• Korean Journal of Food Science and Technology
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• v.52 no.6
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• pp.595-603
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• 2020

To elucidate the structure-function relationship of polysaccharides obtained from Colocasia esculenta, the immuno-stimulating polysaccharide, CE-4a was purified to homogeneity from the crude polysaccharide (CE) extracted from the corms of C. esculenta by two subsequent column chromatographies using DEAE-Sepharose FF and Sephadex G-100, and analysis of their immuno-stimulatory activities and structure were conducted. CE-4a showed an increase in anti-complementary activity in a dose-dependent fashion. The molecular mass was estimated to be 182.4 kDa, which mainly consisted of galactose (43.5%) and mannose (18.2%). Methylation analysis indicated that CE-4a comprised at least 10 different glycosyl linkages, such as terminal Galp, 3-linked Galp, and 4-linked Manp, as well as a characteristic linkage, 2,4,6-branched Manp residue. To analyze the fine structure of CE-4a, it was sequentially digested using endo-α-(1→4)-polygalacturonase, exo-α-galactosidase and endo-β-1,4-D-mannanase. These analyses suggested that CE-4a is to be a highly branched galactomannan with a (1→4)-mannan backbone and galactopyranosyl oligosaccharide side chains.

• International Journal of Industrial Entomology and Biomaterials
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• v.36 no.1
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• pp.15-24
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• 2018

N-glycosylation is an important posttranslational modification that results in a variety of biological activities, structural stability, and protein-protein interactions. There are still many mysteries in the structure and function of N-glycans, and detailed elucidation is necessary. Baculovirus expression system (BES) is widely used to produce recombinant glycoproteins, but it is not suitable for clinical use due to differences in N-glycan structure between insects and mammals. It is necessary to develop adequate model glycoproteins for analysis to efficiently alter the insect-type N-glycosylation pathway to human type. The previous research shows the recombinant alpha 1-acid glycoprotein (${\alpha}1AGP$) secreted from silkworm cultured cells or larvae is highly glycosylated and expected to be an excellent research candidate for the glycoprotein analysis expressed by BES. Therefore, we improved the ${\alpha}1AGP$ to be a better model for studying glycosylation. The modified ${\alpha}1AGP$ (${\alpha}1AGP{\Delta}$) recombinant protein was successfully expressed and purified by using BES, however, the expression level in silkworm cultured cells and larvae were lower than that of the ${\alpha}1AGP$. Subsequently, we confirmed the detailed profile of N-glycan on the ${\alpha}1AGP{\Delta}$ by LS/MS analysis the N-glycan structure at each glycosylation site. These results indicated that the recombinant ${\alpha}1AGP{\Delta}$ could be usable as a better model glycoprotein of N-glycosylation research in BES.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.9
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• pp.1234-1239
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• 2006

Murrah and NiliRavi are the important North Indian buffalo breeds occupying the prominent position of being the highest milk producers. These breeds are more or less similar at morphological as well as physiological levels. The technique of RAPD-PCR was applied in the present study to identify a battery of suitable random primers to detect genetic polymorphism, elucidation of the genetic structure and rapid assessment of the differences in the genetic composition of these two breeds. A total of 50 random primers were screened in 24 animals each of Murrah and NiliRavi buffaloes to generate RAPD patterns. Of these, 26 (52%) primers amplified the buffalo genome generating 263 reproducible bands. The number of polymorphic bands for the 26 chosen RAPD primers varied from 3 (OPG 06 and B4) to 26 (OPJ 04) with an average of 10.1 bands per primer and size range of 0.2 to 3.2 kb. DNA was also pooled and analyzed to search for population specific markers. Two breed specific RAPD alleles were observed in each of Murrah (OPA02 and OPG16) and NiliRavi (OPG09) DNA pools. RAPD profiles revealed that 11 (4.2%) bands were common to all the 48 individuals of Murrah and NiliRavi buffaloes. Pair-wise band sharing calculated among the individual animals indicated considerable homogeneity of individuals within the breeds. Within breed, band sharing values were relatively greater than those of interbreed values. The low genetic distance (Nei's) value (0.109) estimated in this study is in accordance with the origin and geographical distribution of these breeds. The RAPD analysis indicated high level of genetic similarity between these two important North Indian buffalo breeds.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.1972-1984
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• 2013

Microtubules play an important role in intracellular transport, mobility, and particularly mitosis. Paclitaxel (Taxol$^{TM}$) and paclitaxel-like compounds have been shown to be anti-tumor agents useful for various human tumors. Paclitaxel-like compounds operate by stabilizing microtubules through interface binding at the interface between two ${\beta}$-tubulin monomers in adjacent protofilaments. In this paper we present the elucidation of the structural features of paclitaxel and paclitaxel-like compounds (e.g., epothilones) with microtubule stabilizing activities, and relate their activities to spatial and chemical features of the molecules. CATALYST program was used to generate three-dimensional quantitative structure activity relationships (3D-QSARs) resulting in 3D pharmacophore models of epothilone- and paclitaxel-derivatives. Pharmacophore models were generated from diverse conformers of these compounds resulting in a high correlation between experimental and predicted biological activities (r = 0.83 and 0.91 for epothilone and paclitaxel derivatives, respectively). On the basis of biological activities of the training sets, five- and four-feature pharmacophore hypotheses were generated in the epothilone and paclitaxel series. The validation of generated hypotheses was achieved by using twelve epothilones and ten paclitaxels, respectively, which are not in the training sets. The clustering (grouping) and merging techniques were used in order to supplement spatial restrictions of each of hypothesis and to develop more comprehensive models. This approach may be of use in developing novel inhibitor candidates as well as contributing a better understanding of structural characters of many compounds useful as anticancer agents targeting microtubules.

• Natural Product Sciences
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• v.26 no.3
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• pp.214-220
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• 2020

Brassica oleracea var. gongylodes (red kohlrabi) is a biennial herbaceous vegetable whose edible bulbotuber-like stem and leaves are consumed globally. Sliced red kohlrabi tubers were extracted using methanol and the concentrated extract was partitioned successively with dichloromethane (CH₂Cl₂), ethyl acetate (EtOAc), n-butanol (n-BuOH) and water (H₂O). Repeated column chromatography of EtOAc fraction through silica, sephadex LH-20 and RP-18 gel led to isolation of eleven compounds of which compound 1 was a new glycosylated indole alkaloid derivative, 1-methoxyindole 3-carboxylic acid 6-O-β-D-glucopyranoside. Others were known compounds namely, β-sitosterol glucoside (4), 5-hydroxymethyl-2-furaldehyde (5), methyl-1-thio-β-D-glucopyranosyl disulfide (6), 5-hydroxy-2-pyridinemethanol (7), (3S,4R)-2-deoxyribonolactone (8), n-butyl-β-D-fructopyranoside (9), uridine (10) and three fructose derivatives, D-tagatose (11), β-D-fructofuranose (12) and β-D-fructopyranose (13). Similarly, isolation from CH₂Cl₂ fraction gave two known indole alkaloids, indole 3-acetonitrile (2) and N-methoxyindole 3-acetonitrile (3). The structure elucidation and identification of these compounds were conducted with the help of ¹³C and ¹H NMR, HMBC, HMQC, EIMS, HR-ESIMS and IR spectroscopic data, and TLC plate spots visualization. Compounds 2, 3, 4, 5, 6, 7, 8 and 9 are noted to occur in kohlrabi for the first time. Different bioactivities of these isolated compounds have been reported in literature.

• Journal of Korean Society of Steel Construction
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• v.18 no.3
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• pp.395-403
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• 2006

Recently constructed bridges often have long spans and simple structure details considering not only the function but other important factors such as aesthetics, maintenance, construction duration and life cycle cost. Therefore, bridges require high-performance steels like extra-thick plate steels and thermo-mechanical control process (TMCP) steels. TMCP stels are now gaining wide attention due to their weldability improved strength and toughness. Recently, SM570-TMC steel, which is a high-strength TMCP steel with a tensile strength of 600 MPa, has been developed and applied to steel structures. However, using this steel in building steel structures requires the elucidation of not only material characteristics but also the mechanical characteristic of welded joints. In this study, high-temperature tensile properties of SM570-TMC steel were investigated through the elevated temperature welded joints of SM570-TMC steel were studied through the three-dimensional thermal elasticplastic analyses on the basis of mechanical properties at high temperatures obtained from the experiment.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.469-475
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• 1993

In order to elucidate the metabolism of the systemic insecticide, phosphamidon(2-chloro-2-diethylcarbamoyl-1-methylvinyl dimethyl phosphate), treated to pine trees against pine leaf gall midges (Thecodiplosis japonensis Uchida et Inouye), $[vinyl,\;carbonyl-^{14}C]$phosphamidon was implanted into the trunks of 10-year-old Korean red pine (Pinus densiflora Sieb. et Zucc.) and Japanese black pine (Pinus thunbergii Parl.), respectively. This chemical was degraded very quickly in pine trees after implanting, as confirmed by TLC/autoradiography of the extracts of pine needles. Phosphamidon metabolites in phosphate buffer extracts of pine needles include the major metabolite, ${\alpha}-chloroacetoacetic$ acid diethyl-amide, ${\alpha}-chloroacetoacetic$ acid ethylamide, 3-hydroxy-N,N-d iethylbutanamide, acetoacetamide, and trimethyl phosphate. The metabolism within pine trees is expected to be similar to this. Based on these findings, it is believed that the major pathway leading to the metabolites would be related to the P-O-vinyl hydrolysis of the chemical structure.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.39-46
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• 2018

Column chromatographic separation of the MeOH extract from the roots of Dicentra spectabilis yielded fourteen compounds, menisdaurin (1), menisdaurilide (2), trans-N-p-coumaroyltyramine (3), trans-N-p-feruloyltyramine (4), 4-O-feruloylquinicacid (5), chlorogenic acid (6), 3-O-feruloylquinicacid (7), ferulic acid (8), protopine (9), Kaempferol 3,7-di-O-${\beta}-{\text\tiny{D}}$-glucopyranoside (10), kaempferol 3-O-${\beta}-{\text\tiny{D}}$-glucopyranosyl-7-O-${\alpha}-{\text\tiny{L}}$-rhamnopyranoside (11), ${\alpha}-rhamnoisorobin$ (12), astragalin (13), and nicotiflorin (14). Their structures were determined on the basis of NMR spectroscopic data. Among them, compound 1, 3-8, and 10-14 isolated from this plant were reported for the first time. The isolated compounds (1-14) were tested for nitric oxide (NO) inhibitory activity on lipopolysaccharide-stimulated RAW 264.7 cells. Compound 3, 4 and 12 significantly inhibited NO production. Moreover, Compound 3 suppressed pro-inflammatory cytokines ($TNF-{\alpha}$, $IL-1{\beta}$ and IL-6) in a dose- dependent manner. These data suggest that compound 3 possess anti-inflammatory activity and might be useful natural materials for development of anti-inflammatory agent.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.615-618
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• 2016

Ethyl acetate extracts obtained from culture of endophytic fungi Aspergillus sp isolated from Piper crocatum Ruiz & Pav, have been shown to possess cytotoxic activity against T47D breast cancer cells. Investigations were here conducted to determine bioactive compounds responsible for the activity. Bioassay guided fractionation was employed to obtain active compounds. Structure elucidation was performed based on analysis of LC-MS, $^1H$-NMR, $^{13}C$-NMR, COSY, DEPT, HMQC, HMBC data. Cytotoxity assays were conducted in 96 well plates against T47D and Vero cell lines. Bioassay guided isolation and chemical investigation led to the isolation of pyrophen, a 4-methoxy-6-(1'-acetamido-2'-phenylethyl)-2H-pyran-2-one. Further analysis of its activity against T47D and Vero cells showed an ability to inhibit the growth of T47D cells with IC50 values of $9.2{\mu}g/mL$ but less cytotoxicity to Vero cells with an $IC_{50}$ of $109{\mu}g/mL$. This compound at a concentration of 400 ng/mL induced S-phase arrest in T47D cells.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.2
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• pp.145-151
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• 2012

In the present work, we studied the structure-activity relationship (SAR) of tautomycetin (TMC) and its derivatives. Further, we demonstrated the correlation between the immunosuppressive fuction, anticancer activity and protein phosphatase type 1 (PP1) inhibition of TMC and its derivatives. We have prepared some TMC derivatives via combinatorial biosynthesis, isolation from fermentation broth or chemical degradation of TMC. We found that the immunosuppressive activity was correlated with anticancer activity for TMC and its analog compounds, indicating that TMC may home at the same targets for its immunosuppressive and anticancer activities. Interestingly, TMC-F1, TMC-D1 and TMC-D2 all retained significant, albeit reduced PP1 inhibitory activity compared to TMC. However, only TMC-D2 showed immunosuppressive and anticancer activities in studies carried out in cell lines. Moreover, TMC-Chain did not show any significant inhibitory activity towards PP1 but showed strong growth inhibitory effect. This observation implicates that the maleic anhydride moiety of TMC is critical for its phosphatase inhibitory activity whereas the C1-C18 moiety of TMC is essential for the inhibition of tumor cell proliferation. Furthermore, we measured $in$ $vivo$ phosphatase activities of PP1 in MCF-7 cell extracts treated with TMC and its related compounds, and the results indicate that the cytotoxicity of TMC doesn't correlate with its $in$ $vivo$ PP1 inhibition activity. Taken together, our study suggests that the immunosuppressive and anticancer activities of TMC are not due to the inhibition of PP1. Our results provide a novel insight for the elucidation of the underlying molecular mechanisms of TMC's important biological functions.