• Title/Summary/Keyword: Geometrical isomer

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Phytochemical Studies on Paeoniae Radix (4);Cerebrosides and Other Constituents

  • Kim, Yoon-Jung;Yean, Min-Hye;Lee, Eun-Ju;Kim, Ju-Sun;Lee, Je-Hyun;Kang, Sam-Sik
    • Natural Product Sciences
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    • v.14 no.3
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    • pp.161-166
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    • 2008
  • A mixture of sixteen cerebrosides, which comprised four cerebroside molecular species (PL-1 ${\sim}$ PL-4) was separated from the roots of Paeonia lactiflora. The structures of cerebrosides were characterized as $1-O-{\beta}$-D-glucopyranosides of phytosphingosines, which comprised a common long-chain base, (2S,3S,4R,8E/Z)-2-amino-8-octadecene-1,3,4-triol with eight fatty acids or 2-hydroxy fatty acids of varying chain lengths ($C_{16}$, $C_{18}$, $C_{20-26}$) linked to the amino group. Aralia cerebroside and its 8Z isomer (PL-1), $1-O-{\beta}$-D-glucopyranosyl-(2S,3S, 4R,8E/Z)-2-[(2'R)-2'-hydroxytetracosanoylamino]-8-octadecene-1,3,4-triol (PL-2), $1-O-{\beta}$-D-glucopyranosyl-(2S,3S,4R, 8E/Z)-2-[(2'R)-2'-hydroxydocosanoylamino]-8-octadecene-1,3,4-triol (PL-3), and $1-O-{\beta}$-D-glucopyranosyl-(2S,3S,4R, 8E/Z)-2-[(2'R)-2'-hydroxytricosanoylamino]-8-octadecene-1,3,4-triol (PL-4) were identified as major components of these cerebroside molecular species. All the major cerebrosides were shown to be a mixture of geometrical isomers (8E and 8Z) of phytosphingosine-type glucocerebrosides possessing 2R-hydroxy fatty acids. In addition, three ${\beta}-sitosterol$ derivatives and adenosine were also separated. The structures of these isolates have been determined on the basis of chemical and spectroscopic evidence.

Stereospecific Reaction of S,S-prodien(= 1,9-bis(S)-prolyl-1,9-dioxo-2,5,8-triazanonane) (Ⅰ); Synthesis of ${\wedge}-{\alpha}{\beta}$(ffm)-[Co(S,S-prodien)$H_2O$]$ClO_4$ (S,S-prodien(=1,9-bis(S)-prolyl-1,9-dioxo-2,5,8-triazanonane)의 입체특이성 반응(I); ${\wedge}-{\alpha}{\beta}$(ffm)-[Co(S,S-prodien)$H_2O$]$ClO_4$의 합성)

  • Lee, Bae Wook;Kim, Jin Woo;Lee, Dong Jin;Kim, Bong Gon;Oh, Chang Eon;Doh, Myung Ki
    • Journal of the Korean Chemical Society
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    • v.41 no.9
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    • pp.465-470
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    • 1997
  • A chiral pentadentate ligand, 1,9-bis(S)-prolyl-1,9-dioxo-2,5,8-triaza-nonane, (S,S-prochen) which shows the stereospecific reaction was synthesized from the reaction of S-proline and diethylenetriamine (dien). The red-violet $[Co(SS-prodien)H_2O]ClO_4$ was prepared by the oxidation of the aqueous solution dissolving $CoCl_2{\cdot}6H_2O$ and S,S-prodien. Elemental analysis, electronic absorption spectroscopy, and $^{13}C-NMR$ spectroscopy suggest that the geometrical structure of the Co(III) complex to be an ${\alpha}{\beta}$ (ffm) form, where the dien moiety of the ligand chelates the metal center to comprise a facial isomer, and an aqua ligand coordinates a cis site to the secondary nitrogens of the dien. Based upon the CD spectroscopic analysis, it seems that the absolute configuration of the ${\alpha}{\beta}$(ffm)-$[Co(SS-prodien)H_2O]ClO_4$ has the ${\Lambda}$-form.

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