• 청정기술
• /
• 제15권1호
• /
• pp.54-59
• /
• 2009

비튜멘으로부터 효과적으로 물을 제거하기 위하여 화학적 항유화제에 의한 물/비튜멘 에멀젼의 분리를 연구하였다. 비튜멘 에멀젼을 모사하기 위해 모사물질로 엔진오일(GS Caltex Deluxe Gold V 7.5W/30, Hyundai gear oil 85W/140)과 아스팔트(AP-5, KS M 2201, (주)동남유화)를 사용하여 예비실험을 수행하였다. 그리고 오일센드로부터 추출한 비튜멘을 이용하여 실험하였다. 예비실험으로 수행된 물/오일 에멀젼의 분리실험에서 함유화제를 첨가하지 경우 에멀젼이 분리되지 않았으며, 항유화제의 농도가 낮을 때 Hyundai 엔진오일은 GS Caltex 엔진오일보다 분리효율이 높았다. 그러나 GS Caltex 엔진오일에 비해서 분리효율의 증가율은 낮았다. Hyundai 엔진오일은 GS Caltex 엔진오일보다 점도가 높아서 물의 분산이 잘 이루어지지 않았기 때문으로 판단된다. 그리고 HLB (hydrophilic-lipophilic balance) 값이 높을수록 분리효율이 높았으며, 사용된 항유화제 중 TWEEN 20 (polyoxyethylene sorbitan monolaurate solution)이 가장 좋은 분리효율을 나타내었다.

• 분석과학
• /
• 제21권3호
• /
• pp.191-200
• /
• 2008

의약물질(PPCPs)은 수질 환경 시료에서 새로운 오염물질로 대두되고 있다. 본 연구에서는 LC/ESI-MS/MS를 이용하여 환경 수질 시료로부터 7 종(2-퀴노사린카르복시산, 아세틸살리실산, 디클로페낙-소듐, 나프록센, 이부프로펜, 메페남산, 탈니플루메이트)의 산성의약물질을 동시 분석하는 방법을 비교하여 개선하였으며 폐수처리장의 유입수 및 방류수 그리고 연장선상의 하천수의 오염도를 측정하였다. LC/ESI-MS/MS 분석을 위해서 MCX (Mixed Cation eXchange) 카트리지와 HLB (Hydrophilic-Lipophilic Balance) 카트리지를 연결하는 텐뎀 고체상 추출법과 MCX 카트리지만을 사용하는 고체상 추출법을 이용하여 효과적인 시료 정제 및 추출을 수행하였다. 검출한계(LODs)와 방법검출한계(MDLs)는 각각 0.05~1.50 pg/mL, 0.17~4.90 pg/mL 범위를나타내었다. 시료중 1.0 ng/mL 농도(n=3)에서절대회수율은 81.9%~116.3%를 나타내었다. 수질 환경 시료에서 수 pg/mL~ng/mL의 농도로 산성의약물질이 측정되었다.

• Journal of Microbiology and Biotechnology
• /
• 제19권4호
• /
• pp.387-390
• /
• 2009

Microbial UDP-glycosyltransferases can convert many small lipophilic compounds into glycons using uridine-diphosphate-activated sugars. The glycosylation of flavonoids affects solubility, stability, and bioavailability. The gene encoding the UDP-glycosyltransferase from Bacillus cereus, BcGT-3, was cloned by PCR and sequenced. BcGT-3 was expressed in Escherichia coli BL21(DE3) with a glutathione S-transferase tag and purified using a glutathione S-transferase affinity column. BcGT-3 was tested for activity on several substrates including genistein, kaempferol, luteolin, naringenin, and quercetin. Flavonols were the best substrates for BcGT-3. The enzyme dominantly glycosylated the 3-hydroxyl group, but the 7-hydroxyl group was glycosylated when the 3-hydroxyl group was not available. The kaempferol reaction products were identified as kaempferol-3-O-glucoside and kaempferol-3,7-O-diglucoside. Kaempferol was the most effective substrate tested. Based on HPLC, LC/MS, and NMR analyses of the reaction products, we conclude that BcGT-3 can be used for the synthesis of kaempferol 3,7-O-diglucose.

• Bulletin of the Korean Chemical Society
• /
• 제31권5호
• /
• pp.1165-1171
• /
• 2010

The lyotropic mesomorphism of lamellar liquid crystalline phase was examined by observing the swelling behavior of Distearoylphosphatidylcholine(DSPC) in glycerin and panthenol without water. The lyotropic mesomorphism was examined by using DSC, XRDs and Cryo-SEM. Increase of two polar solvents under non-hydrous condition showed distinctive differences in the lyotropic mesomorphism from forming different anisotropic structures with DSPC. Glycerin did not affect to the crystalline region of lamellar phase, whereas typical swelling mesomorphism was shown in the noncrystalline region. In contrast, panthenol showed some effect on the crystalline region, but common swelling mesomorphism was found in the non-crystalline region. In this case, the isopropyl and propyl groups in panthenol were the main factor to affect to the lipophilic domain in the crystalline region of lamellar phase. Also, it was found that the formation of well-arranged lamellar structure only by introducing glycerin and panthenol as a solvent without water, was possible. These results were confirmed by examination of the swelling mesomorphism of liquid crystal membrane triggered by introducing the two polar solvents.

• Bulletin of the Korean Chemical Society
• /
• 제31권5호
• /
• pp.1192-1198
• /
• 2010

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in the aquatic environment. Many pharmaceuticals are not completely removed during wastewater treatment, leading to their presence in wastewater treatment effluents, rivers, lakes, and ground water. Here, we developed analytical methods for monitoring ten pharmaceuticals from surface water by LC/ESI-MS/MS. For sample clean-up and extraction, MCX (mixed cation exchange) and HLB (hydrophilic-lipophilic balance) solid-phase extraction (SPE) cartridges were used. The limits of detection (LOD) in distilled water and the blank surface water were in the range of 0.006 - 0.65 and 1.66 - 45.05 pg/mL, respectively. The limits of quantitation (LOQ) for the distilled water and the blank surface water were in the range of 0.02 - 2.17 and 5.52 - 150.15 pg/mL, respectively. The absolute recoveries for fortified water samples were between 62.1% and 125.4%. Intra-day precision and accuracy for the blank surface water were 2.9% - 24.1% (R.S.D.) and -16.3% - 16.3% (bias), respectively. In surface wastewater near rivers, chlortetracycline and acetylsalicylic acid were detected frequently in the range of 0.017 - 5.404 and 0.029 - 0.269 ng/mL, respectively. Surface water near rivers had higher levels than surface water of domestic treatment plants.

• Bulletin of the Korean Chemical Society
• /
• 제29권8호
• /
• pp.1479-1484
• /
• 2008

Protein tyrosine phosphatase (PTP) 1B is the superfamily of PTPs and a negative regulator of multiple receptor tyrosine kinases (RTKs). Inhibition of protein tyrosine phosphatase 1B (PTP1B) has been proposed as a strategy for the treatment of type 2 diabetes and obesity. Recently, it has been reported that amentoflavone, a biflavonoid extracted from Selaginella tamariscina, inhibited PTP1B. In the present study, docking model between amentoflavone and PTP1B was determined using automated docking study. Based on this docking model and the interactions between the known inhibitors and PTP1B, we determined multiple pharmacophore maps which consisted of five features, two hydrogen bonding acceptors, two hydrogen bonding donors, and one lipophilic. Using receptor-oriented pharmacophore-based in silico screening, we searched the biflavonoid database including 40 naturally occurring biflavonoids. From these results, it can be proposed that two biflavonoids, sumaflavone and tetrahydroamentoflavone can be potent allosteric inhibitors, and the linkage at 5',8''-position of two flavones and a hydroxyl group at 4'-position are the critical factors for their allosteric inhibition. This study will be helpful to understand the mechanism of allosteric inhibition of PTP1B by biflavonoids and give insights to develop potent inhibitors of PTP1B.

• KSBB Journal
• /
• 제29권5호
• /
• pp.385-391
• /
• 2014

In this study, the emulsion dispersion stability of optimizing storage temperature was investigated. The system was based on oil/water (O/W) emulsions. In order to evaluate the stability, mean diameter of droplet was measured as a function of temperature with various mixed hydrophilic lipophilic balance (HLB). In addition, the correlations between phase inversion temperature (PIT) and the optimum storage temperature were probed. In this system, majority of the smallest droplet was shown at temperature of $20^{\circ}C$ below PIT. Whether the temperature was increased or decreased from the optimum, size of the droplet increased. According to the mixed HLB, the particle size and optimum storage temperature were also affected. As the concentrations of surfactant were increased, the size of particle decreased with lower optimum temperature for storage. If the surfactant (4 wt%) were mixed with HLB, the optimum storage temperature was $21^{\circ}C$ for maintaining the size of smallest droplet at 108.3 nm in diameter. At above optimum condition, increased size of particle was observed approximately 4 % increases from 108.2 nm to 112.3 nm after 600 hours. The size of particle in emulsion was maintained stably without any considerable effect of Ostwald ripening phenomena at the optimum storage temperature with low polydispersity index.

• Nuclear Medicine and Molecular Imaging
• /
• 제42권3호
• /
• pp.259-260
• /
• 2008

Tetrofosmin is a ligand that forms a lipophilic, cationic complex with Tc-99m. Tc-99m tetrofosmin was developed as a myocardial perfusion imaging agent and also used to depict tumors. Mediastinal tumors is also detected by Tc-99m tetrofosmin. We report a case of extracardiac mediastinal activity detected by Tc-99m tetrofosmin scintigraphy, which revealed thymoma.

• Journal of Pharmaceutical Investigation
• /
• 제22권2호
• /
• pp.139-148
• /
• 1992

A prodrug of cefazolin pivaloyloxymethyl ester (CFZ-PV) was synthesized to improve oral absorption and bioavailability of parent drug by esterification of sodium cefazolin (CFZ) with chloromethyl pivalate. The successful synthesis of CFZ-PV was confirmed by spectroscopic analysis. Partition coefficient studies showed that CFZ-PV is more lipophilic than CFZ. The pharmacokinetic characteristics of CFZ-PV and CFZ preparations were compared following oral administrations of these compounds to rabbits. The analysis of CFZ in plasma was conducted by HPLC method. The ester compound (prod rug) was not detected in plasma following oral administration of CFZ-PV, and although CFZ-PV had not microbiological activity in vitro, the plasma taken after CFZ-PV administration had microbiological activity. From above observations, it was noted that CFZ-PV is rapidly hydrolyzed to CFZ in the body. And it was found that the oral absorption of CFZ-PV was increased, yielding 2-fold higher bioavailability than CFZ. From the results of this experiment, it was concluded that CFZ-PV could be a novel prodrug of CFZ which can improve the oral bioavailability of CFZ.

• Journal of Pharmaceutical Investigation
• /
• 제22권2호
• /
• pp.77-96
• /
• 1992

In recent years intranasal administration of drugs has received great attention as a convenient and efficent method of drug delivery because of its potential to improve the systemic effect of substances with a poor oral bioavailability. In addition to offering advantages such as rapid absorption, fast onset of action and avoiding the first -pass effect, it provides for delivery of drugs from very lipophilic drugs such as steroids to polar and hydrophilic drugs such as peptides and proteins. However, little is still known about the nature of various barriers existing in the nasal mucosae as well as mechanism by which these molecules are absorbed. This review article therefore intends to discuss nasal physiology, experimental methods and evaluation of absorption from the nasal cavity, factors influencing nasal absorption, mechanism of nasal absorption, approaches to improve the residence time and to obtain the sustained-release effect of intranasally administered drugs, promoters and mechanism for the enhancement of nasal absorption, Several examples for intranasal delivery of various systemically effective drugs will be reviewed and illustrated. Drug metabolism in the nasal mucosae and problems associated with intranasal administration of drugs will be also discussed.