• Journal of Microbiology and Biotechnology
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• v.6 no.3
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• pp.184-188
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• 1996

The Acinetobacter sp. BE-254 isolated from soil sources produced a bioemulsifier in the medium supplemented with n-hexadecane. This bioemulsifier was purified by the procedures of fractionation (ammonium sulfate and chilled acetone), extraction by hexane, and column chromatography on silica gel 60. The results from various color reactions indicated that the bioemulsifier was a glycolipid. The purified emulsifier was very stable at pHs ranging from 4 to 10 and under heat treatment at $100^{\circ}C$ for 30 min. Emulsification activity was also hardly influenced by pH. The critical micelle concentration (CMC) and surface tension at the point ($\gamma_{cmc}$) of the bioemulsifier were approximately 35 mg/l and 30 mN/m, respectively. The bioemulsifier showed a fairly good emulsification activity and stability in comparison with other commercial emulsifiers in the basic formula composed of emulsifier, oil, and water.

• Journal of Microbiology and Biotechnology
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• v.17 no.8
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• pp.1403-1406
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• 2007

An antiproliferative agent, streptochlorin, was isolated from the fermentation broth of a marine actinomycete isolated from marine sediment. Phylogenetic analysis of the 16S rRNA gene sequence indicated that the strain belongs to the genus Streptomyces. Bioactivity guided fractionation of the culture extract by solvent partitioning, ODS open flash chromatography, and reversed-phase HPLC gave a pure compound, streptochlorin. Its structure was elucidated by extensive 2D NMR and mass spectral analyses. Streptochlorin exhibited significant antiproliferative activity against human cultured cell lines.

• Archives of Pharmacal Research
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• v.11 no.3
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• pp.240-243
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• 1988

The hexane extract from Nutmeg, the seed of Myristica fragrans significantly inhibited hepatic drug-metabolizing enzyme activity. Through systematic fractionation by $SiO_2$ column and vacuum liquid chromatography monitoring by bioassay, three components, myristicin, (I), licarin-B (II) and dehydrodiisoeugenol (III) were isolated as active principles. Compounds II and III, with a single treatment (200mg/kg, i.p.) showed not only a significant prolongation of hexobarbital-induced sleeping time but also a significant inhibition of aminopyrine N-demethylase and hexobarbital hydroxylase activities in mice. Compounds I and II provoked a sleep episode at a subhypnotic dose of HB, suggesting that they possess CNS-depressant properties.

• Fisheries and Aquatic Sciences
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• v.9 no.3
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• pp.115-117
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• 2006

A micro algal growth-enhancing polysaccharide compound was isolated from the green alga Monostroma nitidum using water extraction, molecular fractionation, a DEAE-cellulose column, and fast protein liquid chromatography using a Superose-12 column. The yield of the compound from the seaweed powder was 8.3$\times$l0$^{-3}$%. At 2 mg/mL concentration, the polysaccharide enhanced Tetraselmis suecica cell growth in f/2 medium by approximately 160%.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.729-733
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• 1998

The crude extract of Streptomyces sp. strain KM86-9B, isolated from a marine sponge, displayed significant inhibition on topoisomerase I activity. Investigation of the ca usative components by bioactivity-directed fractionation resulted in the isolation of a series of iso- and anteiso-fatty acids.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.718-722
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• 1998

Scopoletin (7-hydroxy-6-methoxycoumarin), a coumarin, was isolated from the aerial part of Solanum lyratum Thunb. by the activity-guided fractionation employing carbon te trachloride-intoxicated primary cultured rat hepatocytes as a screening system. Its hepatoprotective activity was first evaluated by measuring the release of glutamic pyruvic transaminase and sorbitol dehydrogenase from carbon tetrachloride-intoxicated rat hepatocytes into the culture medium. Scopoletin significantly reduced the releases of glutamic pyruvic transaminase and sorbitol dehydrogenase from the carbon tetrachloride-intoxicated primary cultured rat hepatocytes by 53% and 58%, respectively, from the toxicity in a dose-dependent manner over concentration ranges of 1mcM to 50mcM. Further studies revealed that at the concentration of 10mcM, scopoletin significantly preserved glutathione content by 50% and the activity of superoxide dismutase by 36% and also inhibited the production of malondialdehyde to the degree as seen in the control.

• Natural Product Sciences
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• v.11 no.1
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• pp.50-53
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• 2005

Bioassay-directed fractionation of the lipophilic extract of a marine sponge Sarcotragus sp. led to the isolation of a known trisoxazole containing macrolide, mycalolide B (1). Its structure was identified by NMR and MS analyses. This is the first report on the isolation of macrolide from a sponge of the genus Sarcotragus (Order: Dictyoceratida).

• 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.

• Natural Product Sciences
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• v.13 no.3
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• pp.268-271
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• 2007

Glutamate-induced oxidative injury contributes to neuronal degeneration in many central nervous system (CNS) diseases, such as epilepsy and ischemia. Bioassay-guided fractionation of the MeOH extract of the seeds of Alpinia katsumadai Hayata (Zingiberaceae) furnished three phenolic compounds, alpinetin (1), pinocembrin (2), and (+)-catechin (3). Compounds 2 and 3 showed the potent neuroprotective effects on glutamate-induced neurotoxicity and reactive oxygen species (ROS) generation in the mouse hippocampal HT22 cells. In addition, Compounds 2 and 3 showed significant DPPH free radical scavenging effect. These results suggest that compounds 2 and 3 could be the effective candidates for the treatment of ROS-related neurological diseases.

• Natural Product Sciences
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• v.13 no.3
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• pp.247-250
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• 2007

A new sphingosine (1) was isolated from the MeOH extract of a marine sponge Haliclona (Reniera) sp. by bioactivity-guided fractionation. The 1D and 2D NMR, and MS spectroscopic analyses were used to establish the planar structure of 1. The stereochemistry of the compound was defined on the basis of modified Mosher's method, comparison of optical rotation and NMR data with those of the reported. Compound 1 was mildly cytotoxic to a panel of five human solid tumor cell lines.