• Journal of Plant Biotechnology
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• v.46 no.1
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• pp.37-44
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• 2019

The objective of this study was to compare the effects of different concentration of ethanol extraction on the total phenol and flavonoid contents and physiological activities. The total phenol content of the extracts ranged from 35.54 to 71.52 mg GAE/g. An increase in the ethanol concentration of the solvent led to an increase in the phenol content, with the highest content being found in the 80 and 99.5% ethanol extract. The same trend was observed for flavonoid content. DPPH, nitric oxide, superoxide, hydroxyl radical scavenging activity and TEAC, FRAP and ORAC were measured by antioxidant assay. Radical scavenging activity of aqueous ethanol extracts was better than that of water and 99.5% ethanol extracts. TEAC and FRAP were highly dependent on ethanol concentration and ORAC showed high activity in 40 ~ 80% ethanol extract. Antioxidant activity of Dolwoe leaves tea showed different results among the assay systems. In most experiments, the activities of water and 99.5% ethanol extracts was relatively low. ${\alpha}$-Glucosidase inhibitory activity and microorganism inhibitory activity were highest in the 80% and 99.5% ethanol extracts. Therefore, it was considered that extraction with 80% ethanol was appropriate when considering the antioxidative and physiological activities of Dolwoe leaves tea. Based on these results, it can be used as a basic data for the development of food of Dolwoe leaves tea.

• Journal of Ginseng Research
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• v.45 no.1
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• pp.1-21
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• 2021

Panax species have gained numerous attentions because of their various biological effects on cardiovascular, kidney, reproductive diseases known for a long time. Recently, advanced analytical methods including thin layer chromatography, high-performance thin layer chromatography, gas chromatography, high-performance liquid chromatography, ultra-high performance liquid chromatography with tandem ultraviolet, diode array detector, evaporative light scattering detector, and mass detector, two-dimensional high-performance liquid chromatography, high speed counter-current chromatography, high speed centrifugal partition chromatography, micellar electrokinetic chromatography, high-performance anion-exchange chromatography, ambient ionization mass spectrometry, molecularly imprinted polymer, enzyme immunoassay, 1H-NMR, and infrared spectroscopy have been used to identify and evaluate chemical constituents in Panax species. Moreover, Soxhlet extraction, heat reflux extraction, ultrasonic extraction, solid phase extraction, microwave-assisted extraction, pressurized liquid extraction, enzyme-assisted extraction, acceleration solvent extraction, matrix solid phase dispersion extraction, and pulsed electric field are discussed. In this review, a total of 219 articles published from 1980 to 2018 are investigated. Panax species including P. notoginseng, P. quinquefolius, sand P. ginseng in the raw and processed forms from different parts, geographical origins, and growing times are studied. Furthermore, the potential biomarkers are screened through the previous articles. It is expected that the review can provide a fundamental for further studies.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.582-587
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• 2022

Biphasic solvents are attracting attention as energy-reducing solvents for capturing CO₂ from flue gas in combustion process. In this study, considering diethylenetriamine (DETA) and diethylethanolamine (DEEA) mixed solvents, one of the biphasic solvents by blending of two types of amines, the CO₂ absorption rates of DETA and DEEA was measured by wetted wall column. The effects of DETA and DEEA concentrations and operating temperature on the overall mass transfer coefficient were investigated. As a result, the overall mass transfer coefficient was proportional to the DETA concentration. However, in the case of the DEEA concentration, the effect was small and when the concentration was exceeded, the overall mass transfer coefficient decreased. The DETA aqueous solution showed little change in the overall mass transfer coefficient with the operating temperature, whereas the DEEA aqueous solution increased the overall mass transfer coefficient with the operating temperature. As a result of obtaining the observed reaction rate constant under the pseudo-first-order reaction assumption, it was found that the observed reaction rate constant in DETA aqueous solution was proportional to the DETA concentration, but DEEA did not fit the pseudo-first-order reaction assumption.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.4
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• pp.357-364
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• 2022

In this study, antioxidant efficacy was analyzed to verify the value of use as an antioxidant-related functional cosmetic material using Cheongtaejeon tea extract. Cheongtaejeon tea was extracted, concentrated, and freeze-dried with hot water and 70% ethanol as a solvent to prepare samples, and then ABTS⁺ radical scavenging activity, electron donating ability, SOD-like ability, reducing power, ferric reducing antioxidant power (FRAP), total phenolic, and flavonoid contents were analyzed. In the ABTS⁺ radical scavenging activity experiment, both the Cheongtaejeon hydrothermal extract (CTW) and the Cheongtaejeon 70% ethanol extract (CTE) showed erasure activity of more than 98% at a concentration of 1,000 ㎍/mL, and in the electron donating analysis experiment, CTW and CTE, respectively, 42.20% and 78.82%. As a result of SOD-like activity measurement, activity of 39.73% and 67.39% of CTW and CTE, respectively, was confirmed. In the case of FRAP and reducing power experiments, both CTW and CTE showed high effects, and as a result of analyzing the total phenol and flavonoid contents, both CTW and CTE showed high contents. Based on the results of the experiment, the Cheongtaejeon tea extract is expected to have a highly valuable as a functional cosmetics material related to antioxidants.

• Applied Chemistry for Engineering
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• v.33 no.4
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• pp.394-401
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• 2022

The synthesis of 1,2-alkylaminopropanediols (1,2-AAPs) was designed to improve the hydrophilicity of linear 1,2-alkanediols having 10, 12, 14, and 16 carbon atoms in the alkyl chain. 1,2-AAPs were synthesized by reacting 3-monochloro-1,2-propanediol (3-MCPD) with linear alkylamines having 10, 12, 14 or 16 carbon atoms in an ethanol solvent at 40℃ for 2 h. The yield and purity of four types of 1,2-AAPs synthesized were found to be in the range of 51-58% and 85-99%, respectively. The amine salts of four types of 1,2-AAPs were prepared from a purified paste or solid compound by adding an acidic solution (HCl) to pH 7, and then their solubilities and antibacterial effects were tested. 1,2-decylaminopropanediol, 1,2-dodecylaminopropanediol, and 1,2-tetradecylaminopropanediol were all dissolved in water at concentrations of 100%, 50%, and 0.1%, respectively, however 1,2-hexadecylaminopropanediol was not. The antibacterial effect was improved as the length of the alkyl chain increased. As a result of confirming the preservative effect of the lotion (cosmetic formulation) applied with 1,2-AAP for application, it showed very strong antibacterial activity at low concentrations ranging from 0.005% to 0.2%.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.426-433
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• 2023

Capacitor performance was considered using coffee grounds-based activated carbon produced through oil extraction and KOH activation to increase the utilization of boiwaste. Oil extraction from coffee grounds was performed by solvent extraction using n-Hexane and isopropyl alcohol solvents. The AC_CG-Hexane/IPA produced by KOH activation after oil extraction increased the specific surface area by up to 16% and the average pore size by up to 2.54 nm compared to AC_CG produced only by KOH activation without oil extraction. In addition, the pyrrolic/pyridinic N functional group of the prepared activated carbon increased with the extraction of oil from coffee grounds. In the cyclic voltage-current method measurement experiment, the specific capacitance of AC_CG-Hexane/IPA at a voltage scanning speed of 10 mV/s is 133 F/g, which is 33% improved compared to the amorphous capacity of AC_CG (100 F/g). The results show improved electrochemical properties by improving the size and specific surface area of the mesopores of activated carbon by removing components from coffee grounds oil and synergistic effects by increasing electrical conductivity with pyrrolic/pyridinic N functional groups. In this study, the recycling method and application of coffee grounds, a bio-waste, is presented, and it is considered to be one of the efficient methods that can be utilized as an electrode material for high-performance supercapacitors.

• Resources Recycling
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• v.32 no.3
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• pp.3-8
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• 2023

This study discussed production, demand, and future prospects of rubidium, which is an alkali group metal that is highly reactive to various media and requires carefulness in handling, but no significant environmental hazard of rubidium has been reported yet. Rubidium is used in various fields such as optoelectronic equipment, biomedical, and chemical industries. Because of difficulty in production as well as limited demand, the transaction price of rubidium is relatively high, but its detail information such as market status and potential growth is uncertain. However, if the mass production of versatile ultra-high-performance equipment such as quantum computers and the necessity of rubidium use in the equipment are confirmed, there is a possibility that the rubidium market will expand in the future. Rubidium is often found together with lithium, beryllium, and cesium, and may be present in granite containing minerals such as lepidolite and pollucite, as well as in seawater and industrial waste. Several technologies such as acid leaching, roasting, solvent extraction, and adsorption are used to recover rubidium. The maximum recovery efficiency of the rubidium from the sources and the processing above is generally high, but, in many practices, rubidium is not the main recovery target, and therefore the actual recovery effects should depend on presence of other valuable components or impurities, together with recovery costs, energy consumption, environmental issues, etc. In conclusion, although the current production and consumption of rubidium are limited, with consideration of the possible market fluctuations according to the emergence of large-scale demand sources, etc., further investigations by related institutions should be necessary.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.176-183
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• 2023

The extraction and filtration of red ginseng with a mixed solvent of water and alcohol-a common processing method-and the production of a concentrate through heat treatment, such as steaming, leads to its hydrolysis or polymerization. Approximately 200 ginsenosides have consequently been detected in small amounts, in addition to the identification of the functions of approximately 30 major ginsenosides. This complicates the identification of the functionality of red ginseng and its efficacy, and has negative effects as a functional food, as the astringent taste becomes stronger with an increase in the number of extractions. The red ginseng concentrate was, therefore, extracted at a low temperature (less than 40 ℃) and processed to eliminate these negative aspects, with a specific focus on the characteristics of the functional components of ginsenosides.

• Journal of Environmental Health Sciences
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• v.49 no.6
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• pp.372-379
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• 2023

Background: Laundry workers are known to be exposed to organic solvents in various works including dry cleaning. Long-term exposure to organic solvents may cause adverse health effects among laundry workers. Objectives: To investigate the association between exposure to organic solvents and symptom of headache or eyestrain among laundry workers. Methods: The subjects were total 267 laundry workers who participated in the 6th Korean Working Conditions Survey (KWCS). Responses to exposure to 'inhalation of vapor from organic solvent' was categorized into two (non-exposed: rarely or absolutely not exposed during working hours; exposed: ≥1/4 working hours) or three (non-exposed; low exposure: 1/4 of the working hours; high exposure: ≥1/2 working hours) groups. Logistic regression analysis was performed to evaluate the association between exposure to organic solvents and symptom of headache or eyestrain in the last 12 months among laundry workers. Odds ratios (ORs) and the 95% confidence intervals (CIs) were calculated for experience of the symptom of headache or eyestrain with adjustment for age, sex, education, workplace size (by the number of workers), working hours per week, and current working period (year). Results: The proportions of exposure groups, i.e., non-exposed, low exposure, and high exposure, were 80.4%, 11.1%, and 8.5%, respectively. The proportion of those who had symptom of headache or eyestrain in the last 12 months was 18.7%. There was a significant association between exposure to organic solvents and experience of headache or eyestrain (OR=3.2, 95% CI=1.4~7.4). And, the proportion of those who experienced symptom of headache or eyestrain tended to increase significantly as the level of exposure to organic solvents increased (P_trend=0.002). Conclusions: Our results suggest that exposure to organic solvents are associated with symptom of headache or eystrain among laundry workers in Korea. However, further studies with more relevant design is needed to replicate the association.

• Journal of the Korean Applied Science and Technology
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• v.40 no.5
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• pp.988-1000
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• 2023

Hesperetin(HT) is a potent antioxidant flavonoid aglycone derived from hesperidin(HD). The antioxidant, anti-inflammatory, and antimicrobial activities of HT and its cyclodextrin(CD) inclusion complexes were compared in vitro. HT was prepared by enzymatic hydrolysis of HD, and HT/CD complexes were prepared using 𝛽-cyclodextrin(𝛽-CD) and hydroxypropyl-𝛽-cyclodextrin(HP-𝛽-CD) by solvent co-evaporation method. The solubility of the HT/HP-𝛽-CD inclusion complex increased 93.5-fold compared to HT, and the solubility of HT/𝛽-CD increased 22.5-fold. The HT/HP-𝛽-CD inclusion complex showed a similar effect as HT on radical scavenging activity in antioxidant assays, whereas the HT/𝛽-CD inclusion complex showed slightly lower activity than HT. Cytotoxicity was low in the following order; HT/HP-𝛽-CD, HT/𝛽-CD, and HT in murine macrophage RAW264.7 cells. Treatment with HT and HT/CD inclusion complexes reduced the levels of inflammatory mediators such as nitric oxide(NO), tumor necrosis factor-𝛼(TNF-𝛼) and interleukin-6(IL-6) in the cells. HT and HT/HP-𝛽-CD inclusion complex were more effective than HT/𝛽-CD inclusion complex at relatively low concentrations. Inhibitory effects were tested on skin-pathogenic bacteria, Staphylococcus aureus and Pseudomonas aeruginosa, and they showed an antimicrobial effect on S. aureus in the order of HT = HT/HP-𝛽-CD > HT/𝛽-CD, but they did not show any significant inhibitory effect on P. aeruginosa. In conclusion, HT, the aglycone form of HD, and its CD inclusion complexes showed various biological activities. HT/HP-𝛽-CD inclusion complex, which is the highly soluble form of HT, showed relatively higher activity compared to HT/𝛽-CD inclusion complex.