• Natural Product Sciences
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• 제14권1호
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• pp.51-55
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• 2008

Three sesquiterpene-lignans, eudeshonokiol B (1), eudesobovatol B (2), and clovanemagnolol (3), were isolated from the stem bark of Magnolia obovata, together with magnolol (4), honokiol (5), and obovatol (6) on the basis of spectroscopic and physicochemical analyses including 2D NMR and Mass. Compounds 1 - 3 were belongs to a unique class of natural products made up of a sesquiterpene and biphenyl-type neolignan via an ether bond. All the isolated compounds were tested in vitro for their cytotoxic activity against the HeLa, A549, and HCTll6 cancer cell lines. Compounds 1 - 6 showed the cytotoxic activity against tested cancer cell lines, with $IC_{50}$ values ranging from 7.1 to 14.4 ${\mu}g/mL$.

• Natural Product Sciences
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• 제14권3호
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• pp.196-201
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• 2008

Five neolignans (1 - 4, 8), two sesquiterpene-lignans (5 - 6), and two phenylpropanoids (7, 9) were isolated from the stem bark of Magnolia obovata Thunberg (Magnoliaceae) by repeated column chromatography. The structures of isolated compounds were identified as 4-methoxyhonokiol (1), obovatol (2), magnolol (3), honokiol (4), eudeshonokiol B (5), eudesobovatol B (6), coumaric acid (7), magnaldehyde B (8), and ${\rho}-coumaric$ acid (9) on the basis of spectroscopic analysis including 2D-NMR and MS data. Compounds 1 - 9 were evaluated for their anti-complement activities against the classical pathway of the complement system. Of them, compound 8 showed significant anti-complement activity on the classical pathway with $IC_{50}$ value of 102.7 ${\mu}M$, whereas compounds 1 - 7 and 9 were inactive. This result indicated that an aldehyde group in the neolignan is important for the anti-complement activity against the classical pathway.