• Title/Summary/Keyword: 탈아세틸화도

Search Result 35, Processing Time 0.031 seconds

Gelation of Chitosan by Sol-Gel Method (졸-겔법에 의한 키토산의 겔화)

  • Kim, Tae-Young;Lee, Dong Il;Moon, Hee;Yang, Jai-Ho
    • Applied Chemistry for Engineering
    • /
    • v.9 no.3
    • /
    • pp.399-403
    • /
    • 1998
  • The gelation characteristics of chitosan of different molecular weight were investigated in terms of concentration and temperature of alkari aqueous solution. The average molecular weights and the degrees of deacetylation of the chitosan used were $2.0{\times}10^5$, $5.2{\times}10^5$, $8.2{\times}10^5$ and 85%, respectively. Sodium hydroxide solution was used as a gelation agent. A simple diffusion model was applied to study the gelation rate. The diffusion coefficients of the gelation agent in the chitosan gel increased with increasing its concentration, temperature of the casting solution, and molecular weight of the chitosan.

  • PDF

An Investigation for the Adsorption of Heavy Metal Ions by Polyamine Organic Adsorbent from the Aqueous Solution - The Influence of Molecular Weight and Degree of Deacetylation of Chitosan - (수용액 중에서 Polyamine계 유기응집제를 이용한 중금속 이온의 흡착 - 키토산의 분자량과 탈아세틸화도 -)

  • Park, Young-Mi;Jeon, Dong-Won
    • Fashion & Textile Research Journal
    • /
    • v.8 no.4
    • /
    • pp.458-464
    • /
    • 2006
  • The adsorption ability of heavy metal ions from the aqueous solution by chitosan, which it is well known natural biopolymer, has been investigated. The fundamental study in this research is focusing on the physicochemical adsorption utilizing the chitosan as a organic chelating adsorbent, adsorb especially heavy metal ions from the waste liquid solution. The adsorption ability of the chitosan between metal ions, having different characteristics with Mw of 188,600, 297,200, and 504,200 g/mol and degree of deacetylation (DD) of 86.92% and 100% were investigated targeting on the $Ni^{2+}$, $Co^{2+}$, $Zn^{2+}$, and $Pb^{2+}$ ions, respectively. The uptake of heavy metal ions with chitosan was performed by atomic absorption flame emission spectrophotometer (AAS) as conducted residual metal ions. It was found that chitosan has an strong adsorption capacity for some metals under certain conditions. Chitosan, which have 100% degree of deacetylation showed high adsorption recovery ratio and have an affinity for all kinds of heavy metals. In contrast, the molecular weight of chitosan was not completely affected on metal ion adsorption.

A Study on Decrease in Degree of Deacetylation of Low Molecular Weight Chitosan Prepared by H2O2 and Change of Whiteness upon Time (H2O2로 분자량이 조절된 저분자화 키토산의 탈아세틸화도와 백도변화에 관한 연구)

  • Kim, Hee-Jung;Jeon, Dong-Won
    • Fashion & Textile Research Journal
    • /
    • v.5 no.5
    • /
    • pp.529-538
    • /
    • 2003
  • Chitosan should be satisfied a certain Mw range for the final application, Low molecular weight chitosan(LMWC) can be acquired by depolymerizing high molecular weight starting chitosan. Using $H_2O_2$ in depolymerizing chitosan is very effective and reproducible in controlling Mw of resulting LMWC. However, $H_2O_2$ can break glycoside linkage of chitosan and oxidize some $-NH_2$ groups in chitosan. It has been reported that decrease in DA(degree of deacetylation) of LMWC prepared by $H_2O_2$. However, any quantitative data of decrease in DA has not been reported yet. In this study, DA of initial chitosan and DA of $H_2O_2$ treated chitosan were measured and the change in DA of chitosan upon $H_2O_2$ treatment were investigated. Change in DA was very different upon $H_2O_2$ treatment condition. LMWC also showed DA change upon time passage. Pre-swelling treatment of initial chitosan and low ratio of $H_2O_2$/chitosan prevented a decrease in DA significantly. Yellowing of LMWC was detected upon time passage, however, decrease in DA was minimal (around 1%).

Measurement of Deproteinization and Deacetylation of Chitin and Chitosan by Near Infrared Spectroscopy (근적외선 분광분석법을 이용한 Chitin 및 Chitosan의 탈단백 및 탈아세틸화도 측정)

  • SONG Ho-Su;LEE Keun-Tai;PARK Seong-Min;KANG Ok-Ju;CHEONG Hyo-Sook
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.36 no.2
    • /
    • pp.88-93
    • /
    • 2003
  • NIR spectroscopic analysis was used for the measurement of deproteinization and deacetylation to apply the merits of NIR spectroscopic analysis to the quality management in the process of chitin and chitosan production. In measuring squid pen and red snow crab shell, which are raw materials of chitin and chitosan by NIR there were typical peaks in 1200 nm, 1510 nm, 2050 nm and 2180 nm. Squid pen had somewhat higher peak than red snow crab shell. In producing chitin, amount of protein was decreased. Measuring it by NIR, reduction of protein caused by deproteinization was identified in producing chitin. Chitosan is a derivative material made from chitin by processing the deacetylation. During this processing, acetyl groups were removed and amide bends were appeared. From NIR spectra, peaks at 1530 nm and 2030 nm indicated amide II peak of chitosan, and these peaks were used for identifying the differences of structure between chitin and chitosan. The error in measurement of nonidentified sample was below $1\%$ and the error in the standard curve was below 0.006. These errors were very low and the accuracy of NIR was considered to be superior to the existing methods.

Physical Properties of Chitosan Film made from Crab Shell (꽃게 껍질에서 분리제조한 키틴산 필름의 물성에 관한 연구)

  • Cho, Jeong-Suk;Han, Jeong-Jun;Lee, Cherl-Ho
    • Korean Journal of Food Science and Technology
    • /
    • v.24 no.6
    • /
    • pp.574-580
    • /
    • 1992
  • Chitin was isolated from the residue of enzymatically hydrolyzed crab, Portunus trituberculatus, and further deacetylated by alkaline boiling to make chitosan. The physical properties of chitosan solution and its film forming properties were examined. The functional characteristics of chitosan film were compared to those of cellophane, polyvinyl chloride (PVC) and polyethylene (PE) films. The proximate chemical composition of chitin obtained from crab residue was 6.95% nitrogen, 0.3% crude ash and 4.57% moisture and the product yield was 12.8% based on a dry material basis. The degree of deacetylation of chitosan was $79{\sim}92%$ and $70{\sim}86%$ as determined by IR spectroscopy, and $70{\sim}86%$ as determined by colloid titration method each respectively. The chitosan at 1% acetic acid solution showed distinct pseudoplastic flow behavior. The flow behavior index and consistency index were 0.8886, 0.2084 $MPa{\cdot}s^n$ for 0.4% solution and 0.8498, 0.6190 $MPa{\cdot}s^n$ for 0.8% solution, respectively. The chitosan film had the highest tensile strength $(888 kg/cm^2)$ and water permeability $(100\;g/m^2{\cdot}24\;hrs)$ among the tested films, but relatively low elongation property (49%). It showed the similar tear strength (90kg/cm) and light permeability (87.7%) to other films tested in spite of the relatively high haze value (12.5%). As the thickness of chitosan film increased from 0.025 to 0.050 mm, the tensile strength of film decreased distictively, and the degree of elongation, tear strength, and water permeability of film also decreased slightly. Whereas the light permeability of film did not change and the haziness of film slightly increased by the increase of film thickness.

  • PDF

합성보존제(benzalkoniumchloride)와 천연보존제(키토산)의 세포독성 및 항균활성에 관한 연구

  • Park, Hyeon-Ju;Lee, Gi-Yeong
    • 한국생물공학회:학술대회논문집
    • /
    • 2001.11a
    • /
    • pp.261-264
    • /
    • 2001
  • Cytotoxicity and antibacterial activity of preservatives were examined. Fibroblast cell L929 was used for cytotoxicity experiment and Pseudomonas aeruginosa A TCC27853, Staphylococcus aureus ATCC25923. Trichoderma reesei ATCC6967 were used for antibacteria and antifungi. Benzalkoniumchloride(BAK) as synthetic preservative and chitosan as natural preservative were used. Minimum inhibitary concentration (MIC) of BAK was 0.1 % for P. aeruginsa and 0.001% for S. aureus and 0.1 % for T reesei MIC of chitosan was 2% for P. aeruginosa and 1 % for S. aureus.

  • PDF

Decolorization of Shrimp Chitin Using Sodium Hypochlorite (차아염소산나트륨을 이용한 새우 키틴의 탈색)

  • Ahn, Chang-Won;Nam, Hee-Sop;Lee, Hyung-Jae;Shin, Yong-Choul
    • Korean Journal of Food Science and Technology
    • /
    • v.26 no.6
    • /
    • pp.787-790
    • /
    • 1994
  • An effective process manufacturing the decolorized chitin with high quality was established using shrimp shell powder. Ash and protein in shrimp shell powder were efficiently removed by 1.66% HCl and 3% NaOH treatments, respectively. A bleached chitin could be also obtained by 0.16% NaClO for 30 minutes, the treatment of which was much better than previously reported decolorization methods such as ethanol, acetone and $H_2O_2$ treatments. Since the pattern of IR spectrum of sample chitin was closely similar to those of commercially available chitins and the degree of deacetylation showed low value of 22.8%, it could be concluded that the bleached chitin obtained had highly-purified character as well as high quality of appearance.

  • PDF

A Study on the Cytotoxicity and Antimicrobial activity of Synthetic preservative(benzalkonium chloride) and Natural preservative(chitosan) (합성보존제(benzalkonium chloride)와 천연보존제(chitosan)의 세포독성 및 항균 활성에 관한 연구)

  • Park, Hyun-Ju;Kim, Jai-Min
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.6 no.2
    • /
    • pp.149-153
    • /
    • 2001
  • This study was performed to examine the cytotoxicity and antimicrobial activity of synthetic or natural preservative. Fibroblast cells L929 were used for cytotoxicity test and Pseudomonas aeruginosa ATCC27853, Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, Trichoderma reesei ATCC6967 were used for antibacterial and antifungal activities. Benzalkonium chloride(BAC) as a synthetic preservative and chitosan as a natural preservative were used for this study. Minimum inhibitory concentration(MIC) of BAC was 0.1~0.01% for P. aeruginosa and 0.001~0.0001% for S. aureus and 0.1~0.01% for T. reesei, MIC of chitosan was 2% for P. aeruginosa and 1I % for S. aureus. This study suggest that chitosan might be useful as an eyedrop.

  • PDF

Physicochemical Properties of Chitin and Chitosan Prepared from Lobster Shrimp Shell (가시발새우 껍질에서 제조한 키틴.키토산의 물리화학적 특성)

  • Chung, Gea-Hwan;Kim, Bong-Sub;Hur, Jong-Wha;No, Hong-Kyoon
    • Korean Journal of Food Science and Technology
    • /
    • v.28 no.5
    • /
    • pp.870-876
    • /
    • 1996
  • The physicochemical properties of chitin and chitosan produced from lobster shrimp (Metanephrups thomosonii) shell were investigated. Lobster shrimp chitin contained 6.84% nitrogen, 0.57% fat and 0.32% ash, while chitosan contained 7.52% nitrogen, 0.13% fat and 0.33% ash. Degree of deacetylation and molecular weight of chitosan were 67.5% and $9.1{\times}105$, respectively. Yields of chitin from the shell portion and chitosan from the chitin were 15.7% and 75%, respectively. Chitin and chitosan contained 2.64 and 1.39mg/g of residual amino acids, respectively, with both the most predominant being lysine. Chemical structures of the lobster shrimp chitin and chitosan have been investigated by the IR and solid state $^{13}C-NMR$ spectra.

  • PDF

Chitosan and Acetylchitosan from Squid Pen and Their Characteristics (오징어 연골을 이용한 Chitosan 및 Acetylchitosan의 제조와 특성)

  • CHOI Hyeon-Mee;HWANG Sun-Young;PARK Seong-Min;LEE Keun-Tai
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.34 no.5
    • /
    • pp.563-569
    • /
    • 2001
  • In order to utilize the processing wastes of squid, chitosan was prepared by intermittent deacetylation treaoent of $\beta-chitin$ contained richly in the pen of squid. Acetylchitosan also was synthesized from squid pen chitosan with anhydrous acetic acid and their characteristics were investigated. The amounts of nitrogen and ash of squid pen chitosan were $5.80.2\% and 0.2\pm0.03\%$ respectively, the yield of squid pen chitosan was $25\pm3\%$, the degree of deacetylation was $92\%$, and the molecular weight was $1.15\times10^6$, Acetyl contents of N-acetylchitosan powder, acetylchitosan bead, N-ACF-1 (N-acetylchitosan film-1) and N-ACF-2 (N-acetylchitosan film-2) were $55.9\%, 63.2\%, 56\% and 58.7\%$ respectively. Two major peaks, amide I ($1,653 cm^{-1}$) and II ($1,558 cm^{-1}$) bent, on FT-IR spectra of the N-acetylchitosan from squid pen were almost similar to these of $\beta-chitin$, While there was a broad single peak at $1,601 cm^{-1}$assigned to be an amide I bend in squid pen chitosan. The CP/MAS NMR spectra of $\beta-chitin$, squid pen chitosan and N-acetylchitosan from squid pen showed a relative broad and single peak at 74 ppm assigned to fifth carbon (C-5) and third carbon (C-3). In case of $\beta-chitin$ and N-acetylchitosan from squid pen, single peak at 74 ppm was showed as the same of $\beta-chitin$ type.

  • PDF