• 한국식품과학회지
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• 제27권6호
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• pp.997-1002
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• 1995

상업적으로 제조된 키틴으로 부터 키토산을 제조할 때 반응온도, 시간, 키틴의 입자크기가 제조된 키토산의 물리 화학적 성질에 미치는 영향을 검토하였다. 78% 이상의 탈아세틸화를 시키기 위하여서는 $100^{\circ}C$에서는 6시간, $120^{\circ}C$에서는 20분, $140^{\circ}C$에서는 10분 정도를 처리하였으며 이때 생성된 키토산의 점도는 각각 180cps, 130 cps, 30 cps로 측정되었다. 또한 반응 후 잔류시간이 키토산의 점도를 감소시킴을 보였으며 키틴의 입자크기가 작은 경우에 탈아세틸화를 촉진시키며 동일한 탈아세틸화도에서 높은 점도를 유지하였다. 한편 생성된 키토산은 키틴에 비하여 수분흡수, 지방흡수성에서 차이를 보이지 않았으나 색소흡수능력은 평균 4배이상 증가하였다. IR스펙트럼에서는 전반적으로 둔화된 모습을 보였으며 특히 $1,000{\sim}1,800\;cm^{-1}$에서 흡수pattern이 둔화되었다.

• 한국의류산업학회지
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• 제17권6호
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• pp.1030-1038
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• 2015

The purpose of this study is to investigate the dyeability of crabyon fiber contained cotton towels after dyeing with gallut. In this study, the colorants of gallnut were extracted with boiling water at 60℃ and 60min. Crabyon, composite fiber of Chitin/Chitosan and cellulose, is manufactured by uniformly blending Chitin/Chitosan and cellulose viscose and extruding the blended viscose into spin-bath. Cotton towels with crabyon fiber dyed with extracted solution from gallnut according to concentration, temperature and time. Crabyon fiber contained cotton towels dyed using gallnut were pre of post-mordanted using Al, Cu, and Fe. The dyeability(K/S) and color characteristics(L^*, a^*, b^*, C, and h(color angle)) of dyed crabyon fiber contained cotton towels were measured by computer color matching machine and photographs. The crabyon fiber composition of cotton towels was conformed by amide peak(-CONH-) of chitin or chitosan of FT-IR spectroscopy. The results obtained were as follows; The amide peak of crabyon fiber contained cotton towels appeared at about 1652 cm⁻¹. The dyeability of crabyon fiber contained cotton towel was increased gradually with increasing concentration of gallnut dyeing solution and saturated at about 150%(o.w.f). The optimum dyeing temperature and dyeing time were 90~100℃ and 80minutes expectively. The crabyon fiber contained cotton towels were dyed reddish yellow by non, Al, and Cu mordanting, reddish blue by Fe mordanting, respectively. The fastness to washing according to concentration of gallnut in and mordanting method indicated good grade result as more than 3~4 degree in all conditions.

• 한국키틴키토산학회지
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• 제23권4호
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• pp.220-227
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• 2018

Amyloid plaque is a product of aggregation of ${\beta}$-amyloid peptide ($A{\beta}$) and is an important factor in the pathogenesis of Alzheimer's Disease (AD). $A{\beta}$ is a major component of amyloid plaque and vascular deposits in the AD brain. The enzyme ${\beta}$-secretase is required for the production of $A{\beta}$; thus, prevention of the formation of $A{\beta}$ through the inhibition of ${\beta}$-secretase is a major focus in the study of the treatment of AD. In this study, we investigated ${\beta}$-secretase inhibitory activity of an Arctoscopus japonicus peptide. An Alcalase hydrolysate had the highest ${\beta}$-secretase inhibitory activity. A ${\beta}$-secretase inhibitory activity peptide was separated using ion exchange column chromatography (carboxy-methyl: CM, quaternary methyl ammonium: QMA) and reverse phase high performance liquid chromatography (RP-HPLC) on a C18 column. The $IC_{50}$ value of the purified peptide was $248.2{\pm}1.73{\mu}g/mL$. The ${\beta}$-secretase inhibitory peptide was identified as a six amino acid residue of Gly-Pro-Val-Gly-Ala-Pro (MW: 497.27 Da). In cell viability experiments, the final purified fraction, the carboxy-methyl ion exchange column fraction (CM-F1) showed no significant cytotoxic effect in SH-SY5Y cells at concentrations below $100{\mu}g/mL$ in 24 h. The results of this study suggest that peptides separated from Arctoscopus japonicus may be beneficial as ${\beta}$-secretase inhibitor compounds in functional foods.

• 한국수산과학회지
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• 제33권4호
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• pp.356-360
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• 2000

${\beta}-chitin$으로 되어 있는 오징어 연골로부터 간헐적으로 chitosan을 만든 다음 Chitosan 및 acetylchitosan 필름을 제조하여 생물 기능성 소재로서의 필름의 특성에 대하여 검토한 결과 N-ACF-1을 만들 때 사용되는 무수초산과의 반응시간은 12시간 정도가 적당하였으며 이 때 I.R. spectrum상에 $1,732cm^(-1)$에서 bend가 나타났으며 이 ester carbonyl group은 1M KOH/MeOH로 실온에서 4시간 정도 침지시켰을 때 bend가 사라졌다. 두께가 0.02 mm인 chitosan film의 인장강도가 $1,240kg/cm^2$, 신장율 $58.25{\%}$로 가장 컸으며 N-ACF-1이 투습도 $5391m^2{\cdot}24hr$, 산소투과도 $20,000cm^3/m^2{\cdot}24hrs{\cdot}atm$로 3개의 필름 중 가장 높았다. 필름의 흡수능은 두께가 0.02mm인 N-acetylchitosan film이 $60min에서 350{\%}$ 정도 흡수하였다. 두께가 0.04mm N-ACF-1은 $60min$에서 약 $300{\%}$ 흡수하여 두께가 얇은 것이 더 높은 흡수능을 나타냈다.

• 한국토양비료학회지
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• 제39권4호
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• pp.185-194
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• 2006

몇 년동안 게껍질이 풍부하게 있었던 밭토양에서 강한 키틴분해능력을 가진 Trichoderma 곰팡이를 분리하였다. 분리된 곰팡이의 5.8S rRNA, partial 18S, 28S rRNA genes, ITS1, ITS2 sequence 분석과 형태학적 특징을 살펴본 결과 Trichoderma asperellum으로 동정되었고, 이를 Trichoderma asperellum T-5 (TaT-5)로 명명하였다. 이 곰팡이는 chitianse와 ${\beta}$-1,3-glucanase같은 lytic enzyme을 분비하며, 키틴배지 상에서 6가지의 항 곰팡이성 물질을 생산했다. R. solani가 원인인 오이의 모잘록병에 대해 TaT 5의 방제효과를 보기 위해서 TaT-5 배양액(TA), chitin medium(CM), 증류수(DW)를 씨를 심은 후 10일 째에 각 pot에 관주했다. 그리고 관주 1주일 후에 R. solani의 균사를 갈아서 각 pot에 주었다. 실험기간 동안에 오이의 지상부와 지하부 생체중은 다른 처리구에 비하여 TA 처리구가 더 많이 증가하였다. 오이 잎에서 PR-protein (chitianse, ${\beta}$-1,3-glucanase) 활성은 R. solani 감염 후 CM과 DW에서 증가를 보였고, TA 처리구에서는 증가하다가 감소하는 경향을 보였다. 뿌리에서는 모든 처리구가 감소하는 경향을 보였지만 TA 처리구가 CM과 DW 처리구보다 감소하는 정도가 적었다. 오이의 잎과 뿌리에서 lignification related enzyme(POD, PPO, PAL)활성은 R. solani 감염 초기에는 증가하다가 점점 감소하는 경향을 보였다. 이러한 결과들은 TaT-5에 의하여 생산된 lytic enzymes와 항 곰팡이성 물질들이 오이에 R. solani의 공격을 줄여준다고 생각된다.

• Archives of Pharmacal Research
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• 제10권2호
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• pp.88-93
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• 1987

Chitosan ($\beta$-D-glucosaminan) is chemically prepared from chitin (N-acetyl-$\beta$- D-glucosaminan) which is an unutilized natural resource. We now report on the suitability of the chitosan matrix for use as vehicles for the controlled release of drugs. Salicylic acid and aspirin were used as model drugs in this study. The permeation of salicylic acid in the chitosan membranes was determined in a glass diffusion cell with two compartments of equal volume. Drug release studies on the devices were conducted in a beaker containing 5% sodium hydroxide solution. Partition coefficient (Kd) value for acetate membrane (472) is much greater than that for fluoro-perchlorate chitosan membrane (282). Higher Kd value for acetate chitosan membrane appears to be inconsisstent with the bulk salicylic acid concentration. The permeability constants of fluoro-perchlorate and acetate chisotan membranes for salicylic acid were 3.139 ${\times}10^{-7}cm^2$ min up to 60 min and that of 30% aspirin in the devices was 4.739${\times}10^{-7}cm^2$sec upto 60 min. As the loading dose of aspirin in a chitosan device increased, water up-take of chitosan device increased, but in case of salicylic acid it decreased. The release rate increased with increase in the molecular volume of the drugs. Thses result suggest that the release mechanism may be controlled mainly by diffusion through pores.

• 한국재료학회지
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• 제31권7호
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• pp.375-381
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• 2021

Chitosan powder is synthesized by a deasetylation process of chitin, obtained from processing of dried shrimp shell powder. Subsequently, chitosan (CS) membranes filled by montmorillonite (MMT) particles and phosphotungstic acid are prepared, and characterized by FT-IR and SEM. The morphology, obtained by SEM for the composite membrane, showed that MMT filler is successfully incorporated and relatively well dispersed in the chitosan polymer matrix. Water and methanol uptake for the CS/MMT composite membranes decrease with increasing MMT loadings, but IEC value increases. In all prepared CS/MMT composite membranes, the CS membrane filled by 5 wt% MMT particles exhibits the best proton conductivity, while that with 10 wt% MMT loading exhibits the lowest methanol permeability; these values are 2.67 mS·cm^-1 and 3.40 × 10^-7 cm²·s^-1, respectively. The best membrane selectivity is shown in the CS/MMT10 composite membrane; this shows that 10 wt% filled MMT is the optimum loading to improve the performance of the chitosan composite membrane. These characteristics make the developed chitosan composite membranes a promising electrolyte for direct methanol fuel cell (DMFC) application.

• Archives of Pharmacal Research
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• 제14권3호
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• pp.255-260
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• 1991

Chitinase was partially purified from Allium fistulosum L (green onion_. Protein fraction precipitated from ammonium sulfate was passed through CM-Sepharose and Sephacryl HR-200. The specific activity of the chitinase was 6.4 units/mg and total recovery was 6.3%. The analysis of the products from the digestion of N-acetychitohexaose indicated that chitinase was endo in action, with oligerms from N-acetylchitobiose to chitotetraose. N-Acetylglucosaminidase from the same species hydrolyzed oligomers obtained from chitinase reaction to lower oligosaccharides. These data demonstrated that chitinolytic system exists in green onion.

• Mycobiology
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• 제39권3호
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• pp.182-186
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• 2011

Four Trichoderma strains (CH2, SH16, PQ34, and TN42) were isolated from soil samples collected from Quang Tri and Thua Thien Hue provinces in Vietnam. The strains exhibited high chitinolytic secretion. Strain PQ34 formed the largest zone of chitinase-mediated clearance (> 4 cm in diameter) in agar containing 1% (w/v) colloidal chitin. Analysis of the internal transcribed spacer regions of these strains indicated that they were Trichoderma asperellum. The molecular weights of the chitinases were approximately 42 kDa. Chitinase genes (chi42) of T. asperellum strains TN42, CH2, SH16, and PQ34 were 98~99% homologous to the ech42 gene of T. harzianum CB-Pin-01 (accession No. DQ166036). The deduced amino acid sequences of both T. asperellum strains SH16 and TN42 shared 100% similarity.

• BMB Reports
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• 제35권3호
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• pp.313-319
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• 2002

N-Acetyl-$\beta$-D-hexosaminidase ($\beta$-HexNAc'ase) (EC 3.2.1.52) was purified from rice seeds (Oryza sative L. var. Dongjin) using ammonium sulfate (80%) precipitation, Sephadex G-150, CM-Sephadex, and DEAE-Sephadex chromatography, sequentially. The activities were separated into 7 fractions($F_1-F_7$) by CM-Sephadex chromatography. Among them, F6 was further purified to homogeneity with a 13.0% yield and 123.3 purification-fold. The molecular mass was estimated to be about 52 kDa on SDS-PAGE and 37.4 kDa on Sephacryl S-300 gel filtration. The enzyme catalyzed the hydrolysis of both p-nitrophenyl-N-acetyl-$\beta$-D-hexosaminide (pNP-GlcNAc) and p-nitrophenyl-N-acetyl-$\beta$-D-hexosaminide (pNP-GalNAc) as substrates, which are typical properties of $\beta$-HexNAc'ase. The ratio of the pNP-GlcNAc'ase activity to the pNP-GalNAc'ase activity was 4.0. However, it could not hydrolyze chitin, chitosan, pNP-$\beta$-glucopyranoside, or pNP-$\beta$-glucopyranoside. The enzyme showed $K_m$, $V_{max}$ and $K_{cat}$ for pNP-GlcNAc of 1.65 mM, $79.49\;mM\;min^{-1}$, and $4.79{\times}10^6\;min^{-1}$, respectively. The comparison of kinetic values for pNP-GlcNAc and pNP-GalNAc revealed that the two enzyme activities are associated with a single binding site. The purified enzyme exhibited optimum pH and temperature for pNP-GlcNAc of 5.0 and $50^{\circ}C$, respectively. The enzyme activity for pNP-GlcNAc was stable at pH 5.0-5.5 and $20-40^{\circ}C$. The enzyme activity was completely inhibited at a concentration of 0.1 mM $HgCl_$ and $AgNO_3$, suggesting that the intact thiol group is essential for activity. Chloramine T completely inhibited the activity, indicating the possible involvement of methionines in the mechanism of the enzyme.