• Korean Chemical Engineering Research
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• 제44권2호
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• pp.121-128
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• 2006

티타늄 함유 제올라이트 촉매 TS-1과 Ti-MCM-22를 이용하여 과산화수소를 산화제로 한 프로필렌 에폭시화반응을 수행하였으며, 반응에 미치는 촉매량, 한계 반응물인 과산화수소의 양, 교반 속도, 반응 온도, 압력, 용매 및 생성물 억제 효과를 조사하였다. TS-1은 우수한 부분 산화반응 촉매로 표준 반응조건($45^{\circ}C$, 7 atm, 0.5 g catalyst, 2.5 wt％ $H_2O_2$, 메탄올 용매, 1,000 rpm 교반)에서 95％ 이상의 $H_2O_2$ 전화율과 94％ 이상의 산화프로필렌(propylene oxide, PO) 선택도를 얻을 수 있었다. 한편 아세토나이트릴(acetonitrile) 용매 하에서 반응 실험을 한 결과 Ti-MCM-22는 99％의 $H_2O_2$ 전화율과 100％에 근접하는 산화프로필렌 선택도를 보이며, 양론비에 가까운 수율을 보였다.

• Bulletin of the Korean Chemical Society
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• 제16권1호
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• pp.53-58
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• 1995

Heats of solution of aniline (AN), benzylamine (BA), ethyl-(EBS) and 2-phenylethyl benzenesulfonates (PEB) are calorimetrically measured in acetonitrile-methanol mixtures at 25.0 $^{\circ}C$. The activation parameters, ${\Delta}H^{\neq}$, ${\Delta}S^{\neq}$ and ${\Delta}G^{\neq}$, are determined for the reactions of EBS and PEB with AN and BA using the kinetic data at three temperatures. Calorimetric transfer enthalpies of initial state, ${\delta}H_t^{0{\rightarrow}x})$(IS), and kinetically derived activation enthalpies, ${\delta}\;{\Delta}H^{\neq}$, in the MeCN-MeOH mixtures are combined to determine the transfer enthalpies of transition state, ${\delta}H_t^{0{\rightarrow}x})$(TS); ${\delta}H_t^{0{\rightarrow}x})$(IS) = ${\delta}{\Delta}H^{\neq}\;+\;{\delta}H_t^{0{\rightarrow}x}$(IS) The preferential solvation of anionic charge in the TS predicts a loose TS with a greater degree of bond cleavage for the reactions of PEB than for EBS, and also for the reactions with BA compared to the reactions with AN.

• Bulletin of the Korean Chemical Society
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• 제28권10호
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• pp.1670-1674
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• 2007

Addition reactions of anilines (XC6H4NH2) to β-nitrostilbene (YC6H4CH=C(NO2)C6H4Y') have been investigated in acetonitrile at 30.0 oC. The magnitude of βX values (=0.11-0.34) indicates relatively earlier transition state for additions with anilines than with benzylamines. The signs of ρY and ρY' are positive with Δρ = ρY?ρY' = 0.04, demonstrating a TS imbalance with a negative charge development on the Cβ in the TS. The signs of cross-interaction constants ρXY (<0), ρXY' (<0) and ρYY' (>0) are consistent with bond forming and breaking processes. The relatively weak normal kinetic isotope effects involving deutarated nucleophiles, kH/kD>1, suggest an early, hydrogen-bonded, 4-member cyclic TS.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2707-2710
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• 2012

The nucleophilic substitution reactions of O-ethyl phenyl phosphonochloridothioate with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are kinetically investigated in acetonitrile at $55.0^{\circ}C$. The deuterium kinetic isotope effects (DKIEs) invariably increase from a secondary inverse DKIE ($k_H/k_D$ = 0.93) to a primary normal DKIE ($k_H/k_D$ = 1.28) as the substituent of nucleophile (X) changes from electron-donating to electron-withdrawing. These can be rationalized by the gradual transition state (TS) variation from a backside to frontside attack. A concerted $S_N2$ mechanism is proposed. A trigonal bipyramidal TS is proposed for a backside attack while a hydrogen-bonded, four-center-type TS is proposed for a frontside attack.

• Toxicological Research
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• 제31권4호
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• pp.371-392
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• 2015

TS-DP2 is a recombinant human granulocyte colony stimulating factor (rhG-CSF) manufactured by TS Corporation. We conducted a four-week study of TS-DP2 (test article) in repeated intravenous doses in male and female Sprague-Dawley (SD) rats. Lenograstim was used as a reference article and was administered intravenously at a dose of $1000{\mu}g/kg/day$. Rats received TS-DP2 intravenously at doses of 250, 500, and $1000{\mu}g/kg/day$ once daily for 4 weeks, and evaluated following a 2-week recovery period. Edema in the hind limbs and loss of mean body weight and body weight gain were observed in both the highest dose group of TS-DP2 and the lenograstim group in male rats. Fibro-osseous lesions were observed in the lenograstim group in both sexes, and at all groups of TS-DP2 in males, and at doses of TS-DP2 $500{\mu}g/kg/day$ and higher in females. The lesion was considered a toxicological change. Therefore, bone is the primary toxicological target of TS-DP2. The lowest observed adverse effect level (LOAEL) in males was $250{\mu}g/kg/day$, and no observed adverse effect level (NOAEL) in females was $250{\mu}g/kg/day$ in this study. In the toxicokinetic study, the serum concentrations of G-CSF were maintained until 8 hr after administration. The systemic exposures ($AUC_{0-24h}$ and $C_0$) were not markedly different between male and female rats, between the administration periods, or between TS-DP2 and lenograstim. In conclusion, TS-DP2 shows toxicological similarity to lenograstim over 4-weeks of repeated doses in rats.

• Biotechnology and Bioprocess Engineering:BBE
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• 제2권2호
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• pp.122-125
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• 1997

The utilization of excess whey is necessary to reduce dairy waste because the large amount of whey disposal in waste streams has caused environmental problems. During whey protein film production as the effective means of utilization of excess whey, we have examined the effects of pH, temperature, and plasticizers for water vapor permeability(WVP), tensile strength(TS), and elongation rate(%E) of the whey protein films. The 10% whey protein films had the highest WVP(28.73g$.$mm/kPa$.$day$.$㎡) and TS(1.85${\pm}$0.11Mpa). But, in this case, an increase of WVP was caused by the thickness of whey protein films. At the concentration of 8% whey protein, appropriate thickness was obtained. Whey protein films prepared at the pH 6.75 and 95$^{\circ}C$ showed lower WVP(28.38g$.$mm/kPa$.$day$.$㎡) and elongation rate(12.9%) and higher TS value(3.769${\pm}$0.407 MPa) than at the pH 6.75 and 75$^{\circ}C$. As the temperature increased, WVP of films decreased slightly and tensile strength increased slightly, while elongation rate decreased significantly. Higher WVP and TS were observed at pH6.75 compared to pH7-9. In contrast, significantly higher elongation was observed at pH 9comapred to pH6.75-8. Among the plasticizer types used, the addition of sorbitol showed the highest TS value(6.244${\pm}$0.297 MPa) at the concentration 0.4g sorbitol and elongation rate(49%) at the concentration of 0.6g sorbitol.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2628-2632
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• 2011

The nucleophilic substitution reactions of Y-O-aryl phenyl phosphonochloridothioates with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are kinetically investigated in acetonitrile at $55.0^{\circ}C$. The deuterium kinetic isotope effects (DKIEs) invariably increase from an extremely large secondary inverse ($k_H/k_D$ = 0.439; min) to a primary normal ($k_H/k_D$ = 1.34; max) as both substituents of nucleophile (X) and substrate (Y) change from electron-donating to electron-withdrawing. These results are opposite to the DKIEs on Y-O-aryl methyl phosphonochloridothioates, and can be rationalized by the gradual transition state (TS) variation from backside to frontside attack. The trigonal bipyramidal pentacoordinate TS is proposed for a backside attack, while the hydrogen-bonded, four-center-type TS is proposed for a frontside attack. The negative values of the cross-interaction constants (${\rho}_{XY(H)}$ = -0.38 for $XC_6H_4NH_2$ and ${\rho}_{XY(D)}$ = -0.29 for $XC_6H_4ND_2$) indicate that the reactions proceed by a concerted $S_N2$ mechanism.

• 한국미생물·생명공학회지
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• 제36권3호
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• pp.182-188
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• 2008

내열성 Trehalose synthase를 생산하는 초고온성 균주 HJ6은 일본 Arima 온천수에서 분리하였다. 세포의 길이는 $2{\sim}4\;um$, 직경 0.4 um의 간균으로 생육최적 pH와 온도는 각각 6.5와 $80^{\circ}C$이였다. 분리된 균주의 16s rRNA 염기서열을 분석하고 계통학적으로 분류한 결과, HJ6 균주는 Thermus thermophilus에 속하는 것으로 동정되었다. PCR법을 이용하여 trehalose synthase(TS) 유전자를 클로닝하고 염기서열을 분석한 결과, ORF는 2,898개의 뉴클레오타이드로 구성되고 915개의 아미노산을 암호화하였다. 아마노산 서열을 바탕으로 상동성을 분석한 결과, Thermus caldophilus GK24 유래 TS와 99%, Meiothermus ruber 유래 TS와 83%의 identity를 나타내었다. 이 유전자를 온도감수성 프로모터를 포함하는 pJLA503 벡터를 이용하며 대장군에서 발현하고 정제하여 약 110 kDa 단백질을 얻을 수 있었다. 정제된 효소는 트레할로스 전환활성에 대한 최적 pH가 7.5이고, 최적온도는 $80^{\circ}C$이며, 활성의 반감기는 $90^{\circ}C$에서 40분으로 확인되어 높은 내열성을 가지는 것으로 확인되었다. 본 효소의 트레할로스 최대 전환율은 기질농도 500mM에서 55.7%를 나타내었고, 기질 농도가 증가함에 따라 더불어 증가하였기 때문에 본 효소의 트레할로스 전환율을 기질농도에 의존적인 것으로 생각되었다.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.3065-3072
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• 2013

Direct synthesis of $H_2O_2$ and in situ oxidative desulfurization of model fuel over Au/Ti-HMS and Au/TS-1 catalysts has been comparatively investigated in water or methanol. Maximum amount (82%) of active $Au^0$ species for $H_2O_2$ synthesis was obtained. Au/Ti-HMS and Au/TS-1 exhibited the contrary performances in $H_2O_2$ synthesis as $CH_3OH/H_2O$ ratio of solvent changed. $H_2O_2$ decomposition and hydrogenation in water was inhibited by the introduction of methanol. Effect of $O_2/H_2$ ratio on $H_2O_2$ concentration, $H_2$ conversion and $H_2O_2$ selectivity revealed a relationship between $H_2O_2$ generation and $H_2$ consumption. The highest dibenzothiophene removal rate (83.2%) was obtained over Au/Ti-HMS in methanol at 1.5 of $O_2/H_2$ ratio and $60^{\circ}C$. But removal of thiophene over Au/TS-1 should be performed in water without heating to obtain a high removal rate (61.3%). Meanwhile, $H_2$ conversion and oxidative desulfurization selectivity of $H_2$ were presented.

• 생명과학회지
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• 제28권6호
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• pp.648-655
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• 2018

신령버섯 액체배양추출물(Agaricus blazei mycelial liquid culture extract: ABMLCE)과 eritadenine (EA)의 mouse 정소 Leydig TM3 세포에서 testosterone (TS) 생성에 관한 연구를 정상 조건과 산화스트레스 조건에서 수행하였다. 정상 조건에서는 TM3 세포를 DMEM 배지에 배양하면서 EA (0~100 ppm)와 EA (0~50 ppm) + ABMLCE (10 ppm)를 24 hr처리하였다. 산화스트레스 조건에서는 TM3 세포를 $H_2O_2$ ($50{\mu}M$)를 4 hr 처리하고 정상 조건과 동일하게 처리하였다. DMEM 배양물에 함유된 TS 함량, HSD3B2 효소 활성, $5{\alpha}-R2$ 효소 활성과 NO 함량을 assay kit를 사용하여 측정하였다. EA는 정상 조건이나 산화스트레스 조건에서 TS 함량을 유의성 있게 증가시켰고, ABMLCE와 ABMLCE + EA도 TS의 함량을 증가시켰다. TS 전구체 생성에 관여하는 HSD3B2 효소 활성은 두 조건에서 모두 EA, ABMLCE, ABMLCE + EA에 의해서 증가되었다. 또한 TS를 DTH로 전환시켜 TS함량을 감소시키는 역할을 하는 $5{\alpha}-R2$ 효소활성은 정상 조건 및 산화스트레스 조건에서 ABMLCE에 의해서만 감소되었다. Free radical로 작용하는 NO의 함량은 두 조건 모두 EA, ABMLCE, ABMLCE + EA에 의해 감소되었다. 이 결과는 EA, ABMLCE, ABMLCE + EA 처리가 TM3 세포의 HSD3B2 효소 활성을 증가시키고, NO 생성을 억제하여 TS 함량을 증가시켰음을 의미하며 EA + ABMLCE 혼합물이 남성 성기능개선 물질로 사용될 수 있음을 의미한다.