• 제목/요약/키워드: Conformation

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Molecular Dynamics Simulation of Enantioselectivity in Metoprolol in complex

  • Jang, Seok-Young;Park, Kyung-Lae
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.356.3-357
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    • 2002
  • Metoprolol (MT) is one kinds of adrenergic beta-blockers. Its (S)-enantiomer is known to be more active than the (R). Recently. the x-ray structure of beta-blocker. (S)-propranolol (a-naphthyl analogue), complexed in a mould fungal cellulase. Cel7A. was reported and the (R)-form did not build any complex. And in our previous study the conformation and stability of MT in carboxymethylated beta-cyclodextrin (BCD) complex was determined by NMR. HPLC, UV and electrophoresis measurement. (omitted)

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Importance of Cytochrome P450 3A4 Conformation for the Activity Stimulation by Cytochrome b5 : Specific Inhibition of Cytochrome P450 3A4 by Zinc (II) Ion

  • Kim, Joon-Sik;Yun, Chul-Ho
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.149.3-150
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    • 2003
  • CYP3A4 is the most abundant human CYP and oxidizes a diversity of substrates. including various drugs. steroids. and carcinogens. A variety of metal ions are known to affect microsomal monooxygenase activities. Effects of a series of divalent metal ions on the CYP3A4-catalyzed reaction of reconstituted system containing purified CYP3A4. NADPH-P450 reductase (NPR), and cytochrome b5 (b5) were examined. (omitted)

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The Chiroptical Properties and Absolute Configuration of 28-nor-$\beta$-amyrins

  • Woo, Won-Sick
    • Archives of Pharmacal Research
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    • v.14 no.2
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    • pp.160-164
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    • 1991
  • The existence in nature of two isomers of 28-nortriterpenes is known. One is normal D/E cis form and the other is $17\alpha$-hydrogen D/E trans form. Since the latter cannot exist with ring D in the chair conformation, the chiroptical method is not applicable to determination of the absolute configuration. The stereochemical assignment would now be made by NMR data. Confirmation of this view could be provided by the synthesis of $3\beta, 21\beta-{dihydroxy-16-keto-28-nor-17}\alpha, \;18\beta-{olean-12-ene}$ as a model compound.

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NMR Techniques for the Structure Elucidation and Conformational Analysis of Natural Products

  • Cordell, Geoffrey A.
    • Korean Journal of Pharmacognosy
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    • v.19 no.3
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    • pp.153-169
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    • 1988
  • The combined use of the J-modulated selective INEPT and CSCM 1DNMR techniques is described for the structure elucidation of several new classes of compound including prionitin, the loureirins and larreantin, and for the regiosubstitution of the furanonaphthoquinones. Spectroscopic studies on the conformation of the cytotoxic agent savinin are also described, together with the NMR assignments and preliminary biosynthetic experiments on the antitumor antibiotic staurosporine.

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N-Anthracenylmethyl Calix[4]azacrowns as New Fluorescent Ionophores

  • Yang, Seung-H.;Shon, Ok-J.;Park, Ki-M.;Lee, Shim-S.;Park, Ho-J.;Kim, Moon-J.;Lee, Joung-H.;Kim, Jong-S.
    • Bulletin of the Korean Chemical Society
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    • v.23 no.11
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    • pp.1585-1589
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    • 2002
  • Two novel calixarene-based fluoroionophores were synthesized. Their conformations were confirmed to 1,3-alternate by X-ray crystal structures. From CHEF by blocking the PET mechanism in fluorescence spectra, we observed $In^{3+}$ and $Pb^{2+}$ selectivity over other metal ions. For $In^{3+}$ion, calix[4]-bis-azacrown-5 showed about 20 times more sensitive than calix[4]-mono-azacrown-5 because the source of the binding selectivity comes from the calixarene framework and azacrown ligand by controlling the fluorescence and PET mechanisms as-sociated with the amine moiety.

Stereospecific Synthesis of Methyl-6-deoxy-$\beta$-L-idopyranoside (Methyl-6-deoxy-$\beta$-L-idopyranoside의 합성)

  • 민신홍;박복구;옥광대
    • YAKHAK HOEJI
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    • v.30 no.6
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    • pp.352-355
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    • 1986
  • Methyl-6-deoxy-$\beta$-L-idopyranoside was prepared in good yield by treatment of methyl 2,3,4-tri-O-benzyl-6-deoxy-$\alpha$-D-xylo-hex-5-enopyranoside with H$_2$ on pd, followed by reaction of Na/NH$_3$ at $-50^{\circ}C$. The ratio of L-idopyranoside and D-glucopyranoside was 7 to 1 in 80.7%. It was confirmed that L-idopyranoside was 1C conformation as being expected.

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PHYSICAL PROPERTIES OF HIGHLY-ORIENTED POLYVINYLALCOHOL FIBER

  • Kim Byeong-Cheol;Im Seung-Sun;Kim Seung-Gyu;Han Jeong-Ryeon
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.10a
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    • pp.223-226
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    • 1998
  • Polyvinylalcohol (PVA) is a crystalline polymer, capable of hydrogen bonding, which makes the polymer useful for many industrial applications. production of high strength fibers, medical substitutes, adhesives, and so on[1], Specially, among fiber-forming polymers, PVA has the second highest crystal modulus and extreme strength after polyethylene because the polymer chain can take a planar zig-zag conformation. (omitted)

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