• Bulletin of the Korean Chemical Society
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• v.17 no.6
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• pp.529-531
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• 1996

Muricellaxanthin, a novel carotenoid pigment has been isolated by activity-guided separation from an undescribed gorgonian of the genus Muricella collected from Jaeju Island. Structure of this compound has been determined by a combination of spectral methods. Stereochemistry has been defined by interpretation of nOe data and comparison of CD data with related compounds. Muricellaxanthin exhibited potent lethality against brine-shrimp larvae.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.369.1-369.1
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• 2002

In our previous study, the leaves of Ixeris sonchifolia afforded two new and two known guaiane type sesquiterpene lactones by activity-guided fractionation. Now we report additional isolation of sesquiterpene lactones from the roots of Ixeris sanchi!a!ia. They are glucozaluzanin C and ixerin H. Ixerin H is germacranolide type sesquiterpene glucuside. Theil structures were determined by 1 D and 2D NMR spectroscopy. (omitted)

• Natural Product Sciences
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• v.14 no.1
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• pp.56-61
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• 2008

Bioactivity guided phytochemical study of the petroleum ether and butanol extracts of Clematis hirsuta resulted in the isolation of 12 compounds. Rat paw edema as a model of acute inflammation was used to evaluate the anti-inflammatory activity of the extracts and the chromatographic fractions. Five known sterols and triterpenes namely: ${\beta}-amyrin$ (1), lupeol (2), ${\beta}-sitosterol$ (3), oleanolic acid (4) and stigmasterol glycoside (5) were isolated from the petroleum ether extract. The n-butanol extract afforded two compounds reported for the first time from natural source: (S)-(+)-dihydro-5-(hydroxymethyl)-2(3H)-furanone (7) and (s)-(-)-5-hydroxymethyl-2(5H)-furanone (8). In addition, anemonin (6), dihydro-4-hydroxy-5-(hydroxymethyl)-2(3H)-furanone (2-deoxy-D-ribono-1,4-lactone) (9), biophenol (cimidahurin) (10), glucose (11) and sucrose (12) were also identified. The structures were determined from spectroscopic data including 1D- and 2D-NMR experiments.

• Archives of Pharmacal Research
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• v.26 no.2
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• pp.147-150
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• 2003

To find anticancer agents from higher plants, DNA strand-scission assay method was employed for bioassay-guided fractionation as well as for screening the crude extracts. During the screening, an ethyl acetate extracts of the heartwood of Caesalpinia sappan L. (Leguminosae) exhibited potent DNA strand-scission activity. Therefore, the ethyl acetate extracts of the dried heartwood of C. sappan was subjected to the bioassay-guided fractionation, which led to the isolation of a known compound, brazilin (1) as the active constituent. In addition, caesalpine J (2) was also isolated as an inactive constituent.

• Natural Product Sciences
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• v.11 no.3
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• pp.136-138
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• 2005

Bioassay-guided fractionation of an organic extract of the broth from the marine-derived fungus of the genus Aspergillus led to the isolation of the polyketides, (+)-epoxydon (1), (+)-epoxydon monoacetate (2), gentisyl alcohol (3), 3-chlorogentisyl alcohol (4), and methylhydroquinone (5). Compounds 1-5 showed a potent antibacterial activity against the methicillin-resistant and multidrug-resistant Staphylococcus aureus (MRSA and MDRSA) with MIC (minimum inhibitory concentration) values of 12.5, 12.5, 12.5, 50.0, and $6.2\;{\mu}g/mL$, respectively. Compounds 1-4 also exhibited a significant radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with $IC_{50}$ values of 6.0, 15.0, 7.0, and $1.0\;{\mu}M$, respectively.

• Journal of Photoscience
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• v.9 no.2
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• pp.421-423
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• 2002

Phellinus linteus mycelia have many pharmacological effects, although their pharmacological efficacy principles have not been known yet. In the course of screening for biological activity of the extracts of Phellinus linteus mycelia, we found strong antioxidative activity in some fraction of water-insoluble. Therefore, we tried to isolate the active principle(s) from the extract. The isolation of the active compound was guided by superoxide anion radical scavenging activity. As a result, caffeic acid was isolated as an active compound. The IC$\_$50/ of the compound was 3.05 $\mu$g/ml (16.9$\mu$M).

• Archives of Pharmacal Research
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• v.29 no.3
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• pp.191-194
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• 2006

Twigs from llex macropoda were extracted with MeOH, and the concentrated extracts were partitioned with $CH_2Cl_2$, EtOAc, n-BuOH, and $H_2O$. Repeated column chromatography of the $CH_2Cl_2$ fraction ultimately resulted in the isolation of two compounds, via activity-guided fractionation, using ACAT inhibitory activity measurements. According to the physico-chemical data, the chemical structures of these isolated compounds were identified as lupeol (1) and betulin (2). Compounds 1 and 2 were shown to inhibit the activity of hACAT-1 and hACAT-2 in a dose-dependent manner, and compounds 1 and 2 inhibited hACAT-1 with $IC_{50}$ values of 48 and $83{\mu}M$, respectively.

• Korean Journal of Pharmacognosy
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• v.47 no.2
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• pp.110-116
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• 2016

As a part of an ongoing search for natural plants with antioxidant compounds by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH), a total extract of the aerial parts of Bidens frondosa L. (Compositae) was found to show potent antioxidant activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of five compounds, quercetin-3-O-${\beta}$-D-glucopyranoside (1), luteolin-7-O-${\beta}$-D-glucopyranoside (2), 7,8,3',4'-tertrahydroxy-flavanone (3), okanin-4-O-${\beta}$-D-glucopyranoside (4), and okanin (5). Their structures were elucidated by spectroscopic studies. Compounds 3-5 were isolated for the first time from this plant. Among them, compounds 3 and 5 showed the significant radical scavenging effects on DPPH, and compounds 3 and 5 also showed the potent riboflavin and xanthine originated superoxide quenching activities.

• Natural Product Sciences
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• v.17 no.2
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• pp.100-103
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• 2011

Phytochemical study on the ethanol extract of a Crinum species by bioassay-guided fractionation resulted in the isolation of an active principle, which was determined as parthenin (1) on the basis of physicochemical and spectroscopic analyses. This is the first report on the existence of a sesquiterpenoid from Crinum ensifolium. Compound 1 was found to show strong cytotoxic activity against some cancer cell lines and strongly inhibit NF-${\kappa}$B activity with the $IC_{50}$ value of 1.82 ${\mu}M$.

• Natural Product Sciences
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• v.17 no.2
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• pp.142-146
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• 2011

In the course of screening for antioxidant compounds by measuring the radical scavenging effect on 1,1-diphenyl- 2-picrylhydrazyl (DPPH), a total extract from the whole plant of Veronica peregrina (Scrophulariaceae) was found to show potent antioxidant activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of six phenolic compounds including chrysoeriol (1), diosmetin (2), 4-hydroxybenzoic acid (3), apigenin (4), caffeic acid methylester (5) and protocatechuic acid (6). Their structures were elucidated by spectroscopic studies. Compounds 1-5 were isolated for the first time from this plant. Compounds 5 and 6 showed significant antioxidative effects in DPPH free radical scavenging and superoxide quenching activity assays.