• Journal of Applied Biological Chemistry
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• 제58권4호
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• pp.295-301
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• 2015

Five phenylpropanoids (1-5), a benzofuran neolignan (6), two 8-O-4'-neolignans (7-8), and five tetrahydrofuran lignans (9-13) were isolated from a methanol extract of Myristica fragrans seeds. The structures of 1-13 were determined by $^1H$- and $^{13}C$-NMR spectroscopic data analyses and a comparison with the literature data. Compound 3 was isolated for the first time from this plant. All the isolated compounds were evaluated for their inhibitory activity against tyrosinase. Among them, safrole (1) showed significant inhibitions against both the monophenolase ($IC_{50}=32.11{\mu}M$) and diphenolase ($IC_{50}=27.32{\mu}M$) activities of tyrosinase. The kinetic analysis shows that safrole (1) is competitive inhibitors for both monophenolase and diphenolase. The apparent inhibition constant ($K_i$) for safrole (1) binding with free enzyme was determined to be 16.05 and $13.66{\mu}M$ for monophenolase and diphenolase, respectively.

• 한국식품영양학회지
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• 제32권6호
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• pp.611-619
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• 2019

The purpose of this study was to investigate the antioxidant activity and tyrosinase inhibitory activity of Codonopsis lanceolata 50% ethanol extract, and its solvent fractions (n-hexane, ethyl acetate (EA), n-butanol, water). The main components of the EA fraction were qualitatively analyzed using UPLC Q-ToF/MS. Additionally, a quantitative analysis was performed using UPLC. As a result, the total polyphenol content was 113.36 mg gallic acid/g in the EA fraction, which contained the largest amount of the C. lancolata solvent fractions. Also EA showed the highest antioxidant activity than other fractions. The IC₅₀ of DPPH(2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity was 0.03 mg/mL and the IC₅₀ of ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate)] radical scavenging activity was 0.049 mg/mL. The EA fraction showed tyrosinase inhibitory activity than other fractions and especially inhibited monophenolase oxidase reaction higher than diphenolase oxidase reaction. The monophenolase oxidase inhibited 55% when the concentration of the EA fraction was 0.25 mg/mL. As a result of Q-ToF/MS analysis, it was confirmed that tangshenoside I and lobetyolin were the main components of EA fraction. Thus, these results suggest that C. lanceolata may be used as a potent source of cosmetic agents.

• 청정기술
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• 제22권3호
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• pp.175-180
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• 2016

본 연구에서는, 저온 및 약산성 조건에서 높은 활성을 보이는 티로시나아제인 tyrosinase-CNK의 반응 안정성을 조사하였다. Tyrosinase-CNK는 지금까지 알려진 중온성(mesophilic) 및 호열성(thermophilic) 환경 유래의 티로시나아제 보다는 열 안정성이 낮았으나 0 ℃에서 효소 안정성이 매우 뛰어났고, 반복적인 동결-해동(freeze-thaw) 과정에서도 효소 활성을 안정적으로 유지하였다. 또한, 물과 ethanol 및 acetonitrile이 혼합된 유기용매 환경에서 초기 상대 활성 값의 변화가 관찰되었으나 유기용매 농도의 증가로 인한 추가적인 활성 저하를 유발하지 않고 활성을 일정하게 유지하였다. 한편, 효소 반응의 염(salt)에 대한 저해는 chaotropic 특성이 많이 나타나는 염일수록 적게 나타났다. 결과적으로, tyrosinase-CNK는 통상의 티로시나아제를 이용하여 반응을 수행하기 어려운 환경에서도 원하지 않는 반응을 억제하고 효소 불활성화를 최소화면서 반응을 촉매할 것으로 기대된다.

• 생명과학회지
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• 제25권11호
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• pp.1298-1303
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• 2015

후박나무(녹나무과)는 한국과 일본 등지에 서식하는 상록 교목으로 한국, 중국, 일본에서 부종, 복통, 복부 팽만 등의 질병 치료를 위해 오랫동안 사용되어오고 있다. 본 연구에서는 후박나무 껍질을 메탄올에 추출하고 메탄올 추출물을 헥산, 클로로포름, 부탄올에 순차적으로 분획하였다. 클로로포름 분획물로부터 2종의 화합물을 분리하였으며 분리된 화합물1과 2의 구조는 ¹H-, ¹³C-NMR과 참고 문헌 데이터에 의해 dibenzylbutane lignin 화합물인 macelignan (1)과 meso-dihydroguaiaretic acid (2)로 동정되었다. 분리된 화합물들의 tyrosinase 저해 활성을 측정한 결과, 화합물 2는 tyrosinase 저해 활성 중 monophenolase (IC₅₀ = 10.2 μM)에 대해 높은 저해활성을 나타내는 경쟁적 저해제였으며 효소에 결합하는 화합물 2의 저해 상수(K_i 값)는 4.8 μM였다. 따라서 meso-dihydroguaiaretic acid (2)는 멜라닌 생합성과 관련된 피부 질환 치료를 위한 잠재적 후보가 될 수 있을 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1319-1325
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• 2010

Tyrosinase ubiquitously existing from microorganisms to animals and plants is known to be the most critical and rate limiting enzyme during melanin biosynthesis. In order to develop new tyrosinase inhibitor we have synthesized 14 diphenyl ether compounds possessing hydroxyl, bromo, and nitro groups in the structure. Among the compounds prepared, 18 and 19 have shown much stronger inhibition of tyrosinase monophenolase function than arbutin used as a positive control. Both compounds 18 and 19 possess para-hydroxyphenyl moiety in their structure, which might reinforce the importance of p-hydroxyphenyl group in the tyrosinase inhibitory process. In the DPPH radical scavenging activity test, none of the compounds even 18 and 19 showed significant antioxidant activity. The results suggest that elaborate adjustment of diphenyl ether analogues with proper substituents have potential to be developed as new skin whitening agents working on the tyrosinase function.

• KSBB Journal
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• 제29권1호
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• pp.1-8
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• 2014

Tyrosinases catalyze the hydroxylation of monophenolic compounds and the conversion of o-diphenols to oquinones. The enzymes are mainly involved in the modification of tyrosine into L-3,4-dihydroxyphenyl-alanine (L-DOPA) and DOPA/DOPAquinone-drived intermolecular cross-linking, which play the key roles of pigmentation to the cells. It is ubiquitously distributed in microorganisms, plants, and animals all around the nature world. They are classified as copper- containing dioxygen activating enzymes; two copper ions are coordinated with six histidine residues in their active sites and they are distinguished as met-, deoxy-, and oxy-form depending on their oxidative states. Natural extraction and recombinant protein approaches have been tried to obtain practical amounts of the enzymes for industrial application. Tyrosinases have been widely applied to industrial and biomedical usages such as detoxification of waste water containing phenolic compounds, L-DOPA as a drug of Parkinson's disease, biomaterials preparation based on the cross-linking ability and biosensors for the detection of phenolic compounds. Therefore, this review reports the mechanism of tyrosinase, biochemical and structural features and potential applications in industrial field.

• Journal of Microbiology and Biotechnology
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• 제32권5호
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• pp.594-601
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• 2022

This study evaluated the biological properties of lemongrass (Cymbopogon citratus) extracts. The EtOAc extract of lemongrass had DPPH, TEAC, and nitric oxide-scavenging activity assay results of 58.06, 44.14, and 41.08% at the concentration of 50, 10, and 50 ㎍/ml, respectively. The EtOAc extract had higher elastase and collagenase inhibitory activities than the 80% MeOH, n-hexane, BuOH, and water extracts and comparable whitening activity toward monophenolase or diphenolase. Also, the EtOAc fraction had higher lipase inhibitory and antimicrobial activities against Cutibacterium acnes among extracts which is known to an important contributor to the progression of inflammatory acne vulgaris, and an opportunistic pathogen present in human skin. Total phenolic and flavonoid concentrations in the EtOAc extract were 132.31 mg CAE/g extract and 104.50 mg NE/g extract, respectively. Biologically active compounds in lemongrass extracts were analyzed by LC-MS. This study confirms that lemongrass extracts have potential use as cosmetic skincare ingredients. Thus, lemongrass can be considered a promising natural source of readily available, low-cost extracts rich in antioxidant, skincare, and antimicrobial compounds that might be suitable for replacing synthetic compounds in the cosmeceutical industry.

• 한국동물학회지
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• 제39권1호
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• pp.36-46
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• 1996

붉은 지렁이(Lumbricus rubellus)로부터 체내에 존재하는 phenoloxidase (EPO)를 ammonium sulfate. Blue-2, Phenyl-, Q-sepharose chromatography등을 이용하여 정제하였다. 이 효소는 SDS-PAGE상에서 59 kDa의 분자량을 갖는 단일 단백질로 나타났으며 nondenatudng-PAGE를 이용하여 DL-dopa를 기질로 in situ 염색 결과, 210 kDa 보다 다소 큰 단일 band가 dopachrome 침착에 의해 형성되었다. 이는 곧 이 효소가 자연상태에서 복합체의 형태로 존재하고 있음을 의미한다. 또한 이 효소는 monophenolase 활성도, 즉 tyrosine을 dopa로 전환시키는 활성도도 갖고 있음을 470nm에서 dopachrome축적을 관찰함으로써 확인할 수 있었다. Phenyithiourea(PUT), 1, 10-phenanthroline, EDTA, EGTA등을 사용한 효소억제 실험 결과, PTU만이 65 $\mu$M의 IC 0.5로 효소 활성도를 효과적으로 억제시켰다. 이는 EPO의 촉매기작에서 구리가 매우 중요한 역할을 하고 있음을 의미한다. 이 효소는 L-dopa를 기질로 사용하였을 때 35$^{\circ}C$와 pH8.0에서 최적의 활성도를 나타내었다. EPO의 L-dopa에 대한 Km은 pH6.5와 8.0에서 각각 1.86 mM과 13.8 mM로 나타났다. 또한, pH 8.0에서 Vmax는 pH 6.5에서 보다 약 6.6배 높은 반면, 각 조건에서 촉매 효율성은 거의 차이가 없음 [(kat/Km)pH8.0/(kcat/Km)pH6.5 = O.92]을 알 수 있었다. 따라서, 이 사실은 EPO 촉매기작에 미치는 pH의 효과가 효소 자체에보다는 기질 또는 효소-기질 복합체 형성과정에 영향을 줌을 의미한다. 이와 같은 사실을 종합해 보면, L. rubellus에 존재하는 phenoloxidase는 oligomeric form을 가지며 활성화 되기 위한 제한적 단백질 가수분해를 필요로 하지 않는다. 따라서, prophenoloxidase activating system의 존재 가능성을 완전히 배재할 수는 없으나 지렁이 체내의 PO는 최소한 부분적으로나마 latent from으로 존재함을 확인할 수 있었다. 이는 외부 침입시 host를 보호하기 위한 방법으로 EPO를 latent from으로 유지 시킬 수 있는 또는 활성화 시킬 수 있는 조절기작의 존재를 예측하게 한다.