• 한국자원식물학회지
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• 제18권1호
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• pp.57-63
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• 2005

인삼 callus의 기내배양에 의해서 항암물질을 대량생산하기 위한 연구의 일환으로 인삼 callus의 polyacetylene생산에 미치는 전구물질 및 elicitor의 효과를 조사하였다. 5mg/l의 L-phenylalanine첨가배지에서 인삼 callus의 생장과 polyacethylene합성이 가장 양호하였으며 panaxynol뿐만 아니라 panaxydol도 형성되었다. 반면에 $\alpha-methyl-D.L.methionine$과 D.L.-norleucine 첨가구에서는 polyacetylene이 전혀 생성되지 않았다. Elicitor로 사용되는 nigeran은 농도가 높아질수록 인삼 callus의 생장을 억제시키지만 polyacetylene생성에는 전혀 영향을 미치지 못했다. 그러나 chitosan은 0.5mg/l의 농도에서 는 인삼 callus의 생장과 polyacetylene의 생성에 영향을 주지 못하였으나, 1mg/l 이상 처리구에서는 panaxynol은 검출되지 않았지만 panaxydol은 검출되었다.

• Carbon letters
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• 제11권3호
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• pp.216-223
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• 2010

Two-types of ionically modified multi-walled carbon nanotube (MWNTs) based sensors were developed by radiationinduced graft polymerization using vinyl monomers such as 3-(butyl imidazol)-2-(hydroxyl)propyl methyl methacrylate and 1-[(4-ethenylphenyl)methyl]-3-buthyl-imidazolium chloride with ionic properties, in aqueous solution at room temperature. Subsequently, the tyrosinase-immobilized biosensor was fabricated by a hand-casting of the ionic property-modified MWNTs, tyrosinase, and chitosan solution as a binder onto ITO glass surface. The sensing ranges of the tyrosinase-biosensor for phenol in phosphate buffer solution was in the range of 0.005~0.2 mM. The total phenolic compounds mainly such as caffeine of the tyrosinase-immobilized biosensor for commercial coffee were also determined.

• Biomolecules & Therapeutics
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• 제31권1호
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• pp.16-26
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• 2023

Diabetes is an untreatable metabolic disorder characterized by alteration in blood sugar homeostasis, with submucosal insulin therapy being the primary treatment option. This route of drug administration is attributed to low patient comfort due to the risk of pain, distress, and local inflammation/infections. Nanoparticles have indeed been suggested as insulin carriers to allow the drug to be administered via less invasive routes other than injection, such as orally or nasally. The organic-based nanoparticles can be derived from various organic materials (for instance, polysaccharides, lipids, and so on) and thus are prevalently used to enhance the physical and chemical consistency of loaded bioactive compounds (drug) and thus their bioavailability. This review presents various forms of organic nanoparticles (for example, chitosan, dextron, gums, nanoemulsion, alginate, and so on) for enhanced hypoglycemic drug delivery relative to traditional therapies.

• 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.

• BMB Reports
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• 제36권1호
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• pp.35-42
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• 2003

Heterocyclic amines (HCAs) are potent mutagens generated during the cooking of meat and fish, and several of these compounds produce tumors in conventional experimental animals. During the past 5 years or so, HCAs have been tested in a number of novel in vivo murine models, including the following: lacZ, lacI, cII, c-myc/lacZ, rpsL, and $gpt{\Delta}$ transgenics, $XPA^{-/-}$, $XPC^{-/-}$, $Msh2^{+/-}$, $Msh2^{-/-}$ and $p53^{+/-}$ knock-outs, Apc mutant mice ($Apc^{{\Delta}716}$, $Apc^{1638N}$, $Apc^{min}$), and $A33^{{\Delta}N{\beta}-cat}$ knock-in mice. Several of these models have provided insights into the mutation spectra induced in vivo by HCAs in target and non-target organs for tumorigenesis, as well as demonstrating enhanced susceptibility to HCA-induced tumors and preneoplastic lesions. This review describes several of the more recent reports in which novel animal models were used to examine HCA-induced mutagenesis and carcinogenesis in vivo, including a number of studies which assessed the inhibitory activities of chemopreventive agents such as 1,2-dithiole-3-thione, conjugated linoleic acids, tea, curcumin, chlorophyllin-chitosan, and sulindac.

• 한국축산식품학회지
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• 제36권4호
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• pp.547-557
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• 2016

This review discusses the status, antimicrobial mechanisms, application, and regulation of natural preservatives in livestock food systems. Conventional preservatives are synthetic chemical substances including nitrates/nitrites, sulfites, sodium benzoate, propyl gallate, and potassium sorbate. The use of artificial preservatives is being reconsidered because of concerns relating to headache, allergies, and cancer. As the demand for biopreservation in food systems has increased, new natural antimicrobial compounds of various origins are being developed, including plant-derived products (polyphenolics, essential oils, plant antimicrobial peptides (pAMPs)), animal-derived products (lysozymes, lactoperoxidase, lactoferrin, ovotransferrin, antimicrobial peptide (AMP), chitosan and others), and microbial metabolites (nisin, natamycin, pullulan, ε-polylysine, organic acid, and others). These natural preservatives act by inhibiting microbial cell walls/membranes, DNA/RNA replication and transcription, protein synthesis, and metabolism. Natural preservatives have been recognized for their safety; however, these substances can influence color, smell, and toxicity in large amounts while being effective as a food preservative. Therefore, to evaluate the safety and toxicity of natural preservatives, various trials including combinations of other substances or different food preservation systems, and capsulation have been performed. Natamycin and nisin are currently the only natural preservatives being regulated, and other natural preservatives will have to be legally regulated before their widespread use.

• Membrane and Water Treatment
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• 제9권2호
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• pp.105-113
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• 2018

Maillard reaction products like melanoidins present in industrial fermentation wastewaters are complex compounds with various functional properties. In this work, novel ultrafiltration (UF) mixed matrix membrane (MMM) composed of polysulfone (PSF) and nanocomposites was prepared through a phase inversion process for the recovery of melanoidins. Nanocomposites were prepared with acid functionalized multiwalled carbon nanotubes (MWCNTs) as the reinforcing filler for chitosan-thermoplastic starch blend. Higher nanocomposites content in the PSF matrix reduced the membrane permeability and melanoidins retention indicating tighter membrane with surface defects. The membrane surface defects could be sealed with dilute polyvinyl alcohol (PVA) solution. The best performing membrane (1% nanocomposites in 18% PSF membrane sealed with 0.25% PVA coating) resulted in uniform melanoidins retention of 98% and permeability of 3.6 L/m2 h bar over a period of 8h. This demonstrates a low fouling PSF membrane for high melanoidins recovery.

• 한국미생물·생명공학회지
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• 제26권6호
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• pp.515-522
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• 1998

길항미생물로 분리.동정된 Pseudomonas sp. 3098이 생산하는 chitinase를 황산암모늄 침전, DEAE-cellulose column chromatography, Bio-Gel P-100에 의한 겔여과, 1차 및 2차 hydroxyapatite column chromatography 과정을 거쳐 회수율 5.8%,정제도 15.7배의 정제효소를 얻었고, 효소의 순도는 SDS-PAGE로 확인하였으며, 분자량은 45kDa으로 추정되었다. 정제된 chitinase의 최적 온도와 pH는 45$^{\circ}C$와 5.0이었고, 정제효소는 pH 5.0~9.0 사이에서 안정하였고, 5$0^{\circ}C$, 3시간 및 6$0^{\circ}C$, 30분까지는 비교적 안정하였다. 금속염 및 화학물질의 영향을 조사한 결과 Fe$^{2+}$, Ag$^{1+}$ 및 단백질변성제인 Hg$^{2+}$ 이온에 의해 효소활성이 크게 저해되었고, p-CMB, iodoacetic acid, urea, 2,4-DNP 및 EDTA에 의해 효소활성이 약간 저해되었다. 기질특이성을 조사한 결과 colloidal chitin 및 shrimp shell 유래의 chitin은 분해가능하였으나 crab shell 유래의 chitin, chitosan등은 분해하지 못하였다. Colloidal chitin에 대한 본 효소의 Km값은 0.11%였고, 분해율은 24시간 반응시 34%였다.

• 한국식품영양과학회지
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• 제36권5호
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• pp.589-594
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• 2007

된장모델로서 0.2 mM $FeCl_2$를 함유한 0.1 M glucose-0.1 M glutamic acid 모델액에 50 mM citric acid와 이의 synergist로 5종의 금속결합능이 있는 식품첨가물을 첨가하여 시료를 조제한 후 $30^{\circ}C$와 $40^{\circ}C$에서 4주간 저장하면서 식품첨가물들이 된장모델의 갈변억제에 미치는 영향을 알아보았다. $30^{\circ}C$에서 저장시 시료의 갈변억제율은 일정하게 유지 되다가 3주후 급감하였고, $40^{\circ}C$에서 저장한 경우는 저장기간이 증가됨에 따라 감소하였다. $30^{\circ}C$와 $40^{\circ}C$에서 4주 저장후 가장 높은 갈변억제율을 나타낸 첨가구는 tannic acid 0.015%와 pyrophosphate 0.15%이었으며, $30^{\circ}C$에서 저장시 이들 첨가구의 갈변억제율은 synergist 무첨가구보다 32%가 높았다. 또한 $30^{\circ}C$에서 4주 저장 후 gallic acid, tannic acid, pyrophosphate는 형광물질과 3-deoxyglucosone과 같은 Maillard 반응중간생성물의 생성을 크게 억제하였는데, 이는 이들 synergist들의 높은 철 이온 결합능에 의한 것으로 생각되었다. 중간생성물의 생성 억제효과는 0.15% 첨가 시가 0.015% 첨가시보다 높았다. 한편 gallic acid는 갈변도를 증가시키고, tannic acid는 철 이온과 유색의 착체를 형성하므로, 갈변억제제로 citric acid를 된장에 사용할 경우 이의 synergist로는 pyrophosphate가 가장 적당한 것으로 생각되었다.

• 한국식품과학회지
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• 제31권3호
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• pp.593-599
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• 1999

Biogenic amine류는 어육의 부패과정 중 생성되는 성분으로 이를 간편하게 측정하기 위하여 diamine oxidase를 amino기가 관능기인 다공질의 Chitopearl beads에 고정화한 후 이를 충진한 효소 reactor를 제조하였다. 고정화 효소 reactor를 이용한 biogenic amine 연속계측 시스템을 사용하여 putrescine 기질에 대해 15.0 mM까지 검량곡선을 얻을 수 있었다. 이 때, biogenic amine 센서의 최대 감응도는 $35^{\circ}C$, 0.05 M 인산 완충용액(pH 7.2)을 사용한 경우 얻을 수 있었다. Biogenic amine 센서로 측정 시 방해물질로 작용할 수 있는 성분을 조사한 결과, ATP분해산물 및 TMA 등에는 거의 영향을 받지 않아 측정에 무리가 없음을 보여주었고, 0.8%까지의 식염에 대해서는 감응도가 19.2%이하로 감소하였으며 alanine과 glycine을 제외한 아미노산에 대하여 9.8% 이하의 감응도 상승을 나타내었다. 염류 및 아미노산에 의한 감응도 감소 및 증가 현상은 시료를 0.4 M perchloric acid에 의해 전처리하면 해결할 수 있었다. 여러 종류의 polyamines가 공존하는 경우 putrescine 기준으로 하여 putrescine 검량곡선의 26.7% 범위내에서 polyamines의 측정이 가능하였다. Diamine oxidase가 고정화된 Chitopearl 효소 reactor를 이용하는 경우 biogenic amines의 함량 유무를 30분 이내에 측정할 수 있었다.