• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.1018-1027
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• 2019

Natural-derived protein-derived low molecular weight peptides have been known to have physiological activities such as antioxidant, hypertension relief, immunomodulation, pain relief and antimicrobial activity. In this study, the low-molecular peptides were produced using commercial proteases (alcalase, bromelain, flavourzyme, neutrase, papain, protamex), and the antioxidant activity (DPPH scavenging activity, superoxide radical scavenging activity, hydroxy radical scavenging activity, and metals chelation capacity), constituent amino acid and molecular weight of the peptide were analyzed. Enzyme reaction was performed by adding 50 g of chopped Ogae meat slurry and 2%(w/v) protein enzyme into the enzyme reactor for 2 h at a pH of 6 and a temperature of $60^{\circ}C$. The degree of hydrolysis(%) after the reaction ranged from $36.65{\pm}4.10%$ to $70.75{\pm}5.29%$. The highest degree of hydrolysis of protamex was 46.3%, and the highest value of papain hydrolysate was $70.75{\pm}5.29%$. On the other hand, alcalase hydrolysate showed the lowest value of $36.65{\pm}4.10%$. Bromelain-treated low molecular weight peptides showed the highest DPPH radical scavenging activity and the lowest scavenging activity of alcalase-treated peptides. Superoxide radical scavenging activity showed that bromelain treated low molecular peptide showed the highest radical scavenging activity of 50% or more. Hydroxyl radical scavenging activity ranged from about 16.73 to 69.16%, the highest among bromelain-treated low molecular peptides. $Fe^{2+}$ chelation abilities showed a distribution between about 17.85 to 47.84%. The chelation capacity of the hydrolysates was not significantly different without any difference to the enzymes used. The results of amino acid analysis showed differences between hydrolysates of alcalase, bromelain, flavourzyme, neutrase, papain, and protamex enzymes. The most amino acid was glutamic acid. The molecular weight distribution of the enzyme hydrolyzates was in the range of 300-2,000 Da, although the molecular weight distribution differed according to the treated enzymes.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.923-928
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• 2012

Optimizing a water-phase suspending system is very important to manufacture high-quality suspension polymerized toners. Therefore, in this study, the effects of the molar ratio of calcium hydroxide ($CaOH_2$)/phosphoric acid ($H_3PO_4$)(Ca/P), which were used as inorganic suspending agents, and pH of the water-phase on the characteristics of styrene-based suspension polymerized toners were mainly investigated. At first, the water-phase was fixed to neutral condition (pH=7.5) and Ca/P molar ratio was changed from 1.5:1 to 1.76:1. As a result, an ideal calcium phosphate (hydroxyapatite) was prepared at the Ca/P molar ratio of 1.73:1 and polymerized toners prepared at this condition showed good particle size distribution, circularity and charging characteristic. Based on this result, Ca/P molar ratio was fixed to 1.73:1 and pH of the water-phase was changed to weak acidic (pH=5.5) and weak basic (pH=9.5) conditions. As a result, polymerized toners prepared under the weak acidic condition showed very good particle size distribution, circularity and charging characteristic along with excellent printing quality. High-quality suspension polymerized toners could be prepared via optimizing Ca/P molar ratio and pH of the water-phase.

• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.444-453
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• 2011

VO(II), ZrO(II), Hf(IV), $UO_2$(II), Sn(II), V(V)$O_3$, Ru(III), Cd(II), Ho(III) and Yb(III) complexes of N'-(2-hydroxybenzyl)-2-(phenylamino)acetohydrazide ($H_2L^1$, 1) and N'-((3-hydroxy-naphthalen-2-yl)methylene)-2-(phenylamino)-acetohydrazide ($H_2L^2$, 13) have been synthesized and characterized by elemental analyses, $^1H$ NMR, IR, UV-Vis, conductance, thermal analyses (DTA and TG). The spectral data showed that the ligands behave as neutral bidentate, monobasic bidentate, monobasic tridentate or bibasic tridentate ligand bonded to the metal ions through the azomethine nitrogen atoms, phenolic hydroxyl group in protonated or deprotonated form and enolic or ketonic carbonyl group. The ligands and their metal complexes exhibit higher antifungal and antibacterial inhibitory effects than parent ligands and the solution of metal ions. Most of metal complexes exhibit higher antifungal activity than standard antifungal drug (amphotricene B). It is also clear that the ligands and their metal complexes have higher antifungal activity than antibacterial activity.

• Journal of dental hygiene science
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• v.12 no.2
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• pp.155-162
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• 2012

Somok, the heart wood of Caesalpinia sappan is used in traditional Chinese medicine. Adherence of S. mutans to the tooth surface can result in the formation of a dental plaque. This study was performed to investigate the antibacterial activity and bacterial adhesion of ethyl acetate extract from C. sappan against S. mutans ATCC 25175. The bacteria were cultured in brain heart infusion(BHI) broth, and then incubated under 5% $CO_2$ at $37^{\circ}C$ for 18~24 hours. The antimicrobial activity of the ethyl acetate extract of C. sappan was then examined using the paper disc methods and MIC. In addition, bacterial adherence to hydroxyapatite was also examined. The ethyl acetate extract was shown to produce inhibitory effects and had MIC values of 125 mg/ml against S. mutans ATCC 25175. The ethyl acetate extract inhibited adhesion of S. mutans to saliva coated-hydroxyapatite beads(S-HA). At 24 hr, the ethyl acetate extract significantly reduced the adherence of S. mutans to S-HA beads relative to the control. The isolated active substance was identified as brazilin($C_{16}H_{14}O_5$) by $^1H-NMR$ and $^{13}C-NMR$. Thus, the application of C. sappan can be considered a useful and practical method for the prevention of dental caries.

• Journal of Haehwa Medicine
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• v.21 no.1
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• pp.125-133
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• 2012

본 논문은 피부미백에 관한 실험적 연구로서, 봉선화(Impatiens balsamina Linne)의 성분 중에서 하이드록시-나프타-퀴논(hydroxynaphthoquinone)이 멜라닌 생성억제 효능, 색소침착 저해 효과 등의 미백 활성이 있는 것으로 밝혀졌다. 피부흑화(melanogenesis)는 멜라닌 색소생성세포(melanocyte)에서 자외선 등의 자극에 대한 방어기작으로 멜라닌 생성 활동이 증가되고 이로 말미암아 만들어진 다량의 멜라닌이 각질형성세포(keratinocyte)로 전이되어 피부 표피층에 축척된 결과이다. 비록 멜라닌이 피부에 보호작용을 하나 피부의 과색소 침착은 기미, 주근깨, 피부염증 후의 피부흑화, 노인성 색소반점 등을 일으키며 이로 인해 피부미용 상의 불편뿐만 아니라 정신적으로 부정적인 영향을 미쳐 사회활동에 불편을 초래하기도 한다. 멜라닌 생성 과정은 아미노산의 일종인 티로신(tyrosine)에 티로시나제(tyrosinase)라는 효소가 작용하여 도파(DOPA), 도파퀴논(dopaquinone)으로 바뀐 후 비효소적인 산화 반응을 거쳐 만들어 지며, 이것이 피부 내에 이상 침착하여 기미, 검버섯 등이 생기는 것이라고 알려져 있다. 이와 같은 색소침착, 기미, 반점 등의 완화, 예방 및 치료에는 멜라닌 생성을 억제하는 물질, 예를 들면 하이드로퀴논(hydroquinone), 알부틴, 비타민 C 및 그 유도체 등이 개발되어 사용되고 있으나 이 중, 하이드로퀴논은 일단 효과가 인정되고 있지만 감작성이 있기 때문에 일반적으로 사용이 제한되고 있다. 아스콜빈산은 쉽게 산화되어, 이를 배합한 제품에는 변색, 변취가 되는 문제를 야기하고, 식물추출물 유래의 물질들은 식물의 산지에 따라 효능의 차이가 심하여 제품의 균질성이 유지되기 어렵다. 이러한 이유로 많은 멜라닌 생성을 억제하는 물질을 개발하기 위한 연구들이 계속 진행하고 있다. 2-히드록시-[1,4]나프토퀴논 유도체는 다음과 같은 구조를 나타낸다. 상기 구조에서 R은 포화 혹은 불포화된 직쇄 또는 분지쇄의 알킬로서, 바람직하게는 C1 내지 C10의 포화 혹은 불포화된 직쇄 또는 분지쇄의 알킬이고, 보다 바람직하게는 C1 내지 C5의 포화 혹은 불포화된 직쇄 또는 분지쇄의 알킬이다. 실험에 활용된 화합물은 다음과 같은 반응식으로 얻어졌다. 2-히드록시-[1,4]나프토퀴논과 포타슘카보네이트(K2CO3)를 아세토니트릴에 용해한 후, 저온수조로 냉각하고 알킬할라이드를 적당한 당량비로 천천히 적하하여 히드록시기와 에테르(ether) 반응을 통하여 얻어질 수 있다. 상기 반응식에서 R은 C1~10의 포화 또는 불포화된 알킬기로서 직쇄형 또는 분지쇄형 모두 가능하다. 상기 화합물인 2-히드록시-[1,4]나프토퀴논(2-hydroxynaphthoquinone)은 배양된 쥐의 멜라노마 세포에 대하여 하이드로퀴논과 대등한 멜라닌 생성 억제효과를 보였다. 하이드로퀴논은 저농도에서 강력한 멜라닌 생성 억제효과를 보이지만 상기 화합물들은 보다 낮은 농도에서도 세포독성을 나타내지 않으며 하이드로퀴논보다 높은 멜라닌 생성 억제 효과를 보였다.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.338-348
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• 2017

Protein hydrolysates derived from plants and animals having antioxidant, suppression of hypertension, immunodulatory, alleviation of pain, and antimicrobial activity has been known as playing important role like hormone. This study was performed to optimize the hydrolysis of protein of sea of cucumber by a flavourzyme. The ranges of processes were the reaction temperature of 40 to $60^{\circ}C$, pH 6 to 8, and enzyme concentration 0.5 to 1.5%(w/v). As a result, the optimization of process was determined at temperature of $48-50^{\circ}C$, pH of 7.0-7.2, and enzyme concentration of 1.0-1.1%(w/v), and degree of hydrolysis was 43-45 at above conditions. The molecular weight of hydrolysate was distributed to 500-3,500 Da and showed typical peptides. Inhibition concentration ($IC_{50}$) of peptides of DPPH radical scavenging activity, Superoxide anion radical scavenging activity, Hydroxy radical scavenging activity, $Fe^{2+}$ cheating activity was 1.25, 3.40, 10.3, and 22.11 mg/mL, respectively. Therefore, we expect that those products are useful as functional food ingredients.

• Journal of Adhesion and Interface
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• v.17 no.4
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• pp.141-148
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• 2016

In this work, mesoporous silica (SBA-15) was synthesized via self-assembly process using triblock copolymer ($PEO_{20}PPO_{70}PEO_{20}$, P123) as template and tetraethyl orthosilicate (TEOS) as silica source under acidic condition. SBA-15 have high surface area ($704m^2g^{-1}$) and uniform pore size (8.4 nm) with well-ordered hexagonal mesostructure. Spiropyran-functionalized SBA-15 (Spiropyran-SBA-15) was synthesized via post-synthesis process using 3-(triethoxysilyl)propyl isocyanate (TESPI) and 1-(2-Hydroxyethyl)-3,3-dimethy-lindolino-6'-nitrobenzopyrylo-spiran (HDINS). Spiropyran-SBA-15 was produced with hexagonal array of mesopores without damage of mesostructre. Surface area and pore size of Spiropyran-SBA-15 were $651m^2g^{-1}$ and 8.0 nm, respectively. Optochemical properties of Spiropyran-SBA-15 was studied with chemical vapors such as EtOH, THF, $CHCl_3$, Acetone and HCl. Main peaks of photofluorescence of Spiropyran-SBA-15 exhibited blue shift in the range of 603.4~592.1 nm after exposure under EtOH, THF, $CHCl_3$, and Acetone vapors. Normalized peak intensities decreased in the range of 0.8~0.3. The main peak of photofluorescence of Spiropyran-SBA-15 showed significant blue shift of 592.1 nm after exposure under HCl vapor, while normalized peak intensity decreased to 0.1.

• Korean Journal of Environmental Biology
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• v.27 no.4
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• pp.323-333
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• 2009

Parabens are alkyl esters of p-hydroxybenzoic acid, which are widely used in foods, cosmetics, and pharmaceutic products as preservatives. Absorbed parabens are metabolized fastly and excreted. Actually human body is exposed to complex mixture of parabens. Safety assessment at various toxicological end points revealed parabens have a little acute, subacute and chronic toxicities. Some reports have argued that as parabens have estrogenic activity, they are associated with the incidence of breast cancer through dermal absorption by cosmetics. There is an inference that antiandrogenic activity of parabens may give rise to a lesion of male reproductive system, but also there is an contrary. At cellular level, parabens may inhibit mitochondrial function of sperms and androgen production in testis, but also there is an contrary. Parabens seem to have little or no toxicity in embryonic development. Parabens can cause hemolysis, membrane permeability change in mitochondria and apoptosis, suggesting cellular toxicity of parabens. Parabens evoked endocrine disruption in several fish species and have toxic effect on small invertebrates and microbes. Therefore, the toxicity of parabens should be considered as a potentially toxic chemical in the freshwater environment. In conclusion, though parabens may be considered as a low toxic chemical, more definite data are required concerning the endocrine disrupting effect of parabens on human body and aquatic animals according to route and term of exposure as well as the residual concentration of parabens.

• Korean Journal of Food Science and Technology
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• v.52 no.5
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• pp.467-475
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• 2020

Ultraviolet radiation is a major cause of photoaging, characterized by wrinkle formation and skin dehydration. Mojaban (Sargassum fulvellum), belonging to the brown algae of the Sargassaceae family, exerts anti-inflammatory, antioxidant, and anti-atopic activities. Particularly, Mojaban extract alleviated ultraviolet B (UVB)-induced inflammatory responses in human keratinocytes and BALB/c mice. Here, the dorsal skin of hairless mice was exposed to UVB for photoaging. The mice were administrated 300 mg/kg Mojaban extract (S. fulvellum extract; SFE) daily. Phenotypically, SFE reduced wrinkle formation and epidermal thickness and increased skin elasticity. SFE increased hydroxyproline content by upregulating the expression of collagen-related genes and downregulating matrix metalloproteinase expression. Furthermore, SFE increased skin moisture content and inhibited transepidermal water loss. SFE upregulated the expression of involucrin, loricrin, and transglutaminase for cornified envelope formation as well as the expression of filaggrin and caspase-14 for natural moisturizing factors. Collectively, SFE may be employed as a nutraceutical ingredient for anti-photoaging.

• Applied Chemistry for Engineering
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• v.26 no.1
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• pp.111-115
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• 2015

Two new analogs of bestatin were prepared from $\small{D}$-leucine and $\small{D}$-valine in a stereoselective and efficient way. An aminopeptidase inhibitor bestatin shows significant biological effects on immunomodulation and is marketed for the treatment of acute myelocytic leukemia. The key intermediates, trans-oxazolidine methyl esters 2a and 2b, were obtained with more than 20 to 1 stereoselectivity in a one-pot procedure by the three cascade reactions between N-hydroxymethyl protected ${\alpha}$-amino aldehydes (4a and 4b) and phenylsulfonylnitromethane ($PhSO_2CH_2NO_2$) and the following in-situ ozonolysis. Basic hydrolysis of 2a and 2b, and then the peptide coupling with $\small{L}$-Leu-OMe produced the protected derivatives of two new bestatin analogs, 3a and 3b, respectively. The new isobutyl and isopropyl analogs of bestatin (1a and 1b) were produced in overall 51% and 38% yields, respectively, with high stereoselectivity from the corresponding protected ${\alpha}$-amino aldehydes 4 in a six-step process.