전도도법에 의한 치환 피리딘들의 해리상수 측정과 그의 온도와 압력에 따른 영향

黃正儀,鄭倧在,金學成,尹永炷,朴義煥 慶北大學校 1984 論文集 Vol.38 No.-

Generally, pyridine and most of substituted pyridines act as base in aqueous solutions. The strengths of their basicities can be expressed quantitatively by the dissociation constant of base or its conjugated acid. Generally, the acidity of substituted pyridines can be expressed by K_a of the following reaction. ◁그림 삽입▷ (원문을 참조하세요) The dissociation constants of these subtituted pyridines have not been reported under high pressure but under atmospheric pressure. In this papers, the dissociation constants of some substituted pyridines were measured under high pressure by the conductometry. From the ionic conductivity of hydrogen ion, the dissociation constants (K_a) were calculated. The K_a values were increased with increasing temperature and were decreased with increasing presure. The charateristics of dissociation process of some substituted pyridines were deduced from the thermodynamic properties calculated from the dissociation constants.

몇가지 치환 피리딘계 화합물의 해리에 미치는 온도와 압력의 영향

황정의,윤영주,김학성 慶北大學校 物理化學硏究所 1983 硏究論文集 Vol.4 No.-

피리딘이나 치환 피리딘 화합물은 염기로서 작용한다. 염기도는 적량적 표시로 염기의 해리 상수나 공액산의 해리 상수로서 나타낼 수 있다. 즉 ◁그림삽입▷(원문을 참조하세요) 반응의 Ka값으로 나타낼 수 있다. 이들 피리딘 치환체의 해리 상수는 상압에서만 알려져 있으나 고압하에서는 전혀 측정된바 없다. 그래서 본 연구에서는 높은 압력하에서 이들 해리 상수를 분광법과 전도도법으로 측정하는 시도를 하였다. 분광법은 흡수 띠가 UV 영역에 있어서 UV 분광법으로 측정했다. 전도도법은 보통 방법으로는 불가능하였고 상압에서의 해리 상수를 알고 있는 물질에 대해서 용액의 전도도를 측정하고, 이 값에서 관여 이온 전도도를 계산하여 해리 상수를 계산하였다. 측정은 m-chloro, m-bromo 및 o-bromopyridine에 대해서 이루어졌으며 양방법에 의한 값들 사이에 약간의 차이가 있었으나 이온 전도도법에 사용한 가정이나 외삽한 값을 이용한 점을 감안할때 비교적 성공적이라고 할 수 있었다. 또 해리반응에 대한 열역학적 데이터를 감안할때 온도나 압력에 따른 변화가 비슷하게 얻어졌고 이들 값을 미루어 보아 해리과정을 추적하는데 도움이 되었다. Pyridine and most of substituted pyridines react as base in aqueous solutions. Strength of their basicities can be represented quantitatively by the dissociation constant of a base or its conjugated acid. For example, the basicity of pyridine can be represented by Ka of the following reaction. ◁그림삽입▷(원문을 참조하세요) The dissociation constants of these substituted pyridines have been reported only under pressure of atmosphere but not high pressure. In this study, we try to measure the dissociation constants of some substituted pyridines under high pressure by the methods of conductance, spectrophotometry. Because the adsorption band exists in UV range, we used UV spectrophotometry. In conductometry we could not apply the general method of conductivity, hence measured the conductivity of the mixed ionic species and then calculated the ionic conductances. From the ionic conductivity of hydrogen ion the dissociation constants (Ka) can be calculated. We measured the dissociation constants of m-chloro, m-bromo and o-bromopyridine. There is a little difference between the dissociation constants from spectrophotometric and conductometric methods. But when we consider the approximated conditions and extrapolated values used in calculating ionic conductance, we could conclude that its difference is insignificant. We obtained the thermodynamic data on the dissociation reactions that showing the effect of the temperature and the pressure on the dissociation constants are similar and we can deduce the mechanism of the dissociation process of some substituted pyridines.

전도도법에 의한 치환 피리딘들의 해리상수 측정과 그의 온도와 압력에 따른 영향

黃正儀,鄭倧在,金學成,尹永炷,朴義煥 慶北大學校 物理化學硏究所 1985 硏究論文集 Vol.6 No.-

Generally, pyridine and most of substituted pyridines act as base in aqueous solutions. The strengths of their basicities can be expressed quantitatively by the dissociation constant of base or its conjugated acid. Generally, the acidity of substituted pyridines can be expressed by K_a of the following reaction. ◁그림삽입▷(원문을 참조하세요) The dissociation constants of these subtituted pyridines have not been reported under high pressure but under atmospheric pressure. In this papers, the dissociation constants of some substituted pyridines were measured under high pressure by the conductometry. From the ionic conductivity of hydrogen ion, the dissociation constants(K_a) were calculated. The K_a values were increased with increasing temperature and were decreased with increasing pressure. The characteristics of dissociation process of some substituted pyridines were deduced from the thermodynamic properties calculated from the dissociation constants.

분광광도법에 의한 3-Chloro 및 3-Bromopyridine의 해리상수 측정과 그의 온도와 압력에 따른 영향

黃正儀,鄭倧在,尹永炷,金學成 慶北大學校 1984 論文集 Vol.38 No.-

Pyridine and most of substituted pyridines react as base in aqueous solutions. Strength of their basicities can be represented quantitatively by the dissociation constant of a base or its conjugated acid. The dissociation constants of weak acid or base are highly dependent on the pressure and the temperature. The dissociation constants of these substituted pyridines have been reported only under the pressure of atmosphere but not high pressure. In this study, we measured the dissociation constants of 3-chloro and 3-bromopyridine under high pressure by the method of spectrophotometry. Also, we obtained the thermodynamic parameters on the dissociation reactions that show the effects of the temperature and the pressure on the dissociation constants.

A hybrid technique for sinus floor elevation in the severely resorbed posterior maxilla

Jung, Ui-Won,Hong, Ji-Youn,Lee, Jung-Seok,Kim, Chang-Sung,Cho, Kyoo-Sung,Choi, Seong-Ho Korean Academy of Periodontology 2010 Journal of Periodontal & Implant Science Vol.40 No.2

Purpose: This study aimed to evaluate the effectiveness of the modified sinus floor elevation technique described hereafter as a "hybrid technique," in 11 patients with severely resorbed posterior maxillae. Methods: Eleven patients who received 22 implants in the maxillary premolar and molar areas by the hybrid technique were enrolled in this study. A slot-shaped osteotomy for access was prepared on the lateral wall along the lower border of the sinus floor. The Schneiderian membrane was fully reflected through the lateral slot. Following drilling with the membrane protected by a periosteal elevator, the bone was grafted. All implants were placed simultaneously with sinus augmentation. The cumulative success rate was calculated and clinical parameters were recorded. Radiographic measurements were performed. Results: All implants were well maintained at last follow up (cumulative success rate=100%). The mean residual bone height, augmented bone height, crown-to-implant ratio, and marginal bone loss were $4.1{\pm}1.64mm$, $8.76{\pm}1.77mm$, $1.21{\pm}0.34mm$, and $0.34{\pm}0.72mm$, respectively. Conclusions: Simultaneous implant placement with sinus augmentation by hybrid technique showed successful clinical results over a 2-year observation period and may be a reliable modality for reconstruction of a severely resorbed posterior maxilla.

Cytotoxic Constituents from the Aerial Part of Clematis apiifolia L.

Ui-Jung Youn,Wen-Yi Jin,Kyung-Sik Song,Yeon-Hee Seong,Ki-Hwan Bae 한국약용작물학회 2006 한국약용작물학회지 Vol.14 No.5

Three known triterpenoids were isolated from MeOH extract of C. apiifolia (Ranunculaceae). Their structures were identified as oleanolic acid (1), ursolic acid (2), hederagenic acid (3) by comparison of their physicochemical and spectral data with the literature values. Among them, 2 was isolated for the first time from this plant. The isolated compounds were evaluated for their cytotoxicity against L1210, HL-60, SK-OV-3 tumor cell lines. All compounds 1-3 were shown good activities with IC50 values ranging from 7.7 to 25.6 μg/ml. This result suggests that triterpenoids 1-3 are main cytotoxic principles of this plant.

Cytotoxic Constituents from the Aerial Part of Clematis apiifolia L.

Youn, Ui-Jung,Jin, Wen-Yi,Song, Kyung-Sik,Seong, Yeon-Hee,Bae, Ki-Hwan The Korean Society of Medicinal Crop Science 2006 韓國藥用作物學會誌 Vol.14 No.5

Three known triterpenoids were isolated from MeOH extract of C. apiifolia (Ranunculaceae). Their structures were identified as oleanolic acid (1), ursolic acid (2), hederagenic acid (3) by comparison of their physicochemical and spectral data with the literature values. Among them, 2 was isolated for the first time from this plant. The isolated compounds were evaluated for their cytotoxicity against L1210, HL-60, SK-OV-3 tumor cell lines. All compounds 1-3 were shown good activities with $IC_{50}$ values ranging from 7.7 to $25.6\;{\mu}g/ml. This result suggests that triterpenoids 1-3 are main cytotoxic principles of this plant.

Efficacy of the Sonicare Elite□ in plaque removal and reduction of gingival inflammation from hard to reach sites of the moderate periodontitis

( Ji Youn Hong ),( Sung Won Jung ),( Yoo Jung Um ),( Gyung Jun Chae ),( Ui Won Jung ),( Chang Sung Kim ),( Seong Ho Choi ),( Chong Kwan Kim ) 대한치주과학회 2006 대한치주과학회 학술대회자료집 Vol.2006 No.2

Variation of main components according to the number of steaming and drying of Rehmanniae radix preparata

Youn, Ui Joung,Gu, Bon-Seok,Kim, Kyung Hee,Ha, Chulgyu,Jung, In Chan KOREAN PHARMACOPUNCTURE INSTITUTE 2018 Journal of pharmacopuncture Vol.21 No.2

Contents of compounds in Rehmanniae Radix change depending on the number of steaming and drying and the drying method. In this study, as an impregnation method for dried Rehmanniae Radix, takju impregnation and cheongju impregnation were carried out and steaming and drying were repeated for 9 times. The changes of 5-HMF and catalpol contents were analyzed according to the number of repetition times to investigate which stage of steaming and drying is preferable. Also, total nitrogen, crude fat, ash, and crude fiber were measured to analyze changes in general components. 5-HMF was not detected in dried Rehmanniae Radix. As a result of repetitive steaming and drying, the content of 5-HMF increased only slightly from 1 to 4-times steaming and drying but increased significantly from 5-times. The catalpol in dried Rehmanniae Radix was not detected after 5 times of steaming and drying. Sucrose, maltose, and glucose were included in dried Rehmanniae Radix before steaming and drying. However, after the process in both Takju impregnation and Cheongju impregnation, galactose and fructose tended to decrease after production and sucrose and glucose tended to decrease after the increase. In this study condition, 6-times and more steaming and drying were appropriate process which met the content criteria (not less than 0.1%) of the Korean Pharmacopoeia (8th edition) for 5-HMF, an index component for quality control of Rehmanniae Radix Preparata.

Anti-inflammatory and Quinone Reductase Inducing Compounds from Fermented Noni (<i>Morinda citrifolia</i>) Juice Exudates

Youn, Ui Joung,Park, Eun-Jung,Kondratyuk, Tamara P.,Sang-Ngern, Mayuramas,Wall, Marisa M.,Wei, Yanzhang,Pezzuto, John M.,Chang, Leng Chee American Chemical Society and American Society of 2016 Journal of natural products Vol.79 No.6

<P>A new fatty acid ester disaccharide, 2-O-(beta-D-glucopyranosyl)-1-O-(2E,4Z,7Z)-deca-2,4,7-trienoyl-beta-D-glucopyranose (1), a new ascorbic acid derivative, 2-caffeoyl-3-ketohexulofuranosonic acid gamma-lactone (2), and a new iridoid glycoside, 10-dimethoxyfermiloside (3), were isolated along with 13 known compounds (4-16) from fermented noni fruit juice (Morinda citrifolia). The structures of the new compounds, together with 4 and 5, were determined by 1D and 2D NMR experiments, as well as comparison with published values. Compounds 2 and 7 showed moderate inhibitory activities in a TNF-alpha-induced NF-kappa B assay, and compounds 4 and 6 exhibited considerable quinone reductase-1 (QR1) inducing effects.</P>