Kyung-Tack Kim

Simultaneous determination of 30 ginsenosides in Panax ginseng preparations using ultra performance liquid chromatography

A quick and simple method for simultaneous determination of the 30 ginsenosides (ginsenoside Ro, Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, 20(S)-Rg2, 20(R)-Rg2, 20(S)-Rg3, 20(R)-Rg3, 20(S)-Rh1, 20(S)-Rh2, 20(R)-Rh2, F1, F2, F4, Ra1, Rg6, Rh4, Rk3, Rg5, Rk1, Rb3, Rk2, Rh3, compound Y, compound K, and notoginsenoside R1) in Panax ginseng preparations was developed and validated by an ultra performance liquid chromatography photo diode array detector. The separation of the 30 ginsenosides was efficiently undertaken on the Acquity BEH C-18 column with gradient elution with phosphoric acids. Especially the chromatogram of the ginsenoside Ro was dramatically enhanced by adding phosphoric acid. Under optimized conditions, the detection limits were 0.4 to 1.7 mg/L and the calibration curves of the peak areas for the 30 ginsenosides were linear over three orders of magnitude with a correlation coefficients greater than 0.999. The accuracy of the method was tested by a recovery measurement of the spiked samples which yielded good results of 89% to 118%. From these overall results, the proposed method may be helpful in the development and quality of P. ginseng preparations because of its wide range of applications due to the simultaneous analysis of many kinds of ginsenosides.

Antiviral effect of korean red ginseng extract and ginsenosides on murine norovirus and feline calicivirus as surrogates for human norovirus.

Korean red ginseng has been studied various biological activities such as immune, anti-oxidative, anti-microbial, and anticancer activities but antiviral mechanism needs further studies. In this study, we aimed to examine the antiviral effects of Korea red ginseng extract and ginsenosides on norovirus surrogate, including murine norovirus (MNV) and feline calicivirus (FCV). We evaluated the pre-, co-, and post-treatment effects of Korean red ginseng (KRG), ginsenosides Rb1 and Rg1. To measure the antiviral effect and cytotoxicity of KRG extract, and ginsenosides Rb1 and Rg1, we treated Crandell-Reese Feline Kidney for FCV or RAW264.7 cells for MNV with concentrations of 0, 5, 6.7, 10, 20 ug/mL total saponin. There was cytotoxic effect in the highest concentration 20 ug/mL of KRG extract so this concentration was excluded in this study. The FCV titer was significantly reduced to 0.23-0.83 log10 50% tissue culture infectious dose (TCID50)/mL in groups pre-treated with red ginseng extract or ginsenosides. The titer of MNV was significantly reduced to 0.37-1.48 log10 TCID50/mL in groups pre-treated with red ginseng extract or ginsenosides. However, there was no observed antiviral effect in groups co-treated or post-treated with KRG and its constituents. Our data suggest that KRG extract has an antiviral effect against norovirus surrogates. The antiviral mechanisms of KRG and ginsenosides should be addressed in future studies.

Antioxidant Activities of Ginseng Seeds Treated by Autoclaving

Ginseng seeds were treated with different autoclaving temperatures and autoclaving times, and extracted with 80% methanol to measure changes in antioxidant activity. The antioxidant activity of ginseng seeds treated by autoclaving was measured by 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, 2,2’-aziono-bis(3-ethylbenzthiazoline)-6-sulfonic acid radical scavenging activity, superoxide dismutase SOD-like activity, ferric reducing antioxidant power (FRAP), and total phenolic compound content. As autoclaving temperature and time were increased, the L lightness value decreased and the redness value tended to increase. Total phenolic compound content was about three times higher in ginseng seeds treated with autoclaving at 130℃ than in ginseng seeds that were not treated. DPPH radical scavenging activity and ABTS radical scavenging activity increased as autoclaving temperature and time were increased. In particular, when the concentration was 100 ppm, the ABTS radical scavenging activity was 91.80% in ginseng seeds treated by autoclaving at 130℃, which was the highest antioxidant activity. FRAP and SOD-like antioxidant activity tended to increase significantly as autoclaving temperature and time were increased.

Isolation and Characterization of a Theta Glutathione S-transferase Gene from Panax ginseng Meyer

Plants have versatile detoxification systems to encounter the phytotoxicity of the wide range of natural and synthetic compounds present in the environment. Glutathione S-transferase (GST) is an enzyme that detoxifies natural and exogenous toxic compounds by conjugation with glutathione (GSH). Recently, several roles of GST giving stress tolerance in plants have demonstrated, but little is known about the role of ginseng GSTs. Therefore, this work aimed to provide further information on the GST gene present in Panax ginseng genome as well as its expression and function. A GST cDNA (PgGST) was isolated from P. ginseng cDNA library, and it showed the amino acid sequence similarity with theta type of GSTs. PgGST in ginseng plant was induced by exposure to metals, plant hormone, heavy metals, and high light irradiance. To improve the resistance against environmental stresses, full-length cDNA of PgGST was introduced into Nicotiana tabacum. Overexpression of PgGST led to twofold increase in GST-specific activity compared to the non-transgenic plants, and the GST overexpressed plant showed resistance against herbicide phosphinothricin. The results suggested that the PgGST isolated from ginseng might have a role in the protection mechanism against toxic materials such as heavy metals and herbicides.

Comparison of Ginsenoside and Phenolic Ingredient Contents in Hydroponically-cultivated Ginseng Leaves, Fruits, and Roots

In this study, hydroponically-cultivated ginseng leaves, fruits, and roots were respectively extracted with ethanol. The contents of 12 ginsenosides and three phenolics in the extracts were quantitatively analyzed and the free radical scavenging activities were measured and compared. Hydroponically-cultivated ginseng leaves contained higher levels of gensenosides (Rg1, Rg2+Rh1, Rd, and Rg3) and p-coumaric acid than the other parts of the ginseng plants. The 2,2’-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid radical scavenging activities of leaves were also the highest. Accordingly, hydroponically-grown ginseng leaves were shown to hold promise for use as an environmentally-friendly natural anti-oxidant.

Quality and characteristics of ginseng seed oil treated using different extraction methods

Ginseng seed oil was prepared using compressed, solvent, and supercritical fluid extraction methods of ginseng seeds, and the extraction yield, color, phenolic compounds, fatty acid contents, and phytosterol contents of the ginseng seed oil were analyzed. Yields were different depending on the roasting pretreatment and extraction method. Among the extraction methods, the yield of ginseng seed oil from supercritical fluid extraction under the conditions of 500 bar and 65℃ was the highest, at 17.48%. Color was not different based on the extraction method, but the b-value increased as the roasting time for compression extraction was increased. The b-values of ginseng seed oil following supercritical fluid extraction were 3.54 to 15.6 and those following compression extraction after roasting treatment at 200℃ for 30 min, were 20.49, which was the highest value. The result of the phenolic compounds composition showed the presence of gentisic acid, vanillic acid, ferulic acid, and cinnamic acid in the ginseng seed oil. No differences were detected in phenolic acid levels in ginseng seed oil extracted by compression extraction or solvent extraction, but vanillic acid tended to decrease as extraction pressure and temperature were increased for seed oil extracted by a supercritical fluid extraction method. The fatty acid composition of ginseng seed oil was not different based on the extraction method, and unsaturated fatty acids were >90% of all fatty acids, among which, oleic acid was the highest at 80%. Phytosterol analysis showed that β-sitosterol and stigmasterol were detected. The phytosterol content of ginseng seed oil following supercritical fluid extraction was 100.4 to 135.5 mg/100 g, and the phytosterol content following compression extraction and solvent extraction was 71.8 to 80.9 mg/100 g.

Quality and antioxidant activity of ginseng seed processed by fermentation strains

Background Fermentation technology is widely used to alter the effective components of ginseng. This study was carried out to analyze the characteristics and antioxidant activity of ginseng seeds fermented by Bacillus, Lactobacillus, and Pediococcus strains. Methods For ginseng seed fermentation, 1% of each strain was inoculated on sterilized ginseng seeds and then incubated at 30°C for 24 h in an incubator. Results The total sugar content, acidic polysaccharides, and phenolic compounds, including p-coumaric acid, were higher in extracts of fermented ginseng seeds compared to a nonfermented control, and highest in extracts fermented with B. subtilis KFRI 1127. Fermentation led to higher antioxidant activity. The 2,2′-azine-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity was higher in ginseng seeds fermented by Bacillus subtilis than by Lactobacillus and Pediococcus, but Superoxide dismutase (SOD) enzyme activity was higher in ginseng seeds fermented by Lactobacillus and Pediococcus. Conclusion Antioxidant activities measured by ABTS and SOD were higher in fermented ginseng seeds compared to nonfermented ginseng seeds. These results may contribute to improving the antioxidant activity and quality of ginseng subjected to fermentation treatments.

High Frequency of Plant Regeneration through Cyclic Secondary Somatic Embryogenesis in Panax ginseng

Somatic embryogenesis is one of good examples of the basic research for plant embryo development as well as an important technique for plant biotechnology such as medicinally important plants. Single embryos develop into normal plantlets with shoots and roots. Therefore, direct single embryogenesis derived from single cells is highly important for normal plant regeneration. Here we demonstrate that the cyclic secondary somatic embryogenesis in Panax ginseng Meyer is a permanent source of embryogenic material that can be used for genetic manipulations. Secondary somatic embryos were originated directly from the primary somatic embryos on hormone-free Murashige and Skoog medium, and proliferated further in a cyclic manner. EM medium (one third of modified MS medium [MS medium containing half amount of NH4NO3 and KNO3] with 2% to 3% sucrose) favored further development of proliferated secondary somatic embryos into plantlets with root system. The plantlets developed into plants with well-developed taproots in half-strength Schenk and Hildebrandt basal medium supplemented with 0.5% activated charcoal.

Bioconversion of isoflavones during the fermentation of Samso-Eum with Lactobacillus strains

In this study, the possible application of Lactobacillus strains as a functional starter culture to ferment Samso-Eum (SE), an oriental herbal medicine formula, and the production of bioactive isoflavones (daidzein, genistein) were investigated. Four strains of Lactobacillus (Lactobacillus plantarum KFRI 144, L. amylophilus KFRI 161, L. curvatus KFRI 166, and L. bulgaricus KFRI 344) were used for SE fermentation. Declines in pH and in viable cell counts during fermentation were investigated and the quantification of isoflavones using HPLC were performed after fermentation at 37°C for 48 h. All the tested Lactobacillus strains lowered the pH level to approximately 3.6 after 48 h and showed the highest level of growth at 24 h during SE fermentation. During the SE fermentation of the four Lactobacillus strains, the conversion of isoflavone glycosides (daidzin, genistin) into bioactive aglycones (daidzein, genistein) was observed in all of the fermentations, but with different rates depending on the strains. L. plantarum KFRI 144 and L. amylophilus KFRI 161 exhibited the highest bioconversion rate of isoflavone glycosides into their bioactive aglycones. These results demonstrate that L. plantarum KFRI 144 and L. amylophilus KFRI 161 have potentials as functional starter cultures for manufacturing fermented SE with higher isoflavone bioavailability.

Physicochemical Characteristics of Various Ginseng Seeds

The aim of our study was to investigate the chemical composition of the Asian ginseng seed (Panax ginseng C.A. Meyer) and the American ginseng seed (Panax quinquifolium L.) grown in Korea (3 years, KGS3; 4 years, KGS4), China (4 years, CGS4), and USA (4 years, AGS4). AGS had the heaviest 100-seed weight (4.21±0.31 g). The approximate compositions of the ginseng seeds were 13.66-17.00% crude protein, 2.21-8.65% crude ash, 19.06-24.06% crude lipid, and 43.21-47.49% crude fiber. The mineral contents of the ginseng seeds were greater in order of K>P>Ca>Mg>Fe>Na>Zn >Cu. The unsaturated fatty acid content was 96.71-96.94%, and the major fatty acids oleic acid and linoleic acid were present. Total sugar content was 15.00-26.17 mg glucose/g. The acidic polysaccharide content was 0.56-0.80 mg β-D- galacturonic acid/g. These results showed the differences in the physicochemical characteristics of ginseng seeds with respect to cultivation location, cultivation year, and species.