• 제목/요약/키워드: ${\beta}$-product

검색결과 855건 처리시간 0.028초

Flavanone Glycoside from the Fruits of Chaenomeles sinensis

  • Kim, Ho-Kyoung;Jeon, Won-Kyung;Ko, Byoung-Seob
    • Natural Product Sciences
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    • 제6권2호
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    • pp.79-81
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    • 2000
  • Investigation of the fruits of Chaenomeles sinensis (Rosaceae) resulted in the isolation of a minor flavonoid. The structure of flavanone glycoside was determined to be as $2-hydroxynaringenin-7-O-{\beta}-glucoside$ on the basis of FAB-MS and spectral evidence, especially by 2D-NMR $(^1H-^1H\;COSY,\;HMQC,\;HMBC\;and\;NOESY)$.

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Chlorosmaridione; A Novel Chlorinated Diterpene Quinone Methide from Rosemarinus officinalis L.

  • El-Lakany, Abdalla M.
    • Natural Product Sciences
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    • 제10권2호
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    • pp.59-62
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    • 2004
  • A novel chlorinated diterpene quinone methide; chlorosmaridione (7-chloro-11-hydroxy-abeita-7,9(11),13-triene-6,12-diode) was isolated from petroleum ether extract of the stems of Rosemarinus officinalis L. growing in Egypt. In addition, ${\beta}-sitosterol$, stigmasterol, lupeol acetate, ${\alpha}-amyrin,\;{\beta}-amyrin$, lupeol, acetyloleanolic acid, acetylursolic acid taxodione, horminone, and cryptotanshinone were also identified. Chemical structures of the isolated compounds have been elucidated on the bases of physical, chemical, and spectral data including IR, UV, MS, 1D-and 2D-NMR spectra.

Verticilloside, a New Daucosteryl Derivative from the Seeds of Malva verticillata

  • Kim, Jeong-Ah;Yang, Seo-Young;Kang, Sang-Jin;Kim, Young-Ho
    • Natural Product Sciences
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    • 제17권4호
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    • pp.350-353
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    • 2011
  • A new daucosteryl derivative, verticilloside (1), was isolated from the seeds of Malva verticillata L. (Malvaceae). The structure was determined to be 3-O-[${\beta}$-D-(6'-linoleoyl)glucopyranosyl]-${\beta}$-sitosterol based on spectroscopic analyses ($^1H$ and $^{13}C$-NMR, DEPT, COSY, HMQC, and HMBC) and chemical reactions.

Anti-inflammatory Activity of a Flavonol Glycoside from Tephrosia Spinosa

  • Chakradhar, V.;Babu, Y. Hari;Ganapaty, S.;Prasad, Y. Rajendra;Rao, N. Koteswara
    • Natural Product Sciences
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    • 제11권2호
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    • pp.63-66
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    • 2005
  • A rare flavonol glycoside identified as $eupalitin-3-O-{\beta}-D-glucoside$ (I) was isolated from Tephrosia spinosa (Leguminosae) and its anti-inflammatory activity was evaluated against carrageenin induced paw edema. The compound exhibited significant activity when compared to the standard drug indomethacin.

New Dimeric Phenolic Conjugates from the Wood of Tamarix tetragyna

  • Hussein, Sahar A.M.
    • Natural Product Sciences
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    • 제3권2호
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    • pp.127-134
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    • 1997
  • Two new dimeric phenolic conjugates, 2,3-di-O-dehydrodigallicmonocarboxyl-$({\alpha},{\beta})$-$^4C_1$-glucopyranose and ellagic acid 3,3'-dimethylether-4-0-$SO_3K$ were isolated from the debarked heart wood of Tamarix tetragyna (Tamaricaceae) along with the known phenolic compounds, isoferulic acid, ferulic acid, gallic acid, gallic acid 4-methyl ether, syringic acid, ellagic acid 3,3'-dimethyl ether and ellagic acid. All structures were determined mostly by ESI-MS, ID and 2D-NMR spectroscopy.

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A Study on the effect of product recommendation system on customer satisfaction: focused on the online shopping mall

  • CHO, Ba-Da;POTLURI, Rajasekhara Mouly;YOUN, Myoung-Kil
    • 산경연구논집
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    • 제11권2호
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    • pp.17-23
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    • 2020
  • Purpose: The purpose of this study is to understand the effect of the unique product recommendation system on customer satisfaction. Research design, data and methodology: The survey method used the self-recording way in which the respondents selected for the study and distributed 300 questionnaires, and with due personal care, researchers collected all the distributed questionnaires. Results: The result implies that the characteristics of the product recommendation system should be more secure and developed. Conclusions: The aspects of the product recommendation system were selected as factors of price fairness, accuracy, and quality through previous studies, and the empirical analysis of the effect of the characteristics of the product recommendation system on customer satisfaction was summarized as follows. Among the attributes of the product recommendation system, the attributes of price fairness, accuracy, and quality affect customer satisfaction. Among them, the beta value of quality was the highest, and the effect of quality was the largest among the three factors. Based on the results of the study, the implications for the characteristics of the product recommendation system are summarized as follows. The aspects of the product recommendation system have a positive effect on customer satisfaction, so it is necessary to fill the needs of consumers based on the survey focused on quality

Enzymatic Production of Galactooligosaccharide by Bullera singularis $\beta$-Galactosidase

  • SHIN, HYUN-JAE;JI-WON YANG
    • Journal of Microbiology and Biotechnology
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    • 제8권5호
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    • pp.484-489
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    • 1998
  • Galactooligosaccharides (GalOS) were efficiently produced by partially purified $\beta$-galactosidase from the yeast strain Bullera singularis ATCC 24193. Ammonium sulfate precipitation and ultrafiltration methods were used to prepare the enzyme. The enzyme activity decreased at $50^{\circ}C$ and above. A maximum yield of 40% (w/w) GalOS, corresponding to 120 g of GalOS per liter, was obtained from 300 g per liter of lactose solution at $45^{\circ}C$, pH 3.7 when the lactose conversion was 70%. The yield of GalOS did not increase with increasing initial lactose concentration but the total amounts of GalOS did. Volumetric productivity was 4.8 g of GalOS per liter per hour. During this reaction, the by-products, glucose and galactose, were found to inhibit GalOS formation. Reaction products were found to be comprised of disaccharides and trisaccharides according to TLC and HPLC analyses. We propose the structure of the major product, a trisaccharide, to be ο-$\beta$-D-galactopyranosyl-(l-4)-ο-$\beta$-D-galactopyranosyl-(l-4)-$\beta$-D-glucose (4'-galactosyl lactose).

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Enhancement of enzymatic activity of ${\beta}-cyclodextrin$ glucanotransferase from Bacillus firmus var. alkalophilus by site-directed mutagenesis

  • 이광우;신현동;이용현
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2001년도 추계학술발표대회
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    • pp.656-659
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    • 2001
  • Cyclodextrin glucanotransferase (CGTase) (EC 2.4.1.19) use starch to produce cyclic maltooligosaccharides (cyclodextrins, CDs) which are of interest in various applications. To obtain a novel CGTase having high CD-forming activity, ${\beta}-cyclodextrin$ glucanotransferase $({\beta}-CGTase)$ from Bacillus firmus var. alkalophilus was modified through site-directed mutagenesis and constructed five mutants, H59T, H59Q, Y96M, 9O-PPI-93, and ${\Delta}(148-154)D$, respectively. Y96M and ${\Delta}(148-154)D$ showed much higher level of conversion yields of starch into CDs from 28.6% to about 39% compared to wild-type ${\beta}-CGTase$, respectively, but 90-PPI-93 maintained similar convesion yields of starch to CDs. And their ${\beta}-CD$ ratios to total CDs were not changed and maintained, and convesion yields to linear maltooligosaccharides of all mutants were not changed significantly. These results indicates that five mutations of ${\beta}-CGTase$ from Bacillus firmus var. alkalophilus appears to be important roles for increase of overall CD production rather than change of its product specificity, especially.

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Enzymatic Characteristics of Biosynthesis and Degradation of Poly-$\beta$-hydroxybutyrate of Alcaligenes latus

  • Kim, Tae-Woo;Park, Jin-Seo;Lee, Yong-Hyun
    • Journal of Microbiology and Biotechnology
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    • 제6권6호
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    • pp.425-431
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    • 1996
  • The enzymatic characteristics of Alcaligenes latus were investigated by measuring the variations of various enzyme activities related to biosynthesis and degradation of poly-${\beta}$-hydroxybutyrate (PHB) during cultivation. All PHB biosynthetic enzymes, ${\beta}$-ketothiolase, acetoacetyl-CoA reductase, and PHB synthase, were activated gradually at the PHB accumulation stage, and the PHB synthase showed the highest value among three enzymes. This indicates that the rate of PHB biosynthesis is mainly controlled by either ${\beta}$-ketothiolase or acetoacetyl-CoA reductase rather than PHB synthase. The enzymatic activities related to the degradation of PHB were also measured, and the degradation of PHB was controlled by the activity of PHB depolymerase. The effect of supplements of metabolic regulators, citrate and tyrosine, was also investigated, and the activity of glucose-6-phosphate dehydrogenase was increased by metabolic regulators, especially by tyrosine. The activities of ${\beta}$-ketothiolase and acetoacetyl-CoA reductase were also activated by citrate and tyrosine, while the activity of PHB depolymerase was depressed. The increased rate and yield of PHB biosynthesis by metabolic regulators may be due to the increment of acetyl-CoA concentration either by the repression of the TCA cycle by citrate through product inhibition or by the activation of sucrose metabolism by the supplemented tyrosine.

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