• 한국염색가공학회지
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• 제7권4호
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• pp.61-73
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• 1995

Inorganic salts have negative or positive effects on the rates of many chemical reactions and also the rates of acidic and alkaline hydrolysis of carboxylic esters. The direction of salt effects on the hydrolysis of ester depends on the charge of esters. It is expected that the rate of the alkaline hydrolysis of Poly(ethylene terephthalte)(PET), polymeric solid carboxytic polyester with carboxyl end group at the polymer end, is also influenced by inorganic salts. In the present work, to clarify the effect of divalent cations on the alkaline hydrolysis of PET, many salts with divalent cations like $MgCl_{2},CaCl_{2},SrCl_{2},BaCl_{2},$ were added to the aqueous alkaline solutions. Then PET was hydrolyzed with aqueous NaOH solution having many salts under various conditions. Some conclusions obtained from the experimental results were summarized as follows. Many salts with various divalent cations increased or decreased the reaction rate of alkaline hydrolysis of PET depending on their electrophilicity, hydration property, ability of ion pair formation, solubility, and the degree of interactions between divalent cations and anions, etc. The hydrolysis was interrupted in the order of $Ca^{+2} and was generally accelerated in the order of $Ba^{+2}. It was inferred from the increase in ΔS$^*$and the decrease in the ΔG$^*$that the divalent cations $Sr^{+2}$ and $Ba^{+2}$attracted by PET increased the collision frequency between carbonyl carbon and $OH^{-}$ion and then accelerated the reaction rate. $Mg^{+2}$and $Ca^{+2}$decreased the reaction rate because of their strong interaction with $OH^{-}$.

• 생약학회지
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• 제45권4호
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• pp.282-287
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• 2014

The ORI2 (3-[3,4-dihydroxyphenyl]acrylic acid 1-[3,4-dihydroxyphenyl]-2-methoxycarbonylethyl ester) was purified from the extract of Isodon excisus. We confirmed the antiviral effect of ORI2 in a coxsackievirus-induced pancreatitis model. Coxsackievirus B4 (CVB4) is a common cause of pancreatitis and may be reason of the type-1 diabetes. Anti-enteroviral compounds were screened by HeLa cell survival assay. Purified natural compounds were added to HeLa cells cultured 96-well plates after $10^4PFU/ml$ CVB4 pre-incubation for 30 min. ORI2 significantly improved HeLa cell survival in a dose-dependent manner. In addition, ORI2 (1 mM) treatment was dramatically decreased virus protease 2A induced eIF4G-I cleavage and viral VP1 capsid protein production. HeLa cell virus titers and viral RNA replication were significantly decreased in ORI2-treatment in a dose dependent manner (1 mM~0.001 mM). These results demonstrate that ORI2 has a strong antiviral effect. It was significantly decreased virus replication. ORI2 may be developed as a potential therapeutic agent for CVB4.

• Preventive Nutrition and Food Science
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• 제16권2호
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• pp.135-141
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• 2011

Inhibition of intestinal glucose uptake is beneficial in reducing the blood glucose level for diabetes. To search for an effective intestinal glucose uptake inhibitor from natural sources, 70 native edible plants, fruits and vegetables were screened using Caco-2 cells and fluorescent D-glucose analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose (2-NBDG). A compound that was able to inhibit glucose uptake was isolated from methanol extract of Punica granatum L. and called PG-1a. PG-1a appears to be a phthalic acid-diisononyl ester- like compound (PDE) with molecular weight of 418. The inhibitory effect of PG-1a on intestinal glucose uptake was dose-dependent with 89% inhibition at $100\;{\mu}g$/mL. Furthermore, the intestinal glucose uptake inhibitory effect of PG-1a was 1.2-fold higher than phlorizin, a well known glucose uptake inhibitor. This study suggests that PG-1a could play a role in controlling the dietary glucose absorption, and that PG-1a can effectively improve the diabetic condition, and may be used as an optional therapeutic and preventive agent.

• Biomolecules & Therapeutics
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• 제19권3호
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• pp.336-341
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• 2011

As 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 twigs of Galium spurium L. (Rubiaceae) was found to show potent antioxidant activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of nine compounds, asperulosidic acid methyl ester (1), asperuloside (2), caffeic acid (3), kaempferol-3-O-L-rhamnopyranoside (4), quercetin-3-O-[${\alpha}$-Lrhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside] (5), isorhamnetin-3-O-glucopyranoside (6), quercetin-3-O-${\alpha}$-L-rhamnopyranoside (7), kaempferol-3-O-[${\alpha}$-L-rhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside] (8), and quercetin (9). Their structures were elucidated by spectroscopic studies. Compounds 1, 3-8 were isolated for the first time from this plant. Among them, compounds 3 and 9 showed the significant radical scavenging effects on DPPH, and compounds 3 and 7 showed the potent riboflavin originated superoxide quenching activities.

• Natural Product Sciences
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• 제15권4호
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• pp.250-255
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• 2009

Seven compounds including hederagenin 3-[(O-${\alpha}$-L-rhamnopyranosyl-($1{\rightarrow}2$)-${\alpha}$-L-arabinopyranosyl) (1), $3{\beta}$-[(O-${\alpha}$-L-rhamnopyranosyl-($1{\rightarrow}2$)-${\alpha}$-L-arabinopyranosyl)oxy]olean-12-en-28-oic acid (2), caffeic acid methyl ester (3), ferulic acid (4), orebiusin A (5), latifonicinin C (6) and 5-(hydroxymethyl)-2-furfuraldehyde (7) were isolated from the ethyl acetate fraction of the roots of Pulsatilla koreana. Their chemical structures were established based on physicochemical and spectroscopic data analyses. All isolates were investigated for their cytotoxic activity against cancer cell lines. Among them, compound 1 showed inhibitory activity against A549, COLO 205, and L1210 cancer cell lines with $IC_{50}$ values of 15.8, 36.5, and 22.8 ${\mu}g$/mL, respectively.

• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.778-782
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• 2003

In the course of screening anti-influenza agents from natural products, four neuraminidase inhibitors were isolated from the methanol extract of mushroom Microphorus affinis by purification using solvent partition, silica gel column chromatography, Sephadex LH-20, and semi-preparative HPLC. The chemical structures of these compounds were identified as ${\alpha}-lupeol$, methyl linoleate, methyl palmitate, and methyl oleate by means of spectral data including GC-MS, $^1H-,\;and\;^{13}C-NMR\;with\;IC_{50}$ values of 5.65, 7.07, 7.12, and $7.52\;\mu\textrm{M}$, respectively. They did not inhibit other glycosidases such as glucosidase, mannosidase, and galactosidase, indicating that they were relatively specific inhibitors of neuraminidase. The relationship between the fatty acid structure and inhibitory activity was investigated. The result showed that, in the case of an aliphatic linear hydrocarbon skeleton, at least one carboxyl (presumably any carbonyl) moiety and sixteen carbons were the necessary requirements for potent inhibition, whereas saturated, unsaturated, free, and ester forms did not have any significant effect on the activity.

• Journal of Microbiology and Biotechnology
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• 제22권11호
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• pp.1482-1485
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• 2012

A natural furan derivative was isolated from the methanolic extract of the fruit bodies of Fomitiporia ellipsoidea. Its chemical structure was elucidated as methyl 3,5-dioxo-1,3,5,7-tetrahydrobenzo[1,2-c:4,5-c']difuran-4-carboxylate by means of extensive NMR and MS data analysis, and named as fomitiporiaester A (1). Compound 1 showed significant antitumor activity to hepatoma $H_{22}$ in vivo, and the inhibition rates were 42.94%, 49.17%, and 58.15% at concentrations of 5, 10, and 20 mg/kg, respectively. Compound 1 showed weak cytotoxic activities against the human hepatoblastoma (HepG-2) and human oophoroma (Skov 3) cell lines with$IC_{50}$ values of more than $100{\mu}M$.

• Archives of Pharmacal Research
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• 제26권3호
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• pp.232-236
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• 2003

Elsholtzia splendens Nakai has been used in North-East Asia as an ingredient of folk medicines for treating cough, headache and inflammation. The present investigation was carried out to establish its in vivo anti-inflammatory activity using several animal models of inflammation and pain. The 75% ethanol extract of the aerial part of E. splendens significantly inhibited mouse croton oil-induced, as well as arachidonic acid-induced, ear edema by oral administration (44.6% inhibition of croton oil-induced edema at 400 mg/kg). This plant material also showed significant inhibitory activity against the mouse ear edema induced by multiple treatment of phorbol ester for 3 days, which is an animal model of subchronic inflammation. In addition, E. splendens exhibited significant analgesic activity against mouse acetic acid-induced writhing (50% inhibition at 400 mg/kg), while indomethacin (5 mg/kg) demonstrated 95% inhibition. E. splendens ($5-100{\;}{\mu}g/mL$) significantly inhibited $PGE_2$ production by pre-induced cyclooxygenase-2 of lipopolysaccharide-treated RAW 264.7 cells, suggesting that cyclooxygenase-2 inhibition might be one of the cellular mechanisms of anti-inflammation.

• 한국자원식물학회지
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• 제1권1호
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• pp.8-22
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• 1988

Vincristine and vinblastine isolated from Vinco spp. , and podophyllotoxine derivatives isolated from Podophyllum spp. are usefulas anticancerous components obtaned from higher plants. More thanten antineoplastic compounds are now following them as anticancerousagents from higher plants. In my laboratory, Sarcoma 180A has beenused as the first screening test. By this method, I have found outsome kinds of antineoplastic constituents from active plants extracts .For instance, bisaborane type compounds were isolated from Curcumaxanthorrhiza, one of Indonesian plants; a morphinane type compoundfromCocculus trilobus; cyclic hexapeptides from Rubia akane and R.cordiorta. Seven components having antineoplastic actirity wereisolated from Rubia spp. except. R. tinctoria. Their structures wereelucidated except RA-Vl by chemical reaction and variovs instrumentalanalysis as shown in Fig. Among of them, RA-Vll showed strong activityagainst P388 Lymphocytic leukemia, L2O, B16 melanoma, Lewis lungcarcinoma, colon 38 and Ehrlich carcinoma. RA-V revealed excellentactivity against MM2 mammary carcinoma. The· value of acute LD5O ofRA-ViI were 10. Omg/kg( iP) and 16.5mg/kg( po ) respectiveIy . Therapruticratio was 400, compared with 10 of mitomycin C. QSAR was also appliedto these compounds by elongation of ether and ester side chains atR'. Mechanism of action of RA-Vll was also investigated and wasassumed to be inhibition of protein biosynthesis .

• Journal of Microbiology
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• 제35권2호
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• pp.117-122
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• 1997

Several dominant 4-CPA-degrading bacteria were isoalted from agricultural soils. Most of the isolates were identified as Burkholderia species by fatty acid methyl ester (FAME) analysis, but they were idstinct in chromosomal patterns obtained by PCR amplification of repetitive extragenic palindromic (REP) sequences. These strains were generally restricted in their substrate utilization capabilities. The 4-CPA degradative enzymes were idnducible by 4-CPA and some isolates appeared to mineralize 4-CPA via formation of 4-chlorophenol and 4-chlorocatechol as intermediates during its biodegradation pathway. Plasmid DNAs were not detected from most of the isoaltes and their 4-CPA genes wer on the chromosomal DAN. The 4-CPA degradation patterns in axenic cultures and natural soils varied depending on the strains and soils. The inoculation of 4-CPA degraders much improved the removal of 4-CPA from the 4-CPA treated soils.