• Food Science and Biotechnology
• /
• v.14 no.6
• /
• pp.798-802
• /
• 2005

Crude extracts of thirty seaweeds collected in Korea were obtained using 50% ethanol, and total phenolic contents and antioxidant activities were compared. Two brown algae, Ecklonia cava (E. cava) and Sargassum siliquastrum (S. siliquastrum), showing high antioxidant activity based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and superoxide anion radical scavenging activity were further investigated for their inhibitory effects on tyrosinase activity. The E. cava extract had the highest total phenolic content among the seaweeds extracts. Total phenolic contents were strongly correlated with antioxidant activity in the thirty seaweed extracts ($R^2\;=\;0.9169$). The E. cava and S. siliquastrum extracts exhibited higher inhibition to tyrosinase activity than butylated hydroxytoluene (BHT) and epigallocatechin gallate (EGCG).

• Fisheries and Aquatic Sciences
• /
• v.14 no.2
• /
• pp.89-92
• /
• 2011

We investigated the antioxidant and cholinesterase inhibitory activities of the aqueous extract of rainbow trout Oncorhynchus mykiss. The antioxidant activity of O. mykiss aqueous extract was determined by in vitro peroxynitrite scavenging activity and reducing power assays. The aqueous extract of O. mykiss showed potent peroxynitrite radical scavenging activity ($IC_{50}=0.12{\pm}0.001\;mg/mL$) and reducing power (absorbance=$0.47{\pm}0.001$) at the concentration of 1 mg/mL. The in vitro cholinesterase inhibitory activity of O. mykiss aqueous extract was examined using spectrophotometric analyses of acetyl- and butyrylcholinesterase. The aqueous extract of O. mykiss showed acetylcholinesterase inhibitory activity ($IC_{50}=1.61{\pm}0.13\;mg/mL$), but did not exhibit inhibitory activity against butyrylcholinesterase. These results suggest that O. mykiss possesses antioxidant and acetylcholinesterase inhibitory activities and provide scientific evidence for the health benefits of O. mykiss aqueous extract.

• Fisheries and Aquatic Sciences
• /
• v.13 no.1
• /
• pp.49-55
• /
• 2010

A bacterial strain with phytase and glucose-1-phosphatase activity was isolated from seawater. The colony was identified as an Enterobacter cloacae strain and named E. cloacae B11. A gene, agpEnB11, coding for an intracellular acid glucose phosphatase was cloned from the strain and sequenced. It comprised 1,242 nucleotides and encoded a polypeptide of 413 amino acids. Recombinant glucose-1-phosphatase (AgpEn) was overexpressed in Escherichia coli and purified using Ni-NTA column under native conditions. Purified protein displayed a single band of 47 kDa on SDS-PAGE. AgpEn hydrolyzed a wide variety of phosphorylated compounds, with high activity for glucose-1-phosphate and glucose-6-phosphate. Optimum pH and temperature for enzyme activity were pH 5.0 and $50^{\circ}C$, respectively. Enzyme activity was stimulated by $Ca^{2+}$ and $Co^{2+}$, and inhibited by $Cu^{2+}$.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.6
• /
• pp.1891-1896
• /
• 2011

On the basis of potent HDAC-inhibitory activity and anticancer activity of SAHA, novel SAHA derivatives 3a-d and 7 with a bulky cap such as p-dimethylaminophenyl, 4-phenylaminophenyl, 4-phenyloxyphenyl, 9H-fluorenyl or naphthalenyl ring were synthesized starting from the corresponding aryl amines or naphthalenyl acetic acid using an EDC-mediated amide coupling reaction in the presence of HOBt followed by a nucleophilic addition-elimination reaction with hydroxylamine. Compounds 3b, 3c and 3d showed more potent inhibitory activity on total HDACs (14~27-fold), HDAC1 (8~15-fold), HDAC2 (1.3~25-fold) and HDAC7 (1~3-fold) and more potent anticancer activity (2~22-fold) against MCF-7, MDA-MB-231, MCF-7/Dox, MCF-7/Tam, SK-OV-3, LNCaP and PC3 human cancer cell lines than SAHA.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.1
• /
• pp.64-70
• /
• 2015

We investigated the branchial osmoregulatory response of black sea bream Acanthopagrus schlegelii to short-term (3-48 h) exposure to a hyposaline environment (5 psu). Gill $Na^+/K^+$-ATPase (NKA) activity was decreased after 3 h in fish transferred to 5 psu compared to salt water-acclimated (control) fish, but the level of activity returned to that observed in the control fish at 6 h after transfer. NKA activity increased significantly at 24 h after transfer, but it returned to the level observed in the control fish at 48 h after transfer. Immunohistochemical staining revealed that gill NKA was localized to chloride cells. The number of chloride cells tended to change in parallel with NKA activity. Substantial decreases in plasma $Na^+$, $Cl^-$, and osmolality were observed after 12 h of exposure to 5 psu; however, these parameters began to recover to the values detected in the controls at 24 h after transfer. In conclusion, our results suggest that black sea bream are able to adjust their osmoregulatory mechanisms to shift from hypo- to hyperosmoregulation within 6 h of exposure to a hypoosmotic environment.

• Journal of Microbiology and Biotechnology
• /
• v.19 no.4
• /
• pp.378-386
• /
• 2009

A sequential optimization strategy, based on statistical experimental designs, is employed to enhance the production of alkaline protease by a Bacillus pseudofirmus local isolate. To screen the bioprocess parameters significantly influencing the alkaline protease activity, a 2-level Plackett-Burman design was applied. Among 15 variables tested, the pH, peptone, and incubation time were selected based on their high positive significant effect on the protease activity. A near-optimum medium formulation was then obtained that increased the protease yield by more than 5-fold. Thereafter, the response surface methodology(RSM) was adopted to acquire the best process conditions among the selected variables, where a 3-level Box-Behnken design was utilized to create a polynomial quadratic model correlating the relationship between the three variables and the protease activity. The optimal combination of the major medium constituents for alkaline protease production, evaluated using the nonlinear optimization algorithm of EXCEL-Solver, was as follows: pH of 9.5, 2% peptone, and incubation time of 60 h. The predicted optimum alkaline protease activity was 3,213 U/ml/min, which was 6.4 times the activity with the basal medium.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.9
• /
• pp.1260-1268
• /
• 2014

Screening of a gene library from Paenibacillus sp. PBS-2 generated in Escherichia coli led to the identification of a clone with lipolytic activity. Sequence analysis showed an open reading frame encoding a polypeptide of 378 amino acid residues with a predicted molecular mass of 42 kDa. The esterase displayed 69% and 42% identity with the putative ${\beta}$-lactamases from Paenibacillus sp. JDR-2 and Clostridium sp. BNL1100, respectively. The esterase contained a Ser-x-x-Lys motif that is conserved among all ${\beta}$-lactamases found to date. The protein PBS-2 was produced in both soluble and insoluble forms when E. coli cells harboring the gene were cultured at $18^{\circ}C$. The enzyme is a serine protein and was active against p-nitrophenyl esters of $C_2$, $C_4$, $C_8$, and $C_{10}$. The optimum pH and temperature for enzyme activity were pH 9.0 and $30^{\circ}C$, respectively. Relative activity of 55% remained at up to $5^{\circ}C$ with an activation energy of 5.84 kcal/mol, which indicates that the enzyme is cold-adapted. Enzyme activity was inhibited by $Cd^{2+}$, $Cu^{2+}$, and $Hg^{2+}$ ions. As expected for a serine esterase, activity was inhibited by phenylmethylsulfonyl fluoride. The enzyme was remarkably active and stable in the presence of commercial detergents and organic solvents. This cold-adapted esterase has potential as a biocatalyst and detergent additive for use at low temperatures.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.3
• /
• pp.188-194
• /
• 2010

The in vitro antioxidant activities of five melania snails in the genus Semisulcospira (S. coreana, S. forticosta, S. libertina, S. tegulata and S. gottschei) were tested in detail. The total phenolic contents of the snails ranged from $32.3{\pm}1.0$ to $87.9{\pm}6.9$ mg gallic acid equivalent (GAE)/g dry sample. The $EC_{50}$ values for the 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities were $2.245{\pm}0.179$ mg/mL for S. coreana and $9.319{\pm}1.276$ mg/mL for S. gottschei and differed significantly (P<0.05) among the tested species. The superoxide dismutase (SOD)-like activity was highest for S. gottschei at 67.2% and lowest for S. forticosta at 4.7%. However, no significant differences among the species were recognized for the peroxynitrite anion scavenging activity. Comparing the correlation coefficients between the total phenolic contents and the DPPH radical and peroxynitrite anion scavenging activities, there was a low level relationship between each activity.

• KSBB Journal
• /
• v.29 no.6
• /
• pp.437-442
• /
• 2014

In vitro biological activities of Aloe vera gel and skin extracts were evaluated. Total polyphenol contents of Aloe vera skin were measured 41.12 mg/g. DPPH radical scavenging activity of Aloe vera skin-70% EtOH extract, Aloe vera skin-water extract, Aloe vera gel-70% EtOH extract and Aloe vera gel-water extract were 55%, 38%, 11% and 10%, respectively. In addition, 70% EtOH extract and water extract were compared with respect to SOD-like antioxidant activity of Aloe vera-70% EtOH extract has higher activity than Aloe vera water extract. Tyrosinase inhibition rate of Aloe vera gel extract was higher than Aloe vera skin extract. Alcohol dehydrogenase (ADH) and Acetaldehyde dehydrogenase (ALDH) relative percentage activity of Aloe vera gel extract were 126% and 216%, respectively. It was suggested that Aloe vera gel and skin extracts could be used as a functional biomaterial for functional food and cosmetics.

• Archives of Pharmacal Research
• /
• v.24 no.4
• /
• pp.276-280
• /
• 2001

Substituted isoquinolin-1-ones (1) were synthesized to test their in vitro anticancer activity. 3-Biphenyl-H-methylisoquinolin-1-one (7) showed the most potent anticancer activity against five different human cancer cell lines.