• ALGAE
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• v.35 no.2
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• pp.177-187
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• 2020

Cyanobacteria have been widely reported to produce a variety of UV-absorbing mycosporine-like amino acids (MAAs). Herein, we reported production of the unusual MAA, mycosporine-glycine-alanine (MGA) in the cyanobacterium Sphaerospermopsis torques-reginae ITEP-024 using a newly developed UHPLC-DAD-MS/HRMS (ultra-high performance liquid chromatography-diode array detection-high resolution tandem mass spectrometry) method. MGA had previously been first identified in a red-algae, but S. torques-reginae strain ITEP-024 is the first cyanobacteria to be reported as an MGA producer. Herein, the chemical structure of MGA is fully elucidated from one-dimensional / two-dimensional nuclear magnetic resonance and HRMS data analyses. MAAs are unusually produced constitutively in S. torques-reginae ITEP-024, and this production was further enhanced following UV-irradiance. It has been proposed that MAA biosynthesis proceeds in cyanobacteria from the pentose phosphate pathway intermediate sedoheptulose 7-phosphate. Annotation of a gene cluster encoded in the genome sequence of S. torques-reginae ITEP-024 supports these gene products could catalyse the biosynthesis of MAAs. However, addition of glyphosate to cultures of S. torques-reginae ITEP-024 abolished constitutive and ultra-violet radiation induced production of MGA, shinorine and porphyra-334. This finding supports involvement of the shikimic acid pathway in the biosynthesis of MAAs by this species.

• YAKHAK HOEJI
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• v.56 no.5
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• pp.280-287
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• 2012

A high-performance liquid chromatography (HPLC) combined with ultraviolet (UV) method for the simultaneous determination of ${\alpha}$-cyperone and nootkatone was developed for the quality control of Cyperus rotundus Linne. The separation was performed on a KR100-$5C_{18}$ ($4.6{\times}250mm$) column, and an elution gradient composed of methanol and water with a flow-rate of 1.0 ml/min. Detection wavelength was set at 254 nm. The optimum extraction for the detection of the ${\alpha}$-cyperone and nookatone was achieved by ultrasonic with methanol for an hour. Two marker compounds ${\alpha}$-cyperone and nootkatone in Cyperi Rhizoma showed good linearity ($R^2$ >0.999) in the concentration range of $12.5{\mu}g/ml$ to $200{\mu}g/ml$. The developed method provided satisfactory precision and accuracy with overall intra-day and inter-day variations of 0.04~1.23% and 0.08~0.68%, respectively, and the overall recoveries of 97.45~105.58% for the two compounds analyzed. Additionally, a difference was observed in the cluster analysis and principal component analysis between Cyperi Rhizoma in Korea and China. The result demonstrated that the principal component analysis is useful to distinguish between Cyperi Rhizoma in Korea and China.

• Korean Journal of Pharmacognosy
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• v.51 no.4
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• pp.291-296
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• 2020

Filipendula glaberrima (FG) is a plant endemic to South Korea. It is economically important as a food source and used as a medicine in treating ailments. Filipendula flowers are characterized by the presence of several polyphenolic constituents. The aim of this study is to determine the content of (+)-catechin in Filipendula glaberrima collected from different regions at different flowering stages. High-performance liquid chromatography with a gradient elution system (0.5% acetic acid in water : acetonitrile = 95 : 5 to 0 : 100 for 35 min) was used. A reverse-phase INNO column with UV detection at 278 nm was employed. The results revealed that F. glaberrima from Mt. Odae has the highest (+)-catechin content (10.600 mg/g). Furthermore, its content was the lowest in samples collected during the pre-flowering period and the highest at the early-flowering stage. This study provides a basis in establishing the optimal period and the best region for collecting F. glaberrima with maximized (+)-catechin yield.

• Korean journal of food and cookery science
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• v.6 no.4 s.13
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• pp.27-32
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• 1990

Lipids of Job's tears (Yullmoo) were extracted by the mixture of chloroform: methanol (2:1, v/v) and from these lipids, triglycerides were separated by column chromatography (Sephadex G-25 column) and then confirmed by thin layer chromatography (TLC) and reconfirmed by gas chromatography (GC). The triglycerides were fractionated into 6 groups on the basis of their partition numbers (PN) by reverse phase high performance liquid chromatography (HPLC) on a column Shimpack CLC-ODS using tetrahydrofuran-acetonitril (25:75) mixture as a solvent. Each of these collected fractions gave one to two peaks in the GC chromatograms according to the acyl carbon number (CN) of the triglyceride and fatty acid composition of the triglycerides were also analyzed by GC. From the results, the major triglycerides of Job's tears lipids were estimated to be C18:1 C18:2 C18:2 (OLL, 38.2%), C16:0 C18:2 C18:3 (PLLn, 15.7%), C18:1 C18:1 C18:2 (OOL, 12.6%).

• Journal of the Society of Cosmetic Scientists of Korea
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• v.19 no.1
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• pp.20-30
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• 1993

Liquid Chromatographic behavior of Pd(II) in Isonitosoethylacetoacetate imine IEAA-NR: R=H, CH3, C2H5, n-C3H7, n-C4H9, C6H5-CH2) Chelates were investigated by reversed phase high performance 1iquid chromatography on Micropak MCH-5 Column using Methanol /water as mobile phase. The optimum condition for the separation of Pd-Isonitrosoethylacetoacetate imine chelates were examined with respect to the flow rate, mobile phase strength. It was found that Pd(IEAA-NR)2 chelates were eluted in an acceptable range of the capacity factor value (0 $\leq$ log k' $\leq$ 1), The dependence of the logarithm of capacity factor(k') on the volume fraction of water in mixture with in the binary mobile phase was examined. Also, the dependence of k'on the liquid-liquid extraction distribution constant in methanol-water / n-alkane extraction system was on system was invert tigated for Pd(IEAA-NR)2. Both kinds of dependence are linear, which suggests that the retention of the electroneutral metal chelates be largely due to the solvophobic effect.

• Natural Product Sciences
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• v.25 no.2
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• pp.111-114
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• 2019

The herbal formula, DF-02, consisting of Ephedra intermedia and Rheum palmatum are used for the treatment of the metabolic diseases such as obesity and liver fibrosis in Korean local clinics. We aimed to develop the simultaneous analytical conditions for four standards, (+)-pseudoephedrine (PSEP) and (-)-ephedrine (EP) for E. intermedia, and aloe-emodin (AE) and chrysophanol (CP) for R. palmatum using HPLC-UV techniques. The validated conditions yielded the high precision (relative standard deviation (RSD) < 3.65%) and the recoveries (94 - 106%) using the calibration curves with high linearity ($R^2$ > 0.9994). As a result, four standards of DF-02 were simultaneously determined under the developed method, which will be utilized for the quality control or evaluation of DF-02 and many herbal preparations containing E. intermedia and R. palmatum.

• Korean journal of food and cookery science
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• v.19 no.1
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• pp.121-126
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• 2003

Lentinus ededes were irradiated with Utraviolet-B(UV-B) at 0, 2.5, 5.0 J/$\textrm{cm}^2$ levels while culturing in sawdust medium, and the changes in vitamin D$_2$ content, color and flavor of the mushroom were analysed by high-performance liquid chromatography (HPLC), Hunter-Lab Chromatometer and Gas Chromatography-Surface Acoustic Wave (GC-SAW) electric nose, respectively. Irradiation of 0, 2.5, 5.0 J/$\textrm{cm}^2$ doses of UV-B increased the content of vitamin D$_2$ in the mushroom significantly, which was 157∼206% higher than the control group. There was a significant difference in L value between the control group and UV-B irradiated (2.5 and 5.0 J/$\textrm{cm}^2$) groups. The changes of flavor pattern were detected by GC-SAW electric nose. But the color and flavor changes were not detrimental to the quality of the mushroom. The results suggested that UV-B irradiation is a good way to increase the vitamin D$_2$ content of Lentinus edodes during cultivation.

• Bulletin of the Korean Chemical Society
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• v.26 no.5
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• pp.747-754
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• 2005

Liquid chromatographic methods with UV and fluorescence detection have been used to determine the levels of (+)-catechin, (-)-epicatechin, (-)-epicatechin gallate, and (-)-epigallocatechin gallate in Korean green tea infusions. The extracts of Korean green tea leaves or powders in water at various temperatures (100 ${^{\circ}C}$, 80 ${^{\circ}C}$, 60 ${^{\circ}C}$) and time, were washed with chloroform and re-extracted to ethyl acetate. The ethyl acetate phase was dried and re-dissolved in methanol and analyzed. Five catechin compounds were separated by gradient elution. The flavonoids were found decomposed on prolonged extraction, thus exhaustive extraction by a Soxhlet apparatus was found useless for green tea. Some unknown components were found in the extracts at 100 ${^{\circ}C}$. When the green tea was filtered and re-extracted with new fresh water, still some flavonoids were extracted. However, the contents of flavonoids in the third extract were found negligible. The flavonoid extraction rate of green tea powders was higher than that of green tea leaves, but flavonoid decomposition of green tea powders was also faster than that of green tea leaves. The traditional way of drinking green tea was found appropriate in view of flavonoids intake.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2240-2244
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• 2009

A simple high performance liquid chromatographic method was developed to evaluate the quality of Moutan Cortex Radicis based on chromatographic fingerprints that characterize eight pharmacological compounds, namely, gallic acid, paeoniflorin, galloyl paeoniflorin, benzoic acid, quercetin, benzoylpaeoniflorin, paeoniflorigenone, and paeonol. These compounds were identified by their characteristic UV profiles and the mass spectroscopy data, and their contents were determined by HPLC. The chromatographic separation was performed on a $C_{18}$ column by gradient elution with 0.05% formic acid in water and acetonitrile. The methodological validation gave acceptable linearities (r = 0.9996) and recoveries (ranging from 99.4∼103.1%). The limits of detection (LOD) of these compounds ranged from 10 to 30 $\mu$g/mL. The representative chromatographic fingerprints of Moutan Cortex Radicis were obtained by analyzing 20 batches of samples collected from markets in Korea and China. For the efficient evaluation of quality for the commercial Moutan Cortex Radicis it is recommended that the total content of the six characteristic compounds should contain more than a minimum of 2% and that the content of total paeoniflorin and paeonol should exceed a minimum of 1.5% of dry weight of Moutan Cortex Radicis.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.24-27
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• 2006

A simple HPLC quantification method was developed for genistein, genistin, daidzein, and daidzin in soybeans and soybean products. The procedure used a $4.6{\times}100\;mm$ $Chromolith^{(R)}$ RP-18e column with a mobile phase of 1% HOAc in 20% MeOH to 1% HOAc in 80% MeOH for 10 min. The injection volume was $2\;{\mu}L$ at a flow rate of 2 mL/min. Detection was carried out under UV at 254 nm. Under these conditions, the major isoflavones daidzein, daidzin, genistein, and genistin in soybean and soybean pastes were eluted within 7 min with baseline separation. Optimal extraction of the above four major isoflavones was achieved when 40 g of soybean or soybean paste was refluxed in 100 mL of 95% ethanol for 2 hr. Ten different soybean cultivars and nine commercial soybean pastes were analyzed by this method. The total isoflavone content was highest in the cultivar Somyung ($2,497\;{\mu}g/g$ dry weight). The isoflavone content in soybean pastes varied widely from manufacturer to manufacturer (an almost five-fold difference between the highest and lowest values). Such variations were presumably due to differences in fermentation conditions, type of soybeans used, and levels of such additives as starch and salt.