• Title/Summary/Keyword: LC-ESI-MS

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A single-step isolation of useful antioxidant compounds from Ishige okamurae by using centrifugal partition chromatography

  • Kim, Hyung-Ho;Kim, Hyun-Soo;Ko, Ju-Young;Kim, Chul-Young;Lee, Ji-Hyeok;Jeon, You-Jin
    • Fisheries and Aquatic Sciences
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    • v.19 no.4
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    • pp.22.1-22.7
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    • 2016
  • One of the main compounds in Ishige okamurae, diphlorethohydroxycarmalol (DPHC), is known to exhibit antiviral and anti-inflammatory effects. However, it has not been investigated extensively. In this study, preparative centrifugal partition chromatography (CPC) coupled with 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) ($ABTS^+$) online HPLC was employed for effectively separating considerable amounts of antioxidant compounds from marine algae. Two main antioxidant compounds, DPHC and octaphlorethol A (OPA), respectively, were confirmed and isolated from the ethyl acetate (EtOAc) fraction of I. okamurae by $ABTS^+$ online HPLC and preparative CPC systems. The presence of DPHC and OPA was confirmed in the EtOAc fraction of I. okamurae by both liquid chromatography with diode array detection and electrospray ionization mass spectrometry (LC-DAD-ESI/MS) and $ABTS^+$ online HPLC systems: DPHC (39 mg) and OPA (23 mg) were successfully isolated from I. okamurae (500 mg) with optimum solvent composition (0.5:10:4:6; n-hexane/EtOAc/MeOH/water, v/v) with corresponding partition coefficients (K) of 1.62 and 2.71, respectively, by preparative CPC. Hence, CPC coupled with $ABTS^+$ online HPLC is convenient for the efficient and simple isolation of these antioxidant compounds from I. okamurae.

Engineering Human-like Sialylation in CHO Cells Producing hCTLA4-Ig by Overexpressing α2,6-Sialyltransferase (α2,6-Sialyltransferase 과발현을 통한 인간형 시알산 부가 hCTLA4-Ig 생산 CHO 세포주 제작)

  • Lim, Jin-Hyuk;Cha, Hyun-Myoung;Park, Heajin;Kim, Ha Hyung;Kim, Dong-Il
    • KSBB Journal
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    • v.32 no.3
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    • pp.193-198
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    • 2017
  • Sialylation is important in producing therapeutic proteins such as antibody, cytokine and fusion protein. Thus, enhancement of sialylation is usually performed in CHO cell cultures. ${\alpha}2,6$-Sialyltransferase (ST), which plays a key role in the attachment of ${\alpha}2,6-sialic$ acid, is present in human cells but not in Chinese hamster ovary (CHO) cells. Overexpression of ${\alpha}2,6-ST$ can be used for enhancing the degree of sialylation and achieving human-like glycosylation. In this study, we constructed CHO cells producing human cytotoxic T-lymphocyte antigen4-immunoglobulin (hCTLA4-Ig) as well as ${\alpha}2,6-ST$. Transfected CHO cells were selected using G418 and stable cell line was established. Profiles of viable cell density and hCTLA4-Ig titer in an overexpressed cell line were similar to those of a wild-type cell line. It was confirmed that the total amount of sialic acid was increased and ${\alpha}2,6-sialic$ acid was attached to the terminal residues of N-glycan of hCTLA4-Ig by ESI-LC-MS. Compared to 100% of ${\alpha}2,3-sialic$ acid in wild type cells, 70.9% of total sialylated N-glycans were composed of ${\alpha}2,6-sialic$ acid in transfected cells. In conclusion, overexpression of ${\alpha}2,6-ST$ in CHO cells led to the increase of both the amount of total sialylated N-glycan and the content of ${\alpha}2,6-sialic$ acid, which is more resemble to human-like structure of glycosylation.

The Production of Lunasin Peptide Using E. coli and P. pastoris, and Inhibitory Effect of Histone Acetylation (대장균과 효모를 이용한 lunasin peptide의 생산 및 histone acetylation 억제활성)

  • Park, Jae Ho;Park, Gwang Hun;Song, Hun Min;Jeong, Jin Boo
    • Korean Journal of Plant Resources
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    • v.30 no.1
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    • pp.1-7
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    • 2017
  • In this study, we produced the recombinant lunasin peptide using E. coli and P. pastoris, and evaluated biological activity of the recombinant lunasin peptide. Lunasin peptide was produced from E. coli transfected with pPGEX-lunasin expression vector and P. pastoris GS115 transfected with pPIC-lunasin expression vector. These recombinant lunasin peptides were similar to the synthetic lunasin peptide in the identification by LC-ESI-MS. In addition, the recombinant lunasin peptide from E. coli and P. pastoris was bound in the chromatin, and inhibited histone acetylation and the activity of histone acetyltransferase. These findings suggest that the production of the lunasin peptide using E. coli and P. pastoris will be useful for industrial utilization of lunasin peptide.

Anti-Aging Activity of Lavandula angustifolia Extract Fermented with Pediococcus pentosaceus DK1 Isolated from Diospyros kaki Fruit in UVB-Irradiated Human Skin Fibroblasts and Analysis of Principal Components

  • Ha, Ji Hoon;Kim, A Rang;Lee, Keon-Soo;Xuan, Song Hua;Kang, Hee Cheol;Lee, Dong Hwan;Cha, Mi Yeon;Kim, Hye Jin;An, Mi;Park, Soo Nam
    • Journal of Microbiology and Biotechnology
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    • v.29 no.1
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    • pp.21-29
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    • 2019
  • The effects of Lavandula angustifolia extract fermented with Pediococcus pentosaceus DK1 on UVB-mediated MMP-1 expression and collagen decrease in human skin fibroblasts were determined, and the conversion of its components was also analyzed. Fermentation was performed at varying L. angustifolia extract and MRS medium concentrations, and optimal fermentation conditions were selected. L. angustifolia extracts showed decreased cytotoxicity after fermentation in the fibroblasts. UVB-irradiated fibroblasts treated with fermented L. angustifolia extract showed MMP-1 expression 8.2-14.0% lower than that in UVB-irradiated fibroblasts treated with non-fermented extract. This was observed even at fermented extract concentrations lower than those of non-fermented extracts. Fibroblasts treated with fermented L. angustifolia extract showed 20% less reduction in collagen production upon UVB irradiation than those treated with non-fermented extracts. UVB-irradiated fibroblasts treated with fermented L. angustifolia extracts showed 50% higher inhibition of ROS generation than those treated with non-fermented extract. Luteolin and apigenin glycosides of L. angustifolia were converted during fermentation, and identified using RP-HPLC and LC/ESI-MS. Therefore, the effects of L. angustifolia extract on MMP-1 expression and collagen decrease in UVB-irradiated human skin fibroblasts were increased through fermentation by P. pentosaceus.

Antioxidant Effect and Component Analysis of Cardiospermum halicacabum Leaf Extracts (풍선덩굴 잎 추출물의 항산화 효과 및 성분 분석)

  • Jeong, Hyo Jin;Kim, A Rang;Lee, Keon Soo;Park, So Hyun;Shin, Hyuk Soo;Lee, Sang Rae;Song, Ba Reum;Lee, Yun Ju;An, Hyun Jin;Lee, Jae Duk;Park, Soo Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.43 no.2
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    • pp.175-187
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    • 2017
  • In this study, the antioxidant effect and component analysis for extract and fractions of Cardiospermum halicacabum leaf were investigated. All experiments were performed with 50% ethanol extract, ethyl acetate fraction and aglycone fraction obtained from dried C. halicacabum leaf. The yields of extract and fractions were 16.4, 0.9 and 0.3% per dried powder, respectively. DPPH (1,1-phenyl-2-picrylhydrazyl) radical scavenging activity ($FSC_{50}$) of ethyl acetate fraction ($92.5{\mu}g/mL$) was the greatest radical scavenging activity, but lower than (+)-${\alpha}$-tocopherol ($8.9{\mu}g/mL$). In reactive oxygen species (ROS) scavenging activity (total antioxidant capacity, $OSC_{50}$) on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system, aglycone fraction ($4.2{\mu}g/mL$) was the highest total antioxidant capacity and similar to L-ascorbic acid ($1.5{\mu}g/mL$). The cellular protective effects of C. halicacabum leaf extract and fractions on the $^1O_2$-induced cellular damage of human erythrocytes were exhibited at all concentration-dependent ($5.0-25.0{\mu}g/mL$). Especially, aglycone fraction (${\tau}_{50}$, 76.4 min) in $25.0{\mu}g/mL$ showed the most protective effect among extracts. Components of the ethyl acetate fraction obtained from C. halicacabum extracts were analyzed by TLC, HPLC chromatogram and LC/ESI-MS. Results showed that the ethyl acetate fraction contained some flavonoids, such as apigenin-7-O-glucuronide, apigenin-7-glucosdie and quercitrin hydrate. These results suggest that the extracts and fractions of C. halicacabum leaf may be applied as antioxidant functional cosmetic raw materials.

Determination of Heterocyclic Amines in Roasted Fish and Shellfish by Liquid Chromatography-Electrospray Ionization/Mass Spectrometry (Liquid chromatography-mass spectrometry를 이용한 가열 조리된 어패류에서의 heterocyclic amines 함량 분석)

  • Lee, Jae-Hwan;Back, Yoo-Mi;Lee, Kwang-Geun;Shin, Han-Seung
    • Korean Journal of Food Science and Technology
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    • v.41 no.3
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    • pp.326-333
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    • 2009
  • Heterocyclic aromatic amines (HCAs) are mutagenic and carcinogenic substances that are formed during the heating of protein-rich foods. HCAs are generally found at low amounts in a complex matrix, which requires sophisticated analysis. In this study, HCAs were extracted from lyophilized fish and shellfish samples using solid-phase extraction (SPE) and determined by liquid chromatography-electrospray ionization/mass spectrometry (LC-ESI-MS). The HCA recoveries in the fish and shellfish ranged from 15.7 to 74.7% with standard deviations from 0.2 to 7.63%. And HCA concentrations ranged from 0.8 to 1,117.7 $ng/g^{-1}$ in cooked food samples. 1-methyl-9H-pyrido[3,4-b]indole (Harman), 9H-pyrido[3,4-b]indole (Norharman), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) were the most abundant HCAs formed in the muscle of fried mackerel, at levels of 1,117.7, 926.6, and 133.7 ng/g, respectively. 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-aminodipiryrido[1,2-a:3,2-d]imidazole(Glu-P-2), 2-amino-9H-pyrido[2,3-b]indole(A${\alpha}$C), 2-amino-3methyl-9H-pyrido [1,2-a:3,2-d]imidazole(MeA${\alpha}$C), 2-amino-3,4,7,8-tetramethylimidazo[4,5-f]quinoxaline (TriMeIQx), 2-amino-3,7,8-trimethylimidazo [4,5-f]quinoxaline(7,8-DiMeIQx), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) were only detected by small quantities ranged from 1.5 to 98.6 ng/g. Overall, this study provides useful information on HCA levels in fish and shellfish products consumed in Korea.

Changes of Saponin during the Cultivation of Soybean Sprout (콩나물 생장 중 사포닌의 변화)

  • Oh, Bong-Yun;Park, Bock-Hee;Ham, Kyung-Sik
    • Korean Journal of Food Science and Technology
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    • v.35 no.6
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    • pp.1039-1044
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    • 2003
  • We investigated the changes in saponins during the cultivation of soybean sprout. Crude saponin content was 4.15mg/g in germinated soybean and reached its peark (5.33mg/g) in soybean sprout cultivated for six days. Saponin content in the cotyledon, stem, and root of the soybean sprout cultivated for six days were 4.17, 7.46, and 7.45mg/g, respectively. Soyasaponins extracted from the soybean sprout were analyzed with LC-electrospray ionization (ESI)-mass spectrometry, in which a reverse phase $C_18$ column was used for separation of saponins. In the soybeen sprout, group B saponin, I, II, III, IV, and V increased 7, 2, 1.4, 8.7, and 3.3 fold, respectively, compared to those in the soybean seed. Group B saponin I, II, III, IV, and V in the stem of the soybean sprout were 10.53, 1.45, 10.49, 5.72 and 8.14 fold the level of those in the cotyldon, respectively. In the root, the contents of group B saponin I, III, IV, and V were 5.54, 2.77, 4.86 and 9.73 fold, respectively, higher than those in cotyledon, but the content of group B saponin 2 was 2.96 fold less than that in cotyledon. These results indicate that the biosyntheses of group B saponins are differentially regulated in growing soybean sprout.

Simultaneous Characterization of Sofalcone and Its Metabolite in Human Plasma by Liquid Chromatography -Tandem Mass Spectrometry

  • Han, Sang-Beom;Jang, Moon-Sun;Lee, Hee-Joo;Lee, Ye-Rie;Yu, Chong-Woo;Lee, Kyung-Ryul;Kim, Ho-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.26 no.5
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    • pp.729-734
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    • 2005
  • A sensitive and selective method for quantitation of sofalcone and its active metabolite in human plasma has been established using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS). Plasma samples were transferred into 96-well plate using an automated sample handling system and spiked with 10 $\mu$L of 2 $\mu$g/mL $d_3$-sofalcone and $d_3$-sofalcone metabolite solutions (internal standard), respectively. After adding 0.5 mL of acetonitrile to the 96-well plate, the plasma samples were then vortexed for 30 sec. After centrifugation, the supernatant was transferred into another 96-well plate and completely evaporated at 40 ${^{\circ}C}$ under a stream of nitrogen. Dry residues were reconstituted with mobile phase and were injected into a $C_{18}$ reversed-phase column. The limit of quantitation of sofalcone and its metabolite was 2 ng/mL, using a sample volume of 0.2 mL for analysis. The reproducibility of the method was evaluated by analyzing 10 replicates over the concentration range of 2 ng/mL to 1000 ng/mL. The validation experiments of the method have shown that the assay has good precision and accuracy. Sofalcone and its metabolite produced a protonated precursor ion ([M+H]$^+$) of m/z 451 and 453, and a corresponding product ion of m/z 315 and 317, respectively. Internal standard ($d_3$-sofalcone and $d_3$-sofalcone metabolite) produced a protonated precursor ion ([M+H]$^+$) of m/z 454 and 456 and a corresponding product ion of m/z 315 and 317, respectively. The method has been successfully applied to a pharmacokinetic study of sofalcone and its active metabolite in human plasma.

A study of the metabolites for 7-keto-DHEA-acetate in human urine (II) (뇨시료에 함유된 7-keto-DHEA-acetate의 대사체에 관한 연구 (II))

  • Kim, Yunje;Lee, Jinhee
    • Analytical Science and Technology
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    • v.17 no.5
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    • pp.401-409
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    • 2004
  • The 7-keto-DHEA-acetate is converted to 7-keto-DHEA, a metabolite of DHEA, and similar to its metabolism. We studied the metabolite M3, M4, and M5 of 7-keto-DHEA-acetate. The estimated molecular weight of M3 and M4 was 304 which were supposed to have more 3 hydroxyl and/or ketone groups. We could know that M3 is the 7-OH-DHEA which has the hydroxyl groups on 3 and 7-carbon and a ketone group on 17-carbon. In case of M4, it is the 7-oxo-diol metabolite which has the hydroxyl groups on 3 and 17-carbon and a ketone group on 7-carbon. The M5 was supposed that the molecular weight is 320 and has the three hydroxyl groups on 3, 6, and 16 carbon and the ketone group on 17-carbon. After dosing, 7-OH-DHEA showed the maximum urine flow in human urine after 5 hr and decreased rapidly. But we could find it until 58 hr why is a higher remaining substance.

Simultaneous Determination of Five Porphyrins in Human Urine and Plasma Using High Performance Liquid Chromatography-Tandem Mass Spectrometry

  • Hur, Yeoun;Tae, Sookil;Koh, Yun-Joo;Hong, Sung-Hyun;Yoon, Young Ho;Jang, Haejong;Kim, Sooji;Kim, Kyeong Ho;Kang, Seung Woo;Lee, Youngshin;Han, Sang Beom
    • Mass Spectrometry Letters
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    • v.5 no.2
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    • pp.42-48
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    • 2014
  • A specific and sensitive liquid chromatography-electrospray ionization tandem mass spectrometry method (LC-ESI-MS/MS) was developed and validated for the simultaneous quantification of porphyrins (coproporphyrin, pentacarboxylporphyrin, hexacarboxylporphyrin, heptacarboxylporphyrin, and uroporphyrin) in human plasma and urine. Acidified plasma samples and urine samples were prepared by using liquid-liquid extraction using ethyl acetate and protein precipitation with acetonitrile, respectively. The separation was achieved onto a Synergi Fusion RP column ($150mm{\times}2.0mm$, $4{\mu}m$) with a gradient elution of mobile phase A (0.1% formic acid in 2 mmol/L ammonium acetate, v/v) and mobile phase B (20% methanol in acetonitrile, v/v) at a flow rate of $450{\mu}L$/min. Porphyrins and the internal standard (IS), coproporphyrin I-$^{15}N_4$, were detected by a tandem mass spectrometer equipped with an electrospray ion source operating in positive ion mode. Multiple reaction monitoring (MRM) transitions of the protonated precursor ions and the related product ions were optimized to increase selectivity and sensitivity. The proposed method was validated by assessing selectivity, linearity, limit of quantification (LOQ), precision, accuracy, recovery, and stability. The calibration curves were obtained in the range of 0.1-100 nmol/L and the LOQs were estimated as 0.1 nmol/L for all porphyrins. Results obtained from the validation study of porphyrins showed good accuracy, precision, recovery, and stability. Finally, the proposed method was successfully applied to clinical studies on the autism spectrum disorder (ASD) diagnosis of 203 Korean children.