• Journal of Ginseng Research
• /
• v.40 no.3
• /
• pp.220-228
• /
• 2016

Background: Among the various ginseng strains, Shizhu ginseng is endemic to China, mainly distributed in Kuandian Manchu Autonomous County (Liaoning Province, China); however, not much is known about the compounds (especially saponins) in Shizhu ginseng. Methods: A rapid, sensitive, and reliable ultra-high performance liquid chromatography coupled with MS/MS (UHPLC-MS/MS) method was developed to separate and identify saponins in Shizhu ginseng. Results: The separation was carried out on a Waters ACQUITY UPLC BEH $C_{18}$ column ($100mm{\times}2.1mm$, $1.7{\mu}m$) with acetonitrile and 0.1% formic acid aqueous solution as the mobile phase under a gradient elution at $40^{\circ}C$. The detection was performed on a Micromass Quattro Micro API mass spectrometer equipped with electrospray ionization source in both positive and negative modes. Under the optimized conditions, a total of 31 saponins were identified or tentatively characterized by comparing retention time and MS data with related literatures and reference substances. Conclusion: The developed UHPLC-MS/MS method was suitable for identifying and characterizing the chemical constituents in Shizhu ginseng, which provided a helpful chemical basis for further research on Shizhu ginseng.

• Korean Journal of Pharmacognosy
• /
• v.53 no.2
• /
• pp.111-118
• /
• 2022

Chestnut honey is a sweet dark-colored honey with a distinct bitter aftertaste. It contains numerous phenolic compounds and alkaloids and is noted for its antioxidant and anti-inflammatory activities. However, it has been established that there are differences in the composition and activity of chestnut honey constituents depending on the region of origin, the sources of which warrant further research. In this study, we analyzed the kynurenic acid (KA) contents in chestnut honey produced in nine different regions in Korea, using high-performance liquid chromatography in conjunction with ultraviolet detection, and validated the analytical method developed. Use of a reverse-phase column and detection at a wavelength of 240 nm were found to be optimal for the detection of KA. Similar evaluation of an optimal method for extracting KA from chestnut honey revealed that extraction using 10% EtOH at 20 times the sample volume over a 6 h period was the most suitable for obtaining a high content of KA. Among the nine regional chestnut honeys assessed, KA content was found to be highest in the "Gongju" sample (1.14 mg/g), followed by that in the "Cheongdo" and "Damyang" samples. Validation of the KA analytical method revealed a good analyte linearity, with a correlation coefficient (r²) of 0.9995, an accuracy of between 92.37% and 107.35%, and good precision (RSD ≤ 1.05%). Our findings in this study, based on a validated quantitative analytical method for KA, could make an important contribution to establishing a data profiling procedure for characterizing chestnut honeys produced in different regions, and may also provide basic data for the identification of functional honey.

• Food Science and Preservation
• /
• v.20 no.3
• /
• pp.342-347
• /
• 2013

In recent years, polyphenol-rich herbs, fruits and processed foods, which are made of plant origin, have attracted much attention due to their potential health benefits. Pomegranate (Punica granatum L.) is an important source of bioactive compounds and has been used to treat diseases because of its medicinal properties. This research was focused on characterizing Korea's national cultivar and a similar product from California, USA. To evaluate their bioactive compounds and pharmacological activities, their anti-oxidation and cancer inhibition properties, as well as their organic acid and free sugar contents, were investigated. The national cultivar had low total sugar and high organic acid contents, contrary to the imported product. The results showed that the peel of national cultivar had high polyphenol and ellagic acid contents compared to imported product. The free radical scavenging capacity was evaluated via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and its positive correlation with the total polyphenol contents was found. The anti-cancer activity of methanol extracts revealed growth inhibition against the prostate cancer cell. These results signify that while pomegranate, national cultivar, is more sour than the imported product, its health benefits could be excellent. Also, the polyphenol compound content of the non-edible part (such as the peel and the seed) was higher than that of the juice. Thus, it is suggested that the byproduct of the juice extraction could be potentially used in other fields such as medicine or dietary agents.

• Journal of Ginseng Research
• /
• v.37 no.1
• /
• pp.124-134
• /
• 2013

The authentication of the physico-chemical properties of ginsenosides reference materials as well as qualitative and quantitative batch analytical data based on validated analytical procedures is a prerequisite for certifying good manufacturing practice (GMP). Ginsenoside Rb1 and Rg1, representing protopanaxadiol and protopanaxatriol ginsenosides, respectively, are accepted as marker substances in quality control standards worldwide. However, the current analytical methods for these two compounds recommended by Korean, Chinese, European, and Japanese pharmacopoeia do not apply to red ginseng preparations, particularly the extract, because of the relatively low content of the two agents in red ginseng compared to white ginseng. In manufacturing fresh ginseng into red ginseng products, ginseng roots are exposed to a high temperature for many hours, and the naturally occurring ginsenoside Rb1 and Rg1 are converted to artifact ginsenosides such as Rg3, Rg5, Rh1, and Rh2 during the heating process. The analysis of ginsenosides in commercially available ginseng products in Korea led us to propose the inclusion of the (20S)- and (20R)-ginsenoside Rg3, including ginsenoside Rb1 and Rg1, as additional reference materials for ginseng preparations. (20S)- and (20R)-ginsenoside Rg3 were isolated by Diaion HP-20 adsorption chromatography, silica gel flash chromatography, recrystallization, and preparative HPLC. HPLC fractions corresponding to those two ginsenosides were recrystallized in appropriate solvents for the analysis of physico-chemical properties. Documentation of those isolated ginsenosides was achieved according to the method proposed by Gaedcke and Steinhoff. The ginsenosides were subjected to analyses of their general characteristics, identification, purity, content quantification, and mass balance tests. The isolated ginsenosides showed 100% purity when determined by the three HPLC systems. Also, the water content was found to be 0.534% for (20S)-Rg3 and 0.920% for (20R)-Rg3, meaning that the net mass balances for (20S)-Rg3 and (20R)-Rg3 were 99.466% and 99.080%, respectively. From these results, we could assess and propose a full spectrum of physico-chemical properties of (20S)- and (20R)-ginsenoside Rg3 as standard reference materials for GMP-based quality control.

• Korean Journal of Environmental Agriculture
• /
• v.26 no.1
• /
• pp.55-61
• /
• 2007

Metolachlor may pose a threat to surface and ground water qualities due to its high solubility in water, Zerovalent iron (ZVI) releases $e^-$ which can degrade the organochlorinated compounds. The objective of this research was to evaluate the kinetics of metolachlor degradation as affected by ZVI sources [Peerless unannealed (PU) and Peerless annealed (PA)] and ZVI levels (1 and 5%) under batch conditions at different metolachlor concentrations (200 and 1000 mg/l) and temperatures (15, 25, and $35^{\circ}C$). The effectiveness of ZVI on metolachlor degradation was assessed by characterizing the dechlorinated metolachlor byproduct molecules. Metolachlor degradation by ZVI followed the first-ordered kinetics with a higher rate constant at higher level of ZVI treatment. At 5% (w/v) of PU and PA treatment, the half-lives of metolachlor degradation were 9.93 and 6.51 h and all of the initial metolachlor were degraded in 72 and 48 h, respectively. Rate constants (k) of metolachlor degradation were higher at the lower initial metolachlor concentration. The metolachlor degradation by ZVI was temperature dependent showing that the rate constant (k) at 15, 25, and $35^{\circ}C$ were 0.0805, 0.1017, and 0.3116 /h, respectively. The ZVI-mediated metolachlor degradation yielded two byproduct molecules identified as dechlorinated metolachlor $(C_{13}H_{18}NO)$ and dechlorinated-dealkylated metolachlor $(C_{12}H_{17}NO)$. The PA ZVI was more effective than PU ZVI in metolachlor degradation.

• Explosives and Blasting
• /
• v.29 no.1
• /
• pp.17-26
• /
• 2011

In this study, the pollutants contained in water and soil samples taken from the explosive demolition site were examined to investigate the effects on environment, and management plan of non-point source pollution in the demolition site was suggested through characterizing the movement of the pollutant with time. As results, pH value of the water and soil samples after the demolition work was 8.5~9.3 which exceeds the Korean environmental criterion of water and soil range due to calcium hydroxide compounds in the concrete. The concentration level of heavy metals caused by the explosive demolition doesn't exceed the environmental criterion of water and soil doesn't exceed the environmental criterion of water and soil quality, and the influence of water and soil pollution on the environment was not considered. The concentration of the heavy metals was analyzed and that of Cr, Cu, Zn and Hg among the heavy metals increased after the drilling and explosive demolition. This says that concentration of the heavy metals during explosive demolition works needs to be monitored. The most pollutants with time or rain dilution into the demolition site decreased and this means that the pollutants caused by the explosive demolition might have influenced to vicinity of the demolition sites as non-point pollution.

• Journal of Biomedical Engineering Research
• /
• v.25 no.5
• /
• pp.329-334
• /
• 2004

The electronic nose (E-nose) recently finds its applications in medical diagnosis, specifically on detection of diabetes, pulmonary or gastrointestinal problem, or infections by examining odors in the breath or tissues with its odor characterizing ability. The odor recognition performance of E-nose can be improved by manipulating the sensor array responses of vapors in time-profile forms. The different chemical interactions between the sensor materials and the volatile organic compounds (VOC's) leave unique marks in the signal profiles giving more information than collection of the conventional piecemal features, i.e., maximum sensitivity, signal slopes, rising time. In this study, to use them in vapor recognition task conveniently, a novel time-profile method was proposed, which is adopted from digital image pattern matching. The degrees of matching between 8 different vapors were evaluated by using the proposed method. The test vapors are measured by the silicon-based gas sensor array with 16 CB-polymer composites installed in membrane structure. The results by the proposed method showed clear discrimination of vapor species than by the conventional method.

• Journal of the Microelectronics and Packaging Society
• /
• v.31 no.2
• /
• pp.78-84
• /
• 2024

The electrochemical reduction of carbon dioxide (CO₂) is gaining attention as an effective method for converting CO₂ into high-value carbon compounds. This paper reports a facile meth od for synth esizing and characterizing g-C₃N₄-modified porous Au (pAu) electrodes for electrochemical CO₂ reduction using e-beam deposition and anodization techniques. The fabricated pAu@g-C₃N₄ electrode (@ -0.9 VRHE) demonstrated superior electrochemical performance compared to the pAu electrode. Both electrodes exhibited a Faradaic efficiency (FE) of 100% for CO production. The pAu@g-C₃N₄ electrode achieved a maximum CO production rate of 9.94 mg/s, which is up to 2.2 times higher than that of the pAu electrode. This study provides an economical and sustainable approach to addressing climate change caused by CO₂ emissions and significantly contributes to the development of electrodes for electrochemical CO₂ reduction.