• Environmental Analysis Health and Toxicology
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• v.22 no.4
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• pp.299-304
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• 2007

This paper was studied to investigate the equilibrium state between organochlorine pesticides (OCPs) concentration of air and soil, and to know whether soil is a secondary pollution source of OCPs in air or not. The OCPs concentration of air ($C_{air}$) and soil ($C_{soil}$) is not related to molecular weight, vapor pressure ($P_L$) and octanol-air partition coefficient ($K_{oa}$). The slope of the regression line between soil-air partition coefficient ($K_{sa}$) and scavenging coefficient ($C_{soil}/C_{air}$) was 0.2952, which the OCPs concentration between air and soil did not reached to the equilibrium state. The soil/air fugacity quotients ($f_{soil}/f_{air}$) of p, p'-DDT/DDD/DDE and ${\beta}-HCH\;(0.30{\sim}0.67$), which is smaller than 1, means the deposit of OCPs from air to soil. However, $f_{soil}/f_{air}$ of heptachlor, heptachlor epoxide, ${\alpha}/{\gamma}-chlordane$, trans-nonachlor, endosulfan sulfate and ${\alpha}/{\gamma}-HCH\;(1.90{\sim}73.25)$, which is greater than 1, means that soil is secondary pollution source of OCPs in air.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.4
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• pp.265-274
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• 2002

The concentrations of polychlorinated biphenyls (PCBs) in air and plant were measured every other week at Hankyong University located in Ansung, Kyoung-ki province from July to November of 1999. The predicted PCB concentrations in air derived from measured Morus allba were compared with ambient measurement data. This was necessary to test the possibility of using the two equations incorporating Riederer's and Bacci's bioconcentration factors (BCFs) based on the octanol-air partition coefficient (Ksub/oa/) to predict the air-plant equilibrium of PCBs. Ratios of calculated to measured PCB concentrations in air were 2.4 (1.24~4.36), 2.7 (0.17~7.96) using Riederer's and Bacci's equations, respectively Regression analysis between PCBs calculated by Riederer's equation and PCBs directly measured in air, showed correlation ($R^2$= 0.90). However, slope of regression between calculated and directly measured PCB concentrations was above 1. The results thus suggest that calculated PCBs were overestimated comparing with direct measurements. Bio-monitoring using Morus allba may have possibilities in predicting PCBs concentration in air with a further extension of air-plant equilibrium research.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.457-468
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• 2003

Active ingredients have been around in cosmetics for a long time but have they really resulted in active cosmetic products\ulcorner In order to achieve this, the right active needs to be delivered to the right location at the right concentration for the correct period of time. And the extent (and therefore the concentration) of this delivery depends on the formulation. From a rather theoretical approach based on the polarity of the active ingredient, the stratum corneum and the oil phase, the Relative Polarity Index was established that enables the selection of a suitable emollient for ensuring skin penetration of the active ingredient. Practical examples subsequently show the validity of this approach that demonstrates that one can regulate the delivery of an active molecule (and therefore the efficacy of a cosmetic formulation) by selection and control of the emollient system. Cosmetic formulations are generally quite complex mixtures and subsequent experiments using different emulsifier systems indicated that this component of a cosmetic formulation could also have an impact on steering the active ingredient to the right layer of the skin, although it is too early to be able to derive general rules from this.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2361-2367
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• 2010

$TiO_2-ZrO_2$ was prepared with surfactant through a sol-gel method. Catalysts containing 5 - 35% $H_3PO_4$ were prepared using these oxides. Subsequently the catalytic performance of prepared catalysts was determined for liquid phase esterification of aromatic acids. $H_3PO_4/TiO_2-ZrO_2$ has been used as catalyst to synthesize various novel esters by esterification of some aromatic acids with aliphatic alcohols (2-propanol, 1-butanol, iso butanol, 3-pentanol, 1-hexanol, heptanol, cyclo heptanol, octanol and decanol). Under optimized conditions, maximum yields and selectivity (100%) to the corresponding ester, was obtained by using 25 wt % $H_3PO_4/TiO_2-ZrO_2$ as catalyst. The Catalyst can be easily recycled after reaction and can be reused without any significant loss of activity/selectivity performance. No by-product formation, high yields, short reaction times, mild reaction conditions, operational simplicity with reusability of the catalyst are the salient features of the present synthetic protocol. The reaction was carried out under solvent-free condition.

• Archives of Pharmacal Research
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• v.21 no.2
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• pp.174-178
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• 1998

As a new colon-specific prodrug of 5-aminosalicylic acid (5-ASA), 5-aminosalicyl-glycine (5-ASA-Gly) was prepared by a simple synthetic route in good yield. Apparent partition coefficients of 5-ASA-Gly were lower than those of 5-ASA, which determined in$ CHCl_{3}$/pH 6.8 buffer or n-octanol/pH 6.8 buffer system. Stability of 5-ASA-Gly by peptidases was investigated by incubation of 5-ASA-Gly with the homogenates of tissue and contents of stomach, proximal small intestine or distal small intestine of rats at $37^{\circ}C$. 5-ASA was not detected, indicating that the prodrug was stable in the upper intestine. The amount of 5-ASA liberated from incubation of the prodrug in cecal or colonic contents of rats was about 65% or 27% in 8 hrs, respectively, which indicated that the prodrug activation took place more readily in the rat cecum whose bacterial counts are high like human colon. Results from in vitro experiments suggested 5-ASA-Gly as a promising candidate of a colon-specific prodrug of 5-ASA.

• Food Industry And Nutrition
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• v.9 no.1
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• pp.53-57
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• 2004

홍경천(Rhodiola sachalinensis)의 성분을 분석하여 식품학적 특성을 검토하고 식품소재로서의 기초자료로 활용할수 있도록 건조된 홍경천을 분쇄, 분말화한 후 일반성분 및 무기성분, 유리당, 구성아미노산, 유리지방산, 그리고 향기성분을 분석하였다. 홍경천 건조분말의 수분은 10.14%, 조단백 3.90%, 조지방 1.33%, 총당 41.17%, 환원당 11.40% 회분은 3.05%로 분석되었고, 무기성분은 Ca, K, Kg이 높은 함량으로 나타났다. 유리당으로는 glucose, fructose, sucrose 등으로 특히 glucose와 fructose가 높게 함유되어있었다. 주된 구성아미노산은 glutmic acid, cystine arginine, proline, aspartic acid, isoleucine, histidine 등의 함량 순으로 나타났으며, 특히 glutamic acid, cystine, arginine 함량이 각각 176.24, 168.60, 159.90 mg%로 높은 함량 수준을 보였다. 유리지방산은 linoleic acid가 32.46%로 함량이 가장 높았으며 그 다음으로 palmitic acid가 21.42%, lignoceric acid 14.83%, oleic acid 13.09% behenic acid가 5.80% 순으로 나타났다. 향기성분은 GC-MS로 분석한 결과 2-cinnamic aldehyde 함량이 가장 높았으며 geraniol, myrtenol, octanol 등의 함량이 높게 나타났다. 이러한 결과로 볼 때 홍경천 뿌리는 다양한 일반성분 조성과, 필수아미노산, 불포화지방산, 필수 무기질 등이 균형있게 함유된 식품학적 성분 가치가 충분한 소재임이 확인되었다. 따라서 향후 홍경천 뿌리에서 유효성분을 추출하여 생리활성 및 동물실험을 통해 이들 식품학적 성분들의 유용성을 탐색하는 작업이 필요하리라 사료된다.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.2
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• pp.134-139
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• 2006

Methanotrophs are microorganisms that possess the unique ability to utilize methane as their sole source of carbon and energy. A novel culture system, known as the compulsory circulation diffusion system, was developed for rapid growth of methanotrophic bacteria. Methanol dehydrogenase (MDH, EC 1.1.99.8) from Methylomicrobium sp. HG-1, which belongs to the type I group of methanotrophic bacteria, can catalyze the oxidation of methanol directly into formaldehyde. This enzyme was purified 8-fold to electrophoretic homogeneity by means of a 4 step procedure and was found in the soluble fraction. The relative molecular weight of the native enzyme was estimated by gel filtration to be 120 kDa. The enzyme consisted of two identical dimers which, in turn, consisted of large and small subunits in an ${\alpha}_2{\beta}_2$ conformation. The isoelectric point was 5.4. The enzymatic activity of purified MDH was optimum at pH 9.0 and $60^{\circ}C$, and remained stable at that temperature for 20 min. MDH was able to oxidize primary alcohols from methanol to octanol and formaldehyde.

• Applied Chemistry for Engineering
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• v.8 no.2
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• pp.246-251
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• 1997

The phase behavior of sucrose monopalmitate/alkanol/water ternary system was investigated. According to compositions of three components ranging from micellar(or inverse micellar) solution up to various lyotropic liquid crystalline(LC) phase, each texture of the separated phases was identified by crossed polarizers equipped with a camera whose stage was connected to a thermostatic circulator. As the carbon atom number in alkanol of the polar oily substance increases, patterns of the various LC phases were also observed hexanol

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.107-107
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• 1993

결과 및 고찰: 이 약의 흰쥐에서의 체내동태는 혈중농도로 볼 때 2-exponential pharmacokinetics에 따르고, HPLC법으로 정량한 경우의 $T_1$/$_2$$\alpha$, $T_1$/$_2$$\beta$, AUC, C $L_{T}$, C $L_{R}$, V $D_{SS}$ 는 각각 1.90min, 21.89min, 1899.36$\mu\textrm{g}$ㆍmin/ml, 10.66ml/min/kg, 7.48ml/min/kg, 0.28l/kg으로 bioassay법과는 약간의 차이를 보였다. 분포특성은 간장과 신장에 많이 이행하였으며, 폐로의 이행도 적지만 관찰되었다. 이 약의 단백결합률은 그 농도가 31.3$\mu$M일 때 42.3%였고 water/n-octanol계에서의 유상으로의 분배는 거의 일어나지 않았다. 이 약의 분포용적이 작은 것은 단백결합 때문이라기보다는 높은 극성때문으로 추정되었다. 이 약의 C $L_{R}$은 GFR의 문헌치보다 컸으며 C $L_{T}$의 약 2/3을 차지하므로 약물소실에 있어서 신장의 기여도가 크고 신배설 과정에 신분비가 관여하고 있음을 알 수 있었다. 이런 사실은 CAZ나 CTX등의 기존 세파계 항생제들과 유사했으며, 추후 다회투여시와 용량의존적 체내동태에 관해 더 많은 연구가 필요하리라 생각되었다.되었다.

• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.926-932
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• 2006

A series of bench-scale membrane filtration experiments were performed to systematically investigate the removal mechanisms of reverse osmosis (RO) and nanofiltration (NF) membranes for BTEX (benzene, toluene, ethylene, xylene), trichloroethylene (TCE) and tetrachloroethylene (PCE). The molecular weight of these organic compounds ranged from 78 to 166 dalton. The rejection of organic compounds by RO/NF membranes varied significantly from 59.6 to 99.2% depending on solute and membrane types. Specifically, experimental results demonstrated that the removal efficiency of RO/NF membranes increased as solute molecular characteristics such as W/L (molecular width/length) ${\times}$ $M_W$ (molecular weight) and octanol-water partition coefficient increased. This observation suggested that the rejection of small organic compounds by RO/NF membranes was determined by the combined effect of physical (molecular size and shape) and chemical (hydrophobicity) properties.