• Korean Journal of Microbiology
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• v.33 no.3
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• pp.170-174
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• 1997

In order to design a novel synthetic peptide with improved fungicidal activity but low hemolytic activity, a hybrid peptide, cecropin A(l-8)-magainin 2(1-12), and its analogue peptides were synthesized by the solid phase method. Antifungal and hemolytic activities of the synthetic peptides were assessed by the growth inhibition against Trichosporon beigelii and the cell membrane lysis against human red hlood cells, respectively. Analogue 2 in which Lys at position 12 in cecropin A(1-8)-magainin 2(1-12) was substituted with Ala showed most potent antifungal activity (MIC: 2.5.$\mu$g/ml) with minimal hemolytic activity (0.5% hemolysis at the (200.$\mu$g/ml peptide). This peptide (A2), therefore, could be useful as a model for further designing potent antifungal peptides without cytotoxicity.

• The Plant Pathology Journal
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• v.33 no.1
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• pp.87-94
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• 2017

Citrus canker disease decreases the fruit quality and yield significantly, furthermore, emerging of streptomycin-resistant pathogens threatens the citrus industry seriously because of a lack of proper control agents. Small synthetic antimicrobial peptides (AMPs) could be a promising alternative. Fourteen hexapeptides were selected by using positional scanning of synthetic peptide combinatorial libraries. Each hexapeptide showed different antimicrobial spectrum against Bacillus, Pseudomonas, Xanthomonas, and Candida species. Intriguingly, BHC10 showed bactericidal activity exclusively on Xanthomonas citri subsp. citri (Xcc), while BHC7 was none-active exclusively against two Pseudomonas spp. at concentration of $100{\mu}g/ml$ suggesting potential selectivity constrained in hexapeptide frame. Three hexapeptides, BHC02, 06 and 11, showed bactericidal activities against various Xcc strains at concentration of $10{\mu}g/ml$. When they were co-infiltrated with pathogens into citrus leaves the disease progress was suppressed significantly. Further study would be needed to confirm the actual disease control capacity of the selected hexapeptides.

• Journal of the Korean Applied Science and Technology
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• v.21 no.2
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• pp.140-147
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• 2004

An aqueous solution of a commercial liquid synthetic detergent for kitchen use was photodecomposed in the presence of titanium dioxides powder under an atmosphere of air at room temperature. Titanium dioxides were prepared by sol-gel method from titanium iso-propoxide at different R ratio($H_2O$/titanium iso-propoxide) and calcined at $500^{\circ}C$. All titanium dioxides were characterized by XRD, BET surface area analyzer and UV-VIS spectrometer. The surface area of titanium dioxides prepared at R ratio=6 appeared higher volume about 20% than commercial $TiO_2$ catalysts. XRD patterns of titania particles were observed mixing phase together with rutile and anatase type. Titanium dioxides prepared by sol-gel method show higher activity about 6% than commercial $TiO_2$ catalysts on the photocatalytic degradation of a commercial liquid synthetic detergent for kitchen. The concentration of the detergent decreased to about 90% of its initial value at illumination times of 2 hour. Illumination for 30 minutes decreased the concentration of oxygen to about one-fifth of the initial value.

• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.228-234
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• 1991

- A synthetic gene coding for human interleukin-2 (IL-2) was constructed from the oligonucleotides synthesized by an automatic DNA synthesizer. The nucleotide sequence of the synthetic gene was chosen considering the preferred codons of E. coEi by not changing the amino acid sequence of IL-2 polypeptide. The synthetic gene was expressed in E. coli by placing the gene under the control of the $\lambda$ PL promoter. IL-2 was produced in the E. coli cytoplasm in the form of inclusion bodies. The recombinant IL-2 showed growth promoting activity on the IL-2 dependent cell line.

• Journal of the Korean Society of Safety
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• v.16 no.3
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• pp.76-82
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• 2001

An aqueous solution of a commercial liquid synthetic detergent for kitchen use was photodecomposed in the presence of titanium dioxides ponder under an atmosphere of air at room temperature. Titanium dioxides were prepared by sol-gel method from titanium iso-propoxide at different R R ratio($H_2O$/titanium iso-propoxide) and calcined at $500^{\circ}C$. All titanium dioxides m characterized by XRD, BET surface area analyzer and UV-VIS spectrometer. The surface mea of titanium dioxides prepared at R ratio=6 appeared higher volume about 20% than commercial $TiO_2$ catalyses. XRD patterns of titania particles were observed mixing phase together with rutile and anatase type. Titanium dioxides prepared by sol-gel method show higher activity about 6% than commercial $TiO_2$ catalysts on the Photocatalytic foundation of a commercial liquid synthetic detergent for kitchen. The concentration of the detergent decreased to about 90%, of its initial value at illumination times of 2 hour. illumination for 30 minutes decreased the concentration of oxygen to about one-fifth of the initial value.

• Elastomers and Composites
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• v.48 no.1
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• pp.61-66
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• 2013

A family of Cr(III) complexes supported on tridentate dibenzimidazolyl ligands having a general formula: $[N(CH_3)(CH_2)_2(Bm-R)_2]CrCl_3$ [where Bm = benzimidazolyl, R = H (3a); -Me(3b); -Bn (3c)] have been synthesized and utilized them for the trans-1,4-specific polymerizations of 1,3-butadiene (BD), activated with methylalumoxane (MAO). The activity of BD polymerizations was sensitive to the type of ligand on the Cr metal, so that the activity decreases in the order of 3a > 3c > 3b. All the catalysts combined with MAO yielded polybutadienes with perfect trans-1,4 structure with moderate molecular weight.

• Korean Journal of Pharmacognosy
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• v.35 no.3 s.138
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• pp.207-214
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• 2004

This study was investigated antioxidatve activity for the purpose of developing antioxidant from Morus bombycis Koidzumi. Antioxidant activities of four different organs of Morus bombycis Koidzumi such as fruit, leaf, stem, and root were examined by radical scavenging effect with 1,1-diphenyl-2-picrylhydrazyl (DPPH). 80% methanol extract from the stem showed strongly antioxidative activity and 80% Ethanol extracts from the root, stem, and fruit had high antioxidative activity among 24 samples tested. The 80% ethanol extract has strong absorbency at UVA region (350 nm). The ethyl acetate (EtOAc) fraction exhibited antioxidative activity with $IC_{50}$ of $15.0\;{\mu}g/ml$ similar to those of synthetic antioxidant, BHT The EtOAc fraction has a good absorbency property as synthetic filter. In the absorbance of various extracts, the 80% ethanol and ethyl acetate extracts from the root of Morus bombycis Koidzumi showed higher absorbancy at 285 nm. The ethyl acetate fraction from the root of Morus bombycis Koidzumi contained total phenolic compounds of 654.8 mg/100 g. These results indicate that phenolic compounds are the major was biological components in the root of morus bombycis Koidzumi extracts. Considering these biological activities, the extracts of Morus bombycis Koidzumi showed a possibility to be used as a new material for natural anti-oxidants and substitutes for synthetic UV sunscreen agents.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.143-154
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• 2016

This study is related to develop a snail extract through a snail secondary fermentation process, getting anti-aging activity with healthy and beauty skin care scientific applications. In order to obtain a primary fermentation was incubated with Hericium erinaceus mycelium. Through the secondary fermentation process using Leuconostoc mesenteroides, was deeply described a total process of obtaining second fermented extract using snail body. Mycelium is applied in this study was extracted using Hericium erinaceus mycelium and Leuconostoc mesenteroides. The final yield of the extract was 62 wt%. Experimental results of secondary fermentation snail extract were contained with 32 wt% water, 31.5 wt% total amino acid protein, 15.7 wt% polysaccharide, 12.3 wt% fatty acid and others 8.5 wt%. In addition, in order to study about skin beauty care and anti-aging activity, we evaluated antioxidant activity with DPPH, elastin enzyme (elastase) inhibitory activity, tyrosinase inhibition rate, collagen synthetic function, fibroblast synthetic activity. First; anti-oxidative activity of secondary fermentation snail extract (IC50%) was spent with 7.27 mg/mL, control samples were spent with green tea extract was 11.8 mg/mL, common snails extract was 15.7 mg/mL, DL-a-tocopherol was 9.25 mg/mL respectively. Second; elastin enzyme inhibitory activity of secondary fermentation snail extract (IC50%) was spent with 32.5 mg/mL, control samples were also spent with green tea extract was 45.9 mg/mL, general snail extract was 67.7 mg/mL. Third; tyrosinase inhibitory activity of secondary fermentation snail extract (IC50%) was spent with 140.3 mg/mL, control samples were also spent with green tea extract was 250.7 mg/mL, general snails extract was 389.5 mg/mL, niacineamide was 125.9 mg/mL. Forth; fibroblast synthetic activity of secondary fermentation snail extract was increased with 125.6%, control samples were also spent with green tea extract was 98.9%, general snails extract was 109.5%, niacineamide was 125.9 mg/mL, DL-a-tocopherol was 96.2%. Fifth; collagen synthetic activity of secondary fermentation snail extract was increased with 118%, control samples were also spent with green tea extract was 87.3%, general snails extract was 93.2%, adenosine was 127.9%. In conclusion, on the basis of this study, in the future it is expected to be applied to the skin beauty care application and development of Korean style cosmetic products.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.277-288
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• 2017

Rhizomucor miehei NRRL 5282 and Rhizopus oryzae NRRL 1526 can produce lipases with high synthetic activities in wheat bran-based solid-state culture. In this study, the purification and biochemical characterization of the lipolytic activities of these lipases are presented. SDS-PAGE indicated a molecular mass of about 55 and 35 kDa for the purified R. miehei and Rh. oryzae enzymes, respectively. p-Nitrophenyl palmitate (pNPP) hydrolysis was maximal at $40^{\circ}C$ and pH 7.0 for the R. miehei lipase, and at $30^{\circ}C$ and pH 5.2 for the Rh. oryzae enzyme. The enzymes showed almost equal affinity to pNPP, but the $V_{max}$ of the Rh. oryzae lipase was about 1.13 times higher than that determined for R. miehei using the same substrate. For both enzymes, a dramatic loss of activity was observed in the presence of 5 mM $Hg^{2+}$, $Zn^{2+}$, or $Mn^{2+}$, 10 mM N-bromosuccinimide or sodium dodecyl sulfate, and 5-10% (v/v) of hexanol or butanol. At the same time, they proved to be extraordinarily stable in the presence of n-hexane, cyclohexane, n-heptane, and isooctane. Moreover, isopentanol up to 10% (v/v) and propionic acid in 1 mM concentrations increased the pNPP hydrolyzing activity of R. miehei lipase. Both enzymes had 1,3-regioselectivity, and efficiently hydrolyzed p-nitrophenyl (pNP) esters with C8-C16 acids, exhibiting maximum activity towards pNP-caprylate (R. miehei) and pNP-dodecanoate (Rh. oryzae). The purified lipases are promising candidates for various biotechnological applications.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.868-874
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• 2013

Efficient synthetic route to novel 2'-spirocyclopropanoid 4'-deoxythreosyl phosphonic acid nucleosides was described from 1,4-dihydroxy-2-butene. Cyclopropane moiety was prepared via ester enolate alkylation using (2-chloroethyl)dimethylsulfonium iodide. Synthesized nucleoside analogues 16, 19, 23 and 26 were tested for anti-HIV activity as well as cytotoxicity. However, none of them showed any anti-HIV activity or cytotoxicity up to 100 ${\mu}M$.