• Microbiology and Biotechnology Letters
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• v.50 no.3
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• pp.375-386
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• 2022

In the present study, four distinctly colored bacterial isolates that show intense pigmentation upon brief ultraviolet (UV) light exposure are chosen. The strains are identified as Micrococcus luteus (Milky yellow), Cryseobacterium pallidum (Yellow), Cryseobacterium spp. (Golden yellow), and Kocuria turfanensis (Pink) based on their morphological and 16S rDNA analysis. Moderate salinity (1.25%), 25-37℃ temperature, and pH of 7.2 are found to be the most favorable conditions of growth and pigment production for all the selected isolates. The pigments are extracted using methanol: chloroform (1:1) and the purity of the pigments are confirmed by high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC). Further, Fourier transform infrared (FTIR) and UV-Visible spectroscopy indicate their resemblance with carotenoids and flexirubin family. The antioxidant activities of the pigments are estimated, and, all the pigments have shown significant antioxidant efficacy in 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picryl-hydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. The UV protective property of the pigments is determined by cling-film assay, wherein, at least 25% of UV sensitive Escherichia coli survive with bio-pigments even after 90 seconds of UV exposure compared to control. The pigments also hold a good sun protective factor (SPF) value (1.5-4.9) which is calculated with the Mansur equation. Based on these results, it can be predicted that these bacterial pigments can be further developed into a promising antioxidant and UV-protectant for several biomedical applications.

• Tribology and Lubricants
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• v.35 no.3
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• pp.151-157
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• 2019

Insulated oil degradation produces charged by-products, such as acids and hydro-peroxides, which tend to reduce the insulating properties of the oil. In this study, UV-vis spectroscopy measurement technology is developed and experimentally compared with other measurement methods, such as the titration method and IR spectroscopy, to validate its ability to monitor the degradation of electrical insulating paper. The degradation characteristics of the insulating paper are appropriately represented through various types of measurement methods, such as the Tan (delta) method, $CO_2$ gas production measurement, the titration method, and IR spectroscopy. The results are demonstrated to be well comparable to a change in the fluorescence emission ratio (FER), which is defined as the shift in fluorescence intensity in the measured wavelength range, and also to the chromatic ratio, which is defined as a color shift to longer wavelength ranges. The results also show that, by using UV-vis spectroscopy, it is possible to detect the degradation of the insulating paper. This study suggests that UV-vis spectroscopy can be applied as an alternative to high-performance liquid chromatography, which is the internationally recognized measurement technology for cellulose paper degradation. The FER detector is also verified to be useful as an effective condition-monitoring device for power transformers.

• YAKHAK HOEJI
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• v.42 no.5
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• pp.473-479
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• 1998

Lovastatin (LOVA), a fungal metabolite isolated from cultures of Aspergillus terreus, is a competitive HMG-CoA reductase inhibitor used for the treatment of primary hyper cholesterolemia, and has also been shown to suppress growth in a variety of non-glioma tumor cell lines. A sensitive reversed-phase high-perfonnance liquid chromatographic method with ultraviolet (UV) absorbance detection has been developed to quantitate LOVA in human plasma and urine samples using liquid-liquid extraction procedure. Baseline separation of LOVA and internal standard, simvastatin was achieved on a Novapak $C_{18}$ analytical column with a mobile phase containing 0.025M $NaH_2PO_4$: CAN (35:65, v/v%), adjusted pH to 4.5. The flow rate was set at 1.5ml/min, and the column effluent was monitored by a UV detection at 238nm. The limit of quantification was determined to be 0.5${\mu}$g/ml while extraction efficiency of LOVA ranged from 73.4-82.9% at LOVA concentrations of 0.5 to 10${\mu}$g/ml. Good linearity with correlation coefficients greater than 0.999 was obtained in the range of LOVA concentrations from 0.5 to 10${\mu}$g/ml. The accuracy and the precision were proven excellent with relative standard deviation (RSD, %) and relative error (RE, %) of less than 4.2 and 4.0, respectively. Intraday precision, evaluated at five LOVA concentrations (0.5, 1, 2, 5, 10${\mu}$g/ml) and expressed as RSD ranged from 0-1.82% while the interday precision at the same concentrations ranged from 0.7-10.5%. The analytical method described was then successfully employed for the determination of LOVA concentrations in plasma samples obtained during a phase II clinical trial using high doses of LOVA (30-40mg/kg/day). This method could be further utilized for the ongoing pharmacolkinetic studies and therapeutic drug monitoring of the high-dose LOVA therapy in adenocarcinoma patients.

• Journal of Pharmaceutical Investigation
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• v.24 no.1
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• pp.29-32
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• 1994

In order to improve the sensitivity of the current assay methods of selenium in dried-yeast preparations, atomic absorption spectrophotometry (AAS), high performance liquid chromatography (HPLC) and UV-Vis spectrophotometry were employed. The sample was prepared with the digestion by acid mixture of hydrochloric acid, nitric acid and perchloric acid after elimination of ether-soluble substances. The range of quantitation of selenium was $1.0{\sim}6.0\;{\mu}g/ml$ by UV-Vis spectrophotometry, $5.0{\sim}20.0\;{\mu}g/ml$ by HPLC and $0.03{\sim}0.10\;{\mu}g/ml$ by AAS.

• Journal of Applied Biological Chemistry
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• v.58 no.4
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• pp.303-309
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• 2015

${\gamma}$-Aminobutyric acid (GABA) content in fermented plant products and their main plant materials (aerial part of Acanthopanax sessiliflorus, fruit of Crataegus pinnatifida, and whole plant of Morus alba) was determined by high-performance liquid chromatography. GABA was quantified using a reverse-phase column with a gradient elution program (water:acetonitrile =90:10 to 0:100 for 40 min). UV detection was conducted at 280 nm. GABA content was measured in fermented plant products (15.07 mg/g), aerial part of A. sessiliflorus (4.49 mg/g), fruit of C. pinnatifida (10.59 mg/g), and whole plant of M. alba (2.31 mg/g). The presence of GABA in fermented plant products, including A. sessiliflorus, C. pinnatifida, and M. alba is important in industrial application for health supplements.

• Journal of environmental and Sanitary engineering
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• v.7 no.1
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• pp.79-86
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• 1992

Rapid determination of chlorpyrifos and fluvalinate in mixed insecticide was established by using high performance liquid chromatography. Result were as follows : 1. On Lichrosorb${\circledR}$ RP-8(10 ${\mu}m$) Column with on fluent of acetanitrile : water=75 . 25, sufficient separation of Chlorpyrifos and Fluorinate of base was obtained. 2.410td portion the diluted solution was injected in to the cdumn, and the effluent was monitored by on UV-Detector at 270 nm. 3. Relative Standard Deviation were 0.97% (chlorpyrifos) and 0.5% (fluorinate) under analysis conditions. 4. The UV-Detector response at 270 nm were linear (Y=421.8X-2090, $R^2=0.9997$ : Chlorpyrifos, Y= 1062.7X-4017.7, $R^2=0.9998$ : Fluorinate) over a range of 30~500 ${\mu}g/ml$.

• YAKHAK HOEJI
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• v.59 no.5
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• pp.222-229
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• 2015

Lithospermi radix, the dried roots of Litospermum erythrorhizon Sieboid et Zuccarini (Boraginaceae), has long been used to treat detoxification and inflammation. In this study, we isolated two main quinoid compounds, ${\beta}$-hydroxyisovalerylshikonin (1) and acetylshikonin (2) from L. erythrorhizon. As acetylshikonin is considered as a marker compound of L. erythrorhizon, a rapid analysis method for the simultaneous determination of quinoid compounds including 2 was also developed by HPLC (High Performance Liquid Chromatography) and validation of this analytical method. By the developed method, two quinoid marker compounds (${\beta}$-hydroxyisovalerylshikonin and acetylshikonin) were successfully quantified in 31 commercial samples which were collected from different regions. The contents were 0.20% (${\beta}$-hydroxyisovalerylshikonin) and 0.22% (acetylshikonin), respectively.

• Korean journal of food and cookery science
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• v.2 no.2
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• pp.16-20
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• 1986

The major pungent component from Korean radish roots was purified by reverse phase high performance liquid chromatography (RPHPLC), and characterized as 4-methylthio-3-butenyl isothiocyanate on the basis of the sensory test (pungency), UV spectrum and mass spectrum analysis. The purified isothiocyanate moved as a single peak(retention time, 5.2 min) in RP-HPLC analysis, and as a single spot(Rf, 0.9) in TLC analysis.

• Natural Product Sciences
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• v.27 no.4
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• pp.280-283
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• 2021

Cercidiphyllum japonicum is being used for the treatment of obesity and liver fibrosis in Korean local clinics. In the present study, we tried to develop an analytical methodology for the determination of the chemical markers of Cercidiphyllum japonicum. Four chemicals, maltol (1), chlorogenic acid (2), quercetin (3), and avicularin (4), were selected for method validation, and the analytical conditions were optimized and validated using high-performance liquid chromatography coupled with an ultraviolet detector (HPLC-UV). Additionally, the seasonal variations of four markers were monitored every month for six months. The contents of four chemicals markers were most detected in a sample collected in June.

• Journal of Environmental Science International
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• v.21 no.1
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• pp.49-55
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• 2012

In this study, the characteristic of offensive major odorous compound from the Bon-San industrial complex in Gimhae were determined by analytical methods of Gas Chromatography, High Performance Liquid Chromatography and UV/VIS Spectrophotometer. The kind of major odorous compounds examined acetaldehyde, sulfur compounds, ammonia and styrene. The concentration of all odorous compounds at 3 sampling points of industrial complex were lower than those of regulation standard levels of the industrial complex in Korea. The mean concentration of hydrogen sulfide was 0.0235 ppm at sampling point 2, it was higher than other sampling point. Complex odors was lower than regulation standard levels of the industrial complex in Korea.