• Analytical Science and Technology
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• v.21 no.6
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• pp.543-552
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• 2008

This paper described the relatively sensitive and simultaneous analytical method for 3-monochloropropane-1,2-diol (3-MCDP, $C_3H_7ClO_2$, MW. 110) as well as 1,3-dichloropropan-2-ol (1,3-DCP, $C_3H_6Cl_2O$, MW. 128) in various foods. Food samples were homogenized in 5M NaCl solution, mixed with aluminum oxide and eluted with dichloromethane. The extracted chloropropanols were concentrated by rotary evaporator and $N_2$ blow serially were derivatized with HFBA (Heptafluorobutyric anhydride, $C_8F_{14}O_3$, MW. 410) and were determined by GC/MS using isotope dilution method. The characteristic molecular ions at m/z 253, 275, 289, 291, and 453 for HFBA derivatives of 3-MCPD (MW. 502) and 110, 275, and 277 for HFBA derivatives of 1,3-DCP (MW. 325) were chosen in selected ion mode. The method validation data showed sufficiently good properties of LOD (0.003 mg/kg), LOQ (0.010 mg/kg), linearity ($R^2{\geq}0.999$ at 0.010~1.000 mg/kg), and recovery rate (${\approx}97%$). The levels of chloropropanols in soy sauce, sauces, processed meat products, fishery products, and seasonings (n=56/157) determined by the presented method were 0.0~0.3 mg/kg.

• KSBB Journal
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• v.9 no.3
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• pp.246-252
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• 1994

Enzyme-catalyzed polycondensatlon reaction of aliphatic polyesters with several repeating units was studied using the biocatalytic activities of lipases from different sources. Porcine pancreatic lipase (PPL) was found to be best in utilizing bls(2,2,2-trichloroethyl) glutarate and 1,4-butanediol as substrafes. The reaction was also catalyzed to some extent by the lipases from Humicola lanuginos and Psudomonas sp. In the series of short-chain diols(C2-C4), bis(2,2,2-trichloroethyl) glutarate was iransesterified fastest with 1,4-butanediol and for the long-chain diols (PEG-300-PEG-1000), the reaction was fastest with PEG-400. With PEGs, only monoesterification product was obtained. PPL functioned well in relatively hydrophilic organic solvents such as tetrahydrofuran(THF), ether and acetonitrile. The reaction rate was accelerated as the reaction temperature was raised from $20^{\circ}C$ to $60^{\circ}C$ while Mn values of the reaction products were not affected by the reaction temperature. End group analysis by NMR showed that Mn values of the polymer were in the range of 1500-4000 daltons.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.360-365
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• 2007

The studies for the derivatization of 3-monochloropropane-1,2-diol (3-MCPD) were performed mainly as acylation with HFBI (heptafluorobutyrylimidazole), alkylation with PBA (phenylboric acid) and silylation with BSTFA (N,O-bis[trimethylsilyl]trifluoroacetamide). Also silylation with MTBSTFA(N-methyl-N-[tert.-butyldimethylsilyl] trifluoroacetamide) and acylation with MBTFA (N-Methyl-bis[trifluoro-acetamide]) were also considered. Except the TBDMS derivative of 3-MCPD, all the derivatives were detected well. The derivatives of 3-MCPD with HFBI, PBA and BSTFA showed below 10 ${\mu}g/kg$ which was sensitive enough to satisfy Korea maximum residue limit 0.3 mg/kg. Among the tested adsorbents, Extrelut20 and Florisil were evaluated as the proper adsorbents to eliminate the soy sauce matrix for 3-MCPD. Ethyl acetate was the most efficient eluent with good recovery rate. The desired surrogate compound and internal standard were 1,2-butanediol and 1,2-dibromo-3-chloropropane, respectively. The limit of detection for PB-MCPD and TMS-MCPD were 10.16 and 7.06 ${\mu}g/kg$ on GC/MSD, respectively. HFB-MCPD derivative showed the lowest detection limits 2.98 and 5.32 ${\mu}g/kg$ by GC/ECD and GC/MSD, respectively.

• Journal of Applied Biological Chemistry
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• v.55 no.2
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• pp.103-107
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• 2012

Acanthopanax sessiliflorus Seeman fruits (Araliaceae) were extracted at room temperature with 70% aqueous ethanol (EtOH). The concentrated extract was partitioned with ethyl acetate (EtOAc), n-butyl alcohol, and $H_2O$, successively. From the EtOAc fraction, four compounds were isolated through the repeated silica gel and octadecyl silica gel (ODS) column chromatographies. According to the results of physico-chemical and spectroscopic data including NMR, IR, and gas chromatography/mass spectrometer, the chemical structures of the compounds were determined as stigmasterol (1), linoleic acid (2), ${\beta}$-sitosterol (3), and stigmast-5-en-$3{\beta}$,$7{\beta}$-diol (4).

• Analytical Science and Technology
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• v.20 no.3
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• pp.198-203
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• 2007

The analysis method of 3-Monochloropropane-1,2-diol (3-MCPD) compound in water was developed using liquid chromatography with mass spectrometric detection. Aqueous solution was controlled in strong basic condition with sodium hydroxide, and then $25{\mu}L$ of benzoyl chloride was added to the solution for the derivatization of 3-MCPD. The derivative was extracted using pentane and analyzed by the selected ion monitoring (SIM) method of LC-MS. The results of analyses showed that the calibration curves was in the range of 1.0 to $100{\mu}g/mL$ with a good linearity (correlation coefficient of $r^2=0.992$) and limit of detection was below $0.01{\mu}g/mL$. The recoveries of this analysis method by LC-MS were 92.3-98.0 %.

• YAKHAK HOEJI
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• v.40 no.2
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• pp.163-169
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• 1996

Glycosidation of 20(S)-protopanaxadiol obtained by the alkaline hydrolysis of total ginsenosides with 2,3,4,6-tetra-O-acetyl-${\alpha$-D-glucopyranosyl bromide in the presence of $CdCO_3$ in benzene-dioxane gave a mixture of acetylated monoglucosides and diglucosides in a total yield of 68%. Under the same condenstion condition, 20-dehydroxyglucosides were formed by dehydration of 12-O-glucosides. The structures of produced glycosides were elucidated as 3-O-${\beta$-D-glucopyranosyl-20(S)-protopanaxadiol, 12-O-${\beta$-D-glucopyranosyl-dammar-20(22), 24-dien-$3{\beta},12{\beta}$-diol, 3,12-di-O-${\beta}$-D-glucopyranosyl-dammar-20(22), 24-dien-$3{\beta},\;12{\beta}$-diol, respectively.

• Biomolecules & Therapeutics
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• v.9 no.3
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• pp.143-155
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• 2001

Many attention has been focused on developing new chemotherapeutic agents for a treatment of cancer from natural products. From Carpesium divaricatum S. et Z. (Compositae), various monoterpenoid compounds were isolated and exhibited mild antitumor activity against human tumor cell lines. These facts prompted us to explore the structure-activity relationship of these compounds. The synthesis of monoterpenoid compound was accomplished by Fries rearrangement, Grignard reaction, elimination, allylic oxidation, esterification and epoxidation as key steps. The results of in vitro cytotoxicity (A549, SK-OV-3, SK-MEL-2, XF498, HCT15) of the synthesised compounds are as follows: First of all, epoxide moiety is prerequisite for cytotoxic activity in diester compound. Any kind of compounds with olefin or diol moiety instead of epoxide ring exhibited poor or mild cytotoxic activity respectively. Of o-acetoxy and isobutoxy epoxy esters, p-sub-stituted phenylacetate compounds exhibited high cytotoxic activities against SK-MEL-2 and HCT15.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.418-418
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• 2012

We fabricated a new type of hybrid film using molecular layer deposition (MLD). The MLD is a gas phase process analogous to atomic layer deposition (ALD) and also relies on a saturated surface reaction sequentially which results in the formation of a monolayer in each sequence. In the MLD process, polydiacetylene (PDA) layers were grown by repeated sequential surface reactions of titanium tetrachloride and 2,4-hexadiyne-1,6-diol with ultraviolet (UV) polymerization under a substrate temperature of $100^{\circ}C$. Ellipsometry analysis showed a self-limiting surface reaction process and linear growth of the hybrid films. Polymerization of the hybrid films was confirmed by infrared (IR) spectroscopy and UV-Vis spectroscopy. Composition of the films was confirmed by IR spectroscopy and X-ray photoelectron (XP) spectroscopy. The titanium oxide cross-linked polydiacetylene (TiOPDA) hybrid films exhibited good thermal and mechanical stabilities.

• Elastomers and Composites
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• v.55 no.1
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• pp.20-25
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• 2020

The effect of the isocyanate index (NCO index) on the particle size and particle size distribution of a waterborne polyurethane dispersion (WPUD) with polycarbonate-diol was determined. The WPUDs were prepared using a conventional acetone process with polycarbonate-polyol (M_n = 2028), 4,4'-methylenebis(cyclohexyl isocyanate) (H₁₂MDI), 2,2-bis(hydroxymethyl) propionic acid (DMPA), and dibutyltin dilaurate catalyst. At NCO index values below 1.5, the number average particle diameter of the WPUDs significantly increased with the NCO index, whereas the particle diameter slightly varied at higher NCO indexes. The dependency of the WPUD viscosity on the NCO index exhibited similar behavior to that of the particle size. The relative values of the full width at half maximum of the WPUD particle distribution curves at various NCO indexes were not influenced by the NCO index.

• Bulletin of the Korean Chemical Society
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• v.19 no.3
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• pp.314-319
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• 1998

One flask synthesis of dithienylmethane and difurylmethane is reported. The reaction of aldehydes with excess furan or thiophene affords the meso-phenyldithienylmethane (DTM) and meso-phenyldifurylmethane (DFM), respectively. The reaction is catalyzed with trifluoroacetic acid or with BF3·O(Et)2. An acyl group is selectively introduced in 1 and 9 position of difurylmethane and dithienylmethane by use of an acid chloride and tin (IV) chloride. The reduction of resulting 1,9-bisacyldifurylmethane or 1,9-bisacyldithienylmethane affords the corresponding 1,9-bis-diol. An acid catalyzed condensation of diol with meso-phenyldipyrromethane followed by oxidation with DDQ gives the porphyrins. The reaction resulted meso-5,10,15,20-tetraphenyl-21,22-dithiaporphyrin (SSNN) or 15-mesityl-5,10,20-triphenyl-21,22-dioxaporphyrin (OONN), respectively. The formation of small amount of meso-tetraphenylporphyrin (TPPH2) is also observed. The formation of TPP indicates that meso-phenyldipyrromethane is reversibly cleaved and form pyrrole and pyrrylbenzylcarbocation during the condensation. The proton nmr and electronic spectrum of the SSNN and OONN porphyrins are somewhat different from the previously synthesized meso-5,10,15,20-tetraphenyl-21,23-dithiaporphyrin (SNSN) or meso-5,10,15,20-tetraphenyl-21,23-dioxaporphyrin (ONON).