혼합용매에서의 용매화 (제 7 보). 등유전상수 용매에서 t-Butyl Halide 의 가용매분해반응

이익춘,이해황,엄태섭,성대동,류준하,Lee, Ick-Choon,Lee, Hai-Whang,Uhm, Tae-Seop,Sung, Dae-Dong,Ryu, Zoon-Ha 대한화학회 1988 대한화학회지 Vol.32 No.2

등유전상수 용매로 취급되는 MeOH-nitromethane, MeOH-nitrobenzene 및 MeOH-ethylene glycol 혼합용매 하에서 t-butyl halides (X = Cl, Br, I)의 가용매 분해반응을 연구 하였다. MeOH-NM 및 MeOH-NB에서 t-butyl halide의 가메탄올 분해반응 속도는 40~100 % (v/v) MeOH 조성에서 최대치를 보였다. 최대속도 현상은 용매의 극성-편극성과 수소결합 주게능력의 협력적인 결과로 설명하였다. Y값의 변화로 부터 극성-편극성과 수소 결합 주게능력의 협력적인 결과로 설명하였다. Y값의 변화로 부터 극성-편극성과 수소결합 주게능력이 기질의 반응성에 미치는 효과를 논의 하였다. E.G.에서 기질의 반응성은 MeOH에 비해 20배 이상 빠름을 보였으며 이는 아마도 E.G.의 특이한 용매구조에 기인 한다고 여겨 진다. Solvolyses of t-butylhalides (X = Cl, Br, I) in quasi isodielectric solvent system, MeOH-nitromethane, MeOH-nitrobenzene and MeOH-ethyleneglycol have been studied kinetically. Methanolyses for t-butylhalides in MeOH-NM and MeOH-NB show rate maxima at 40~100 % (v/v) MeOH. The rate maxima observed have been interpreted as a result of cooperative enhancement of polarity-polarizability and hydrogen bonddonor ability of solvents. The influences of polarity-polarizability and hydrogen bonddonor ability on reactivities of substrates have been discussed in terms of Y value changes. The solvolysis rates for t-butylhalides in E.G. are more than 20 fold faster than those in MeOH and this was attributed to the solvent structure of E.G.

항산화 및 암전이 관련 단백질의 발현에 미치는 콩잎낙엽 에탄올 추출물의 영향

송채은(Chaeeun Song),이수경(Su-Gyeong Lee),홍수경(Sugyeong Hong),류준하(Zoon Ha Ryu),김문무(Moon-Moo Kim),오영희(Yunghee Oh) 한국생명과학회 2016 생명과학회지 Vol.26 No.4

콩잎은 골다공증 및 유방암 발생을 예방한다고 널리 보고되고 있다. 이를 바탕으로 콩잎낙엽 에탄올 추출물(SBFL)을 제조하여 암 전이와 관련 있는 세포침윤에 대한 효과를 조사하기 위하여 섬유아육종세포(HT1080)에서 SBFL이 항산화와 matrix metalloproteinases (MMPs)에 미치는 영향을 분석하였다. 본 연구에서 활성산소의 소거효과에 대한 SBFL효과는 DPPH radical, 환원력 및 지질과산화실험으로 평가되었다, 본 연구에서 SBFL은 양성대조군으로 사용된 vitamin C 및 vitamin E와 비교 시 우수한 항산화 효과를 보여주었다. 다음으로 SBFL의 세포독성을 측정하기 위하여 MTT assay를 수행한 결과 16 μg/ml 이상의 농도에서 세포독성을 보여주었다. SBFL은 gelatin zymography 실험에서 phorbol 12-myristate 13-acetae (PMA) 혹은 phenazine methosulfate (PMS)로 자극된 암 전이에서 중요한 MMP-9의 활성을 감소시켰다. 특히 SBFL은 단백질 발현 실험에서 SOD-1, p-FoxO-1의 발현을 증가시켰다. 더욱이 vascular endothelial growth Factor (VEGF)로 자극된 세포 침윤이 SBFL처리에 의하여 억제되는 것으로 나타났다. 이러한 연구결과를 바탕으로 SBFL은 뛰어난 항산화 효과는 산화적 스트레스를 감소시키고 MMP-9의 활성과 세포침윤을 억제시켜 암 전이의 예방을 위한 유효성분으로 이용될 수 있다는 것을 암시하고 있다. Soybean leaves, a Korean edible plant material, have been reported to prevent the development of osteoporosis and breast cancer. Based on this rational, soybean fallen leaves ethanolic extract (SBFL) was used for the experiment of cell invasion related to metastasis and antioxidant activity. The effect of SBFL on matrix metalloproteinases (MMPs) in human fibrosarcoma cells, HT1080 as well as its antioxidant activity was investigated in this study. The effect of SBFL on scavenging activity of reactive oxygen species was evaluated in vitro using lipid peroxidation assay,DPPH radical and reducing power assay. SBFL showed the positive effects on antioxidant activity, compared with vitamin C and vitamin E used as positive controls. Furthermore, SBFL showed cytotoxicity above 16 μg/ml in MTT assay. In particular, it was found that SBFL decreased the activation of MMP-9 stimulated by phorbol 12-myristate 13-acetae (PMA) and phenazine methosulfate (PMS). SBFL treatment increased the expression levels of p-FoxO-1 and SOD-1. Moreover, SBFL inhibited cell invasion stimulated by vascular endothelial growth Factor (VEGF). These results indicate that SBFL could inhibit cell invasion related to the activation of MMP-9 and oxidative stress, suggesting that it could be available as a main ingredient for prevention of metastasis.

Solvolytic Reactions in Fluorinated Alcohols. Role of Nucleophilic and Other Solvation Effects

Ryu, Zoon Ha,Llewellyn, Gareth,Bentley, T. William 동의대학교 기초과학연구소 1999 基礎科學硏究論文集 Vol.9 No.1

Rate constants and products for solvolyses of chlorodiphenylmethane (Ph₂CHCl) and p-methoxybenzyl chloride in 2,2,2-trifluoroethanol (TFE)/water and TFE/ethanol are reported, along with additional kinetic data for solvolyses of tert-butyl and other alkyl halides (RX) in 97% w/w TFE/water and in 97% w/w hexafluoropropan-2-ol/water (HFIP). Results are discussed in terms of the solvent ionizing power(Y) and the solvent nucleophilicity(N), and contributions from other solvation effects are considered. Comparisons with other S_N1 solvolyses show that solvolyses of Ph₂CHCl in TFE mixtures are unexpectedly fast, but product ratios are unexceptional. An additional solvation effect influences solvolyses leading to delocalized cations, and a delocalized cationic transition state for concerted elimination may explain the recent results of Takeuchi et al., (J. Org. Chem. 1997, 62, 4904) without the need to postulate additional specific solvation effects for adamantyl systems, such as Bronsted-base solvation of α- and β-hydrogen atoms; concerted elimination may occur because simple tertiary alkyl cations are too unstable to form in predominantly aqueous media. Iodide/bromide and bromide/chloride rate ratios are very similar for 1-adamantyl halides and corresponding solvolyses of tert-butyl halides; these ratios decrease in the order aq EtOH $gt; TFE $gt; HFIP, as expected for an electrophilic solvation effect (this effect can readily be incorporated into Y values). From kinetic data for a series of tertiary alkyl chlorides in 97% TFE/water, it is shown that the susceptibility of rates of solvolyses of RCl to N decreases with an increase in steric hindrance or with an increase in charge stabilization. Also, the small kinetic solvent isotope effects for typical solvolyses (e.g., methyl tosylate) indicate that nucleophilic attack lags behind heterolysis of the C-X bond.

Solvent Effect on the Reactions of DANSYL and BANSYL Chlorides with Substituted Pyridines

Ryu, Zoon Ha,Sung, Dae Dong,Kang, Dong Hyo,Chang, Jeong Ah,Park, Sung Bae 동의대학교 기초과학연구소 1999 基礎科學硏究論文集 Vol.9 No.1

Solvent effects on the reactions of DANSYL and BANSYL chlorides with substituted pyridines have been investigated using two parameters of Taft's solvatochromic correlation and four parameters of Kirkwood-Onsager, Parker, Marcus, Hildebrand equation. The acetonitrile molecules accelerate charge separation of the reactants and stabilize the transition state. The coefficient of the solvent parameters provide a good information to predict and to analyze the reaction mechanism. The nucleophilic substitution reaction of DANSYL and BANSYL chlorides with substituted pyridines are ruled by the contribution of the change in dipole moment term and polarity-polarizability term.

Methanol-1,1,2,2-Tetrachloro ethan 혼합용매계에서 치환 피리딘과 염화벤젠 술포닐의 친핵성 치환반응에 대한 속도론적 연구

옥치율,류준하 부산교육대학교 과학교육연구소 1990 科學敎育硏究 Vol.15 No.-

Kinetic studies on the nucleophilic substitution of benzenesulfonyl chloride with substituted pyridines have been conductometically carried out in 10-50(v/v)% MEOH-TCE mixtures. From the kinetic data, Hammett ρ_N values, Bro¨nsted β calues, and solvatochromic coefficients were determined caused by change in substitutents, and solvent properies. It is concluded that the reaction proceed associative S_N2 which bond formation is more advanced than bond cleavage.

多面體 硼素化合物의 反應性과 메카니즘

成大東,金奎喆,柳俊夏,徐敬賢,金良姬 東亞大學校附設基礎科學硏究所 1990 基礎科學硏究論文集 Vol.7 No.1

1,2-dicarba-closo-dodecaborane과 carbene들과의 icosahedral carborane반응에 대한 반응성과 cage borane반응에 대한 메카니즘을 icosahedral skeleton 의 구조적 관점에서 연구하였다. 반응 생성물은 주로 B-inserted-o-carborane이였으며, B-inserted methyl-??-carborane과 di-,tri-o-carborane은 상대적으로 적게 생성되었다. B-inserted chloro-o-carborne과 carbene반응으로부터 carbone의 전자배열은 cage carborane의 구조변화에 따라 open-shell, lowest triplet 그리고 lowest closed-shell 전자배열이 유리한 것으로 나타났다. Reactivity for the reaction of icosahedral carborane, 1,2-dicarba-closo-dodecaborane with various carbenes and the mechanism for the reaction of cage borane have been studied in view point of structure of icosahedral skeleton. From Friedel-Craft reaction, the reaction products were B-inserted-0-carborane mainly and B-inserted methyl-0-carborane and di-and tri-0-carborane were produced only a little. From the carbenic reaction with B-inserted chloro-0-carboranes the electronic configurations of carbenes were favored open-shell, lowest triplet, and lowest closed-shell electronic configurations along with the structure variation of cage carboranes.