• Analytical Science and Technology
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• v.24 no.1
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• pp.15-23
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• 2011

An accurate mass and isotope ratio were determined using a gas chromatography/time of flight mass spectrometer in CI positive mode for the identification of unknown metabolites. High mass tune was used to improve the ion intensity of $[M+H]^+$. Chromatographic resolution and dynamic range enhancement were performed to obtain more reliable accurate masses and correct isotope abundance ratios. Average absolute errors of mass and isotope ratios for 24 reference metabolite -TMS (trimethylsilyl) derivatives were 6.8 ppm, 1.5% of (M+1/M ratio) and 1.7% of (M+2/M ratio), respectively. The correct formulas of twenty one compound were retrieved within top-2 hit from the heuristic algorithm for elemental composition using each accurate mass and isotope abundance ratio.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.582-584
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• 2004

The light-emitting properties of poly(2-triethylgermyl-1,4-phenylenevinylene) (TEG-PPV) are compared with those of the silyl-substituted PPV homologue, poly(2-trimethylsilyl-1,4phenylenevinylene) (TMS-PPV). The precursor polymer is solution-processable. After carrying out thermal elimination on the precursor polymer film, the resulting fully conjugated polymer film was found to exhibit high thermal stability in air, and absorption that is shifted to the longer wavelength region owing to the extension of the n-conjugated system. TEG-PPV exhibits efficient green light emission; the maximum PL emission of a TEG-PPV thin film was found to be at 515 nm. The HOMO and LUMO energy levels were also determined using photo-emission spectroscopy. The performance of the TEG-PPV EL device was found to be comparable to that of the TMS-PPV device.

• YAKHAK HOEJI
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• v.20 no.3
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• pp.125-129
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• 1976

The aim of this investigation was to develop a quantitative gas-liquid chromatographic method of analysis forhyosyamine and scopolamine, and to apply this method to the analysis of preparations. The trimethylsily(TMS) derivatives of the alkaloids were found to be far superior to the nonsilylating compounds in charomatagrams. Bis(trimethylsilyl) acetamide(BSA) was evaluated and found to be a good reagent for silyation of the alkaloids. The optimum derivatization conditions were heating the alkaloids in a closed tube at $70^{\circ)$ for 30 min with a 150 molar excess of BSA to the alkaloids were found to be alkaloids. Calibration curves for the two alkaloids were alkaloid. The standard deviations were 1.1% for hyoscyamine and 1.5% for scopolamine. The minimum detectable amount using the hydrogen flame ionization edtector was determined to be 2$\times$10$^{-11}$ moles of each alkaloid injected.

• Biomolecules & Therapeutics
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• v.1 no.2
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• pp.143-150
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• 1993

The metabolic profile of triprolidine, 2-[(4-methylphenyl)-3-(1-pyrrolidinyl-1-propenyl)] pyridine, was determined. Urinary extracts obtained with enzyme hydrolysis were derivatized with MSTFA/TMSCl (N-methyl-N-trimethylsilyl trifluoroacetamide/trimethylchlorosilane) and analyzed by GC/MSD. In human urine, which were obtained after the oral administration with triprolidine, hydroxymethyltriprolidine, triprolidine carboxylic acid, oxotriprolidine carboxylic acid and unchanged triprolidine were detected. The maximum urinary excretion rate of triprolidine and hydroxymethyltriprolidine which were extracted from human urine was at 2 to 4 hours after the drug administration. Triprolidine and hydroxymethyl triprolidine were identified by comparison with authentic standards In chromatographic and mass spectral properties. Triprolidine carboxylic acid was detected as a major metabolite of its metabolites in the urine. Oxotriprolidine carboxylic acid and triprolidine carboxylic acid were tentatively identified by the interpretation of its mass spectral patterns. These data suggest that in human, hydroxylation of either the benzyl or pyrrolidine ring can occur during triprolidine elimination.

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2319-2323
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• 2007

Introduction of a difluoromethylene group into organic compounds has been observed to impart them with positive properties, as viewed by a wide range of industries. Here, synthesis of 3,3-difluoro-2-pyrrolidone derivatives (7) was accomplished by the reaction of ethyl 2,2-difluoro-4-iodo-4-(trimethylsilyl) butanolate (4) with primary amines followed by desilylation. The key intermediate (4) was prepared from the addition reaction of trimethylvinylsilane (3) to ethyl difluoroiodoacetate (2) in the presence of Cu(0). Ethyl difluoroiodoacetate (2) was prepared starting from ethyl bromodifluoroacetate (1) via Reformatsky-type reaction.

• Journal of Life Science
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• v.9 no.6
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• pp.653-658
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• 1999

A novel marine microorganism, Vibrio sp. YE-101, was isolated from pufferfish and investigated for its ability to synthesize tetrodotoxin (TTX). Various strains isolated from the intestine of pufferfish were grown on TCBS agar plate, and then cultured on Ocean Research Institute (ORI) medium supplemented with 3% NaCl at 23$^{\circ}C$ for 3days. The cells were harvested, disrupted, fractionated by Bio-Gel P-2 column chromatography and then TTX-producing strain, Vibrio sp. YE-101, was identified using mouse bioassay. The isolated TTX from Vibrio sp. YE-101 was also analyzed and identified by HPLC and gas chromatography-mass spectrometer (GC-MS). The mass fragmentation of trimethylsilyl derivatives of C9-base of TTX from Vibrio sp. YE-101 was interpreted and the pattern of fragmentation was same with that of authentic standard. The purfied TTX was also positive to the mouse bioassay, which clearly represents that Vibrio sp. YE-101 can synthesize TTX.

• Bulletin of the Korean Chemical Society
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• v.27 no.8
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• pp.1099-1114
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• 2006

Our studies in the area of single electron transfer (SET) photochemistry have led to the discovery of efficient processes, in which regioselective formation of carbon-centered radicals takes place by nucleophile assisted desilylation of $\alpha$-trialkylsilyl substituted ether, thioether, amine and amide centered cation radicals. The rates of bimolecular desilylation of the intermediate cation radicals exceed those of other cation radical $\alpha$-fragmentation processes (e.g.,-deprotonation). This sereves as the basis for the design of highly regioselective, SET-induced photomacrocyclization reactions of polyether, polythioether, polyamide, and polypeptide linked phthalimides. Photocyclization reactions of trimethylsilyl-terminated substrates in these families are unique in that they produce polyfunctionalized macrocyclic substances in a highly efficient and regioselective manner. In addition, our studies in this area have led to important information about the factors that govern chemical and quantum efficiencies that should be applicable to a wide variety of redox processes promoted by SET from substrates containing more than one electron donor site.

• Journal of Photoscience
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• v.1 no.2
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• pp.89-94
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• 1994

The reaction of decaborane with trimethylsilyldiazomethane gives 1, 2-bis (trimethylsilyl)-1, 2-carba-closo-dodecaborane(12). This compound is similar to the icosahedral cage structure of o-carborane. This formation of the first adduct proceeds through deprotonation of the acidic center of B(9) and B(6) by intermolecular attack by the lone electron pair of the carbene, : CHSiMe$_3$. The yield of product is influenced by irradiation and thermal conditions.

• Journal of the Korean Society of Tobacco Science
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• v.23 no.2
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• pp.162-167
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• 2001

This study was carried out to quantitatively determine phenol compounds in smoke total particulate matter(TPM) to evaluate the qualititive characteristics of flue-cured tobacco varieties(NC82, KFl14 and KFl18). After collecting The TPM by using smoking machine, the concentration of phenol compounds were analyzed by gas chromatography as their trimethylsilyl derivative on a fused capillary column bonded with a 5％ PE ME siloxane stationary phase. In all the flue-cured tobacco varieties, the major phenol components were monohydroxy compounds. The order of the highest concentration of total phenol compounds in TPM was NC82, KF114 and KFl18 but the contents of dihydroxy compound in the KFl18 was higher than those of NC82 and KF114.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.169-172
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• 2004

A gas chromatography/mass spectrometric assay method was developed for the determination of propylene oxide adduct, N-(3-hydroxypropyl)valine. Adduct was released from hemoglobin by alkaline hydrolysis and extract at pH 8 with ethyl ether. The dried extract was completely derivatized with N-Methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA)/TMS-I (100:3). The detection limits of the assay were 0.08 ng/g for N-(3-hydroxypropyl)valine based upon assayed hemoglobin of 0.1 g. The method was applied to the determination of propylene oxide adduct formed in young female Sprague-Dawley rats after treatment for 1, 2 and 3 weeks with 0.008 % propylene oxide via the drinking water. An adduct was detected by proposed procedure. The structure of the adduct could be assigned to N-(3-hydroxypropyl)valine.