• Title/Summary/Keyword: Strong acids

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Assessment on Antioxidant Properties of Oplopanax elatus Nakai in vitro

  • Kim, Jun-Heong;Eom, Seok-Hyun;Lee, Han-Shin;Kim, Jae-Kwang;Yu, Chang-Yeon;Kwon, Yong-Soo;Lee, Ju-Kyong;Kim, Myong-Jo
    • Korean Journal of Medicinal Crop Science
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    • v.15 no.2
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    • pp.112-119
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    • 2007
  • Effects of Oplopanax elatus have known to various pharmaceutical therapies. However, chemical prosperities in the plant are rarely investigated. In order to detect biological activity, we evaluated the antioxidant activity of five fractions from methanolic extracts in each part of O. elatus. Also, contents of polyphenols and polysaccharides were measured. Five fractions were of sub-fractions using n-hexane, ethyl-acetate, n-butanol, and water from methanolic extracts. Ethylacetate and n-butanol fractions from stem and root exhibited strong antioxidant activity and high total phenolics content. On the HPLC analysis, ten free phenolics, including p-hydroxybenzoic acid, chlorogenic acid, caffeic acid, syringic acid, p-cou maric acid, ferulic acid, naringin, hesperidin, quercetin and trans-cinnamic acid, were identified from the fractions and were shown to different quantitative proportions. Furthermore, ethylacetate and n-butanol fraction had the highest amount of chlorogenic acids, one of the cinnamic acid derivatives possessing pharmacological properties. These results indicated that the fractions of O. elatus, as well as methanolic extracts, could be used as natural antioxidative ingredients.

Expression of Acetohydroxyacid Synthase from Bacillus anthracis and Its Potent Inhibitors

  • Choi, Kyoung-Jae;Pham, Chien Ngoc;Jung, Hoe-Il;Han, Sung-Hwan;Choi, Jung-Do;Kim, Jin-Heung;Yoon, Moon-Young
    • Bulletin of the Korean Chemical Society
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    • v.28 no.7
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    • pp.1109-1113
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    • 2007
  • Acetohydroxyacid synthase (AHAS, EC 2. 2. 1. 6) is the enzyme that catalyses the first step in the common pathway of the biosynthesis of the branched chain amino acids, valine, leucine and isoleucine. For the first time, the AHAS gene from Bacillus anthracis was cloned into the expression vector pET28a(+), and was expressed in the E. coli strain BL21(DE3). The purified enzyme was checked on 12% SDS-PAGE to be a single band with molecular weight of 65 kDa. The optimum pH and temperature for B. anthracis AHAS was at pH 7.5 and 37 oC, respectively. Kinetic parameters of B. anthracis were as follows: Km for pyruvate, K0.5 for ThDP and Mg2+ was 4.8, 0.28 and 1.16 mM respectively. AHAS from B. anthracis showed strong resistance to three classes of herbicides, Londax (a sulfonylurea), Cadre (an imidazolinone), and TP (a triazolopyrimidine). These results indicated that these herbicides could be used in the search for new anti-bacterial drugs.

산화안정성이 높은 어유 캡슐 제품 개발

  • Eo, Myeong-Hui;Gang, Hyeon-Ju;Kim, Ok-Seon;Ju, Dong-Sik;Jo, Sun-Yeong
    • 한국생물공학회:학술대회논문집
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    • 2000.11a
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    • pp.769-772
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    • 2000
  • Fish oil has abundant highlly unsaturated fatty acids such as EPA and DHA. Therefore, fish oil is very susceptible to peroxidation. Adding any antioxidants to fish oil is acceptable to prevent the peroxidation. However, nontoxic and strong naturally occurring antioxidants for fish oil was not developed. ${\alpha}-tocopherol$ is one of useful natural antioxidants, but it is not good to prevent the fish oil peroxidation. In this study, we examined the development of microencapsulated squid liver oil product to prevent effectively peroxidation of the fish oil. The acceptable materials for encapsuling the squid liver oil were gum arabic and gelatin. The ultimate encapsulation rate of squid liver oil was 45.5%.

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Plant Protein Improvement by Synthetic Gene (합성유전자를 이용한 식물단백질의 향상)

  • 김태금;양문식
    • KSBB Journal
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    • v.7 no.3
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    • pp.155-160
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    • 1992
  • To improve the nutritional quality of plant proteins, a synthetic gene, called HEAAE (high essential amino acid encoding)-DNA, was introduced and expressed in tobacco plants. The synthetic gene, which is 292 basepair-long, codes for a protein composed of about 80% essential amino acids. To improve its expression level in plants, Cauliflower Mosaic Virus (CaMV) 355 and CaMV duplicate 35S promoters which are known as strong promoters were used with Nopaline Synthase promoter as a control. Transformed and regenerated tobacco plants were subject to analysis for introduction and expression of this gene. Integration of the gene into the plant genome and its expression into mRNAs and its proteins have been demonstrated using Southern, northern blot analysis and amino acid analysis. The differences of expression levels among CaMV duplicate 35S, CaMV 35S and Nopaline Synthase promoters are significant in term of mRNAs, but not in terms of proteins.

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Review on Changes in Surface Properties and Performance of Polyamide Membranes when Exposed to Acidic Solutions (산성용액 노출 시 폴리아마이드 분리막의 표면성질 및 투과성능 변화에 관한 총설)

  • Lee, Hyung Kae;Dao, Huyen Thi Thanh;Kang, Wooseok;Kwon, Young-Nam
    • Membrane Journal
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    • v.30 no.5
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    • pp.283-292
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    • 2020
  • Various kind of solutions need to be separated, purified, and concentrated using membranes in the field of industries. However, when the solution contains strong acids, the use of membrane is limited. Acid resistant membrane currently available in market does not show high efficiency of flux. This review explains the causes and mechanisms of changes in surface properties and performance of polyamide membranes when exposed to acidic solutions, and this can be used in the development of a membrane with acid resistance and high flux.

Heterologous Expression of Novel Cytochrome P450 Hydroxylase Genes from Sebekia benihana

  • Park Nam-Sil;Park Hyun-Joo;Han Kyu-Boem;Kim Eung-Soo
    • Journal of Microbiology and Biotechnology
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    • v.16 no.2
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    • pp.295-298
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    • 2006
  • Actinomycetes are ubiquitous Gram-positive soil bacteria and a group of the most important industrial microorganisms for the biosynthesis of many valuable secondary metabolites as well as the source of various bioconversion enzymes. Cytochrome P450 hydroxylase (CYP), a hemebinding protein, is known to be involved in the modification of various natural compounds, including polyketides, fatty acids, steroids, and some aromatic compounds. Previously, six different novel CYP genes were isolated from a rare actinomycetes called Sebekia benihana, and they were completely sequenced, revealing significant amino acid similarities to previously known CYP genes involved in Streptomyces secondary metabolism. In the present study, these six CYP genes were functionally expressed in Streptomyces lividans, using an $ermE^{*}$ promoter-containing Streptomyces expression vector. Among six CYP genes, two S. benihana CYP genes (CYP503 and CYP504) showed strong hydroxylation activities toward 7-ethoxycoumarin. Furthermore, the recombinant S. lividans containing both the S. benihana CYP506-ferredoxin genes as well as the S. coelicolor feredoxin reductase gene also demonstrated cyclosporin A hydroxylation activity, suggesting potential application of actinomycetes CYPs for the biocatalysts of natural product bioconversion.

Bio-functions of Marine Carotenoids

  • Hosokawa, Masashi;Okada, Tomoko;Mikami, Nana;Konishi, Izumi;Miyashita, Kazuo
    • Food Science and Biotechnology
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    • v.18 no.1
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    • pp.1-11
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    • 2009
  • Carotenoids being most important pigments among those occurring in nature, have received increased interest owing to their beneficial effects on human health. An effort is made to review marine carotenoids as important bioactive compounds with reference to their presence, chemical, and biofunctional benefits they afford. The potential beneficial effects of marine carotenoids were particularly focused on astaxanthin and fucoxanthin, major marine carotenoids found in marine animals and aquatic plants, respectively. Both carotenoids show strong antioxidant activity which is attributed to quenching singlet oxygen and scavenging free radicals. The potential role of the carotenoids as dietary antioxidants has been suggested as being one of the main mechanism by which they afford their beneficial health effects such as anticancer activity and anti-inflammatory effect. Only recently, antiobesity effect and antidiabetic effect have been noted as specific and novel bio-functions of fucoxanthin. Nutrigenomic study reveals that fucoxanthin induces uncoupling protein 1 (UCP1) expression in white adipose tissue (WAT) mitochondria to lead to oxidation of fatty acids and heat production in WAT. Fucoxanthin improves insulin resistance and decreases blood glucose level, at least in part, through the down-regulation of tumor necrosis factor $\alpha$ ($TNF{\alpha}$) in WAT of animals.

Comparison of Promoters Suitable for Regulated Overexpression of $\beta$-Galactosidase in the Alkane-Utilizing Yeast Yarrowia lipolytica

  • Thomas Juretzek;Hui-Jie wang;Nicaud, Jean-Marc;Stephan Mauersberger;Gerold Barth
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.5
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    • pp.320-326
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    • 2000
  • Promoters of the genes G3P, ICL1, POT1, POX1, POX2 and POX5 of the yeast Y. lipolytica were studied in respect to their regulations and activities during growth on different carbon sources. The aim of this study was to select suitable promoters for high expression of heterologous genes in this yeast. For this purpose the promoters were fused with the reporter gene lacZ of E. coli and integrated as single copies into the genome of Y. lipolytica strain PO1d. The measurement of expressed activities of ${\beta}$-galactosidase revealed that pICL1, pPOX2 and pPOT1 are the strongest regulable promoters available for Y. lipolytica, at present. pPOX2 and pPOT1 were highly induced during growth on oleic acid and were completely repressed by glucose and glycerol. pICL1 was strongly inducible by ethanol besides alkanes and fatty acids, however, not completely repressible by glucose or glycerol. Ricinoleic acid methyl ester appeared as a very strong inducer for pPOT1 and pPOX2, in spite of that it inhibited growth of Y. lipolytica transformants.

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Isolation and Identification of Antagonistic Bacteria for Biological Control of Ginger Rhizome Rot Caused by Pythium zingiberum

  • Lee, Du-Ku;Shim, Jai-Sung;Shim, Hyeong-Kwon;Lee, Yong-Hoon;Lee, Wang-Hyu
    • Plant Resources
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    • v.2 no.2
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    • pp.81-87
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    • 1999
  • Sixteen isolates showing relatively strong antagonicity against the ginger rhizome rot pathogen, Pythium zingiberum, were selected among the 155 isolates from ginger rhizome surfaces and rhizospheres of ginger cultivation fields in Wanju, Chonbuk. The isolate, 'HB 26-5'showing the strongest antagonicity was finally selected by testing duration of inhibition effect and pathogenicity to ginger. The isolated antagonistic microorganism, 'HB 26-5' was rod shape, gram positive and formed endospore. The isolate produced acids utilizing glucose, arabinose, xylose and mannitol, and acetoin at VP test, and grew anaerobically. Temperature range for growth was from 10 to 4$0^{\circ}C$ . Reaction to catalase and gelatin, hydrolysis were positive, and casein hydrolysis and indol production were negative. Based on the mycological characters and the fatty acid composition, it was identified as Bacillus polymyxa. The pathogenicity test of isolated Bacillus polymyxa 'HB 26-5'on 22 crop cultivars resulted that only the lettuce was influenced in germination, and the others were not affected.

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Antioxidant Activities of Various Berries Ethanolic Extract (베리류 에탄올 추출물의 항산화 활성)

  • Li, Hua;Jeong, Jong Moon
    • Korean Journal of Medicinal Crop Science
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    • v.23 no.1
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    • pp.49-56
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    • 2015
  • Edible berries are rich in anthocyanins and phenolic acids, compounds that possess antioxidant, anti-inflammatory, and other biological activities. Antioxidant and anti-inflammatory activities of five berries including acaiberry (Euterpe oleracea Mart.), Aronia/black chokeberry (Aronia melanocarpa), blueberry (Vaccinium angustifolium), black currant (Ribes nigrum L.), and cranberry (Vaccinium macrocarpon) were assessed. The Aronia G (prepared by GreenField s.c.) exhibited the highest antioxidant activities as shown in total phenolic (138.81 mg CAE/g), flavonoid (3.68 mg QE/g), and anthocyanin (20.31 mg/g) contents compared to the other berries. It also showed the strongest scavenging activities such as DPPH (69.69 mg vitamin C/g) and ABTS radical scavenging activity ($757.79{\mu}mol$ trolox/g). Aronia G exhibited strong ferric reducing antioxidant power ($553.98{\mu}mol$ vitamin C/g), and oxygen radical absorbance capacity ($820.92{\mu}mol$ trolox/g). In addition, black currant and Aronia showed stronger inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cell than the other berries. According to the above results, the Aronia and other edible berries have notably high level of antioxidant activities and they could be used as a potential source of natural antioxidants.