• 전기화학회지
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• 제10권1호
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• pp.1-6
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• 2007

금 나노 입자를 회합시킨 흑연전극 표면에 mercaptopropionic acid(mpa)를 사용하여 자기조립 단층막(self-assembled monolayer: SAMs)을 생성시키고 이어서 도파민(dopa)과의 짝지움 반응을 통하여 Gr(Au)/mpa-dopa형의 수식된 전극을 제작하여 NADH의 전기촉매 산화반응에 적용하였다. 이 수식 전극이 전자전달반응속도와 반응과정에 대하여 연구하였다. 전극 표면에 고정된 도파민이 NADH와 이차반응 속도상수는 회전 전극법으로 0.1 M 인산염 완충용액(pH=7.0)에서 결정하였으며 그 값이 $5.06{\times}10^5M^{-1}s^{-1}$였고, $EC_{cat}$ 및 전자전달이 지배적인 과정이었다. 그러나 반응초기 즉, $10^{-3}s$ 이내에서는 이 전극에서 확산에 영향을 받으며 그 때 확산계수는 $4.64{\times}10^{-4}cm^2s^{-1}$이다.

• 약학회지
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• 제49권2호
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• pp.156-161
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• 2005

Tetrahydropapaveroline (THP) at 5-15 ${\mu}$M has been found to induce L-DOPA-induced oxidative apoptosis in PC12 cells. In this study, the inhibitory effects of THP on dopamine bios ynthesis in PC12 cells and tyrosine hydroxylase (TH) activity in bovine adrenal were investigated. Treatment of PC12 cells with THP at 2.5-10 ${\mu}$M significantly decreased the intracellular dopamine content in a concentration-dependent manner (18.3% inhibition at 10 ${\mu}$M THP). In these conditions, TH activity was markedly inhibited by the treatment with THP at 2.5-10 ${\mu}$M in PC12 cells (23.4% inhibition at 10 $\mu$ M THP). In addition, THP had an inhibitory effect on bovine adrenal TH activity IC50 value, 153.9${\mu}$M). THP exhibited uncompetitive inhibition on bovine adrenal TH activity with a substrate L-tyrosine with the KI value of 0.30 mM. Treatment with L-DOPA at 20~50 ${\mu}$M increased the intracellular dopamine content in PC12 cells, and the increase in dopamine content by L-DOPA was inhibited in part when THP at non-cytotoxic (5-10 ${\mu}$M) or cytotoxic (15${\mu}$M) concentrations was associated with L-DOPA (20 and 50 ${\mu}$M) for 24 h incubation. These results suggest that THP at 5-10${\mu}$M decreases the basal dopamine content and reduces the increased dopamine content induced by L-DOPA in part by the inhibition of TH activity, and that THP at 15${\mu}$M also decreases dopamine content by oxidative stress in PC12 cells.

• Biomolecules & Therapeutics
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• 제13권1호
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• pp.32-34
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• 2005

Effect of isoliquiritigenin isolated from the heartwood of Dalbergia odorifera T. Chen (Leguminosae) on mushroom tyrosinase activity was investigated in vitro using L-tyrosine and L-3, 4-dihydroxyphenylalanine (L-DOPA) as the substrates. When L-tyrosine was used as a substrate, both isoliquiritigenin and kojic acid, a positive control, inhibited tyrosinase activity in a concentration-dependent manner. IC$_{50}$ values of isoliquiritigenin and kojic acid were 61.4 and 52.2 ${\muM}$, respectively. However, isoliquiritigenin showed week inhibitory effect on the oxidation of L-DOPA by tyrosinase with inhibition ratio of 9.1 ${\pm}$ 7.1% at 100 ${\muM}$. It is also suggested that 3-unsubstituted and 4-hydroxyl phenyl group in isoliquiritigenin plays an important role on the inhibition of tyrosinase activity when L-tyrosine was used as a substrate. Analysis of Lineweaver-Burk plot showed that isoliquiritigenin acts as a competitive inhibitor in case of L-tyrosine as a substrate.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2003년도 제46회 춘계 학술연구 발표회
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• pp.49-49
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• 2003

DOPA decarboxylase (DDC), which converts DOPA to dopamine, is important for many biological event such as cuticular melanization, sclerotization and neurotransmission in insects. Recently, it has been also shown that DDC activity is correlated with pupal diapause in M. brassicae. The silkworm, Bombyx mori is a typical insect diapausing at early embryonic stage. (omitted)

• Journal of Genetic Medicine
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• 제17권1호
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• pp.34-38
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• 2020

The term dopa-responsive dystonia (DRD) is used to describe a group of neurometabolic disorders, which are characterized by dystonia, and are typically associated with diurnal fluctuations and respond to levodopa treatment. Autosomal dominant DRD (DYT5a, MIM# 128230) is caused by a heterozygous mutation in the GTP cyclohydrolase 1 (GCH1) gene (MIM# 600225). GCH1 encodes an enzyme, which is involved in the biosynthesis of tetrahydrobiopterin, an essential co-factor for tyrosine hydroxylase. Herein, we report the case of a 16-year-old girl who was diagnosed with DYT5a. She exhibited additional unusual clinical features, including intellectual disability, depression, multiple skeletal anomalies, and short stature, which are not commonly observed in patients with DYT5a. The patient harbored a heterozygous missense variant, c.539A>C, p.Gln180Pro, in the GCH1 gene, which was identified by targeted gene panel analysis using next-generation sequencing.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.298.1-298.1
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• 2002

Tyrosinase (monophenol. 3.4-${\beta}$-dihydroxyphenylalanin oxygen oxidoreductase. EC 1.14.18.1 J. which plays a pivotal role in melanogenesis. It is single chain glycoprotein catalyzing the hydroxylation of tyrosine to ${\beta$\mid$$-3.4-dihydroxyphenylalanin (DOPA) and the oxidation of DOPA to DOPA quinone. To investigate whitening effect of chitosan oligosaccharide. we obtained chitosan oligosaccharide ［(glucosamine)2-6］ by NaNO2 oxidation and measured the effect of chitosan oligosaccharide on tyrosinase activity. Chitosan oligosaccharide dose-dependently inhibited tyrosinase (2 unit) activity and inhibited by 18.8% at dose of 100${\mu}$g/ml. Vitamin C. arbutin and kojic acid that are well known to be inhibitor of melanin production dose-dependently inhibited tyrosinase (2unit) activity. These results suggest that chitosan oligosaccharide may be used as inhibitor of melanin production in melanocyte. which will be further studied.

• 생명과학회지
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• 제28권3호
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• pp.331-338
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• 2018

멜라닌은 생체 내에서 발모 및 피부색을 결정하는데 중요한 역할을 하는 고분자 물질이다. 하지만 활성산소에 의해 과도하게 생성된 멜라닌은 노화와 관련된 기미, 주근깨와 과색소 침착증 등을 야기한다고 알려져 있다. 이와 관련된 천연물 중 서목태 성분의 하나인 polyphosphate는 자외선에 의해 손상되는 피부 노화를 억제한다고 보고되고 있다. 본 연구의 목적은 멜라닌 합성에 대한 RNEE의 직접적인 효과를 조사한 것이다. 본 연구에서 RNEE는 DPPH radical의 소거효과 및 환원력과 같은 항산화 효과는 없는 것으로 나타났다. MTT 실험을 수행한 결과, RNEE는 농도 의존적으로 세포독성을 증가시켰다. 또한, RNEE는 tyrosinase 활성과 DOPA-oxidation 실험 결과에서 멜라닌 합성을 증가시켰다. RNEE는 살아있는 세포에서 L-DOPA에 의한 유발되는 melanin생성 촉진 효과는 없는 것으로 나타났으나, 과산화수소를 처리하여 melanin 생성을 감소시킨 대조군과 비교시 과산화수소 전처리 후 RNEE를 처리한 군에서는 melanin 생성 촉진 효과가 있는 것으로 나타났다. 뿐만 아니라 RNEE는 tyrosinase related protein-2 (TRP-2)의 발현을 증가시키는 것으로 나타났으며, tyrosinase related protein-1 (TRP-1)의 단백질발현도 대조군과 비교시 $16{\mu}g/ml$의 농도에서 증가되는 것으로 나타났다. 특히 superoxide anion을 과산화수소로 변환시키는 SOD-3의 발현을 조사한 결과 $16{\mu}g/ml$ 이상의 농도에서 대조군과 양성 대조군인 ${\alpha}$-MSH보다 단백질 발현이 증가하는 것으로 나타났다. 그러므로, 이상의 결과는 서목태가 흑모와 관련 있는 멜라닌 생성을 촉진하는 기능적인 잠재성을 가지고 있다는 것을 암시한다.

• 대한화장품학회지
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• 제31권2호
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• pp.153-159
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• 2005

본 연구는 한방제제의 구성 약재인 마황이라는 천연한방소재로부터 미백효과가 있는 화장품 원료를 개발하고자 하였다. 본 실험에서 마황추출물의 tyrosinase 억제 효과를 확인하고 마황추출 과정을 세분화하여 methylene chloride 및 물분획물을 얻었으며 이들을 가지고 다시 tyrosinase 억제 실험을 실시하였다. 그 결과 수층부분에서만 $0.2\%$ 농도에서 $60.6\%$의 tyrosinase 억제 효과를 보여주었으며 이후 수층부분만을 농축하여 L-DOPA 산화억제 실험 및 B-16 melanoma를 이용한 미백 실험을 실시하였다. 그 결과 마황추출물 $0.5\%$ 농도에서 $87\%$의 L-DOPA 산화억제 효과를 보여주었으며, $0.75\%$에서는 $98.8\%$의 억제효과를 보여주었다. 또한 B-16 melanoma에서는 $0.05\%$에서 $70.2\%$, $0.075\%$에서는 $79.9\%$의 억제효과를 보여주었다. 그리고 수층부분만을 농축한 마황추출물의 in vivo상에서의 미백 효과를 검증하기 위하여 마황추출물 $0.5\%$를 함유한 제형으로 미백 임상실험을 실시하였다. 그 결과 마황추출물을 함유한 제형에서 10주 경과 후에 육안 및 기기평가 모두에서 미백효과를 보여주었으며 통계적으로도 유의한 차이(p<0.05)를 보여주었다.

• Bulletin of the Korean Chemical Society
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• 제26권7호
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• pp.1135-1137
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• 2005

• 대한핵의학회지
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• 제19권2호
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• pp.69-79
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• 1985

To evaluate the effect of dopaminergic activity on aldosterone secretion, the plasma renin activity, serum cortisol and aldosterone were measured by radioimmunoassay in 6 normal controls and 12 patients who had hyponatremia and generalized edema or ascites with possible condition with secondary aldosteronism before and after(15, 30, and 60 min) 15 mg of metoclopramide by iv bolus injection and same method with 500 mg of L-dopa by per oral in 6 normal controls and 12 patients with edema ascites. The result were as follows; 1) The basal level of PRA was higher in patients rather than normal controls but PRA was not influenced by MC or L-dopa administration on both normal controls and patients group. 2) The serum cortisol level was significantly elevated at 30 min after MC injection compared with basal level in normal controls but no significant change was noted in patients group. After L-dopa administration the serum cortisol level was not changed in both normal controls and patients group. 3) The serum aldosterone level was significantly elevated in 15, 30 and 60 min after MC injection in normal controls, and there also same tendency of aldosterone secretion was noticed in patients group. On the other hands, there was no changes in aldosterone level in both normal controls and patients group with L-dopa administration. Above result means that MC stimulate aldosterone secretion by dopaminergic antagonist and aldosterone secretion in normal subject is controlled by maximal tonic dopaminergic inhibition. In edematous patients, however, both of the dopaminergic inhibitory and stimulating effect of PRA, ACTH etc on the aldosterone secretion seems to be variable.