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Characterization of Chitosan Hydrolysates Depolymerized under the Action of Non-specific Enzymes
( Da Gyung Lee ),( You Jin Hwang ),( Jae Kweon Park ) 한국키틴키토산학회 2017 한국키틴키토산학회지 Vol.22 No.3
The aim of this study is to elucidate the features of enzymatic depolymerization of high molecular weight chitosan (CTSN-H). Depolymerization of CTSN-H was mediated by non-specific enzymes action, showed that variations of organic biomasses have a substantial enzymatic effect on the degree of depolymerization of CTSN-H. Additionally, we found that the antimicrobial activity of chitosan hydrolysates derived from the depolymerization of CTSN-H against Candida albicans has shown to be dependent on molecular weight (MW) of chitosan. Although various biological activities of CTSN-H were proposed, less antifungal effect against C. albicans was observed as it. Therefore, the results of this study demonstrates that depolymerization of CTSN-H by non-specific enzyme feature can provide some potent possibility to produce antifungal active forms of chitosan.
( Da Gyung Lee ),( Jhulee Park ),( Hae Jung Yoo ),( Seo Ju Oh ),( Joo Young Jang ),( Shaheen Amna ),( Jae Kweon Park ) 한국키틴키토산학회 2016 한국키틴키토산학회지 Vol.21 No.3
The synergistic or additive effect of active molecular chitosan (AMC) with Sorghum bicolor ethanol extract (ES) and fermentative supernatant was invesigated in this study. ES had 29% less content of phenolic compounds, 78% less contents of total carbohydrates containing reducing sugars, and 56% less tannin contents than that of S. bicolor fermentative supernatant (SF). It has shown the significantly higher antioxidant activity than SF and other fermantative substances (S and Y). These results suggest that flavonoid in the ES may be the key molecule as it contains 28% higher concentration of flavonoids than SF and Y substances and hence ES showed the remarkablely higher specific activity of whitenning effect. Further more SF was selected for heat stability studies, tyrosinase inhibitory, and antibacterial activity in the presence or absence of active molecular chitosan (AMC). Although less significant synergistic antibacterial activity of SF toward Candida albicans in the presence of AMC was observed, both substances still can be useful as antioxidant or whitenning substances in combination with AMC. whereas a strong antibacterial activity of AMC toward Candica albicans was observed, and also is one of the ingredients in functional food and cosmaceutical compounds with potential health-promoting properties.
Antibacterial Activity of Chitosan against Antibiotics Resistance Bacteria in Porcine Semen
( Da Gyung Lee ),( Dae Young Kim ),( Jae Kweon Park ) 한국키틴키토산학회 2014 한국키틴키토산학회지 Vol.19 No.3
Bacteria in porcine semen having resistance on antibiotics decrease the quality and viability of sperms. In the continuing search for potential antibacterial of chitosan with different molecular weight, we have isolated bacterial strain from porcine semen and applied chitosan to address their antibacterial activity. However, definitive evidence for this relationship between different molecular weight chitosan and its antibacterial activity toward some bacterial strains in porcine semen was in lacking. The results showed that no significant synergic effects of chitosan with different molecular weight with antibiotics on bacteria isolated from two different sources of semen were observed. However all chitosan and glucosamine used in this study showed antibacterial activity toward ARB, which showed the resistance especially toward ampicillin and erythromycin. Our data suggest that chitosan can be used as potential therapeutic agents in the treatment of porcine semen that could specifically target antibiotics resistance bacterial cells (ARB).
Da Gyung Lee,Seung Jun Yang,Young Ju Park,Jae Kweon Park 한국당과학회 2016 한국당과학회 학술대회 Vol.2016 No.01
Understanding sulfated polysaccharides from pants or seaweed are well known for antioxidant, anticoagulant activity or other biological activities. The aim of the present study is to optimize the condition for the isolation of water soluble polysaccharides (WSP) and evaluate the biological activity. WSP was isolated from defatted microalgae B. braunii using Chlorosulfonic acid or Sulfuric acid. Also the preliminary structural analysis of WSP was performed by FT-IR spectroscopy analysis. Among WSP isolated using sulfuric acid showed the lowest the content of total carbohydrates (g/L), whereas showed the highest antioxidant activity. High production of WSP may allow further exploration of microalga B. braunii as a potential biomass provider for biological and industrial exploitation of bioactive substrates.
Mi-Gyung Lee,Da-i Jung 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.5
Six pesticides were determined in hot pepper leaves after successive processing steps of washing, blanching, and drying. The tested pesticides included dichlofluanid, flusilazole, folpet, iprodione, λ-cyhalothrin, and lufenuron. Each pesticide was singly applied to the leaves of the pepper plants, which were being cultivated in a greenhouse. The processing factors were dependent on the type of pesticide, and were in the following ranges: 0.09-0.73 by washing, <0.00-0.48 after blanching, and <0.00-3.30 after drying. Only lufenuron showed a processing factor of more than 1, at 3.30 in dried leaves, while the processing factors of the other pesticides were less than 1. The removal ratios of the tested pesticides by washing ranged from 27 to 90%. The blanching step increased their removals by 10-25%. However, drying did not have an effect on residue reduction. Finally, after proceeding to the drying step, removal ratios ranged from 85 to 100%, with the exception of lufenuron at 47%.
탈지 미세조류 Botryococcus braunii 로부터의 수용성 다당의 항산화 활성과 항균활성
이다경,박제권,Lee, Da Gyung,Park, Jae Kweon 한국해양바이오학회 2015 한국해양바이오학회지 Vol.7 No.2
Sulfated polysaccharides from plants or seaweed are well known for antioxidant, anticoagulant activity or other biological activities. The aim of the present study is to optimize the condition for the isolation of water soluble polysaccharides (WSP) and evaluate the biological activity. WSP was isolated from defatted microalgae B. braunii using chlorosulfonic acid or sulfuric acid. Among WSP isolated using sulfuric acid showed the lowest the content of total carbohydrates (g/L), whereas showed the highest antioxidant activity. Also the preliminary structural analysis of WSP was performed by FT-IR spectroscopy analysis.
( Babita Dogra ),( Da Gyung Lee ),( Jae Kweon Park ) 한국키틴키토산학회 2017 한국키틴키토산학회지 Vol.22 No.1
Isolation, quantification and characterization of bioactive compounds from microalgae Tetraselmis species have been performed to elucidate the potential use as a bioactive material. Microalga are a promising source of lipids for biofuel production and represent a diverse group of microscopic photosynthetic organisms and are able to convert solar energy into biomasses. The imposition of oxidative stresses by various environmental factors leads to the production of reactive oxygen species (ROS) in plant cells, including algal cell. Antioxidant activity of water soluble bioactive substances (WSBS) was determined by DPPH, ABTS, FRAP and similar SOD radical-scavenging assay. The content analysis of lipid, sugar, polyphenol and protein was performed to evaluate the potent usefulness of WSBS from the whole cells cultivated under the optimum conditions for the production of biodiesel. The yield of WSBS was determined to be 17% based on the total carbohydrate assay. The relative activity of WSBS toward FRAP and DPPH reagent was observed ranging from 13 to 55%, showing the significant anti-oxidative properties with wide range of temperatures from room temperature to 80℃. The outcomes of this study support utilization of WSBS from microalgae Tetraselmis species as a potential source of naturally occurring antioxidants.
Differences in agricultural activities related to incidence of scrub typhus between Korea and Japan
Chang-Jin Ma,Gyung-Jae Oh,Gong-Unn Kang,Jeong Mi Lee,Da-Un Lee,Hae-Sung Nam,So Yeon Ryu,Young-Hoon Lee 한국역학회 2017 Epidemiology and Health Vol.39 No.-
OBJECTIVES: The purpose of this study was to establish a basis for improving or strengthening the preventive strategy against scrub typhus in Korea by comparing and analyzing the difference of prevention behaviors contributing to the occurrence of scrub typhus in Japan and Korea. METHODS: The survey was carried out in Jeollabuk-do, which is a high risk and high incidence area, and Fukuoka Prefecture, which is a high risk and low incidence area. The study included 406 Korean farmers and 216 Japanese farmers. Data were collected through face-to-face surveys by interviewers who had completed standardized education. RESULTS: Korean farmers have a higher percentage of agricultural working posture that involved contact with weeds than Japanese farmers (p<0.05). The frequency and proportion of weeding were lower in Korean farmers than in Japanese farmers(p<0.05). The level of knowledge about scrub typhus was significantly higher among Korean farmers than among Japanese farmers (p<0.05). Mostly, the behavior of agriculture work was more appropriate for Japanese farmers than for Korean farmers (p<0.05). The total average level of agricultural work was lower in Korea than in Japan, lower in men than women, and lower in part-time farmers than full-time farmers (p<0.05). CONCLUSIONS: This study suggests that it is reasonable to develop and provide a program that can improve the level of preventive behavior taking into consideration the characteristics of the subject in order to reduce the incidence of diseases in high-risk areas for scrub typhus.
이춘근 ( Choon Geun Lee ),이다경 ( Da Gyung Lee ),황유진 ( You Jin Hwang ),박제권 ( Jae Kweon Park ) 한국키틴키토산학회 2015 한국키틴키토산학회지 Vol.20 No.1
In present study, a soluble Taxus berry saccharide (sTS) was purified by water extraction, size exclusion filtration and ethanol precipitation from the Taxus cuspidata. Meanwhile, primary structure of sTS affecting on the level of activity was analyzed using TLC. With a purpose of finding potent pre-drug, antioxidant (DPPH, ABTS, FRAP) and superoxide dismutase (SOD) activity of sTS were evaluated, respectively. sTS could concentration-dependently significantly increase of antioxidant activities as compared to those in control. These results indicated that sTS could be developed to a potential antioxidant used in vary commercial industry.