• Fisheries and Aquatic Sciences
• /
• v.21 no.9
• /
• pp.21.1-21.8
• /
• 2018

In the present study, we first evaluated the melanin inhibitory effect of four crude 70% ethanol extracts separated from soft corals abundantly growing along the seawaters of Jeju Island, South Korea, including Dendronephthya castanea (DC), Dendronephthya gigantea (DG), Dendronephthya puetteri (DP), and Dendronephthya spinulosa (DS). Among the four ethanol extracts, the ethanol extract of DP (DPE) did not possess any cytotoxic effect on B16F10 cells. However, all other three extracts showed a cytotoxic effect. Also, DPE reduced the melanin content and the cellular tyrosinase activity without cytotoxicity, compared to the ${\alpha}-MSH$-stimulated B16F10 cells. Specifically, DPE downregulated the expression levels of tyrosinase and microphthalmia-associated transcription factor by activating the ERK signaling cascade in ${\alpha}-MSH$-stimulated B16F10 cells. Interestingly, the melanin inhibitory effect of DPE was abolished by the co-treatment of PD98059, an ERK inhibitor. According to these results, we suggest that DPE has whitening capacity with the melanin inhibitory effects by activating ERK signaling and could be used as a potential natural melanin inhibitor for cosmeceutical products.

• Proceedings of KOSOMES biannual meeting
• /
• 2017.04a
• /
• pp.157-157
• /
• 2017

• Proceedings of the KSRS Conference
• /
• v.1
• /
• pp.454-454
• /
• 2006

• Ocean and Polar Research
• /
• v.44 no.4
• /
• pp.355-364
• /
• 2022

When the 60-ton-class patrol boat '72' of the Korea Coast Guard (KCG) was on duty and she accidentally collided with another patrol boat ('207', 200-ton-class) and sank. A month-long search found a small amount of lost items, but neither the crew nor the ship was found. For the first time in 39 years since the accident, the Korea Institute of Ocean Science and Technology (KIOST) searched the boat 72 using the latest integrated geophysical techniques. A number of sonar images presumed to be of a sunken ship was acquired using a combined system of side scan sonar and marine magnetometer, operated at an altitude of approximately 30 m from the seabed. At the same time, a strong magnetic anomaly (100 nT) was detected in one place, indicating the presence of an iron ship. A video survey using a remotely operated underwater vehicle (ROV) confirmed the presence of a shielding part of a personal firearm at the stern of the sunken vessel. Based on these comprehensive data, the sunken vessel discovered in this exploration was assumed to be '72'. This result is meaningful in terms of future ocean exploration and underwater archaeology, as the integrated system of various geophysical methods is an efficient means of identifying objects present in the water.

• ALGAE
• /
• v.32 no.1
• /
• pp.75-86
• /
• 2017

Polysaccharides of marine algae exhibit different structural characteristics and interesting biological functions. In this study, crude polysaccharides (CP) of eleven Sri Lankan marine algae obtained through hot water extraction and ethanol precipitation were investigated for DPPH, alkyl, and hydroxyl radical scavenging activities using electron spin resonance spectrometry and for intracellular reactive oxygen species scavenging activity in the Chang liver cell line. Characterization of CPs was done by Fourier transform infrared (FTIR) spectroscopy and by analysis of the monosaccharide composition. Time-dependent density functional theory quantum-chemical calculations at the RB3LYP/6-31G(d,p) level for constructed dimeric units of the corresponding polysaccharides were used to resolve the FTIR spectra. CPs from Chnoospora minima showed the highest DPPH and alkyl radical scavenging activities and higher intracellular reactive oxygen species scavenging effects for both AAPH and $H_2O_2$ induced ROS production in "Chang" cells. The major polysaccharide constituent in C. minima CP was identified as fucoidan and it displayed a higher sulfate content. The degree of sulfation of these polysaccharides suggests a positive correlation with the observed antioxidant properties.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.6
• /
• pp.1115-1123
• /
• 2016

_L-Asparaginase (E.C. 3.5.1.1) is an enzyme involved in asparagine hydrolysis and has the potential to effect leukemic cells and various other cancer cells. We identified the _L-asparaginase gene (_L-ASPG86) in the genus Mesoflavibacter, which consists of a 1,035 bp open reading frame encoding 344 amino acids. Following phylogenetic analysis, the deduced amino acid sequence of _L-ASPG86 (_L-ASPG86) was grouped as a type I asparaginase with respective homologs in Escherichia coli and Yersinia pseudotuberculosis. The _L-ASPG86 gene was cloned into the pET-16b vector to express the respective protein in E. coli BL21 (DE3) cells. Recombinant _L-asparaginase (r-_L-ASPG86) showed optimum conditions at 37-40℃, pH 9. Moreover, r-_L-ASPG86 did not exhibit glutaminase activity. In the metal ions test, its enzymatic activity was highly improved upon addition of 5 mM manganese (3.97-fold) and magnesium (3.35-fold) compared with the untreated control. The specific activity of r-_L-ASPG86 was 687.1 units/mg under optimum conditions (37℃, pH 9, and 5 mM MnSO₄).

• Proceedings of KOSOMES biannual meeting
• /
• 2017.11a
• /
• pp.243-243
• /
• 2017

• Proceedings of KOSOMES biannual meeting
• /
• 2017.04a
• /
• pp.159-159
• /
• 2017

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2005.05a
• /
• pp.74-75
• /
• 2005

• Proceedings of the Korean Magnestics Society Conference
• /
• 2007.05a
• /
• pp.167.2-167.2
• /
• 2007