• Analytical Science and Technology
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• v.26 no.5
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• pp.326-332
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• 2013

Geosmin and 2-methylisoborneol (2-MIB) are volatile organic compounds responsible for the majority of unpleasant taste and odor events in drinking water. Geosmin and 2-MIB are byproducts of blue-green algae (cyanobacteria) with musty and earthy odors. These compounds have odor threshold concentration at ng/L levels. It is needed to develop a sensitive method for determination of geosmin and 2-MIB to control the quality of drinking water. In this study, geosmin and 2-MIB in water samples were determined by gas chromatography-mass spectrometry (GC-MS) with headspace-solid phase microextraction (HS-SMPE). The detection limits of this method were 1.072 ng/L and 1.021 ng/L for geosmin and 2-MIB, respectively. Good accuracy and precision was also obtained by this method. Concentrations of the two compounds were measured in raw waters from Nakdong River in the cyanobacterial blooming season. Water bloom formed by cyanobacteria has been occurred currently in Nakdong River. It is needed to investigate the concentrations of geosmin and 2-MIB to control the quality of drinking water from Nakdong River. Both geosmin and 2-MIB were detected in raw waters from Nakdong River at concentrations ranging from 4 to 24 ng/L and 6 to 16 ng/L, respectively.

• Membrane and Water Treatment
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• v.9 no.3
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• pp.137-146
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• 2018

Soil washing is one of the most frequently used remediation technologies for heavy metal-contaminated soils. Inorganic and organic acids and chelating agents that can enhance the removal of heavy metals from contaminated soils have been employed as soil washing agents. However, the toxicity, low removal efficiency and high cost of these chemicals limit their use. Given that humic substance (HS) can effectively chelate heavy metals, the development of an eco-friendly, performance-efficient and cost-effective soil washing agent using a nano-scale chelator composed of HS was examined in this study. Copper (Cu) and lead (Pb) were selected as target heavy metals. In soil washing experiments, HS concentration, pH, soil:washing solution ratio and extraction time were evaluated with regard to washing efficiency and the chelation effect. The highest removal rates by soil washing (69% for Cu and 56% for Pb) were achieved at an HS concentration of 1,000 mg/L and soil:washing solution ratio of 1:25. Washing with HS was found to be effective when the pH value was higher than 8, which can be attributed to the increased chelation effect between HS and heavy metals at the high pH range. In contrast, the washing efficiency decreased markedly in the low pH range due to HS precipitation. The chelation capacities for Cu and Pb in the aqueous phase were determined to be 0.547mmol-Cu/g-HS and 0.192mmol-Pb/g-HS, respectively.

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.35-42
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• 2009

Headspace micro solid phase extraction using mulberry paper bag (HS-MPB-$\mu$-SPE) has been developed and validated for the analysis of volatile flavor compounds from five spice by gas chromatography-mass spectrometry (GC/MS). HS-MPB-$\mu$-SPE was performed with adsorbent particles enclosed inside a mulberry paper bag. Four different kinds of adsorbents such as Tenax TA, Porapack Q, dimethylpolysiloxane and polyethylene glycol were tested. The extraction solvents compared were petroleum ether, methylene chloride, and chloroform. Better results were obtained when Tenax TA and petroleum ether were used. The limit of detection (LOD) and the limit of quantitation (LOQ) were in the range of 1.3 ng/mL and 4.3 ng/mL, respectively, for o-cymene as a model compound of monoterpene. Proposed method showed good reproducibility (3.3%, RSD) and good recoveries (94.0%). The HS-MPB- μ-SPE is very simple to use, inexpensive, rapid, requires small sample amounts and solvent consumption. Because the solvent for extraction is reduced to only a very small volume (0.6 mL), there is minimal waste or exposure to toxic organic solvent and no further concentration step. This method allows successful characterization of the headspace in contact with the five spice sample. Strong trans-anethole from star anise or fennel is a characteristic flavor of five spice powders. HS-MPB-$\mu$-SPE combined with GC/MS can be a promising technique for the broad spectrum measurement of volatile aroma compounds from solid spices.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.130-136
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• 2009

The present study was conducted to determine the protective ability of the ethanol extracts of Hypericum scabroides Robson & Poulter (HS) and Hypericum triquetrifolium Turra (HT) against the protein oxidation and DNA damage induced by Fenton system. The ability of HS and HT to prevent oxidative damage to bovine serum albumin (BSA) induced by $Fe^{3+}/H_2O_2$ and ascorbic acid was investigated. The ethanol extracts of HS and HT at different concentrations ($50-1,000{\mu}g/mL$) efficiently prevented protein oxidation induced by hydroxy radical as assayed by protein oxidation markers including protein carbonyl formation (PCO) and polyacrylamide gel electrophoresis. The effect of ethanol extracts of HS and HT on DNA cleavage induced by UV-photholysis of $H_2O_2$ using pBluescript M13+ plasmid DNA were investigated. These extracts significantly inhibited DNA damage induced by reactive oxygen species (ROS). Therefore, HS and HT extracts may be useful in the food industry as effective synthetic antioxidants.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.97.2-97.2
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• 2003

(1R,9S)-(${\beta}$)-Hydrastine (HS) at 10-50 ${\mu}$M has been proven to have an inhibitory effect on dopamine biosynthesis in PC12 cells by the inhibition of tyrosine hydroxylase (TH) activity and TH gene expression. In the present study, therefore, the effects of HS on the basal and K$\^$+/-induced dopamine release, and Ca$\^$2+/ influx induced by high K$\^$+/ and caffeine in PC12 cells were investigated. The dopamine release by high K$\^$+/ (56 mM) was inhibited by co-incubation of 20 ${\mu}$M HS. Application of HS also significantly reduced the magnitude of the maintained Ca$\^$2+/ influx induced by K$\^$+/ depolarization. (omitted)

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1597-1606
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• 2020

Transcription factor engineering to regulate multiple genes has shown promise in the field of microalgae genetic engineering. Here, we report the first use of transcription factor engineering in Chlorella sp. HS2, thought to have potential for producing biofuels and bioproducts. We identified seven endogenous bZIP transcription factors in Chlorella sp. HS2 and named them HSbZIP1 through HSbZIP7. We overexpressed HSbZIP1, a C-type bZIP transcription factor, in Chlorella sp. HS2 with the goal of enhancing lipid production. Phenotype screening under heterotrophic conditions showed that all transformants exhibited increased fatty acid production. In particular, HSbZIP1 37 and 58 showed fatty acid methyl ester (FAME) yields of 859 and 1,052 mg/l, respectively, at day 10 of growth under heterotrophic conditions, and these yields were 74% and 113% higher, respectively, than that of WT. To elucidate the mechanism underlying the improved phenotypes, we identified candidate HSbZIP1-regulated genes via transcription factor binding site analysis. We then selected three genes involved in fatty acid synthesis and investigated mRNA expression levels of the genes by qRT-PCR. The result revealed that the possible HSbZIP1-regulated genes involved in fatty acid synthesis were upregulated in the HSbZIP1 transformants. Taken together, our results demonstrate that HSbZIP1 can be utilized to improve lipid production in Chlorella sp. HS2 under heterotrophic conditions.

• Analytical Science and Technology
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• v.12 no.6
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• pp.577-582
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• 1999

The blood toluene concentration was determined by using the GC/MSD with HS-SPME technique in postmortem blood, quantitatively. Butane gases was analyzed by using the GC/FID with HS technique in postmortem blood, qualitatively. Seventy five cases of dead associated with inhalation of glue or butane gases happened in Korea for the last 3 years (1996-1998). In 27 cases of deah due to glue sniffing, nine persons died as a result of a fall while intoxication and their blood tolucne concentration was fairly high in the range of $1.3{\sim}21.6{\mu}g/mL$. In case of death due to butane sniffing, fifty four persons died of acute butane gases inhalation or suffocation, and 6 persons died of butane gases as well as glue inhalation.

• The Korea Journal of Herbology
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• v.30 no.6
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• pp.1-6
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• 2015

Objectives : Draconis Resina (DR), the resin of Daemonorops draco Bl., is used to circulate the blood and to stop bleeding. It also has been used to generate flesh including ulceration. The present study investigated the effects of DR extract on collagen metabolism in human fibroblasts and tyrosinase activity in mushroom tyrosinase.Methods : The effect of DR extract on type I procollagen production (collagen type I synthesis) and collagenase (matrix metalloproteinase-1, henceforth referred as MMP-1) activity in human normal fibroblasts cell line. Hs68 cells after ultraviolet B (UVB, 312 nm) irradiation was measured using the enzyme - linked immunosorbent assay (ELISA). The tyrosinase activity was also measured to find out the whitening effects in mushroom tyrosinase by ELISA method.Results : There was no cytotoxicity at DR extract at concentrations of 10 μg/ml, 30 μg/ml, and 100 μg/ml. DR extract significantly inhibited the increase of collagenase activity, whereas it did not show on the reduction of type I procollagen in UVB damaged Hs68 cells. DR extract did not reduce the L - DOPA oxidation. However, it significantly reduced the tyrosinase activity by DR extract at concentraions of 0.1 mg/ml, 1 mg/ml and 10 mg/ml.Conclusions : In conclusion, DR showed the anti-wrinkle and whitening effects via the inhibition of collagenase production and the tyrosinase activity. These results suggest that DR may have potential as an anti-aging ingredient in cosmetic herb markets.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.897-900
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• 2008

Various sequences of pH change were applied in a batch bioreactor to investigate pH shock effects on geldanamycin production by Streptomyces hygroscopicus subsp. duamyceticus JCM4427. In the control culture where the pH was not controlled, the maximum geldanamycin concentration was 414 mg/l. With the pHS1 mode of pH shock, that is, an abrupt pH change from pH 6.5 to pH 5.0 and then being maintained at around pH 5.0 afterward, 768 mg/l of geldanamycin was produced. With pHS2, in which the pH was changed sequentially from pH 6.7 to pH 5.0 and then back to pH 6.0, 429 mg/l of geldanamycin was produced. With pHS3 having a sequential pH change from pH 6.0 to pH 4.0 and then back to pH 6.5 followed by the third pH shock to pH 5.5, no geldanamycin production was observed. Considering that the productivity with pHS1 was about two-fold of that of the control culture with no pH control, we concluded that a more sophisticated manipulation of pH would further promote geldanamycin production.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2675-2679
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• 2009

This paper reports the example of headspace mulberry paper bag micro solid phase extraction (HS-MPB-$\mu$-SPE) as a new sampling method for the determination of volatile flavor composition of coriander seeds. Adsorption efficiencies between two configurations of mulberry paper bag were compared, and several parameters affecting the HS-MPB-$\mu$-SPE were investigated and optimized. The optimized technique uses an adsorbent (Tenax TA, 0.1 mg) contained in a mulberry paper bag of front configuration where fine surface was outside, and minimal amount of organic solvent (0.6 mL). Linalool and $\gamma$-terpinene were found as abundant flavor compounds from coriander seeds. The limit of detection (LOD) and the limit of quantitation (LOQ) for linalool of major flavor in coriander seeds were 10.3 ng/mL and 34.4 ng/mL, respectively. The proposed method showed good reproducibility and good recovery. The HS-MPB-$\mu$-SPE is very simple to use, inexpensive, requires small sample amounts and solvent consumption. Because the solvent for extraction is reduced to only a very small volume, there is minimal waste or exposure to toxic organic solvent and no further concentration step.