP was further fractionated on DEAE-Sepharose CL-6B, GL-GE-15-CP-II displayed more potent activity than subfractions from GL-CP on macrophage stimulation, interleukin-12 production, and intestinal immune system modulation (1.75-, 5.68-, and 1.76-fold, respectively). Anti-metastasis effect against colon 26-M3.1 carcinoma cells was also enhanced by GL-GE-15-CP-II (72.8% inhibition). In addition, GL-GE-15-CP-II contained neutral sugar (83.00%) and uronic acid (9.11%), and consisted of Ara, Man, Gal and Glc (molar ratio of 0.39:0.50:0.75:1.00). Furthermore, GE supplementation helped to enhance the immunomodulation in G. lucidum, and it is assumed that neutral polysaccharides play an important role.

• The Korean Journal of Pesticide Science
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• v.10 no.1
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• pp.15-21
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• 2006

In order to monitor the pesticide residues in/on peppers and pepper powder and to assess their risk, pesticides in/on green pepper from 10 farmgates and fresh red pepper from 9 farmgates in Chungbuk area and pepper powder from 6 wholesale markets in Cheongju city were analyzed with a GLC and an HPLC. Also, pepper powder made by pulverization of the dried red pepper was analyzed to elucidate the change of pesticide residues in fresh red pepper by oven-drying. The number of pesticides detected from peen pepper, fresh red pepper, dried red pepper and pepper powder were 9, 12, 12, and 17, respectively, including 10 pesticides (one fungicide and nine insecticides) which were exceeded the maximum residue limits (MRLs). The exceeding rate of the MRL were higher in dried red pepper and pepper powder than in green pepper and fresh red pepper. Although some pesticides in peppers and pepper powder exceeded the MRLs, their estimated daily intake(EDI) were less than 1.6% of their acceptable daily intakes(ADIs), suggesting that it would be estimated to safe. By oven-drying of fresh red pepper at $65^{\circ}C$ for 72 hours, the weight of dried red pepper was from 1/5.9 from 1/7.8 of fresh red pepper, while the concentration of pesticide residue in dried red pepper increased from 1.7 to 8.2 times, suggesting that further reconsideration was required for the MRL of pepper powder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.5
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• pp.446-452
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• 1986

This paper presents the composition of neutral and polar lipids obtained from puple shell, Rapana venosa and the abalone, Haliotis discus hannai. The fatty acid composition and the classification of neutral lipids from two species were determined by gas chromatography (GLC) and thin layer chromatography (TLC). Total lipid contents of samples were $0.5\%$ in purple shell and $0.4\%$ in the abalone. The predominant fatty acids of total lipids were eicosapentaenoic acid ($19.30\%$). eicosenoic acid ($12.10\%$) and palmitic acid ($11.77\%$) in the purple shell, and palmitic acid ($21.29\%$), oleic acid ($14.55\%$) and linoleic acid ($14.21\%$) in the abalone. The lipid composition of non-polar lipid fractions in purple shell and abalone was separated and identified as free sterol, free fatty acid, triglyceride and hydrocarbon & esterified sterol by TLC. The contents of triglyceride from both neutral lipids were shown more abundant than any other subclasses. The main fatty acids of neutral lipids were eicosapentaenoic acid ($18.6\%$), palmitic acid ($14.90\%$) and eicosenoic acid ($14.76\%$) in the purple shell, and palmitic acid ($28.12\%$), oleic acid($20.5\%$) and myristic acid ($12.5\%$) in the abalone. Eicosapentaenoic acid ($17.57\%$), stearic acid ($13.26\%$) and eicosatetraenoic acid ($11.24\%$) were important fatty acids of glycolipid in the purple shell, and myristic acid ($12.75\%$), stearic acid ($12.10\%$) and eicosatetraenoic acid ($10.64\%$) in the abalone. The major fatty acids of phospholipids were eicosapentaenoic acid ($20.18\%$), palmitic acid ($11.26\%$) and eicosenoic acid ($10.90\%$) in the purple shell, and palmitic acid ($21.10\%$), eicosapentaenoic acid ($12.90\%$) and oleic acid($11.13\%$) in the abalone.