• 한국미생물·생명공학회지
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• 제49권1호
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• pp.24-31
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• 2021

This study aimed to investigate the melanogenesis inhibitory activity of epicatechin-3-O-gallate (ECG) isolated from Polygonum amphibium L. ECG was isolated from the ethanol extract of P. amphibium L, and its chemical structure was determined using spectroscopic methods such as LC-ESI-MS, 1D-NMR, and UV spectroscopy. ECG inhibited the melanogenesis of B16F10 cells in a dose-dependent manner. Particularly, it decreased the melanin content by 27.4% at 200 µM concentration, compared with the control, in B16F10 cells, without causing cytotoxicity. It is noteworthy that the expression of three key proteins, including tyrosinase, tyrosinase-related protein-1 (TRP-1), TRP-2, and microphthalmia-associated transcription factor (MITF), involved in melanogenesis, is significantly inhibited by ECG. The ECG isolated in this study caused the inhibition of body pigmentation and tyrosinase activity in vivo in the zebrafish model. These results suggest that the ECG isolated from P. amphibium L. is an effective anti-melanogenesis agent.

• 한국분말재료학회지
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• 제28권1호
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• pp.44-50
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• 2021

Zinc selenide (ZnSe) nanoparticles were synthesized in aqueous solution using glutathione (GSH) as a ligand. The influence of the ligand content, reaction temperature, and hydroxyl ion concentration (pH) on the fabrication of the ZnSe particles was investigated. The optical properties of the synthesized ZnSe particles were characterized using various analytical techniques. The nanoparticles absorbed UV-vis light in the range of 350-400 nm, which is shorter than the absorption wavelength of bulk ZnSe particles (460 nm). The lowest ligand concentration for achieving good light absorption and emission properties was 0.6 mmol. The reaction temperature had an impact on the emission properties; photoluminescence spectroscopic analysis showed that the photo-discharge characteristics were greatly enhanced at high temperatures. These discharge characteristics were also affected by the hydroxyl ion concentration in solution; at pH 13, sound emission characteristics were observed, even at a low temperature of 25℃. The manufactured nanoparticles showed excellent light absorption and emission properties, suggesting the possibility of fabricating ZnSe QDs in aqueous solutions at low temperatures.

• Biomolecules & Therapeutics
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• 제29권1호
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• pp.98-103
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• 2021

The demand for natural substances with anti-melanogenic activity is increasing due to the recent interest in skin whitening. Intensive investigation on the culture broth of Streptomyces sp. SCO-736, a marine bacterium from the Antarctica coast, has led to the isolation of a new natural product named antaroide (1). The chemical structure was established through the interpretation of MS, UV, and NMR spectroscopic data. Antaroide is a nine-membered macrolide with lactone and lactam moieties. To investigate its applicability in skin whitening cosmetics, its anti-melanogenic activity in B16F10 murine melanoma cells was examined. As a result, antaroide displayed strong inhibitory activities against melanin synthesis and also attenuated the dendrite formation induced by the α-melanocyte stimulating hormone (α-MSH). Antaroide suppressed the mRNA expression of the melanogenic enzymes such as tyrosinase, TRP-1 and TRP-2. This suggests that it may serve as a transcriptional regulator of melanogenesis. Collectively, the discovery of this novel natural nine-membered macrolide and its anti-melanogenic activity could give new insights for the development of skin whitening agents.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.3114-3114
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• 2001

During the last years phytochemistry and phytopharmaceutical applications have developed rapidly and so there exists a high demand for faster and more efficient analysis techniques. Therefore we have established a near infrared transflectance spectroscopy (NIRS) method that allows a qualitative and quantitative determination of new polyphenolic pharmacological active leading compounds within a few seconds. As the NIR spectrometer has to be calibrated the compound of interest has at first to be characterized by using one or other a combination of chromatographic or electrophoretic separation techniques such as thin layer chromatography (TLC), high performance liquid chromatography (HPLC), capillary electrophoresis (CE), gas chromatography (GC) and capillary electrochromatography (CEC). Both structural elucidation and quantitative analysis of the phenolic compound is possible by direct coupling of the mentioned separation methods with a mass spectrometer (GC-MS, LC-MS/MS, CE-MS, CEC-MS) and a NMR spectrometer (LC-NMR). Furthermore the compound has to be isolated (NPLC, MPLC, prep. TLC, prep. HPLC) and its structure elucidated by spectroscopic techniques (UV, IR, HR-MS, NMR) and chemical synthesis. After that HPLC can be used to provide the reference data for the calibration step of the near infrared spectrometer. The NIRS calibration step is time consuming, which is compensated by short analysis times. After validation of the established NIRS method it is possible to determine the polyphenolic compound within seconds which allows to raise the efficiency in quality control and to reduce costs especially in the phytopharmaceutical industry.

• Natural Product Sciences
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• 제29권1호
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• pp.38-41
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• 2023

Two xanthones and 4-phenylcoumarins were isolated from the twigs of Mesua beccariana (Baill.) Kosterm. Among them, one new xanthone, beccarianin A (1), along with 7-isoprenyl-jacareubin (2), mammea A/AA cyclo F (3), and mammea A/BA cyclo F (4). These structures were determined by spectrometric and spectroscopic methods, HRESIMS data, NMR, and UV spectra. Two xanthones (1-2) and two 4-phenylcoumarins (3-4) were evaluated for their cytotoxic effect on the HeLa cells. Compound 1 showed active activity (IC₅₀ = 8.2 µM), and compounds 3-4 showed moderate activity (IC₅₀ = 12.3 and 15.6 µM, respectively).

• 분석과학
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• 제36권2호
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• pp.70-79
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• 2023

The synthesis of the Mannich base as a ligand (L) N-(morpholino (phenyl) methyl) acetamide is the subject of this study. Elemental analyses, FT-IR spectra, UV-vis, ¹H-NMR, and magnetic measurements were used to confirm the synthesis of the [Ni(L)₂]Cl₂ complex, thermal analysis (TG/DTG), atomic absorption, and scanning, and structurally explained as electron microscopy (SEM), and X-ray powder diffraction (XRD) methods. The melting point of the complex and its molar conductivity were also measured. The suggested geometries of the complexes formed have a tetrahedral structure, according to the data acquired using various techniques. Theoretical approaches to the complex formation have been investigated. For molecular mechanics and semi-empirical calculations, the HYPERCHEM6 program had been used. The effect of the novel Ni(II) complex on the cancer cell Hepa-2 (human hepatocellular ademocarcinoma), that is the human laryngeal cancer, was studied. It has been found that these ligand and complex have potent effects on the cancer cell. The antibacterial activity of the free ligand and its complex was evaluated against two kinds of human pathogenic bacteria. The first category is Gram-positive (Staphylococcus aureas, epiderimids), whereas the second group is Gram-negative (Psedamonas aeruginosa, Escherichia coli) (from the diffusion method). Finally, it was discovered that various chemicals had varied growth-inhibiting effects on bacteria.

• Biomolecules & Therapeutics
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• 제32권4호
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• pp.492-498
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• 2024

Bioassay and HPLC-UV guided fractionations of the crude extract of marine-derived Streptomyces sp. SNA-077 have led to the isolation of a red pigment, undecylprodigiosin (1). The chemical structure of undecylprodigiosin (1) was revealed by the interpretation of NMR and mass spectroscopic (MS) data. Further, anti-melanogenic effects of undecylprodigiosin (1) were investigated. First, the melanin contents of undecylprodigiosin (1)-treated B16 cells were evaluated. Furthermore, undecylprodigiosin (1) significantly inhibited the key enzymes involved in melanogenesis, including tyrosinase, tyrosinase related protein-1 (TYRP-1), and dopachrome tautomerase (DCT). The mRNA and protein expression levels of Microphthalmia-associated transcriptian factor (MiTF), a critical transcription factor for tyrosinase gene expression, were also suppressed by undecylprodigiosin (1) treatment in B16 analyses. Collectively, our results suggest for the first time that undecylprodigiosin (1), a potent component isolated from an extract of marine Streptomyces sp. SNA-077, critically exerts the anti-melanogenic ability for melanin synthesis.

• 센서학회지
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• 제33권4호
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• pp.203-208
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• 2024

Every year, approximately 350 million tons of plastic waste are generated worldwide. This waste, can degrade into microplastics, owing to factors such as temperature changes and UV exposure. These smaller plastic particles are increasingly entering the food chain through marine life, thereby raising concerns about their impact on human health. Consequently, there is an increasing need to measure microplastics. Common methods involve direct collection by using a manta trawl equipped with a 330 ㎛ mesh net or performing spectroscopic and thermal analyses on collected samples. However, these methods require complex pre-processing, which risk sample destruction. In this study, we developed a system to directly sample microplastics in aquatic environments by using laser-induced fluorescence spectroscopy. Through an analysis of the fluorescence spectra as well as, the with gradient and integration at specific points, we successfully distinguished microplastics of 100, 200, 300, and 500 ㎛ in size, and we also differentiated between polyethylene (PE) and polystyrene (PS) types.

• 한국결정성장학회지
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• 제19권3호
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• pp.152-158
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• 2009

산업용 뿐만 아니라 보석용으로 가치가 있는 사파이어는 매우 다양한 방법으로 합성 사파이어를 만들어 왔다. 그 중 천연 사파이어와 매우 유사하며 보석용으로 가치가 높은 Chatham사의 플럭스 사파이어를 사용하여 천연 사파이어와 비교하였다. 먼저 WD-XRF(Wavelength dispersive x-ray fluorescence spectrometer)를 사용하여 천연과 합성의 화학 조성을 비교하였다. 천연 사파이어는 화학 조성이 매우 다양하였으나 플럭스 사파이어는 천연과 유사한 화학 성분과 특히 Mo, Pt, Pb 미량원소가 검출되었다. Pt는 플럭스 사파이어라는 결정적인 증거가 된다. 다음으로 $1300^{\circ}C$와 $1500^{\circ}C$의 고온에서 열처리를 한 후 자외선-가시광선 분광광도계(UV-VIS Spectrophotometer)를 사용하여 분광학적 특성을 조사함으로써 천연 사파이어는 $Cr^{3+}$와 관련된 약 690nm의 형광과 관련된 흡수 피크의 변화를 관찰할 수 있었고 플럭스 사파이어는 $Cr^{3+}$와 관련된 약 690nm의 피크와 376nm, 388nm의 $Fe^{3+}$의 흡수 피크가 변화함을 볼 수 있었다. 고온 열처리에 의해 플럭스 사파이어의 흡수 피크의 변화가 천연 사파이어의 흡수 피크의 변화보다 더 큰 것을 알 수 있었다 화학조성 및 분광분석 실험을 통하여 천연 사파이어와 flux 합성 사파이어의 특성을 비교 분석하였다.

• 박물관보존과학
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• 제13권
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• pp.13-22
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• 2012

국립중앙박물관 소장 적의본과 폐슬본은 20세기 초에 제작된 것으로 모두 지본채색되어 있다. 두 본에 사용된 채색 안료 및 염료에 대한 비파괴분석을 통해 채색 재료를 확인하고자 하였다. 채색 안료의 성분분석에는 XRF를 이용하였다. 적의본의 안료 분석결과 백색은 연분, 흑색은 먹, 황색은 석황, 적색은 진사와 연단, 녹색은 구리와 비소화합물 또는 석청과 석황을 혼합하여 사용한 것으로 추정되며 기타색상으로 황동을 사용하였다. 폐슬본에 사용된 백색, 흑색, 황색, 녹색은 적의본에 사용된 안료와 동일하나 적색은 채색 안료에 차이를 보였다. 한편 적의본과 폐슬본에 사용된 청색은 안료의 종류를 확인이 어려우나 연분과 혼합하여 사용한 것으로 추정된다. 또한 적의본의 청색 한지에 대한 UV-Vis 분광분석 결과 인디고(쪽)으로 염색한 것으로 추정되었다.