http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
산성용액 중에서 Phenyl N-(p-chlorobenzoyl)chloroformimidate 유도체의 가수분해 반응 메카니즘
성낙도,전용구,권기성,김태린,Nack-Do Sung,Young-Gu Cheun,Ki-Sung Kwon,Tae-Rin Kim 대한화학회 1987 대한화학회지 Vol.31 No.4
$25^{\circ}C$의 1 : 4 dioxane-물의 혼합용액속에서 파라-치환된 phenyl N-(p-chlorobenzoyl)chloroformimidate (I) 유도체들의 가수분해 반응속도 상수를 측정하고 반응속도식, 치환기 효과$(\rho\>{\rho}^+)$, 생성물 분석 및 분자궤도 함수의 계산 결과로부터 pH3.0 이하에서는 azocarbonium 이온(II)이 생성되는 $S_N1$반응 메카니즘으로 무촉매 반응이 일어나며, pH 4.0이상에서는 전이상태(III)를 지나는 $S_N2$반응 메카니즘을 통하여 염기 촉매반응이 일어남을 제안 할 수 있었다. 4가지 peri planar형태 이성질체들의 상대적인 안정도는 각각 (E-ap) > (Z-ap) > (E-sp) > 및 (Z-ap)이었고, (E-ap)형태의 가장 안정한 입체구조는 benzimidochloroformyl group면에 대하여 Y-치환 phenyl group이 수직$(90^{\circ})$을 이루었으며 (I)의 활성화된 azomethine탄소 원자에 대하여 물분자는 시그마 공격에 의하여 친핵성 반응이 일어난다. Rate constants for the hydrolysis of para-substituted phenyl N-(p-chlorobenzoyl)chloroformimidate (I) derivatives in 1 : 4 dioxane-water at $25^{\circ}C$ have been determined. Rate data, substituent effect $(\rho\>{\rho}^+)$, product analysis and MO calculation indicate that the uncatalyzed reaction proceeds through an $S_N1$ mechanism involving the formation of azocarbonium ion (II) below pH 3.0, and the base-catalyzed reaction proceeds through an $S_N2$ mechanism via transition state (III) above pH 4.0. The relative stability of four peri planar conformational isomers were (E-ap) > (Z-ap) > (E-sp) > (Z-ap), respectively, and the most stable stereo structures shows that the Y-substituted phenyl group $(C_6H_4-Y)$ occupy vertical $(90^{\circ})$ position on the plane of the benzimidochloroformyl group in (E-ap) conformer. The nucleophilic substitution of water molecule occurs by sigma attack to the activatived azomethine carbon atom of (I) derivatives.
정량적인 구조-활성상관(QSAR) 기법에 의한 새로운 농약의 개발 -IV. 국내의 연구 동향과 전망-
성낙도,Sung, Nack-Do 한국응용생명화학회 2003 한국농화학회지 Vol.46 No.3
Biological Hammett Equation에 기초하여 Hansch-Fujita식으로 제안된 정량적인 구조 활성상관(QSAR) 기법 (Sung, Nack-Do (2002) Development of new agrochemicals by quantitative structure-activity relationship (QSAR) methodology. Kor. J. Pestic. Sci. 6: 166-174, 231-243 및 7: 1-11)에 따른 새로운 농약의 탐색과 개발에 관련하여 1990년도를 전후한 국내에서 이루어진 QSAR 기법중 주로 2D QSAR기법의 활용연구 현황에 대하여 조명하였다. It was reviewed for the status of domestic research before and after 1990's for search of a new pesticides using 2D QSAR of quantitative structure-activity relationship (QSAR) methodologies (Sung, Nack-Do (2002) Development of new agrochemicals by quantitative structure-activity relationship (QSAR) methodology. Kor J. Pestic. Sci. 6, 166-174, 231-243 & 7, 1-11) which was proposed according to Hansch-Fujita equation based on the concept of biological Hammett equation.
Benzenesulfonylimido Phosgene 의 加水分解 反鷹메카니즘과 反鷹速度論的 硏究
성낙도,한선호,권기성,김태린,Sung, Nack-Do,Han, Sun-Ho,Kwon, Ki-Sung,Kim, Tae-Rin 대한화학회 1984 대한화학회지 Vol.28 No.4
1 : 4 dioxane-물의 혼합용매중에서 benzenesulfonylimido phosgene의 가수분해 반응속도 상수를 자외선 분광법으로 측정하여 넓은 pH범위에서 잘 맞는 반응속도식을 구하였다. Grunwald-Winstein식에 적용하여 pH4.0에서 m=0.4의 값을 얻었으며 열역학적 활성화 파라미터 값은 pH4.0에서 ${\Delta}H^{\neq}$ = 15kcal/mol과 $ {\Delta}S^{\neq}$ =-21e.u 그리고 pH10.0에서는 $ {\Delta}H^{\neq}$ = 8kcal/mol, ${\Delta}S^{\neq}$ = -39e.u.이었다. 이와 같은 결과로부터 잘 알려져 있지않은 benzenesulfonylimido phosgene의 친핵성 첨가-제거 반응메카니즘을 정량적으로 잘 설명할 수 있었다. The rate constants for the hydrolysis of benzenesulfonylimido phosgene at various pH were determined by ultraviolet spectrophotometry in 1 : 4 dioxane-water mixed solvents at 25$^{\circ}$C and a rate equation which can be applied over a wide pH range was obtained. Based on the Grunwald-Winstein equation, m = 0.4 was obtained. The thermodynamic activation parameters for the hydrolysis were ${\Delta}H^{\neq}$ = 15kcal mol$^{-1}$, ${\Delta}S^{\neq}$ = 21e.u. at pH 4.0 and $ {\Delta}H^{\neq}$ = 8kcal. mol$^{-1}$, ${\Delta}S^{\neq}$ = -39e.u. at pH 11.0, respectively. It was concluded that the hydrolysis of benzenesulfonylimido phosgene in 1 : 4 dioxane-water mixed solvents proceed via nucleophilic addition-elimination.
핵산 모델로서 Phosphate Diester 들의 가수분해 반응
성낙도 ( Nack Do Sung ) 한국응용생명화학회 1994 Applied Biological Chemistry (Appl Biol Chem) Vol.37 No.6
Rate of hydrolysis ethylene phosphate, dimethylphosphate and hydroxyethylmethylphosphate in neutral water have been measured. Hydrolysis of ethylene phosphate proceeds with P-0 bond cleavage (k_(obs)=3×10^(-7)s^(-1) at 100℃, △H^*=24 ㎉, △S^*=25.5 eu). In constrast, hydrolysis of dimethylphosphate proceeds with C-O bond cleavage (k_(obs)=3×10^(-11)s^(-1) at 150℃). The rate constant for P-O bond cleavage of dimethylphosphate is estimated at 1×10^(-11)s^(-1) at 150℃ (△H^*=36 ㎉, △S^*=25.5 eu). A phosphodiesterase catalyzed hydrolysis of dimethylphosphate is 10^(17) times faster than the simple water rate. The observed rate of hydrolysis of hydroxyethylmethylphosphate is comparable to that of dimethylphosphate indicating C-O bond cleavage (k_(obs)=6×10^(-7)s^(-1) at 150℃).
성낙도 ( Nack-do Sung ),정훈성 ( Hoon-sung Jung ),김상진 ( Sang-jin Kim ) 대한화장품학회 2004 대한화장품학회지 Vol.30 No.4
일련의 Alkyl-3,4-dihydroxybenzoate (A)와 N-Alkyl-3,4-dihydroxybenzamide (B) 유도체들의 치환기(R<sub>1</sub> 및 R<sub>2</sub>) 변화에 따른 멜라닌생성 저해활성 관계들을 HQSAR 방법으로 분석하였다. 멜라닌생성 저해활성에 관하여 유도된 HQSAR 모델은 매우 양호한 예측성(cross-validated r<sup>2</sup><sub>cv.</sub>, q<sup>2</sup>=0.674)과 적합성(non-cross-validated, r<sup>2</sup><sub>ncv</sub>=0.936)을 나타내었다. 멜라닌생성 저해활성과 가수분해 반응성은 공히, (A)가 (B)보다 컸으며(A>B), R<sub>1</sub>-치환기가 R<sub>2</sub>-치환기보다 저해활성에 의존적인 경향을 나타내었다(R<sub>1</sub>>R<sub>2</sub>). 또한, 경계분자궤도(FMO) 이론에 따라 가수분해 반응은 (A), (B)의 LUMO와 물분자의 HOMO 사이에 강한 상호작용으로 orbital-control 반응인 친핵성 첨가-제거반응(Ad<sub>N-E</sub>)이 주로 일어나는 것을 알 수 있었다. Holographic quantitative structure activity relationships (HQSAR) between the melanogenesis inhibitory activities of alkyl-3,4-dihydroxybenzoate (A) and N-Alkyl-3,4-dihydroxybenzamide (B) derivatives were analyzed and discussed. The statistical results of HQSAR model for the activities showed the best predictability of the activities based on the cross-validated r<sup>2</sup><sub>cv</sub>(q<sup>2</sup>=0.674), non-cross-validated, conventional coefficient (r<sup>2</sup><sub>ncv</sub>=0.936). The melanogenesis inhibitory activities and hydrolytic reactivity of (A) were slightly higher than that of (B) (A>B) and the activities depends upon the R<sub>1</sub>-substituents (R<sub>1</sub>>R<sub>2</sub>). It has been found using frontier molecular orbital (FMO) theory that the hydrolysis reactions of (A) and (B) proceeded to an orbital-controlled reactions, while the nucleophillc addition-elimination reactions (Ad<sub>N-E</sub>) between LUMO energy of (A) and (B) and HOMO energy of water molecule are occurred.
살충성 Imidacloprid의 가수분해 반응 메카니즘
성낙도,유성재,강문성 ( Nack Do Sung,Seong Jae Yu,Moon Sung Kang ) 한국응용생명화학회 1997 Applied Biological Chemistry (Appl Biol Chem) Vol.40 No.1
The rate of hydrolysis of insecticidal 1-(6-chloro-3-pyridylmethyl)-2-nitro-iminoimidazolidine (common name; imidacloprid) have been investigated in 15%(v/v) aqueous dioxane at 45℃. From the kinetics and non-kinetics data such as pH-effect, solvent effect(m=0.04, n=0.30 & m≪ℓ), thermodynamic parameter(△H^*=16.14㎉·㏖^(-1) & △S^*=-0.03e.u.), rate equation (k_(obs.)=4.56×10^(-3)[OH^-]) and analysis of hydrolysis product, 1-(6-chloro-3-pyridylmethyl-2)-imidazolidinon, the hydrolysis mechanism of imidacloprid is proposed that the specific base catalyzed hydrolysis(k_(OH)) through nucleophilic addition-elimination (Ad_N-E) mechanism proceed via intermediate, 1-(6-chloro-3-pyridylmethyl)-2-hydroxy-2-imidazolidinylisonitraminate (Ⅰ) and β-3-(6-chloro-3-pyridylmethyl)aminoethyl-1-nitrourea(Ⅲ). And the half-life(t½) of hydrolytic degradation at pH 8.0 and 45℃ was about 4.5 months.
새로운 N-치환 benzotriazol-1-yl 유도체의 항균활성에 미치는 치환기 효과
성낙도,유성재,성민규,김대황 ( Nack Do Sung,Seong Jae Yu,Min Gyu Sung,Dae Whang Kim ) 한국응용생명화학회 1997 Applied Biological Chemistry (Appl Biol Chem) Vol.40 No.1
Series of new chiral N-substituted benzotriazol-1-yl derivatives were synthesized and their fungicidal activities in vitro against gray mold(Botrytis cinerea), black spot(Alternaria kikuchiana) and phytophthora blight(Phytophthora capsici) were measured by the agar medium dilution method. The substituents effects between the fungicidal activities (obs. pI_(50)) and a various physicochemical parameters of phenoxy or thiophenoxy group(X) & alkyl or phenyl group(Y) were analyzed by the multiple regression technique. From the analyzed substituent effects, the structure-activity relationship(SAR) equations shows that the antifungal activities depend on the parameters for the optimal molecular hydrophobicity((∑logP)_(opt.)), Van der Waals (∑Vw$gt;0) volume(Å^(-3)) and inductive constant with electron withdrawing group(σ_IY$gt;0). The activity in affected by the inductive effect (σ_IY$gt;σ_RX) of Y-group rather than the X-group. The phenoxy substituents, 1, showed higher antifungal activity than the thiophenoxy substituents, 2. For 1, polar substituent constant(σ^*) was an important factor in determining the activity. And the tribromomethyl substituent, 1g showed the highest activity against the three fungi.