• Natural Product Sciences
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• v.8 no.2
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• pp.55-57
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• 2002

Youngia koidzumiana is an endemic plant growing in Mt. Chiri. In our ongoing research for endemic species in Korea, we investigated the chemical constituents from the MeOH extract of Y. koidzumiana whole plants. The MeOH extract was partitioned with hexane, ethyl acetate and BuOH, successively. Four known compounds were isolated from ethyl acetate fraction by repeated column chromatography. Their structures were elucidated by the physicochemical and spectral data as germanicol acetate (1), oleanolic acid (2), brachynereolide (3) and ixerin Y (4).

• Korean Journal of Medicinal Crop Science
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• v.3 no.2
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• pp.151-155
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• 1995

Chromatographic separation of Laduca raddeana extract afforded a mixture of fatty acyl triterpene, triterpene acetates and primary long chain alcohol. The kind of triterpene moieties in these two triter­penoids was six, i.e., ${\beta}-amyrin,\;{\alpha}-amyrin$, lupeol, pseudotaraxasterol, taraxasterol and germanicol on the basis of chemical and spectroscopic methods. The acyl moieties in the corresponding acyl mixture were characterized as acetates, myristate, palmitate, stearate and arachidate. And a mixture of primary long chain alcohol were composed of teracosanol and hexacosanol.

• Korean Journal of Pharmacognosy
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• v.28 no.1
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• pp.21-25
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• 1997

The diets with three types of triterpenoid constituents, which were isolated from Lactuca indica, provoked significant changes of serum lipoprotein-cholesterol meta bolisms of hypercholesterolemic rats induced by high-cholesterol diet, together with the reduction of atherogenic index. Especially, triterpene acetates which have triterpene moieties such as ${\beta}-amyrin$, ${\alpha}-amyrin$, lupeol, pseudotaraxasterol, taraxasterol and germanicol showed a considerable hypocholesterolemic activity. The rat given orally with triterpene acetates did not exhibit a significantly higher value of atherogenic index than that of normal rats.

• Archives of Pharmacal Research
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• v.28 no.2
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• pp.164-168
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• 2005

The EtOAc extract of Youngia koidzumiana significantly inhibited the diacylglycerol acyltransferase (DGAT) from rat liver microsomes. Bioactivity-guided fractionation led to the isolation of nine compounds, the structures of which were established using physicochemical and spectral data. Of the isolated compounds, oleanolic acid (2), methyl ursolate (7) and corosolic aicd (8) inhibited DGAT, with $IC_{50}$ values of 31.7, 26.4, and $44.3{\mu}M$, respectively. However, sesquit-erpenoids showed only weak inhibitory effects toward DGAT.