• 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).

• 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.