• Title/Summary/Keyword: COSY NMR spectroscopy

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Alkyl Glycosides from the Flowers of Magnolia obovata (황목련 꽃으로부터 Alkyl Glycoside의 분리 동정)

  • Oh, Eun-Ji;Seo, Kyeong-Hwa;Kwon, Jung-Hwa;Lee, Dae-Young;Baek, Nam-In
    • Journal of Applied Biological Chemistry
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    • v.58 no.3
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    • pp.233-236
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    • 2015
  • The flowers of Magnolia obovata were extracted with aqueous MeOH and fractionated into EtOAc, n-BuOH, and $H_2O$ fractination. Three alkyl glycosides were isolated from the EtOAc fraction through repeated silica gel and ODS column chromatography. The structures were identified to be 2-methylbutan-1-ol-${\beta}$-$\small{D}$-galacto-pyranoside (1), 2-methylbutan-1-ol-${\beta}$-$\small{D}$-glucopyranoside (2), and 2-methylpropan-1-ol-${\beta}$-$\small{D}$-glucopyranoside (3) on the basis of spectroscopic analyses such as fast atom bombardment mass spectrometry, infrared spectroscopy, 1D nuclear magnetic resonance (NMR) ($^1H$ and $^{13}C-NMR$), and 2D NMR (gCOSY, gHSQC, and gHMBC). These compounds were isolated for the first time from the flower of M. obovata in this study.

Isolation of Flavonoids and Lignans from the Stem Wood of Lindera obtusiloba Blume (생강나무(Lindera obtusiloba Blume) 목부로부터 Flavonoid 및 Lignan 화합물의 분리)

  • Seo, Kyeong-Hwa;Baek, Mi-Young;Lee, Dae-Young;Cho, Jin-Gyeong;Kang, Hee-Cheol;Ahn, Eun-Mi;Baek, Nam-In;Lee, Youn-Hyung
    • Journal of Applied Biological Chemistry
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    • v.54 no.3
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    • pp.178-183
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    • 2011
  • The stem woods of Lindera obtusiloba Blume were extracted in 80% aqueous methanol and the concentrated extract was partitioned with ethyl acetate (EtOAc), butanol (n-BuOH), and $H_2O$, successively. From the EtOAc and n-BuOH fractions, five compounds were isolated through the repeated silica gel, octadecyl silica gel, and Sephadex LH-20 column chromatographies. On the basis of spectroscopic data including mass spectrometry, IR, $^1H$-NMR, $^{13}C$-NMR, distortionless enhancement by polarization transfer, and two-dimensional-NMR gradient correlated spectroscopy (gCOSY), gradient heteronuclear single quantum correlation (gHSQC), gradient heteronuclear multiple bonding connectivity (gHMBC), the chemical structures of the compounds were determined as asarinin (1), (+)-catechin (2), (-)-epicatechin (3), hyperin (4), and nudiposide (5). Compounds 1 and 5 were isolated for the first time from the stem wood of L. obtusiloba Blume.