• Bulletin of the Korean Chemical Society
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• v.31 no.3
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• pp.588-594
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• 2010

Two types of resin-conjugated Tamiflu analogs were synthesized by modifying our original synthetic route of oseltamivir phosphate (Tamiflu). The prepared resins bound to influenza virus neuraminidase, the main target of Tamiflu. The resins will be useful for isolating and identifying presumed endogenous vertebrate proteins that interact with Tamiflu, which might relate to the rarely observed abnormal behavior exhibited by some influenza patients treated with Tamiflu.

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.1059-1062
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• 2012

• Journal of Veterinary Science
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• v.21 no.1
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• pp.12.1-12.6
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• 2020

Porcine deltacoronavirus (PDCoV) is an emerging swine enteric coronavirus that causes diarrhea in piglets. However, the biological characteristics of PDCoV are unclear. In this study, the hemagglutination (HA) abilities of two PDCoV strains (CH-01 and HNZK-04) were investigated. Our results showed that PDCoV has the ability to agglutinate rabbit erythrocytes after virion pretreatment with trypsin or neuraminidase. Additionally, the HA assay results showed a significant positive correlation with the infectious viral titer. Our results suggest that assessing the HA activity of PDCoV may be a useful diagnostic method for investigating and surveilling PDCoV infections.

• Genomics & Informatics
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• v.14 no.3
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• pp.96-103
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• 2016

The influenza A (H1N1) virus, also known as swine flu is a leading cause of morbidity and mortality since 2009. There is a need to explore novel anti-viral drugs for overcoming the epidemics. Traditionally, different plant extracts of garlic, ginger, kalmegh, ajwain, green tea, turmeric, menthe, tulsi, etc. have been used as hopeful source of prevention and treatment of human influenza. The H1N1 virus contains an important glycoprotein, known as neuraminidase (NA) that is mainly responsible for initiation of viral infection and is essential for the life cycle of H1N1. It is responsible for sialic acid cleavage from glycans of the infected cell. We employed amino acid sequence of H1N1 NA to predict the tertiary structure using Phyre2 server and validated using ProCheck, ProSA, ProQ, and ERRAT server. Further, the modelled structure was docked with thirteen natural compounds of plant origin using AutoDock4.2. Most of the natural compounds showed effective inhibitory activity against H1N1 NA in binding condition. This study also highlights interaction of these natural inhibitors with amino residues of NA protein. Furthermore, among 13 natural compounds, theaflavin, found in green tea, was observed to inhibit H1N1 NA proteins strongly supported by lowest docking energy. Hence, it may be of interest to consider theaflavin for further in vitro and in vivo evaluation.

• Plant Breeding and Biotechnology
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• v.6 no.4
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• pp.404-412
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• 2018

The influenza neuraminidase (NA, E.C. 3.2.1.18), an antiviral, has been the target of high pharmaceutical companies due to its essential role in viral replication cycle. Perilla frutescens (P. frutescens) is used in traditional Chinese medicine for various diseases, such as cold due to wind-cold, headache and cough. In this context, four major polyphenolic compounds including rosmarinic acid-3-O-glucoside (1), rosmarinic acid (2), luteolin (3), and apigenin (4) isolated from P. frutescens were evaluated for their inhibitory effect on recombinant virus H1N1 neuraminidase (rvH1N1 NA). Among the test compounds, rosmarinic acid and luteolin inhibited the rvH1N1 NA with an $IC_{50}$ of 46.7 and $8.4{\mu}M$, respectively. The inhibition kinetics analyzed by the Dixon plots indicated that rosmarinic acid and luteolin were noncompetitive inhibitors and that the inhibition constant, $K_I$, was established as 43.9 and $14.3{\mu}M$, respectively. In addition, 578 genetically diverse accessions and 39 cultivars of P. frutescens were analyzed using HPLC to characterize the diversity of polyphenolic composition and concentration. The individual and total compositions exhibited significant difference (P < 0.05), especially rosmarinic acid which was detected as the predominant metabolite in all accessions (58.8%) and cultivars (62.8%). Yeupsil and Sangback cultivars exhibited the highest rosmarinic acid ($3,393.5{\mu}g/g$) and luteolin ($383.3{\mu}g/g$) content respectively. YCPL177-2 with the high concentration ($889.8{\mu}g/g$) of luteolin may be used as a genetic resource for breeding elite cultivars.

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.257.2-258
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• 2001

• Journal of Life Science
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• v.25 no.7
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• pp.786-794
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• 2015

To identify nutritional and therapeutic properties of the new Korean red waxy sorghum cultivar ‘Hwanggeumchalsusu (HGC)’, we assayed the antioxidative effects and neuraminidase inhibitory activity. A methanol and 70% ethanol extract of HGC exhibited strong antioxidative effects (IC₅₀ values of 83.2±2.7 for DPPH) and 85.6±2.4 μg/ml for ABTS) and neuraminidase (ND) inhibitory activity (IC₅₀ values of 1.8±0.1 from extracted with methanol and 3.4±0.1 μg/ml from extracted with 70% ethanol) compared with that of the control, noncolored sorghum cultivar ‘Huinchalsusu (HC)’ (IC₅₀> 200 μg/ml). We isolated nine polyphenols, Gallic acid (1), Protocatecuic acid (2), p-Hydroxy benzoic acid (3), Vanillic acid (4), Caffeic acid (5), Ferulic acid (6), Luteolinidin (7), Apigeninidin (8), Luteolin (9), from the HGC - methanol extract, to determine whether they were the active components Luteolinidin of one kind of polyphenols from the HGC, exhibited significant antioxidative effects (IC₅₀ values of 10.9±0.5 μM for DPPH and 8.6 0.6 μM for ABTS) and neuraminidase (ND) inhibitory activity (IC₅₀ values of 26.3±0.6) showed noncompetitive inhibition model. The binding affinity of the ND inhibitors in molecular docking experiments correlated with their ND inhibitory activities. These results suggest that HGC may be utilized to serve as a potential effective antioxidant and inhibitor of ND.

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.04a
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• pp.188-188
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• 2018

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1500-1505
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• 2010

The novel swine-origin influenza A/H1N1 virus (S-OIV) first detected in April 2009 has been identified to transmit from humans to humans directly and is the cause of the currently emerged pandemic. In this study, nucleotide and deduced amino acid sequences of the hemagglutinin (HA) and neuraminidase (NA) of the S-OIV and other influenza A viruses were analyzed through bioinformatic tools for phylogenetic analysis, genetic recombination, and point mutation to investigate the emergence and adaptation of the S-OIV in humans. The phylogenetic analysis showed that the HA comes from triple reassortant influenza A/H1N2 and the NA from Eurasian swine influenza A/H1N1, indicating that HA and NA descend from different lineages during the genesis of the S-OIV. Recombination analysis ified the possibility of occurrence of recombination in HA and NA, denoting the role of reassortment in the outbreak. Several conservative mutations were observed in the amino acid sequences of the HA and NA, and these mutated residues were identical in the S-OIV. The results reported herein suggest the notion that the recent pandemic is the result of reassortment of different genes from different lineages of two envelope proteins, HA and NA, which are responsible for the antigenic activity of the virus. This study further suggests that the adaptive capability of the S-OIV in humans is acquired by the unique mutations generated during emergence.

• The Korean Journal of Zoology
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• v.32 no.4
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• pp.412-419
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• 1989

Monoclonal antibodies (MAbs) reacting with the plasmalemma of Amoeba proteus were produced. Specificity of the 3 MAbs was determined by transfer blotting of the SDS polvacryfamide gel. AMS antibody reacted with the mucopolysaccharide bands of the spacer gel, 220 KD and 50 KD proteins of the resolving gel. The maior glycoprotein bands (175 KD, 165 KD) and 50 KD protein of the plasmalemma were recognized by AUG antibody. A third, AMP antibody reacted with the 50 KD protein only. In immunofluorescence microscopy of the enzyme treated cells, the antigens of these MAbs were sensitive to proteases, but not sensitive to neuraminidase. In the assay of cell to substratum attachment after binding with the antibody, AMG and AMP antibodies exerted no effect, but AMS hindered the attachment and cell spreading. Thus the effective components of the plasmalemma in cell to substratum attachment appear to be the mucopolysaccharides and 220 KD protein. The membranes of latex particle infested phagosomes did not show any distinction from the plasmalemma in fluorescence microscopy. Phagosome membranes of amoebae appear to be derived from the plasma membrane without selection in terms of the antigen composition. Amoeba Proteus의 세포막과 반응하는 단세포군 항체를 생산하였다. SDS polyacrylamide gel을 transfer blotting하여 이들 항체의 반응 특이성을 조사해 본 결과 AMS 단항체는 PAS로 염색되는 spacer gel의 mucopolysaccharide 린드, resolving gel의 220 KD 및 50 KD 단백질과 반응하였으며, 세포막의 주요 당단백질인 175 KD 및 165 KD 빈드와 50 KD 단백질은 AMG 단항체에 의해서 인지되었다. 그리고 AMP단항체는 공통인 50 KD 단백질과 특이하게 반응하였다. 효소처리한 아메바의 면역형광칠미경적 조사에서 이들 항체에 대한 항원분자들은 모두 단백질분해효소에 민감하였으며 neuraminidase에 대해서는 변화가 없었다. 이들 항체를 결합시킨 아메바의 용기표면 부착 가능성을 분석한 결과 AMP 및 AMG 단항체는 아무런 영향을 미치지 못하였으며 AMS 단항체는 세포의 용기표면 부착 및 세포의 펴짐을 저해하였다. 따라서 아메바의 용기표면 부착은 mucopolysaccharide 및 220 KD 단백질에 의해서 매게되는 것으로 나타났다. 그리고 latex particle을 담고 있는 식포막은 면역형광형미경적 조사에서 세포막과 차이가 없었다. 따라서 겐포막은 항원 조성에 있어서 비 선택적으로 세포막에서 유도되는 것으로 나타났다.