• Archives of Pharmacal Research
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• v.8 no.2
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• pp.85-89
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• 1985

It was revealed that magnolol and honokiol isolated from the stem bark of Magnolia obovata, had potent antibacterial activity against Bacillus anthracis. A quantitative analytical method of magnolol and honokiol by HPLC has been established, and the amounts of the two components in the dried stem bark of M. obovata were 1, 94% and 0.44%, respectively.

• Natural Product Sciences
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• v.14 no.2
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• pp.90-94
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• 2008

Two sesquiterpenes (1 - 2), a tetralone (3), and two phenylpropanoids (4 - 5) were isolated from the stem bark of Magnolia obovata Thunberg (Magnoliaceae) through repeated column chromatography. Their structures were identified as ${\beta}-eudesmol$ (1), cryptomeridiol (2), 4R-4,8-dihydroxy-${\beta}-tetralone$ (3), trans-pcoumaryl aldehyde (4), and p-coumaric acid (5) on the basis of spectroscopic analysis including two dimensional NMR and mass. Compounds 1 - 3 were tested in vitro for their cytotoxic activity against the K562, HeLa, A549, and HCT116 cancer cell lines. However, compounds 1 - 3 were inactive in this assay system.

• Natural Product Sciences
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• v.14 no.3
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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.

• Korean Journal of Pharmacognosy
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• v.25 no.2
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• pp.188-193
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• 1994

'Hoo Bak' is one of the Chinese crude drugs used mainly to cure a headache, apoplexy and dyspepsia. With regard to the botanical origin of 'Hoo Bak', it has been considered to be Machilus thunbergii of Lauraceae in Korea. But there has no pharmacognostical confirmation on it. To clarify the botanical origin of 'Hoo Bak', the anatomical characteristics of the bark of Machilus thunbergii, Magnolia officinalis and Magnolia obovata were studied. As a result, it was clarified that 'Hoo Bak' from Korea was the bark of Machilus thunbergii of Lauraceae.

• Natural Product Sciences
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• v.27 no.3
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• pp.141-150
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• 2021

This short review on the chemistry, pharmacological properties and patents of obovatol and obovatal from Magnolia obovata is the first publication. Pharmacological properties are focused on anti-cancer, anti-inflammatory, anti-platelet and neuroprotective activities. Obovatol and obovatal were first isolated from the leaves of M. obovata. Also reported in the bark and fruits of M. obovata, obovatol and obovatal are neolignans i.e., biphenolic compounds bearing a C-O coupling. Other classes of compounds isolated and identified from M. obovata include sesquiterpene-neolignans, dineolignans, trineolignan, lignans, dilignans, phenylpropanoids, phenylethanoid glycosides, flavonoids, phenolic acids, alkaloids, sesquiterpenes, ketone and sterols. The anti-cancer properties of obovatol and obovatal involve apoptosis, inhibition of the growth, migration and invasion of cancer cell lines. However, obovatol displays cytotoxicity against cancer cells but not obovatal. Similarly, anti-inflammatory, anti-platelet, neuroprotective, anxiolytic and other pharmacological activities were only observed in obovatol. The disparity in pharmacological properties of obovatol and obovatal may be attributed to the -CHO group present in obovatal but absent in obovatol. From 2007 to 2013, eight patents were published on obovatol with one mentioning obovatal. They were all published at the U.S. Patent and Trademark Office by scientists of the Korea Research Institute of Bioscience and Biotechnology (KRIBB) as inventors and assignee, respectively. Some future research and prospects are suggested.

• Natural Product Sciences
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• v.14 no.1
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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 ${\mu}g/mL$.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.1
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• pp.43-52
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• 2017

EtOAc fractions of Magnolia obovata (M. obovata) Bark extracts were studied for the potential ingredient as a safe and effective whitening cosmetic material. The concentration of active substances honokiol was determined by HPLC. In vitro, the fractions reduced the extracellular and intracellular melanin contents in B16F10 cells in dose dependently and inhibited extracellular melanin secretion ($IC_{50}=11.05{\mu}g/mL$). The $12.5{\mu}g/mL$ treatment of maximum concentration effectively inhibited up to about 60% to the amount of extracullular melanin. Also, the $12.5{\mu}g/mL$ treatment of maximum concentration effectively inhibited up to about 59% to the amount of intracullular melanin ($IC_{50}=10.85{\mu}g/mL$). The $IC_{50}$ value of ${\alpha}-arbutin$ used as a positive control was $59.99{\mu}g/mL$. So, EtOAc fractions of M. obovata Bark extracts showed whitening effect when compared with the non-treatment group. In case of in vivo study, Cosmetic cream with EtOAc fractions of M. obovata Bark extracts was approved by Ethics committee of KDRI (IRB number: KDRI-IRB-1537). As a result in progress for skin sensitization as well as assessment of skin irritation through repeated patch test, skin allergens was identified as non sensitizing agents. Also, cosmetic cream with EtOAc fractions of M. obovata Bark extracts showed significant topical whitening effect and reliable skin safety when compared with the non-treatment group. In conclusion, EtOAc fractions of M. obovata Bark extracts may be a useful cosmetic ingredient for effective skin whitening.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.138.1-138.1
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• 2003

$\beta$-Eudesmol is one of various compounds derived from the bark of Magnolia obovata Thunberg, a medicinal plant. It has been shown that $\beta$-eudesmol also markedly alleviated muscle fasciculation, tremor and convulsion induced by diisopropylfluorophosphate and prolonged the time to death in mice (Chiou et al., 1995). Actually, the extract of magnolia bark has been shown to have depressant actions on the cental nervous system (Watanabe et al., 1973). (omitted)

• Archives of Pharmacal Research
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• v.23 no.1
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• pp.46-49
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• 2000

Two neolignan compound, magnolol $(5,5^{l}-diallyl-2,2^{l}-dihydroxybiphenyl, 1)$ and honokiol $(5,5^{l}-diallyl-2,4^{l}-dihydroxybiphenyl, 2)$ were isolated from the stem bark of Magnolia obovata and evaluated for antifungal activity against various human pathogenic fungi. Compound 1 and 2 showed significant inhibitory activities against Trichophyton mentagrophytes, Microsporium gypseum, Epidermophyton floccosum, Aspergillus niger, Cryptococcus neoformans, and Candida albicans with minimum inhibitory concentrations (MIC) in a range of $25-100{\mu}g/ml$. Therefore, compound 1 and 2 could be used as lead compounds for the development of novel antifungal agents.

• Biomolecules & Therapeutics
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• v.16 no.3
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• pp.270-276
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• 2008

In this study we investigated the effects of Magnolia Bark (MB) extract and its constituents, such as honokiol and magnolol, on gastritis in rats and the growth of human gastric cancer cells. The MB extract, honokiol, and magnolol showed the acid-neutralizing capacities, the antioxidant activities, and the inhibitory effect on the growth of Helicobacter pylori (H. pylori.) at the dose of $50\;{\mu}g/ml$ and over, which is equivalent to that of ampicillin ($100\;{\mu}g/ml$). Honokiol and magnolol had no significant cytotoxicity to human gastric caner cells (AGS and SNU638). However, the MB extract had cytotoxic activity against AGS gastric cancer cell. The MB extract, honokiol, and magnolol significantly inhibited HCI-ethanol-induced gastric lesions without clear change of mucus content. In pylorus ligated rats, honokiol significantly decreased the volume of gastric secretion and gastric acid output, and increased the pH. Magnolol increased the mucus content to almost the same as the control group at oral doses of 50 mg/kg. Therefore, we could guess that antigastritic action of honokiol and magnolol may be associated with the antioxidant activities, acid-neutralizing capacities, inhibition of secretion in gastric acid, and anti-H. pylori action. From these results, we could suggest that MB extract and its constituents, such as honokiol and magnolol, may be useful for the treatment and/or protection of gastritis.