• Applied Biological Chemistry
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• 제42권2호
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• pp.166-169
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• 1999

두충잎으로부터 얻은 MeOH 추출물의 n-BuOH 분획으로부터 silica gel column chromatography를 반복하여 monoamine oxidase B (MAO-B) 억제 활성을 갖는 flavonoid 배당체를 분리하였다. 화합물의 화학구조를 스펙트럼 데이터의 해석과 산가수분해반응을 이용하여 $3-O-[{\beta}-D-glucopyranosyl\;(1{\rightarrow}2)\;{\beta}-D-xylopyranosyl]\;quercetin$으로 결정하였다. 이 화합물의 MAO-B 억제활성에 있어서의 $IC_{50}$ 값은 $8.05\;{\mu}mol/l$로 측정되었다.

• Preventive Nutrition and Food Science
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• 제8권2호
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• pp.141-144
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• 2003

Ixeris dentata Nakai (Compositae) is a perennial herb which has been used as a folk medicine for treating diabetes and gastroenteric troubles in Korea. Active compounds were isolated from the aerial parts of Ixeris dentata through the bioassay-guided fractionation and isolation method evaluated for inhibition of monoamine oxidase (MAO) in vitro. The compounds were identified as 5,7,3',4'-tetrahydroxyflavone (1) and 5,7,3',4'- tetrahydroxyflavone 7-glucoside (2), based on physical and spectroscopic characteristics. Compounds 1 and 2 showed a selective inhibition of type B MAO (MAO-B) activity, with IC/sub 50/ values of 15.3 μM and 36.4 μM, respectively, but did not inhibit type A MAO (MAO-A) activity.

• 한국식품과학회지
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• 제29권1호
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• pp.156-160
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• 1997

식용버섯류들의 MAO 저해활성을 검색할 목적으로 몇가지 유기용매를 이용하여 추출분획을 조제하고 이들의 MAO에 대한 저해활성을 검색하였다. 검색된 3종 버섯류의 유기용매 추출물들은 영지버섯 bud의 $CHCl_3$ 층을 제외하고는 모두 MAO-A에 대한 저해활성이 나타나지 않았으나 영지 bud의 경우 $CHCl_3$ 층에서 비교적 강력한 MAO-A 저해활성을 나타내어 영지 bud의 항암활성이 영지의 항암활성과 비교하여 더욱 강력하다는 기존의 보고와 관련하여 아주 흥미로운 결과로 영지의 성분연구에 아주 중요한 단서를 제공해 줄 것으로 생각된다. 또한 검색된 3종 버섯류의 유기용매 추출물들은 영지 bud, 표고버섯의 EtOAc 층에서 각각 51.3, 55.9%로 역한 정도의 저해활성이 관찰되었으며 그 외의 다른 버섯류들에서는 전혀 MAO-B에 대한 저해활성이 확인되지 않았다. 또한 영지버섯의 경우, $CHCl_3$ 층, EtOAc 층, $H_2O$ 층 모두에서 아주 미약하나마 MAO-B에 대한 저해활성을 나타냈으나 영지 bud의 경우 $CHCl_3$ 층에서 전혀 MAO-B에 대한 저해활성을 나타내지 않고 EtOAc 층에서 약한 MAO-B에 대한 저해활성이 확인되어 MAO-A와 MAO-B에 대한 영지버섯의 작용성분이 다른 성분일 것으로 추측된다.

• Archives of Pharmacal Research
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• 제29권12호
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• pp.1119-1124
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• 2006

The methanol extract from the aerial parts of Dictamnus albus was active in inhibiting monoamine oxidase (MAO) from the mouse brain. Activity-guided fractionation led to the isolation of four known coumarins, 7-(6'R-hydroxy-3', 7'-dimethyl-2'E, 7'-octadienyloxy) coumarin (1), auraptene (2), umbelliferone (3), and xanthotoxin (4), as active compounds along with an inactive alkaloid, skimmianine (5). Compounds 1 and 2 inhibited MAO activity in a concentration-dependent manner with $IC_{50}$ values of 0.7 and $1.7\;{\mu}M$, respectively. Compounds 1 and 2 showed a slight and potently selective inhibitory effect against MAO-B ($IC_{50}\;0.5\;and\;0.6\;{\mu}M,\;respectively$) compared to MAO-A ($IC_{50}\;1.3\;and\;34.6\;{\mu}M,\;respectively$). According to kinetic analyses derived by Lineweaver-Burk reciprocal plots, compounds 1 and 2 exhibited a competitive inhibition to MAO-B.

• Archives of Pharmacal Research
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• 제28권12호
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• pp.1324-1327
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• 2005

A methylene chloride soluble fraction of the fruits of Cudrania tricuspidata significantly inhibited the mouse brain monoamine oxidase (MAO). Three known prenylated isoflavones were isolated and identified by activity-guided fractionation. Gancaonin A (1), 4'-O-methylalpinumisoflavone (2), and alpinumisoflavone (3) inhibited MAO activity in a concentration-dependent manner with $IC_{50}$ values of 19.4, 23.9, and 25.8 $\mu$M, respectively. Of these, gancaonin A (1) showed a selective and potent inhibitory effect against MAO-B ($IC_{50}$ 0.8 $\mu$M) than MAO-A ($IC_{50}$ >800 $\mu$M). The kinetic analysis using Lineweaver-Burk plots indicated that gancaonin A (1) competitively inhibited MAO-B.

• Archives of Pharmacal Research
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• 제11권3호
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• pp.213-217
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• 1988

The effects of ethanol and acetaldehyde on monoamine oxidase activity in mouse liver mitochondrial fraction were studied. In vivo, a single dose of ethanol increased the hepatic monoamine oxidase activity compared to control group, and chronic ethanol consumption also increased the enzyme activity using tyramine, benzylamine or serotonin as substrate. Acetaldehyde, the metabolite of ethanol, significantly increased monoamine oxidase activity more than ethanol did. In contrast to the in vivo results, it was found that the monoamine oxidase activity was inhibited in vitro by ethanol or acetaldehyde in the dose-dependent manner.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.188-188
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• 1998

Extracts of 24 edible vegetables were tested concerning their action on in vitro inhibition on dopamine ${\beta}$-hydroxylase (DBH) and monoamine oxidase (MAO). All vegetables were purchased in Korean market and their common names were kept. Radish sprouts, ‘kkoch-na-mul’, ‘chong-gyong-chae’, ragwort, applemint showed strong DBH inhibitory effect when tyramine and crude bovine adrenal DBH were used as substrate and enzyme, respectively. ‘Cham-chwi’(Aster scaber), kale, ‘cham-na-mul’(Pimpinella brachycarpa), leek were found to have MAO-A inhibitory effect with serotonin and crude rat brain MAO-A. Lettuce, ‘chong-gyong-chae’, radish sprouts, beet leaves were found to have MAO-B inhibitory effect with benzyl amine and crude rat liver MAO-B.

• Archives of Pharmacal Research
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• 제24권1호
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• pp.51-54
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• 2001

Three varieties of methyl citrate and 1 -methyl malate were isolated from the fruits of Opuntia ficus-indica var. saboten Makino through in vitro bioassay-guided isolation for the inhibition on monoamine oxidase(MAO). The $IC_50$ values for MAO-B of 1-monomethyl citrate, 1,3-dimethy citrate, trimethyl citrate and 1-methyl malate were 0.19, 0.23, 0.61 and 0.25 mM, respectively. However, on MAO-A, their inhibitions showed only marginal activity.

• Natural Product Sciences
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• 제19권4호
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• pp.281-285
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• 2013

This study was designed to investigate the nervous sedative effects of green tea. The sedative effect was evaluated by examination of Monoamine oxidases (MAOs) inhibitory activity in vitro in the brain and liver of rat fed on green tea cultivated and harvested from the different regions and periods. It showed that methanol extracts of green tea inhibited significantly the brain MAO-A activity. Especially late harvested green tea extracts showed potential inhibitory activity. The liver MAO-B activity was also inhibited by all of the green tea extracts with strong intensity. This study confirmed that major compounds of green tea such as catechin, epigallocatechin-3-gallate (EGCG) and L-theanine, which were well known for the main bioactive components in the tea plants, were not associated with the MAO inhibitory activities of green tea. These results suggested that a MAO inhibition activity comes from other minor tea components we have to search in the future.

• BMB Reports
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• 제29권2호
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• pp.142-145
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• 1996

To investigate the cause of increased plasma catecholamine levels in liver disease, catechol-O-methyltransferase (COMT), which provides a major route of catabolism for circulating catecholamines, was studied under the cholestasis induced by mechanical biliary obstruction in rats. Monoamine oxidase (MAO) activity and the $K_m$ and $V_{max}$ values for both enzymes were also measured. Cytosolic, microsomal, and mitochondrial COMT activities in the cholestatic liver were significantly decreased throughout the experiment. Microsomal, and mitochondrial MAO activity in the cholestatic liver were also significantly decreased. Vmax values of COMT and MAO were lower. Serum COMT and MAO activities were detected after CBD ligation. These results indicate that plasma catecholamine levels are increased in liver disease due to decreased hepatic degradation of catecholamines by decreased activities of COMT and MAO. The decreased activity of these enzymes is caused by decreased biosynthesis and by flowage into the blood from the damaged hepatocyte.