Azomethine 탄소원자의 친핵성 치환반응 (제 1 보) 물-디옥산 혼합용매중 Aryl N-Aroylchloroformimidate 유도체의 가용매 분해반응

성낙도,권기성,박문규 圓光大學校 1981 論文集 Vol.15 No.1

Kinetic studies on solvolsis reactions of aryl N-aroylchloroformimidate derivatives in 1.4-dioxane-water mixture have been carried out by means of ultra-violet spectrophotometry at 20℃. Results of m values of Grunwald-Weinstein plots(m=0.4~0.8), substituent effect(ρ=0.15), and n values of Kivinen plots(n=0.7~1.2), show that the solvolysis displacement of aryl N-aroylchloroformimidate derivatives proceed via SN₂ mechanism.

p-Methoxystyrylphenylsulfone의 가수분해 반응메카니즘에 대한 반응속도론적 연구

權奇星,高東成,朴文奎,金演斗,成洛道 충남대학교 기초과학연구소 1981 연구논문집 Vol.2 No.-

The rate constants for the hydrolysis of p-methoxystyrylphenylsulfone were determined at wide pH ranges by means of UV spectrophotometer and the rate equations which could be applied to the experimental results were obtained. Form the facts, reaction mechanism was proposed : above pH 11.5, the rate is only dependent on the concentration of hydroxide ion and below pH 9.5, the reaction is initiated by the attack of a water molecule on the activated carbon-carbon double bond. In the range of pH from 9.5 to 11.5, these two reactions occur competitively.

N-phenylbenzohydrazonyl bromide의 加水分解反應

權奇星,成洛道,朴文奎 충남대학교 자연과학연구소 1979 學術硏究誌 Vol.6 No.1

The rate constants for the hydrolysis of phenylbenzohydrazonyl bromide (BPH) at various pH range are determined by spectrophotometry and a rate equation which can be applied over wide pH range is obtained. Analysising pH-rate profile, the total rate constants consists of three parts; (1) pH independent part, (2) dependent on hydrogen ion, and (3) dependent upon hydroxide. A general rate equation which can be applied over wide pH is as following; kt=ko+k^(H)[H₃O^(+)]+k^(OH)[OH^(-)] kobsd.=2.76×10^(-6)+6.41×10^(-4)[H₃O^(+)]+3.77×10^(-19)/[H₃O] The hydrolysis proceed through addition-elimination below pH 2.50 and SN₂reaction above pH 13.0. In the range of pH 4.0-11.50, SN₁reaction occur respectively.

Ethylcrotonate에 對한 Iso-propylmercaptan의 親核性 添加反應

權奇星,朴文奎,成洛道 충남대학교 자연과학연구소 1974 學術硏究誌 Vol.1 No.1

The rate constants for the addition reaction of iso-propylmercaptan to ethylcrotonate have been measured by iodometry and for the proposed reaction mechanism a rate equation which can be applied over wide pH range was derived. From this rate equation, it was found that below pH 6.0 the reaction is started by addition of iso-propylmercaptan molecule and above pH 11.0 this reaction is proceeded by the iso-propylmercaptide ions and a t the range of pH 6.0-11.0 two reactions are competitive. Consequently, it is found that the observed data are satisfactorily accorded with the theoretical values over various pH range.

α-Bromobenzaldehyde-p-nitrophenylhydrazone의 알카리 가수분해 반응 메카니즘

권기성,이천배,박문규,성낙도 충남대학교 기초과학연구소 1980 연구논문집 Vol.1 No.-

The rate constants for the hydrolysis of the derivatives of α-bromobenzaldehyde-p-nitro-phenylhydrazone (p-H, p-OCH_3, p-Cl, p-NO_2) at various pH have been determined by UV spectrophotometry in 50% dioxane at 25℃ and the following rate equations which can be applied over wide pH range were obtained. i. e. α-bromobenzaldehyde-p-nitrophenylhydrazone; kobs.=1.25×10 exp (-7) + 7.92×10 exp (-11)/〔H^+〕+1.51×10 exp (-7) α-bromo-p-chlorobenzaldehyde-p-nitrophenylhydrazone; kobs.=1.06×10 exp (-7) + 1.08×10 exp (-10)/〔H^+〕+1.45×10 exp (-7) α-bromo-p-methoxybenzaldehyde-p-nitrophenylhydrazone; kobs.=1.79×10 exp (-7) + 1.40×10 exp (-10)/〔H^+〕+4.08×10 exp (-7) α-bromo-p-nitrobenzaldehyde-p-nitrophenylhydrazone; kobs.=7.10×10 exp (-8) + 2.89×10 exp (-10)/〔H^+〕+2.37×10 exp (-7) Below pH 2, the rate of hydrolysis of α-bromobenzaldehyde-p-nitrophenylhydrazone is accelerated by electron-donating group (ρ=-0.91). Above pH 5, however, this reaction is slowded down by electron-attracting group (ρ=0.37). From the rate equation and the effect of solvent and substituent upon the rate of reaction, below pH 2, the hydrolysis proceed through SN_1 mechanism. Above pH 5, the hydrolysis proceed through 1.3-dipolar ion mechanism. And in the range of pH 2∼5 these two reactions occur competitively.

Isolation of Soil Bacteria Secreting Raw-Starch-Digesting Enzyme and the Enzyme Production

SUNG, NACK MOON,KIM, KEUN,CHOI, SUNG HO 한국미생물 · 생명공학회 1993 Journal of microbiology and biotechnology Vol.3 No.2

Two strains (No. 26 and 143) of bacteria which secrete both pectinase and raw-starch-digesting amylase simultaneously, were isolated from various domestic soil samples. The two bacteria were identified as Pasteurella ureae judging by their morphological and physiological characteristics. The optimal culture conditions for the production of raw-starch-digesting enzyme by the Pasteurella ureae 26 were using NH_4NO_3 as the nitrogen source at 37℃ with the pH of 7.5, and 15 of C/N ratio. Since the enzyme was produced only when raw or soluble starch was used as a carbon source, but not when glucose or other sugars was used, the enzyme was considered to be an inducible enzyme by starch. Thin layer chromatography of the hydrolyzed product of starch by the raw-starch-digesting enzyme of the strain No. 26 showed that glucose, maltose and other oligosaccharides were present in the hydrolyzates, and therefore the enzyme seemed to be α-amylase. The enzyme had adsorbability onto raw corn starch in the pH range of 3 to 9.

Imidacloprid 와 그 유도체들의 살충활성에 미치는 3 - N - 치환기 ( R ) 의 영향

성낙도(Nack Do Sung),강문성(Moon Sung Kang),장해성(Hae Sung Jang),김대황(Dae Whang Kim) 한국응용생명화학회 1996 Applied Biological Chemistry (Appl Biol Chem) Vol.39 No.2

Imidacloprid and a series of the related compounds were synthesized, and influence of 3-N substituents(R) on the insecticidal activities against Brown plant hopper(Nilaparvata lugens) and Green peach aphid(Myzus persicae) were examined quantitatively from the structure-activities relationships(SAR) techniques. The results indicated that the molecular hydrophobicity(π) and inductive substituent constant(σ^*) of substituents(R) at 3-nitrogen position on the imidazolidine ring were important factors. Variations in the potency were parabolically related to the both constants. In case of Brown plant hopper, optimum value of π constant was 0.52, whereas the value of σ^* constant against Green peach aphid was 1.17, respectively. Among them, the strong electron withdrawing groups(σ^*$gt;0) such as methyl and benzenesulfonyl group(7 & 8) showed lower insecticidal activity and non-substituted, 1(imidacloprid) showed the best insecticidal activity. It seems that the intramolecular associated(H-bond) form between 2-N-nitro group and 3-imid group may contribute to the higher insecticidal activity to the both sucking insects. And in aqueous solution, 1 showed higher residual activity below pH 6.0, and the half-life(T_½) was about 6 month at pH 7.0 (ca. k_(obs) : 5×10^(-8) sec.^(-1)) and 45℃.

Trichorrhexis Nodosa : Report of a case and Scanning Electron Microscopic findings

이성낙,박윤기,치병문 대한피부과학회 1982 大韓皮膚科學會誌 Vol.20 No.3

Trichorrhexis nodosa is a distinctive response of the hair shaft to physical or chemical trauma, characterized by the development of node-like swelling, through which the shaft readily fractures. We have described here a case of trichorrhexis nodosa with scanning electron microscopic findings. Nodular swelling of the affected hair showed longitudinal fissures and fractures in the cortex with loss of cuticular scales. At the site of fracture, a paintbrush-like effect was seen.

일측성 대상 편평태선

이성낙(Sung Nack Lee),이광훈(Kwang Hoon Lee),김덕현(Duck Hyun Kim),최병문(Byung Moon Choi) 대한피부과학회 1984 대한피부과학회지 Vol.22 No.3

A 44 year-old male without a specific past history demonstrated violaceous colored. angulated flat papules in a zosteriform arrangement along the medial aspect of left arm and upper anterior chest for 3 months. In addition, whitish patches with a lace-like pattern were seen on the buccal mucosa. The histopathologic findings were characteristic of lichen planus. The zosteriform lichen planus is a rare variant of lichen planus, Especially, it has been rarely observed in cases that developed without a previous history of herpes zoster or factors that lead to the Koebner phenoinenon In this context, it piqued our scientific curiousity enough to investigate it.

살충성 Imidacloprid의 가수분해 반응 메카니즘

유성재,강문성,성낙도,Yu, Sung-Jae,Kang, Moon-Sung,Sung, Nack-Doo 한국응용생명화학회 1997 Applied Biological Chemistry (Appl Biol Chem) Vol.43 No.1

중성과 알카리성의 $45^{\circ}C$, 15%(v/v) dioxane 수용액중에서 살충성 imidacloprid (lUPAC:1-(6-chloro-3-pyridylmethyl)-3-N-nitro-iminoimidazolidine-2-ylideneamine)의 가수분해 반응속도 상수를 측정하고 pH-효과, 용매효과(m=0.04, n=0.30 및 m${\ll}$l), 열역학적 활성화 파라미터(${\Delta}S^{\neq}$=-0.03e.u. 및 ${\Delta}S^{\neq}=16.14\;kcal{\cdot}mol^-$), 반응 생성물 분석등의 결과로부터 반응 속도식($K_{obs}=4.56{\times}10^{-3}[OH^-]$)을 유도하여 특정 염기촉매 반응($K_{OH^-}$)으로 사면체($sp^3$) 중간체인 1-(6-chloro-3-pyridylmethyl)-2-hydroxy-2-imidazolidinylisonitraminate(I)을 거쳐 imidazolidine 고리 열림반응으로 $\beta$-3-(6-chloro-3-pyridylmethyl)aminoethyl-1-nitrourea(III)를 경유한 다음에 1-(6-chloro-3-pyridylmethyl)aminoethyl-1-nitrourea(III)으로 분해되는 일련의 친핵성 첨가-제거($Ad_N-E$) 반응메카니즘을 제안하였다. 그리고 $45^{\circ}C$의 중성(pH 8.0)에서 반감기(t1/2)는 약 4.5개월로 잔류성이 큰 화합물임을 알았다. 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 $45^{\circ}C$. From the kinetics and non-kinetics data such as pH-effect, solvent effect(m=0.04, n=0.30 IT m<<l), thermodynamic parameter(${\Delta}H^{\neq}=16.14kcal{\cdot}mol^{-1}\;&\;{\Delta}S^{\neq}=-0.03e.u.$), rate equation ($k_{obs.}=4.56{\times}10^{-3}[OH^-]$) 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 ${\beta}$-3-(6-chloro-3-pyridylmethyl)aminoethyl-1-nitrourea(III). And the half-life(t1/2) of hydrolytic degradation at pH 8.0 and $45^{\circ}C$ was about 4.5 months.