Complete ¹H-NMR and <SUP>13</SUP>C-NMR spectral analysis of the pairs of 20(S) and 20(R) ginsenosides

Heejung Yang,Jeom Yong Kim,Sun Ok Kim,Young Hyo Yoo,Sang Hyun Sung 고려인삼학회 2014 Journal of Ginseng Research Vol.38 No.3

Background: Ginsenosides, the major ingredients of Panax ginseng, have been studied for many decades in Asian countries as a result of their wide range of pharmacological properties. The less polar ginsenosides, with one or two sugar residues, are not present in nature and are produced during manufacturing processes by methods such as heating, steaming, acid hydrolysis, and enzyme reactions. ¹H-NMR and <SUP>13</SUP>C-NMR spectroscopic data for the identification of the less polar ginsenosides are often unavailable or incomplete. Methods: We isolated 21 compounds, including 10 pairs of 20(S) and 20(R) less polar ginsenosides (1-20), and an oleanane-type triterpene (21) from a processed ginseng preparation and obtained complete ¹H-NMR and <SUP>13</SUP>C-NMR spectroscopic data for the following compounds, referred to as compounds 1-21 for rapid identification: 20(S)-ginsenosides Rh2 (1), 20(R)-Rh2 (2), 20(S)-Rg3 (3), 20(R)-Rg3 (4), 6´-O-acetyl-20(S)-Rh2 [20(S)-AcetylRh2] (5), 20(R)-AcetylRh2 (6), 25-hydroxy-20(S)-Rh2 (7), 25-hydroxy-20(S)-Rh2 (8), 20(S)-Rh1 (9), 20(R)-Rh1 (10), 20(S)-Rg2 (11), 20(R)-Rg2 (12), 25-hydroxy-20(S)-Rh1 (13), 25-hydroxy-20(R)-Rh1 (14), 20(S)-AcetylRg2 (15), 20(R)-AcetylRg2 (16), Rh4 (17), Rg5 (18), Rk1 (19), 25-hydroxy-Rh4 (20), and oleanolic acid 28-O-β-D-glucopyranoside (21).

Determination of five active compounds in Artemisia princeps and A. capillaris based on UPLC-DAD and discrimination of two species with multivariate analysis

Yang, Heejung,Lee, Dong Young,Jeon, Minji,Suh, Youngbae,Sung, Sang Hyun 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.5

Five active compounds, chlorogenic acid, 3,5-di-O-caffeoylquinic acid, 4,5-di-O-caffeoylquinic acid, jaceosidin, and eupatilin, in Artemisia princeps (Compositae) were simultaneously determined by ultra-performance liquid chromatography connected to diode array detector. The morphological resemblance between A. princeps and A. capillaris makes it difficult to properly identify species properly. It occasionally leads to misuse or misapplication in Korean traditional medicine. In the study, the discrimination between A. princeps and A. capillaris was optimally performed by the developed validation method, which resulted in definitely a difference between two species. Also, it was developed the most reliable markers contributing to the discrimination of two species by the multivariate analysis methods, such as a principal component analysis and a partial least squares discrimination analysis.

Implication of the Stereoisomers of Ginsenoside Derivatives in the Antiproliferative Effect of HSC-T6 Cells

Yang, Heejung,Yoo, Guijae,Kim, Hye Seong,Kim, Jeom Yong,Kim, Sun Ok,Yoo, Young Hyo,Sung, Sang Hyun American Chemical Society 2012 Journal of agricultural and food chemistry Vol.60 No.47

<P>Two ginsenoside derivatives (<B>9</B>, <B>10</B>) along with 10 known ginsenosides (<B>1</B>–<B>8</B>, <B>11</B>, and <B>12</B>) were isolated from BST204, which is a crude ginseng extract fermented by enzyme and acid hydrolysis. The two ginsenosides were determined as 12β,20(<I>S</I>),25-trihydroxydammara-3-<I>O</I>-β-<SMALL>d</SMALL>-glucopyranoside (<B>9</B>) and 12β,20(<I>R</I>),25-trihydroxydammara-3-<I>O</I>-β-<SMALL>d</SMALL>-glucopyranoside (<B>10</B>). Compounds <B>1</B>–<B>12</B> were categorized into stereoisomeric pairs differentiated by <I>R</I>- or <I>S</I>-configuration at C-20, the number or position of sugar residues at C-3 or C-6, and the type of derivative at C-21. Their structure–activity relationship was evaluated by the cell viability assay using HSC-T6 cells. Results showed that 20(<I>S</I>) (<B>3</B> > <B>4</B>, <B>7</B> > <B>8</B>, and <B>9</B> > <B>10</B>), a 2-hydroxy-2-methylbutyl moiety at C-21 (<B>3</B>, <B>7</B> > <B>9</B>), and the number of sugar residues at C-3 (<B>3</B> > <B>7</B>) significantly affected the antiproliferative activity on HSC-T6 cells. The inhibition of the cell proliferation of compound <B>3</B> was assessed by annexin-V/PI staining analysis using flow cytometry.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jafcau/2012/jafcau.2012.60.issue-47/jf303714c/production/images/medium/jf-2012-03714c_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jf303714c'>ACS Electronic Supporting Info</A></P>

Cytotoxic activities of naturally occurring oleanane-, ursane-, and lupane-type triterpenes on HepG2 and AGS cells

Yang, Heejung,Kim, Hyun Woo,Kim, Young Choong,Sung, Sang Hyun Medknow PublicationsMedia Pvt Ltd 2017 Pharmacognosy magazine Vol.13 No.49

<P><B>Background:</B></P><P>It is well known that the naturally occurring modified triterpenes in plants have a wide diversity of chemical structures and biological functions. The lupane-, oleanane-, and ursane-type triterpenes are the three major members of natural triterpenes with a wide range of biological properties. A systematic approach is necessary to review their structures and biological activities according to the backbones and the different substituents.</P><P><B>Objective:</B></P><P>Thirty lupane-(L1-7), oleanane-(O1-14), and ursane-type (U1-9) triterpenes with structural diversity were examined to evaluate their cytotoxic activities against two cancer cell lines, human hepatocellular carcinoma (HepG2) and AGS cells.</P><P><B>Materials and Methods:</B></P><P>They were isolated from <I>Hedera helix</I>, <I>Juglans sinensis</I>, and <I>Pulsatilla koreana</I> using a series of column chromatography methods and were treated to evaluate their cytotoxic activities against HepG2 and AGS human gastric adenocarcinoma cell. Further, two triterpenes showing the most potent activities were subjected to the apoptotic screening assay using flow cytometry.</P><P><B>Results:</B></P><P>The polar groups, such as an oxo group at C-1, a free hydroxyl at C-2, C-3, or C-23, and a carboxylic moiety at C-28, as well as the type of backbone, explicitly increased the cytotoxic activity on two cancer cells. O5 and U5 showed significantly the potent cytotoxic activity in comparison to other glycosidic triterpenes. In annexin-V/propidium iodide (PI) staining assay, the percentage of late apoptosis (annexin-V+/PI+) 12 and 24 h after treatment with O5 and U5 at 25 μM increased from 14.5% to 93.1% and from 46.4% to 49.1%, respectively, in AGS cells. The cytotoxicity induced by O5 showed a significant difference compared to U5 for 12 and 24 h.</P><P><B>Conclusion:</B></P><P>In the study, we can suggest the potent moieties which influence their cytotoxic activities against two cancer cells. The polar groups at C-1, C-2, C-3, C-23, and C-28 and the linkage of sugar moieties influenced the different cytotoxic activities.</P><P><B>SUMMARY</B></P><P><P>Thirty naturally occurring oleanane-, ursane-, and lupane-type triterpenes were isolated from <I>Hedera helix</I>, <I>Juglans sinensis</I>, and <I>Pulsatilla koreana</I></P><P>An oxo, a free hydroxyl, a carboxylic moiety, and the types of aglycone influenced the cell cytotoxicity</P><P>Corosolic acid and α-hederin showed the most potent cytotoxicity via apoptosis.</P></P> >[FIG OMISSION]</BR>

Anti-Differentiation Effect of B, D- <i>Seco</i> limonoids of <i>Swietenia mahogani</i>

Yang, Heejung,Choi, Mina,Lee, Dong Young,Sung, Sang Hyun Medknow PublicationsMedia Pvt Ltd 2017 Pharmacognosy magazine Vol.13 No.50

<P><B>Background:</B></P><P>Obesity is a pathological state caused by abnormal or excessive accumulation of fat. <I>Swietenia mahogani</I> JACQ., known as West Indian mahogany, is a medium-sized semi-evergreen tree belonging to Meliaceae. Their seeds are used in Indonesian folk medicine as a treatment for hypertension, diabetes, malaria, and it also has anti-feedant activities. The major components of <I>S. mahogani</I> are B, D-seco limonoids, a type of irregular triterpenes are well known.</P><P><B>Objective:</B></P><P>We tried to find the bioactive components, which have the inhibitory activity on adipocyte differentiation from the seeds of <I>S. mahogani</I>.</P><P><B>Material and Methods:</B></P><P>3T3-L1 cells, derived from mouse preadipocyte, are widely used in studying adipogenesis process. In this study, we used 3T3-L1 cells to find natural products with the inhibitory activity on adipocyte differentiation. <I>S. mahogani</I> seeds were dried and extracted with 100% MeOH.</P><P><B>Results:</B></P><P>The methanolic extract was fractionated by bioassay-guided method to give nine B, D-seco limonoids (1-9) with slight structural modifications. Among nine compounds, compounds 4, 6 and 8 exhibited significant inhibitory effects of cell differentiation on 3T3-L1 cells. Those compounds have tigloyl residue at C-3 in common. Besides, compounds with no tigloyl residue at C-3 showed insignificant effect. Nevertheless, not all compounds with tigloyl residue at C-3 exerted significant inhibitory effect.</P><P><B>Conclusion:</B></P><P>These results suggested that tigloyl residue at C-3 may play a role in the anti-proliferative activity on a dipogenesis and the refined extract of <I>S. mahogani</I> may have a potential to be developed as a therapeutic agent to treat obesity.</P><P><B>SUMMARY</B></P><P><P>Nine irregular seco-limonoids were isolated from <I>Swietenia mahogani</I>.</P><P>Total extract and CHCl3 fraction of <I>S. mahogani</I> showed the significant inhibitory activities on 3T3-L1 cell differentiation.</P><P>A tigloyl residue at C-3 in an aglycone may play a role in the anti-proliferative activity on adipogenesis.</P></P> >[FIG OMISSION]</BR>

Mechanism for silicide formation in Ag(Cu)/Si and Ag(Co)/Si upon annealing

Heejung Yang,Jaegab Lee,Jinhyung Lee,Jiyoung Kim 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.2

Ag(Co) alloy and Ag(Cu) alloy lms were prepared on HF-cleaned Si by using DC magnetron sputtering and were then annealed in vacuum (3 10

Quantitative Analysis of Bioactive Compounds in a Mixture of the Lindera glauca Leaves Extract and Water-soluble Mastic Gum using an HPLC/UV Method

Heejung Yang 한국생약학회 2023 Natural Product Sciences Vol.29 No.4

This study aimed to establish and validate an HPLC method for the quantitative analysis of bioactive compounds in a mixture of the L. glauca leaves extract and water-soluble mastic gum (MLM). MLM has shown potential as an effective agent for preventing hair loss in the previous study. For the development of the quality evaluation of MLM, quercitrin (1), isoquercitrin (2), and oleanonic acid (3) were selected as analytical markers. The separation was achieved using a reverse-phase column with a gradient solvent system of 0.1% formic acid aqueous-0.1% formic acid acetonitrile at a flow rate of 1.0 mL/min. Detection was carried out at 210 nm and 254 nm. The calibration curves for all three markers exhibited good linearity (R2 > 0.999). Recoveries of the three markers ranged from 100 ± 15%. The concentrations of compounds 1, 2, and 3 in MLM was determined to be 25.73 ± 1.38, 8.36 ± 0.05, and 212.24 ± 12.88 μg/mL, respectively. The validated method will facilitate further compositional investigations in MLM.

ERP 시스템 도입유형이 기업의 IT·SW 활용에 미치는 영향에 관한 실증연구

양희정(Heejung Yang),성욱준(Wookjoon Sung) 한국IT서비스학회 2021 한국IT서비스학회지 Vol.20 No.2

Today s ERP system has become a core system of ITㆍSW that not only supports and manages enterprise resources efficiently, but also encompasses major business tasks. In other words, the ERP system is an essential strategic element for the survival of a company as a powerful means to innovate the management of an organization. This study analyzed the impact on the utilization of ITㆍSW from the perspective of the entire organization s process without limiting the performance evaluation of the ERP system itself, which is a core system of a company. The measurement data for evaluating the performance of the ERP system was the 2018 domestic company ITㆍSW utilization survey result report (subject to survey : 3,017 domestic companies with 10 or more employees). Based on this data, this study analyzed the impact of the ERP system on the entire enterprise s ITㆍSW utilization. In particular, attention was paid to whether there would be a difference in the use of ITㆍSW if the type of ERP system introduction was changed through the improvement of the business process of the company. Multiple regression analysis was performed using the statistical package SPSS 25. As a result, among the ERP system introduction types, the greatest degree of (+)influence on the company s ITㆍSW utilization is when the ERP package SW or ASP service is used as it is. Although the difference is insignificant, the second case was to build an ERP system through self-development or outsourcing, followed by customizing the package SW or system through self-development or outsourcing. Through the results of this study, it is expected that the organization will improve the business process and use the standard ERP package SW as it is without modification, thereby effectively enhancing the use of IT·SW of the company and leading to management performance.

의료취약지역 응급실 전담간호사 근무환경이 근무 불만족과 이직의도에 영향을 미치는 요인

양희정 ( Heejung Yang ),이진희 ( Jin-hee Lee ) 한국보건행정학회 2021 보건행정학회지 Vol.31 No.1

Background: The purpose of this study is to identify factors that affect work dissatisfaction and turnover intention for dedicated nurses working in emergency departments of vulnerable areas of health care. The purpose of this study is to identify risk factors related to the working environment that influence job dissatisfaction and intention to turnover among dedicated nurses working in emergency rooms in areas of medical vulnerability. Methods: We conducted a survey of nurses working in emergency rooms in vulnerable areas of medical care, and the survey was conducted for two consecutive years. A logistic regression analysis was performed with the working environment variable as the independent variable and the work environment dissatisfaction and turnover intention as dependent variables, respectively. Results: The variables that significantly affected both dissatisfactions with the working environment and turnover intention at the current institution were age, overlapping work in other departments, and the total work experience of nurses. Annual salary, the average number of double-duty (continuous work) per month, type of work, and work experience of nurses at the current institution had a significant effect only on dissatisfaction with the working environment. Conclusion: The results of this study are thought to be of great help if the government takes reference when establishing medical policies in vulnerable areas in the future.

전압분포의 선형특성을 이용한 Long-Channel Asymmetric Double-Gate MOSFET의 문턱전압 모델

양희정(Heejung Yang),김지현(Jihyun Kim),손애리(Aeri Son),강대관(Daegwan Kang),신형순(Hyungsoon Shin) 대한전자공학회 2008 電子工學會論文誌-SD (Semiconductor and devices) Vol.45 No.2

Long-channel Asymmetric Double-Gate (ADG) MOSFET의 해석적 문턱전압 모델을 제시한다. 본 모델은 채널 도핑과 채널의 양자효과까지 고려하였으며 더 나아가 문턱전압 영역에서 potential 분포의 선형특성을 이용하여 기존의 모델보다 간단하면서도 정확한 접근을 가능하게 하였다. 개발한 모델의 정확도는 다양한 실리콘 필름의 두께, 채널 도핑, 그리고 산화막 두께변화에 대하여 numerical 시뮬레이션 결과와 비교하여 검증하였다. A compact analytical model of the threshold voltage for long-channel Asymmetric Double-Gate (ADG) MOSFET is presented. In contrast to the previous models, channel doping and carrier quantization are taken into account. A more compact model is derived by utilizing the potential distribution linearity characteristic of silicon film at threshold. The accuracy of the model is verified by comparisons with numerical simulations for various silicon film thickness, channel doping concentration and oxide thickness.