• Title/Summary/Keyword: Strong acids

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Synthesis of Coumarin Analogues and their Antitumor Activity (쿠마린 유도체의 합성과 그들의 항암효과)

  • Lee, Jee-Hyun;Lee, Jae-Ho;Kim, Hyun-Kwan;Kim, Eui-Geom;Shen, Gui-nan;Cho, Soo-Hyun;Myung, Chang-Seon;Kim, Dong-Hee;Yun, Mi-Young;Choi, Yong-Seok;Kim, Sung-Hoon;Song, Gyu-Yong
    • YAKHAK HOEJI
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    • v.50 no.5
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    • pp.338-344
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    • 2006
  • A novel series of 4-senecioyloxymethyl-6,7-dimethoxycoumarin, isolated from Crinum latifolium, was prepared by reacting 4-bromomethyl or 4-bromomethyl-6,7- dimethoxycoumarin with various carboxylic acids and examined for their anti-angiogenic activities in human umbilical vein endothelial cells (HUVECs). Among them, 4e, 4f, 4g and 4i with noncyclic moiety exhibited potent anti-angiogenic activity. However, compounds with cyclic moiety such as phenyl, pyridinyl, thiophenyl and furanyl group did not exhibit any anti-angiogenic activity. Also, compounds 4f and 4g which exhibited strong anti-angiogenic activity in a dose-dependent manner showed antitumor activity.

Development of a thermo-stabel ${\beta}-agarase$ from marine organism

  • Lee, Sang-Hyeon
    • 한국생물공학회:학술대회논문집
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    • 2005.04a
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    • pp.31-32
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    • 2005
  • Neoagaro-oligosaccharides are produced only by enzymatic degradation of agarose by ${\beta}-agarase.^{1)}$ Neoagaro-oligosaccharides inhibit the growth of bacteria, slow the rate of degradation of starch, are used as low-calorie additives to improve food quality, and have macrophage-stimulating activity. Furthermore, neoagarobiose is a rare reagent that has both moisturizing effect on skin and whitening effect on melanoma $cells.^{2)}$ An agar-degrading marine bacterium was isolated from the sea water at the northeast coast in Cheju island, Korea. The strain was gram negative, aerobic, and motile rod. The 16S rRNA of the strain had the closest match of 98% homology, with that from Agarivorans albus. On the basis of several phenotypic characters and a phylogenetic analysis, this strain was designated Agarivorans sp. JA-1. In solid agar plate, Agarivorans sp. JA-1 produced a diffusible agarase that caused agar softening around the colonies. Agarivorans sp. JA-1 was cultured for 36 hr in marine broth 2216 (Difco, USA) and the supernatant that containing an extracellular ${\beta}-agarase$ was prepared by centrifugation of culture media. The enzyme exhibited relatively strong activity at $40^{\circ}C$ and was stable up to $60^{\circ}C$. Using PCR primers derived from the ${\beta}-agarase$ gene of Vibrio sp., the gene encoding ${\beta}-agarase$ from Agarivorans sp. JA-1 was cloned and sequenced. The structural gene consists of 2931 bp encoding 976 amino acids with a predicted molecular weight of 107,360 Da. The deduced amino acid sequence showed 99% and 34% homology to $agaA^{2)}$ and $agaB^{2)}$ genes for ${\beta}-agarase$ from Vibrio sp., respectively. The expression plasmid for ${\beta}-agarase$ gene of Agarivorans sp. JA-1 is being constructed and the recombinant enzyme will be biochemically characterized.

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Differential expression and in situ localization of a pepper defensin (CADEFl) gene in response to pathogen infection, abiotic elicitors and environmental stresses in Capsium annuum

  • Do, Hyun-Mee;Lee, Sung-Chul;Jung, Ho-Won;Hwang, Byung-Kook
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.78.2-79
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    • 2003
  • Pepper defensin ( CADEFl) clone was isolated from cDNA library constructed from pepper leaves infected with avirulent strain Bv5-4a of Xanthomonu campestris pv. vesicatoria. The deduced amino acid sequence of CADEFl is 82-64% identical to that of other plant defensins. Putative protein encoded by CADEFl gene consists of 78 amino acids and 8 conserved cysteine residues to form four structure-stabilizing disulfide bridges. Transcription of the CADEF1 gene was earlier and stronger induced by X campestris pv. vesicatoria infection in the incompatible than in the compatible interaction. CADEF1 mRNA was constitutively expressed in stem, root and green fruit of pepper. Transcripts of CADEFl gene drastically accumulated in pepper leaf tissues treated With Salicylic acid (SA), methyl jasmonate (MeJA), abscisic acid (ABA), hydrogen Peroxide (H$_2$O$_2$), benzothiadiazole (BTH) and DL-${\beta}$-amino-n-butyric acid (BABA). In situ hybridization results revealed that CADEF1 mRNA was localized in the phloem areas of vascular bundles in leaf tissues treated with exogenous SA, MeJA and ABA. Strong accumulation of CADEF1 mRNA occurred in pepper leaves in response to wounding, high salinity and drought stress. These results suggest that bacterial pathogen infection, abiotic elicitors and some environmental stresses may play a significant role in signal transduction pathway for CADEF1 gene expression.

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Determination of Betaine from Saliconia herbacea L. (함초(Saliconia herbacea L.)로부터 베타인 정량)

  • Lee, Chang-Ho;Kim, In-Ho;Kim, Young-Eon;Oh, Se-Wook;Lee, Ho-Jun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.9
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    • pp.1584-1587
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    • 2004
  • The betaine content of Saliconia herbacea L. was determined by reverse-phase high performance chromatog-raphy on a C_(18) column. A 50% methanol extract was passed through a anion exchanger Ambelite IRA 400 (quaternary ammonium type, OH-) column and a strong cation exchanger Ambelite IR 120 (sulfonic acid type, $H^+$) column to remove amino acids, zwitter ions which are interfere with betaine analysis. The betaine extract was derivatized with 18-crown-6-ether and 4-bromophenacyl bromide (PBPB) for UV-labelling. Betaine in Saliconia herbacea L. was analysed on a mobile phase contained 13 mM sodium heptane sulfonic acid and 5 mM $Na_2SO_4$ in deionized water by isocratic elution for 30 min. The recovery ratio of betaine from Saliconia herbacea L. extract was 83.6%. The mean betaine value for Saliconia herbacea L. determined by the described method is 4.85 mg/mL with a standard deviation of 0.127.

Physicochemical and Sensory Characteristics of Baechu Kimchi using Spicy Hot Flavor Graded Hot Pepper Powder (매운맛 등급화 고춧가루로 제조한 배추김치의 이화학적 관능적 특성)

  • Lee, In-Seon;Lee, Yeon-Kyeong;Kim, Hae-Young
    • Korean journal of food and cookery science
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    • v.30 no.1
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    • pp.22-32
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    • 2014
  • This study investigated the spicy hot flavor related quality characteristics of baechu (Kimchi cabbage) Kimchi prepared using hot pepper powder in various capsaicin levels during 8 weeks of storage. The pHs in the Kimchi samples were in the optimum range of the pH 4.2-4.5 due to the relatively low storage temperature of $2^{\circ}C$ during the entire storage periods. The L, a and b values of cap-150 sample group were significantly higher compared to those in the other samples at 8 weeks of storage. Grading hotness of the Kimchi was significantly clearly separated when varied levels of hotness for the hot pepper powder were used at 2-4 weeks of storage (p<0.001). Sensory spicy hotness of the cap-40 showed significantly the lowest with values of 4.57-4.38 representing mild hot:, that of cap-85 was medium hot with values of 5.81-6.00; and finally, that of cap-150 showed the values of 6.86-7.14, representing strong hot flavor at 2-4 weeks of storage (p<0.001). The grading of spicy hotness in the Kimchi increased by about one level at the optimal edible periods due to the leaching out of capsaicin from the hot pepper powder for those storage periods. Thus, the increased hotness of the Kimchi in the optimal edible periods should be considered when the desired hotness of the hot pepper is chosen for the Kimchi preparation. The hotness decreased as the organic acids were generated during ripening by the 8th weeks of storage.

Effect of Rice stripe virus NS3 on Transient Gene Expression and Transgene Co-Silencing

  • Sohn, Seong-Han;Huh, Sun-Mi;Kim, Kook-Hyung;Park, Jin-Woo;Lomonossoff, George
    • The Plant Pathology Journal
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    • v.27 no.4
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    • pp.310-314
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    • 2011
  • Nonstructural protein 3 (NS3) encoded by RNA3 of Rice stripe virus (RSV), known to be a suppressor of gene silencing, was cloned and sequenced. The cloned NS3 gene is composed of 636 nucleotides encoding 211 deduced amino acids, and showed a high degree of similarity with the equivalent genes isolated from Korea, Japan and China. The NS3 gene promoted the enhancement of transient gene expression and suppressed transgene co-silencing. In the transient GFP expression via agroinfiltration, GFP expression was dramatically enhanced in terms of both protein yield and expression period in the presence of NS3. The highest accumulation of GFP protein reached to 6.8% of total soluble proteins, which corresponded to a two-fold increase compared to that obtained in the absence of NS3. In addition, NS3 significantly suppressed the initiation of GFP co-silencing induced by the additive GFP infiltration in GFP-transgenic Nicotiana benthamiana. The NS3 gene was also found to be a stronger suppressor than Cucumber mosaic virus 2b. These observations are believed to be derived from the strong suppressive effect of NS3 on gene silencing, and indicate that NS3 could be used as an effective enhancer for the rapid production of foreign proteins in plants.

Amino Acid Alterations in the $\beta$- Tubulin of Metarhizium anisopliae That Confer Benomyl Resistance

  • Kim Soon Kee;Shim Hee Jin;Roh Jong Yul;Li Ming Shun;Choi Jae Young;Jin Byung Rae;Boo Kyung Saeng;Je Yeon Ho
    • International Journal of Industrial Entomology and Biomaterials
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    • v.11 no.1
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    • pp.37-42
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    • 2005
  • We cloned the $\beta$-tubulin genes from the wild type strain and two benomyl-resistant mutants of Metahizium anisopliae and determined their nucleotide sequences. A $\beta$-tubulin encoding 448-residue protein from wild type M. anisopliae shows strong homology to other $\beta$-tubulins. The coding region is interrupted by four introns. Comparisons of intron position between the M. anisopliae gene and other fungal $\beta$-tubulin genes show considerable positional conservation. The mutations responsible for benomyl resistance were determined in two spontaneous mutants, 8-18 and 8­19. One mutant 8-18 substituted glutamate for aspar­agine at position 33 and lysine for glutamine at position 134. The other mutant 8-19 showed alterations at three positions of $\beta$-tubulin arginine for tryptophan at position 21, lysine for asparagine at position 33, and phenylalanine for leucine at position 240. These data suggest that regions of $\beta$-tubulin containing amino acids 21, 33,134, and 240 interact to form the binding site of benomyl.

Characterization of a Strain of Malva Vein Clearing Virus in Alcea rosea via Deep Sequencing

  • Wang, Defu;Cui, Liyan;Pei, Yanni;Ma, Zhennan;Shen, Shaofei;Long, Dandan;Li, Lingyu;Niu, Yanbing
    • The Plant Pathology Journal
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    • v.36 no.5
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    • pp.468-475
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    • 2020
  • Malva vein clearing virus (MVCV) is a member of the Potyvirus species, and has a negative impact on the aesthetic development of Alcea rosea. It was first reported in Germany in 1957, but its complete genome sequence data are still scarce. In the present work, A. rosea leaves with vein-clearing and mosaic symptoms were sampled and analyzed with small RNA deep sequencing. By denovo assembly the raw sequences of virus-derived small interfering RNAs (vsiRs) and whole genome amplification of malva vein cleaning virus SX strain (MVCV-SX) by specific primers targeting identified contig gaps, the full-length genome sequences (9,645 nucleotides) of MVCV-SX were characterized, constituting of an open reading frame that is long enough to encode 3,096 amino acids. Phylogenetic analysis showed that MVCV-SX was clustered with euphorbia ringspot virus and yam mosaic virus. Further analyses of the vsiR profiles revealed that the most abundant MVCV-vsiRs were between 21 and 22 nucleotides in length and a strong bias was found for "A" and "U" at the 5′-terminal residue. The results of polarity assessment indicated that the amount of sense strand was almost equal to that of the antisense strand in MVCV-vsiRs, and the main hot-spot region in MVCV-SX genome was found at cylindrical inclusion. In conclusion, our findings could provide new insights into the RNA silencing-mediated host defence mechanism in A. rosea infected with MVCV-SX, and offer a basis for the prevention and treatment of this virus disease.

Antiviral Activity of Antibiotic Peptaibols, Chrysospemins B and D, Produced by Apiocrea sp. 14T against TMV Infection

  • Kim, Young-Ho;Yeo, Woon-Hyung;Kim, Young-Sook;Chae, Soon-Young;Kim, Kap-Sik
    • Journal of Microbiology and Biotechnology
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    • v.10 no.4
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    • pp.522-528
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    • 2000
  • A total of about 300 fungal isolates from forest havitats were screened for inhibitors of tobacco mosaic virus (TMV) infection using its local lesion host, Nicotiana tabacum cv. Xanthi nc. Ine of the isolates, 14T, showed a strong activity against TMV infection, and was identified as an Apiocrea sp. based on its morphological characterstics. Rice was an optimum culture medium for its fermentation, and two antiviral compounds, KGT 141 and KGT 142, were resolved from the rice culture through column chromatography, TLC, and HPLC. By NMR and FAB-MS, the two compounds were identified as chrysospermins B (KGT 141) and D (KGT 142), both of which are peptaibols with 19-mer amino acids possessing an acetylated N-terminus and a hydroxy-amino acid (tryptophanol) at the C-terminus. Both compounds showed inhibitory activities against TMV infection, but chrysospermin D showed the stronger activity than chrysospermin B. The former of $100{\;}\mu\textrm{g}/ml$ and 54.7% at $10{\;}\mu\textrm{g}/ml$, respectively. Furthermore, the chrysospermins were highly cytotoxic toward cancer cell lines of PC-3 (prostrate) and K562 (leukemia), and inhibited growth of the Gram-positive bacteria tested, especially the plant pathogenic bacterium Corynebacterium lilium. To the best of our knowledge, this is the first report on the inhibition of plant virus infection by antimicrobial peptaibols.

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Degradation of Lignocelluloses in Rice Straw by BMC-9, a Composite Microbial System

  • Zhao, Hongyan;Yu, Hairu;Yuan, Xufeng;Piao, Renzhe;Li, Hulin;Wang, Xiaofen;Cui, Zongjun
    • Journal of Microbiology and Biotechnology
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    • v.24 no.5
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    • pp.585-591
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    • 2014
  • To evaluate the potential utility of pretreatment of raw biomass with a complex microbial system, we investigated the degradation of rice straw by BMC-9, a lignocellulose decomposition strain obtained from a biogas slurry compost environment. The degradation characteristics and corresponding changes in the bacterial community were assessed. The results showed that rapid degradation occurred from day 0 to day 9, with a peak total biomass bacterium concentration of $3.3{\times}10^8$ copies/ml on day 1. The pH of the fermentation broth declined initially and then increased, and the mass of rice straw decreased steadily. The highest concentrations of volatile fatty acid contents (0.291 mg/l lactic acid, 0.31 mg/l formic acid, 1.93 mg/l acetic acid, and 0.73 mg/l propionic acid) as well as the highest xylanse activity (1.79 U/ml) and carboxymethyl cellulase activity (0.37 U/ml) occurred on day 9. The greatest diversity among the microbial community also occurred on day 9, with the presence of bacteria belonging to Clostridium sp., Bacillus sp., and Geobacillus sp. Together, our results indicate that BMC-9 has a strong ability to rapidly degrade the lignocelluloses of rice straw under relatively inexpensive conditions, and the optimum fermentation time is 9 days.