• Title/Summary/Keyword: $\beta$-Conjugate addition

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Optimum Conversion to the Aglycone Form Using $\beta$-glucosidase and Isoflavone Extraction from Soybean (대두로부터 Isoflavone추출 및 $\beta$-glucosidase를 이용한 Aglycone 형태로의 전환 최적 조건)

  • 김기욱;전병수
    • KSBB Journal
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    • v.16 no.2
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    • pp.174-178
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    • 2001
  • Soybeans contain the phytoestrogens genistein and daidzein, their glucosides genistin and daidzin and coumesterol. These isoflavonoid compounds are capable of producing an estrogenic response in a number of diverse species. This study determined optimum conditions for the extraction of the main isoflavones(daidzin, genistin, daidzein, genistein) in defatted soybean meal using high-performance liquid chromatography. The best optimum extraction was achieved at 75% ethanol, $80^{circ}C$, pH4 and a three hour contact time. In addition, isoflavones with high purity were separated by adding up to 4%(w/v) of calcium chloride dihydrate. Most soybean extracts were composed of $beta$-glucosidic conjugate(daidzin, genistin) which is difficult to adsorb in body. Therefore, $beta$-glucosidase was used to convert as conjugate to aglycone form (daidzein, genistein) which is easy to adsorb. The optimal conditions of enzyme reaction involved to be 8.4 units of enzyme concentration, pH5.0, $40^{circ}C$ and 40 minutes.

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Facile Regiocontrolled Three-Step Synthesis of Poly-Substituted Furans, Pyrroles, and Thiophenes: Consecutive Michael Addition of Methyl Cyanoacetate to α,β-Enone, CuI-Mediated Aerobic Oxidation, and Acid-Catalyzed Paal-Knorr Synthesis

  • Kim, Se-Hee;Lim, Jin-Woo;Lim, Cheol-Hee;Kim, Jae-Nyoung
    • Bulletin of the Korean Chemical Society
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    • v.33 no.2
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    • pp.620-624
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    • 2012
  • An efficient synthesis of poly-substituted furans, pyrroles, and thiophenes was carried out in a regiocontrolled manner via a three-step process; (i) conjugate addition of methyl cyanoacetate derivatives to ${\alpha}$,${\beta}$-enones, (ii) CuI-mediated aerobic oxidation, and (iii) Paal-Knorr type synthesis of five-membered heterocycles.

Regioselective Addition Reactions of the Organoindium Reagents onto α,β-Unsaturated Ketones

  • Lee, Phil-Ho;Kim, Hyun;Lee, Koo-Yeon;Seomoon, Dong;Kim, Sun-Dae;Kim, Hee-Chul;Kim, Hyun-Seok;Lee, Mi-Ae;Shim, Eun-Kyong;Lee, Seok-Ju;Kim, Mi-Sook;Han, Mi-Jeong;Noh, Kwang-Hyun;Sridhar, Madabhushi
    • Bulletin of the Korean Chemical Society
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    • v.25 no.11
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    • pp.1687-1691
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    • 2004
  • Regioselectivity on the reactions of ${\alpha},{\beta}$--enones with organoindium such as in situ generated allylindium and allenylindium was systematically studied in the presence of TMSCl as an additive. Treatment of 2-cyclohexen-1-one, carvone, 2-cyclohepten-1-one, and chalcone with allylindium reagent produced 1,4-addition products in good yields, while 2-cyclopenten-1-one, 2-methyl-2-cyclopenten-1-one, 4,4-dimethylcyclohexen-1-one, 3-nonen-2-one, 4-hexen-3-one, and 4-phenyl-3-buten-2-one afforded 1,2-addition products. Indium reagent derived from indium and propargyl bromide in Grignard type gave addition products in good yields, under which the successive addition of ${\alpha},{\beta}$-enone and TMSCl were necessary. Although organoindium reagent derived from propargyl bromide produced propargylated compound in Grignard type except 2-cyclohepten-1-one, indium reagent obtained from 1-bromo-2-butyne having ${\gamma}$-methyl group gave allenylated product inBarbier type.

Fluorine Labeling in Biosynthetic Studies (I) : Synthesis of Fluorfarnesols

  • Park, O-Sook
    • Archives of Pharmacal Research
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    • v.9 no.4
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    • pp.237-242
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    • 1986
  • The Synthesis of E, E, E-12-fluorofarnesol and E, Z-6-fluorofarnesol which are key intermediates for the study of biosynthesis of some sesquiterpenes, is described. E, E-Farnesyl acetate is treated with selenium dioxide to give E, E, E-12-hydroxy farnesyl acetate, whih is transformed by DAST into E, E, E-12-hydroxy farnesyl acetate, which is transformed by DAST into E, E, E,-12-fluorofarnesylacetate. The latter compound is hydrolyzed to E, E, E,-12-fluorofarnesol. The reformatsky reaction of 6-methyl-5-hepten-2-one with ethyl bromofluoroacetate affords ethyl 2-fluoro-3-hydroxy-3, 7 dimethyl-6-octanoate. This ester is acetylated and eliminated to give ethyl (Z)-2-fluoro-3, 7-dimethylocta-2, 6-dienoate, which is transformed to allyl bromide via allylic alcohol. The allyl bromide is treated with dianion of methyl acetate to give-keto ester. The $\beta$-keto ester is converted to diethyl phosphoryloxy compound. The conjugate addition of lithium dimethylcuprate to the latter compound gives fluoro ester, which is treated with DIBAL to afford E, Z-6-fluorofarnesol.

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Effect of Amine Nature on Rates and Mechanism: Pyridinolyses of 4-Nitrophenyl Benzoate

  • Um, Ik-Hwan;Baek, Mi-Hwa;Han, Hyun-Joo
    • Bulletin of the Korean Chemical Society
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    • v.24 no.9
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    • pp.1245-1250
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    • 2003
  • Pseudo-first-order rate constants ($k_{obs}$) have been measured spectrophotometrically for the reactions of 4-nitrophenyl benzoate with a series of pyridines in $H_2O$ containing 20 mol % DMSO. The plots of kobs vs pyridine concentration are linear up to ca. 0.1 M pyridines, indicating that the effect of self-association of pyridines with their conjugate acids are insignificant in this concentration range. The Bronsted-type plot has been obtained to be linear with a ${\beta}_{nuc}$ value 1.11, suggesting that the pyridinolyses proceed through a rate-determining breakdown of the zwiterionic addition intermediate. The pyridines studied have shown higher reactivity than isobasic primary and secondary amines toward the substrate. 1-Benzoyl-4-dimethylaminopyridinium ion, a possible intermediate, has not been detected since the rate of its hydrolysis in the reaction condition is comparable with or even faster than its formation.

Lewis Acid-Catalyzed Reactions of Anthrone: Preference for Cycloaddition Reaction over Conjugate Addition Depending on the Functionality of α,β-Unsaturated Carbonyl Compounds

  • Baik, Woon-Phil;Yoon, Cheol-Hoon;Koo, Sang-Ho;Kim, Ha-Kwon;Kim, Ji-Han;Kim, Jeong-Ryul;Hong, Soo-Dong
    • Bulletin of the Korean Chemical Society
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    • v.25 no.4
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    • pp.491-500
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    • 2004
  • The Lewis acid-catalyzed reactions of anthrone with a variety of ethylenic substrates under various conditions have been studied. It has been observed that depending on kinds of ethylenic substrates and catalysts, products were varied. In particular, the $ZnCl_2$-catalyzed reaction of anthrone with ${\alpha},{\beta}$ -unsaturated ester gave bridged compounds 3 (Diels-Alder adduct type) and mono-Michael adduct 4 exclusively, while the base-catalyzed reaction gave 10,10-bis-Michael adduct as a major product independent of the amount of ethylenic substrate and base. Bridged compounds 3 were easily converted to the corresponding mono-Michael adduct 4 by a catalytic amount of base. Further Michael reaction of mono-Michael adducts with different ethylenic substrates in the presence of a catalytic amount of alkoxide gave unsymmetrical 10,10-bis Michael adducts in good or moderate yields.

Enhanced antidiabetic efficacy and safety of compound K/β-cyclodextrin inclusion complex in zebrafish

  • Nam, Youn Hee;Le, Hoa Thi;Rodriguez, Isabel;Kim, Eun Young;Kim, Keonwoo;Jeong, Seo Yule;Woo, Sang Ho;Lee, Yeong Ro;Castaneda, Rodrigo;Hong, Jineui;Ji, Min Gun;Kim, Ung-Jin;Hong, Bin Na;Kim, Tae Woo;Kang, Tong Ho
    • Journal of Ginseng Research
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    • v.41 no.1
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    • pp.103-112
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    • 2017
  • Background: 20(S)-Protopanaxadiol 20-O-D-glucopyranoside, also called compound K (CK), exerts antidiabetic effects that are mediated by insulin secretion through adenosine triphosphate (ATP)-sensitive potassium ($K_{ATP}$) channels in pancreatic ${\beta}$-cells. However, the antidiabetic effects of CK may be limited because of its low bioavailability. Methods: In this study, we aimed to enhance the antidiabetic activity and lower the toxicity of CK by including it with ${\beta}$-cyclodextrin (CD) (CD-CK), and to determine whether the CD-CK compound enhanced pancreatic islet recovery, compared to CK alone, in an alloxan-induced diabetic zebrafish model. Furthermore, we confirmed the toxicity of CD-CK relative to CK alone by morphological changes, mitochondrial damage, and TdT-UTP nick end labeling (TUNEL) assays, and determined the ratio between the toxic and therapeutic dose for both compounds to verify the relative safety of CK and CD-CK. Results: The CD-CK conjugate ($EC_{50}=2.158{\mu}M$) enhanced the recovery of pancreatic islets, compared to CK alone ($EC_{50}=7.221{\mu}M$), as assessed in alloxan-induced diabetic zebrafish larvae. In addition, CD-CK ($LC_{50} =20.68{\mu}M$) was less toxic than CK alone ($LC_{50}=14.24{\mu}M$). The therapeutic index of CK and CD-CK was 1.98 and 9.58, respectively. Conclusion: The CD-CK inclusion complex enhanced the recovery of damaged pancreatic islets in diabetic zebrafish. The CD-CK inclusion complex has potential as an effective antidiabetic efficacy with lower toxicity.

Establishment for Improving Productivity of Cattle by Fecal Steroid and Milk Urea Nitrogen Analysis - I. Development of Enzyme-linked Immunosorbent Assay for Progesterone and Milk Urea Nitrogen Analysis in Cattle

  • Chung-Boo Kang;Woo-Song Ha;Ji-In Kwon;Young-Sang Yu;Chul-Ho Kim;Soo-Dong Kwak
    • Biomedical Science Letters
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    • v.8 no.4
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    • pp.235-244
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    • 2002
  • This study was carried out to determine the blood and milk progesterone by enzyme-linked immunosorbent assay (ELISA), and milk urea nitrogen (MUN) in cows. MUN and protein concentration were determined using automated infared procedures. The optimum conditions of ELISA system was investigated including the first and second antibody titres, bound percent, and enzyme conjugate and also the factors on MUN and protein concentration by sampling procedures and addition of preservatives. Progesterone antibodies did not react to pregnenlone, testosterone, estrone, estradiol-l7$\beta$, aldosterone, cortisol, corticosterone and 11$\alpha$-dehydroxycortisone (DOC), but reacted with only progesterone. The intra and inter-assay coefficient of variation 4.5%, 6.1~9.4% when used of bovine serum. The morning, MUN concentration (17.6$\pm$2.8 mg/100 ml) in the 13 herds was similar to that of evening MUN concentration of the lactating cows from the same herd. A significant relationship between morning and evening milk samples of upper parameters was found r=0.93. Difference in MUN concentration with sampling procedures and using of preservatives were investigated.

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Mechanism on the Hydrolysis of Cinnamonitrile in Strong Acid (强酸性 溶液中에서 Cinnamonitrile의 加水分解 反應메카니즘)

  • Ki-Sung Kwon;Nack-Do Sung;Tae-Rin Kim;Jeon, Yong Gu
    • Journal of the Korean Chemical Society
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    • v.28 no.6
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    • pp.418-424
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    • 1984
  • Rate constants for the hydrolysis of cinnamonitrile in the concentration range of 1 ∼ 5M of perchloric acid at 25$^{\circ}$C have been determined by UV spectrophotometry and from the Bunnett equations, hydration parameters (${\omega}$ = 9.8, ${\omega}^*$ = 0.42 & ${\phi}$=1.6) were obtained. CNDO/2 MO calculations were performed to determine relative stability, net charges, and overlap population of various conformational isomers. The results show that the (E)-planar is more stable than the (Z)-planar and protonation is favored on the nitrogen atom. On the basis of above findings, the acid hydrolysis is initiated by the protonation of the nitrogen atom of cinnamonitrile and then water molecule acting as nucleophile and as a proton transfer agent in the rate determining step. In the transition state of the acid hydrolysis, nucleophilic addition of water molecule occurs by sigma approach to the positively charged $C_7({\alpha}$) atom of the conjugate acid. As the results, we may conclude that the hydrolysis of cinnamonitrile in the strong acidic media proceeds through the A-2 type mechanism.

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Stereoselective Synthesis of Novel Bestatin Analogs (새로운 베스타틴 유사체의 입체선택적 합성)

  • Seo, Youngran;Lee, SooBeom;Kim, Young Gyu
    • Applied Chemistry for Engineering
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    • v.26 no.1
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    • pp.111-115
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    • 2015
  • Two new analogs of bestatin were prepared from $\small{D}$-leucine and $\small{D}$-valine in a stereoselective and efficient way. An aminopeptidase inhibitor bestatin shows significant biological effects on immunomodulation and is marketed for the treatment of acute myelocytic leukemia. The key intermediates, trans-oxazolidine methyl esters 2a and 2b, were obtained with more than 20 to 1 stereoselectivity in a one-pot procedure by the three cascade reactions between N-hydroxymethyl protected ${\alpha}$-amino aldehydes (4a and 4b) and phenylsulfonylnitromethane ($PhSO_2CH_2NO_2$) and the following in-situ ozonolysis. Basic hydrolysis of 2a and 2b, and then the peptide coupling with $\small{L}$-Leu-OMe produced the protected derivatives of two new bestatin analogs, 3a and 3b, respectively. The new isobutyl and isopropyl analogs of bestatin (1a and 1b) were produced in overall 51% and 38% yields, respectively, with high stereoselectivity from the corresponding protected ${\alpha}$-amino aldehydes 4 in a six-step process.