• Archives of Pharmacal Research
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• 제26권10호
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• pp.816-820
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• 2003

The chloroform extract of the aerial part of Limnophila geoffrayi showed antimycobacterial and antioxidant activities. Bioassay-guided fractionation has led to the isolation of the flavones nevadensin (5,7-dihydroxy-6,8,4'-trimethoxyflavone, 1) and isothymusin (6,7-dimethoxy-5,8,4'-trihydroxyflavone, 2). Both compounds 1 and 2 exhibited inhibition activity against Mycobacterium tuberculosis, with equal MIC value of $200{\;}\mu\textrm{g}/mL$. Only compound 2 exhibited antioxidant activity against the radical scavenging ability of DPPH, with the $IC_{50}$ value of $7.7{\;}\mu\textrm{g}/mL$. The crude hexane, chloroform and methanol extracts as well as the pure compounds 1 and 2 did not exhibit mutagenic activity in the Bacillus subtilis recassay.

• 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.

• Bulletin of the Korean Chemical Society
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• 제28권6호
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• pp.990-994
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• 2007

Bioassay-guided fractionation of the MeOH extract from the sponge Discodermia calyx collected off the coast of Jeju Island, South Korea, led to the isolation of a polyketide, icadamide C (1), along with previously reported theopederin K (3). Structure elucidation was performed by a combination of high resolution mass and 2D-NMR (principally COSY, HMBC, HSQC, and NOESY) spectroscopy. Stereochemistry of compound 1 was determined as 2R*, 3R*, 6R*, 10S*, 11S*, 12R*, 13S*, 15R* and 2'S by NMR data and Marfey analysis. Isolated metabolites displayed potent cytotoxic activity against a small panel of five human solid tumor cell lines with ED50 values of less than 0.1 μg/mL.

• Journal of Microbiology and Biotechnology
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• 제16권4호
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• pp.637-638
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• 2006

Bioassay-guided fractionation of an organic extract of the culture broth from an unidentified marine-derived fungus led to the isolation of a new metabolite, N-[2-(4-hydroxyphenyl) acetyl]formamide (1), along with four known polyketides, 4-hydroxyphenyl acetamide (2), 4-hydroxyphenyl acetic acid (3), 3,4-dihydroxyphenyl acetic acid (4), and N-[2-(4-hydroxyphenyl)ethenyl]formamide (5). The structures of 1-5 were elucidated by spectral data analyses. Among them, compounds 1, 4, and 5 exhibited significant radical scavenging activity against 1, 1-diphenyl-2-picrylhydrazyl (DPPH) with $IC_{50}$ values of 8.4, 11.9, and $0.2{\mu}M$, respectively.

• Natural Product Sciences
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• 제13권4호
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• pp.328-331
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• 2007

The methanolic extract of the roots of Lithospermum erythrorhizon (Boraginaceae) was found to show inhibitory activity towards farnesyl protein transferase (FPTase). Bioassay-guided fractionation of the methanolic extract resulted in the isolation of three naphthoquinone compounds, as inhibitors of FPTase. These compounds inhibited the FPTase activity in a dose-dependent manner.

• 동의생리병리학회지
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• 제20권6호
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• pp.1625-1628
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• 2006

The (-)-pimara-9 (11), 15-dien-19-oic acid, acanthoic acid was extracted from the roots of Acanthopanax koreanum using bioassay-guided isolation of a MeOH extract. Acanthoic acid was assayed against Streptococcus mutans and Staphylococcus epidermidis causing dental caries and opportunistic pathogen. The minimum inhibitory concentration (MIC) of acanthoic acid against Streptococcus mutans and Staphylococcus epidermidis was 2 and 4 ${\mu}g/mL$, respectively, which was much lower than those of other natural antimicrobial agents such as 8 ${\mu}g/mL$ of tanshinone IIA. Acanthoic acid also significantly inhibited the growth of other cariogenic bacteria such as Streptococcus sobrinus and Streptococcus sanguis, and Streptococcus grodenii in the MIC range of 4${\sim}$32 ${\mu}g/mL$. Our findings suggest that acanthoic acid could be employed as a potential antibacterial agent for preventing dental caries and skin infections.

• Archives of Pharmacal Research
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• 제24권6호
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• pp.524-526
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• 2001

Four prostate-type triterpenes were isolated from a methanol extract of Alismatis Rhizoma by bioassay-guided isolation using in vitro cytotoxic assay. The compounds were identified as alisol B 23-acetate (1), alisol C 23-acetate (2), alisol B (3), alisol A 24-acetate (4) by spectroscopic methods. Amongst the compounds, alisol B (3) showed significant cytotoxicity against SK-OV3, B16-F10, and HT1080 cancer cell lines with $ED_50$ values of 7.5, 7.5, $4.9\mu\textrm{g}/ml$, respectively.

• Archives of Pharmacal Research
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• 제18권2호
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• pp.65-68
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• 1995

The methanol extract from the whole parts of the flowers of Chrysanthemum boreals was found to exhibit a significant inhibition of a rat lens aldose reductase (RLAR) activity in vitro. Bioassay guided systematic fractionation of the methanol extract led to the isolation of four flavonoids which were identified as acacetin (1), apigenin (II), luteolin (III) and linarin (IV). Compounds I-III were demonstrated to exhibit a significant inhibition of RLAR. Luteolin (II) was found to be the most potent AR inhibitor with $IC_{50}$ value of $5{\times}10^{-7}M$.

• Archives of Pharmacal Research
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• 제28권12호
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• pp.1341-1344
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• 2005

Bioassay-guided fractionation of $CHCl_{3}$ extract from the fermentation broth of a sponge Mycale plumose-derived actinomycete Saccharopolyspora sp. nov., led to the isolation of two known prodigiosin analogs - metacycloprodigiosin (1) and undecylprodigiosin (2). These compounds exhibited significant cytotoxic activities against five cancer cell lines: P388, HL60, A-549, BEL­7402, and SPCA4. This is the first report on the significant cytotoxicity of metacycloprodigiosin (1) against human cancer cell lines.

• Archives of Pharmacal Research
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• 제27권7호
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• pp.730-733
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• 2004

Bioassay-guided fractionation has led to the isolation of triterpenoid saponins such as Acutoside A (3-O-[O-${\beta}$-D-glucopyrano$yl-(1${\to}$2)-O-${\beta}$-D-glucopyranosyl] oleanolic acid) from the whole plants of Viola hondoensis. Among them, Saponin 1 exhibited potent inhibitory activity against matrix metalloproteinase (MMP)-1, and prevented the UV-induced changes in the MMP-1 expression. In addition, compound was isolated from this plant for the first time.