• Journal of the Korean Chemical Society
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• v.43 no.6
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• pp.628-635
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• 1999

Direct preparative method of 2,6-diformyl-p-cresol and 2-hydroxy-3-hydroxy-5-methylbenzaldehyde from 2,6-bis(hydroxymethyl)-4-methylphenol using activated $Mn(IV)O_2$ was described. Hexadentate compartmental Iigands, $H_4L[A]\;and\; H_4L[B]$ were prepared by condensation reactions of 2-hydroxy-3-hydroxy methyl-5-methylbenzaldehyde with ethylenediamine and 1,3-diaminopropane respectively. By the reaction of macrocycle($H_4[20]DOTA$) with Ln(III) nitrate {Ln(III)=Pr, Sm, Cd, Dy }, discrete mononuclear Ln(III) complexes of the type $[Ln(H_2[20]DOTA)(ClO_4)(H_2O)]\;{\cdot}\;3H_2O$ were synthesized in the solid state. $[Ln([20]DOTA)(NO_3)(H_2O)](NO_3)_2\;{\cdot}\;xH_2O$ was placed in methanol for 2 days, and $[Ln([20]DOTA)(NO_3)(CH_3OH)]^{2+}$ was formed. The equilibrium constants(K) for the substitution of coordinated $CH_3OH$ in the Ln-[20]DOTA complexes by various auxiliary ligand, $L_a$(=salicylic acid, p-chlorobenzoic acid, benzoic acid, acetic acid, 4-bromophenol) were determined spectroscopically at 25$^{\circ}C$ and 0.1M $NaClO_4$. The K values calculated were in the order of salicylic acid > p-chlorobenzoic acid > benzoic acid > acetic acid > 4-bromophenol, while pKa of auxiliary ligands was in the opposite trend.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.500-505
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• 2010

The antioxidant activity of methanol extracts from five different parts (flesh, peel, core, seed, calyx) of Jangseong Daebong persimmon (Diospyros kaki cv. Hachiya) were evaluated by determining total phenol content (TPC), DPPH radical scavenging activity (RSA), ABTS RSA, and reducing power (RP). The flesh extract gave the highest yield (92.93%) while the lowest yield was obtained from the seed (5.17%). The seed extract showed the highest total phenolic content ($76.47\pm0.009$ mg GAE/g extract), DPPH RSA ($IC_{50}=52.05\pm1.61\;{\mu}g/mL$), ABTS RSA ($IC_{50}=30.94\pm0.41\;{\mu}g/mL$) and RP ($IC_{50}=87.94\pm0.37\;{\mu}g/mL$). In addition, the calyx extract also showed high antioxidant activity. On the other hand, the core extract gave the lowest TPC and all antioxidant assays. In particular, HT-29 cells showed extensive cell death when treated with $500\;{\mu}g/mL$ of calyx extracts. Thus, these results suggest that methanolic extracts of Jangseong Daebong persimmon seed and calyx may serve as a potential source of natural antioxidant for food and nutraceutical application.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.12
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• pp.1628-1632
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• 2007

The present study describes the preliminary evaluation of antioxidant activities and antigenotoxic effect of Rhododendron mucromulatum Turcz. flowers (RMF). The samples were prepared by extracting RMF with four different solvents (methanol, ethanol, acetone, and water), and antioxidant properties were evaluated by determining total phenolic contents (TPC), DPPH radical scavenging activity (RSA), and reducing power (RP). Water extract showed the highest total phenol content (328.1 mg/g gallic acid equivalents). Acetone extract showed the most potent RSA and RP. The $IC_{50}$ for RSA and RP in the acetone extract were 78 mg/mL and 454 mg/mL, respectively. The 200 mM $H_2O_2$ induced DNA damage, measured by Comet assay, was inhibited with water, methanol and acetone extract in dose dependent manner in human leukocytes. The inhibition rates were 42, 62, and 52% at the concentrations of 50 mg/mL of water, methanol and acetone extracts, respectively. These results suggest that R. mucromulatum Turcz. has significant antioxidative activity and protective effect against oxidative DNA damage.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.2
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• pp.69-77
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• 1997

A 12-cm long sediment core was collected from a station in Lake Shihwa where high salinity-anoxic deep water is isolated from low salinity-oxic surface water by a strong halocline barrier. Unprecedented concentrations of porewater ammonia and lead are encountered: at 9 cm sediment depth ammonia builds up to 1420 ${\mu}M$ and at 3 cm lead to 1348 nM. As they are stable in anoxic condition, high concentrations of ammonia and lead suggest a development of notorious anoxic condition in the benthic environment of the lake. The degree of pollution of the deep water is likely to be directly proportional to the magnitude of benthic flux, because the deep water is isolated from the surface water by the halocline. Apparent coincidence of the ammonia residence time in the deep water with the elapsing time after the completion of the artificial lake construction, as about three years, suggests that the deep water pollution is being progressed entirely by benthic flux at least with respect to ammonia. The residence time for lead is such a short 20 days that it suggests a rapid return of the bottom water lead, which is originated from porewater by benthic flux, back to sediments probably as metal sulfide phases. The speculation on the return of lead as sulfide phases is likely to be supported by high concentration of hydrogen sulfide in the deep water and by high sinking rate of non-organic particles in Lake Shihwa.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.724-729
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• 1993

Quality characteristics of 3 kinds of traditional kochujang were investigated during 6 months of fermentation in order to obtain information for the industrial production of traditional kochujarg. Tested kochujang included Sunchang kochujang prepared with glutinous rice, Boeun kochujang prepared with barley, and Sachun kochujang prepared with wheat. The reducing sugar contents of Sunchang, Boeun, and Sachun kochujang increased up to 30, 90, and 150 days of fermentation, respectively, and then decreased thereafter. Ethanol contents of traditional kochujang increased up to $0.4{\sim}1.2%\;at\;120{\sim}150$ days of fermentation and decreased thereafter. Amino nitrogen content of Sunchang kochujang showed a slight increase during fermentation, however, those of Boeun and Sachun kochujang showed a rapid increase up to 150 days of fermentation. Ammoniacal nitrogen content of 100 g kochujang increased up to $50{\sim}75mg$ at 60 days of fermentation and leveled off thereafter. Capsaicin and capsanthin contents of 100 g kochujang were $15{\sim}18mg\;and\;60{\sim}180mg$ before fermentation and decreased to $12{\sim}14mg$ and $50{\sim}120mg$ at 180 days of fermentation, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.4
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• pp.248-253
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• 1991

This study examines the effect of submergence on transformations of inorganic phosphorus and the relation between fractions of inorganic phosphorus and adsorbed phosphorus in Gangseo (paddy soil), Yesan (non-cultivated soil), and Jungdong soil (upland soil). The soils were submerged with glucose sol'n at $28^{\circ}C$ for 17 days. After, the soils were incubated with phosphate solution at $25^{\circ}C$ for 24 hours. The seguential fractionation of inorganic phosphorus and of iron were conducted to investigate transformations of them. Results obtained are as follows; 1. By submergence, Bray I-P were decreased from 53mgP/kg to 48mgP/kg in Gangseo, from 3mgP/kg to 1mgP/kg in Yesan, and from 120mgP/kg to 56mgP/kg in Jungdong soil. 2. $NH_4F$ extractable P was dominant fraction of adsorbed P. It was transformed into NaOH extractable P by submergence in Jungdong soil. 3. Dithionite-citrate-bicarbonate extractable iron (crystalline Fe) was transformed to oxalate extractable iron (amorphous Fe) by submergence in Yesan soil.

• The Korean Journal of Food And Nutrition
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• v.13 no.6
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• pp.578-584
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• 2000

Three kinds of the mashes of 15%, 20% and 25% of boiled wax gourd containing 20% of sugar were fermented by yeast at 5~1$0^{\circ}C$ for 100 days. After fermentation, total sugar content of the 15% mash was 8.0%, 20% mash 8.6%, and 25% mash 8.3%, respectively. Also, it revealed that in reducing sugar content, 15% mash was 7.4%, 20% mash 7.6%, and 25% mash 7.4%, respectively, In protein content, 15% mash was 10.3mg/ml, 20% mash 9.8mg/ml, and 25% mash 11.3mg/ml, and in amino acid content, 15% mash was 0.13 $\mu$mo1/ml, 20% mash 0.03 $\mu$mo1/ml, and 25% mash 0.03 $\mu$mo1/ml, each. In case of pH, 15% mash was 3.88, 20% mash 3.99, and 25% mash 3.97, respectively. In acidity, 15% mash was 0.37, 20% mash 0.44. and 25% mash 0.43, respectively. In the number of yeast cell, 15% mash was 8.33 logCFU/ml, 20% mash 8.56 logCFU/ml, and 25% mash 8.57 logCFU/ml. respectively. In ethanol content, 15% mash was 13.4%, 20% mash 14.9%, and 25% mash 15.5%, respectively. In organic acid content, acetic acid, pyruvic acid, citric acid, and lactic acid were produced, and succinic acid content ranges from 1,407~1,800 mg/l. Five-grade scoring test of sensory evaluation showed that in its taste degree, 15% mash was 3.93, 20% mash 3.66 and 25% mash 3.40, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.4
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• pp.505-511
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• 2013

To investigate the potential use of makgeolli by-products as cosmetic materials, their phenolic and kojic acid contents, antioxidant activity, whitening effect, and anti-wrinkle activity were evaluated. Extracts were obtained with five different solvents (containing 0, 25, 50, 75, and 100% ethanol) from nuruk lees (NL), rice lees (RL), raw makgeolli (RM), and commercial makgeolli (CM) at 20 and $50^{\circ}C$. NL and CM extracts prepared with 75% ethanol had the highest phenolic contents (13.26 and 16.66 mg gallic acid equivalents/g, respectively) at 20 and $50^{\circ}C$, respectively. The highest kojic acid content was found in NL extracts with 0% ethanol at $20^{\circ}C$, while kojic acid was not detected in extracts prepared at $50^{\circ}C$. NL and RL extracts at $20^{\circ}C$ showed significant antioxidant activity. Whitening effects, determined by tyrosinase inhibitory activity, were highest for the NL extract prepared with 75% ethanol at $50^{\circ}C$. Noticeable anti-wrinkling effects, estimated by elastase inhibition activity, were also found in NL and RL extracts. These results suggest that makgeolli by-products could be valuable cosmetic materials with antioxidant, whitening, and anti-wrinkle activities.

• Journal of the Korean GEO-environmental Society
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• v.13 no.9
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• pp.53-59
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• 2012

This study investigated characteristics of decomposition of tetrabutoxysilane (TBOS) as a slow release substrate (SRS) and on effect of TBOS decompostion compounds (acetate and butylate) for anaerobic dechlorination of trichloroethylene (TCE). In the batch experiment, TCE, cis-dichloroethene (cis-DCE), 1-butanol and TBOS were analysed by GC/FID and acetate and butylate were measured by HPLC. 1M of TBOS transferred and accumulated 4M of 1-butanol by abiotically hydrolysis reaction. The hydrolysis rate was in a range of 0.186 ${\mu}M/day$. On other hand, 1-butanol fermented to butyrate and acetate with indigenous culture from natural sediments. This results showed that TBOS could be used a slow release substrate in the natural sites. The dechlorinated potential of TCE with acetate and butyrate was increased with a decreasing initial TCE concentrations. In addition, first order coefficients of dechlorination with acetate as electron donor was higher then that with butyrate. It is because that dechlorination of Geobacter lovleyi was affected by substrate affinity, biodegradability and microbial acclimation on various substrates. However, dechlorinated potential of Geobacter lovleyi was decreased with accumulation cis-DCE in the anaerobic decholoronation process. The overall results indicated that SRS with Geobacter lovleyi might be a promising material for enhancing dechlorination of TCE on natural site and cis-DCE should be treated by ZVI as reductive material or by coexisting other dechlorinated bacteria.

• Journal of the Mineralogical Society of Korea
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• v.31 no.2
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• pp.87-101
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• 2018

The Manjang deposit developed in the Hwajeonri formation of the Okcheon metamorphic belt consists of the Central and Main orebodies of Cu-bearing hydrothermal vein type and the Western orebody of Fe-skarn type. This study focuses on the Cu mineralization of the Central and Main orebodies to compare with the genetic environments of the Western orebody previously studied. The Central orebody produced pyrrhotite and chalcopyrite as major ore minerals with vein texture, while the Main orebody contains pyrite, arsenopyrite, and chalcopyrite as major ore minerals with vein, massive, and brecciated texture. Sphalerite, galena, magnetite, ilmenite, rutile, cassiterite, wolframite, and stannite are also accompanied. Local occurrence of skarn is dominated by grossular and hedenbergite, reflecting the reduced condition of the skarnization. Geothermometries of sphalerite-stannite in the Central orebody and arsenopyrite-pyrite in the Main orebody indicate the formation temperature of $204-263^{\circ}C$ and $383-415^{\circ}C$, respectively. Sulfur fugacity of $10^{-6}-10^{-7}atm$. in the Main orebody decreased toward the Central orebody. Sulfur isotope compositions of sulfide minerals from the Central and Main orebodies are 4.6-7.9‰ and 4.3-7.0‰, respectively, reflecting magmatic origin with slight influence by host rock. Considering ore mineralogy, texture as well as physicochemical conditions, the Main and Central orebodies of hydrothermal Cu mineralization reflect the characteristics of proximal and distal type ore mineralization, respectively, related to hidden igneous rocks, and they were generated under different hydrothermal systems from the Fe-skarn Western orebody.