• Bulletin of the Korean Chemical Society
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• v.21 no.7
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• pp.675-678
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• 2000

The reaction between silver (I) and thiomicher's ketone (TMK) was sensitive at pH 5 and 8 in the presence of non-ionic or anion surfactant. We studied the complex solution and determined the properties by beta-correction spectrophotometry, which included the complex ratio and the stability constant of the complex. The results showed that complex Ag(TMK)2 was formed in the presence of alkylphend ethoxylates (emulsifier OP) and Ag(TMK)2 was formed in the presence of sodium dodecyl benzene sulfonate (SDBS). Their real absorptivities are as follows: $\varepsilonAg(TMK)540$ = 5.23 ${\times}$ 10(4), $\varepsilonAg(TMK)2(555)$ = l.05 ${\times}$ 10(5) Lmol(-l)cm(-1) both at pH 5 and $\varepsilonAg(TMK)2(555)$ = 7,52 ${\times}$ 10(4)lmol(-1)cm(-1) at pH 8. The stability constant of complex Ag(TMK) was equal to 1.23 ${\times}$ 10(5) at pH 5 and that of Ag(TMK)2 8.29 ${\times}$ 10(9) at pH 5 and 1.15 ${\times}$ 10(11) at pH 8.

• Bulletin of the Korean Chemical Society
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• v.10 no.3
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• pp.316-317
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• 1989

• BMB Reports
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• v.30 no.2
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• pp.157-161
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• 1997

The present paper reports characteristics and specificity of the inhibitory action of $N^{\alpha}-tosyl-L-lysine-chloromethyl\;ketone$ (TLCK) and $N^{\alpha}-tosyl-L-phenylalanine-chloromethyl\;ketone$ (TPCK) on the glucose6-phosphate transporter of rat liver microsomes. The TLCK-induced inhibition was pH dependent. The inhibition constants for TPCK were determined by following pseudo-Lst order reaction mechanism. The inhibition was protected by preincubation with excess amount of glucose-6-phosphate. The results proved that (a) TLCK inactivates the microsomal glucose-6-phosphate transporter, (b) the inhibition results from the modification of sulfhydryl groups of the transporter.

• Journal of Environmental Health Sciences
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• v.2 no.1
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• pp.5-9
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• 1975

For analysis of Xanthene dyes according to the developing solvent and adsorbent was applied to Thin-layer chromatography with silicagel and cellulose plate. Silicagel chromato-plate used were prepared under different condition of activation. Using eight developing solvent, the influence of the condition for activation upon the separation of Xanthene dyes was investigated. The results are shown in Table 3. Methyl ethyl ketone+Acetone+$H_2O$ (10:0.1:0.4) mixture and n-butanol+Ammonia water (4:1) mixture gave clear separation for Xanthene dyes, including Fluorescein, Erythrosine Rhodamin B, Eosine, Rose bengale, phloxine and Acid red those Rf values decrease in the described ordor. Methyl ethyl ketone+Acetone+$H_2O$ (10:0.1:0.4) was applied to two adsorbents which were purchased from different manufactures. The results of Chromatograms are obtained Figure 6.

• Bulletin of the Korean Chemical Society
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• v.23 no.6
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• pp.911-914
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• 2002

• The Korean Journal of Zoology
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• v.33 no.1
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• pp.53-62
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• 1990

Fully grown amphibian oocytes undergo their maturation (germinal vesicle breakdown, GVBD) during in vitro follicle culture when they are stimulated with frog pituitary homogenate (FPH) or progesterone. Present experiments were designed to determine whether proteolytic enzymes are involved in the regulation of the matunation process. Treatment of a $\alpha$ -chymoiyypsin inhibitor, N a -tosyl-L-phenylalanine-chloromethyl-ketone(TP) to the oocytes exhibited a biphasic phenomenon, the induction of the maturation without added hormone at relatively low doses (0.001-1 $\mu$M) and inhibition of the hormone induced oocyte maturation at a high dose (100 $\mu$M). Treatment of a trypsin inhibitor, N a -tosyl-L-lysine-chloromethyl ketone(TLCK) to the oocytes did not induce the maturation, but rather suppressed the hormone induced oocyte maturation in a high dose(100 $\mu$ M). Treatment of exogenous iyypsin to the oocyte induced their maturation without added hormone in a dose dependent manner (0.001-1 $\mu$ M). The data presented here indicate that some proteolytic enzymes play a role in the regulation of the maturation(meiotic arrest or reinitiation) in amphibians.

• Journal of Microbiology and Biotechnology
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• v.27 no.6
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• pp.1065-1070
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• 2017

This study aimed to examine the anti-candidal efficacy of a novel ketone derivative isolated from Diaporthe sp. ED2, an endophytic fungus residing in medicinal herb Orthosiphon stamieus Benth. The ethyl acetate extract of the fungal culture was separated by open column and reverse phase high-performance liquid chromatography (HPLC). The eluent at retention time 5.64 min in the HPLC system was the only compound that exhibited anti-candidal activity on Kirby-Bauer assay. The structure of the compound was also elucidated by nuclear magnetic resonance and spectroscopy techniques. The purified anti-candidal compound was obtained as a colorless solid and characterized as 3-hydroxy-5-methoxyhex-5-ene-2,4-dione. On broth microdilution assay, the compound also exhibited fungicidal activity on a clinical strain of Candida albicans at a minimal inhibitory concentration of $3.1{\mu}g/ml$. The killing kinetic analysis also revealed that the compound was fungicidal against C. albicans in a concentration- and time-dependent manner. The compound was heat-stable up to $70^{\circ}C$, but its anti-candidal activity was affected at pH 2.

• Elastomers and Composites
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• v.54 no.2
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• pp.110-117
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• 2019

The characterization of the ozone oxidation for raw natural rubber (NR) was investigated under controlled conditions through image and fourier transform infrared (FT-IR) analysis. The ozone oxidation was performed on a transparent thin film of raw NR coated on a KBr window in a dark chamber at $40^{\circ}C$ under low humidity conditions to completely exclude thermal, moisture, or light oxidation. The ozone concentration was set at 40 parts per hundred million (pphm). Before or after exposure to ozone, the image of the thin film for raw NR was observed at a right or tilted angle. FT-IR absorption spectra were measured in the transmission mode according to ozone exposure time. The ozone oxidation of NR was determined by the changes in the absorption peaks at 1736, 1715, 1697, and $833cm^{-1}$, which were assigned to an aldehyde group (-CHO), a ketone group (-COR), an inter-hydrogen bond between carbonyl group (-C=O) from an aldehyde or a ketone and an amide group (-CONH-) of protein, and a cis-methine group ($is-CCH_3=CH-$, respectively. During ozone exposure period, the results indicated that the formation of the carbonyl group of aldehyde or ketone was directly related to the decrement of the double bond of cis-1,4-polyisoprene. Only carbonyl compounds such as aldehydes or ketones seemed to be formed through chain scission by ozone. Long thin cracks with one orientation at regular intervals, which resulted in consecutive chain scission, were observed by image analysis. Therefore, one possible two-step mechanism for the formation of aldehyde and ketone was suggested.

• Korean Journal of Pharmacognosy
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• v.40 no.1
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• pp.13-17
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• 2009

It was previously reported that yeast elicitor transiently increased oleanolic acid and ursolic acid in Scutellaria baicalensis suspension cultures and also doubled phospholipase $A_2$ ($PLA_2$) activity. Thus, $PLA_2$ was purified from the soluble fractions of S. baicalensis suspension cultures and the characters of the purified $PLA_2$ were identified. The $PLA_2$ was purified about 160 times compared with the starting soluble-protein extract from S. baicalensis suspension culture cells. The purified protein showed a molecular mass of about 43 kDa by SDS-PAGE. The purified plant $PLA_2$ had a neutral pH optimum (pH 7.0) and required $Ca^{2+}$ for activity. The $PLA_2$ activity was inhibited by mammalian $PLA_2$ inhibitors such as 5,8,11,14-eicosatetraynoic acid(ETYA) and arachidonyl trifluoromethyl ketone ($AACOCF_3$).

• Bulletin of the Korean Chemical Society
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• v.18 no.12
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• pp.1236-1238
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• 1997