• Journal of Applied Biological Chemistry
• /
• v.66
• /
• pp.1-6
• /
• 2023

Dendranthema zawadskii is a one of the popular plants as native in South Korea. In this study, linarin was isolated and purified using silica-gel, Diaion, and Sephadex LH-20 from the aerial parts of D. zawadskii. The chemical structure was completely identified through spectroscopic data including 1D, 2D nucleic magnetic resonance, and HRFABMS. Furthermore, linarin inhibited the bacterial neuraminidase (BNA) activity with 13.5 μM of IC₅₀ dose-dependently. Through the enzyme kinetic experiments, linarin as BNA inhibitor exhibited a typical noncompetitive inhibition mode which K_m was contestant and V_max decreased as the concentration of the inhibitor increased. It was further identified that the inhibition constant was 16.0 μM. Linarin was the most abundance metabolite in the aerial part of D. zawadskii extract by UHPLC-TOF/MS analysis. Therefore, D. zawadskii and its main component are expected that it can be effectively used for the infection and inflammation caused by bacteria.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.2
• /
• pp.345-348
• /
• 2002

A rapid spectrophotometric method for detecting the mucinase complex was developed. Bovine submaxillary mucin is cleaved by commercial mucinase between the oligosaccharide chain and the side chain of peptide linkage, thereby liberating the N-acetyl neuraminic acid (NANA). The release of NANA resulted in an increase of absorbance at 280 nm. The susceptibility to NANA by the new method was found to be at least 10-fold more sensitive than the thiobarbituric acid method. Moreover, the quantification of NANA released from mucin by commercial neuraminidase and partially purified Vibrio parahaemolyticus mucinase showed a good linear correlation in proportion to the concentration of the enzyme used. These results demonstrate that the rapid identification of mucin degradation can be determined by a spectrophotometric assay, thereby providing a new, fast, and sensitive method for assaying the bacterial mucinase complex.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.6
• /
• pp.863-868
• /
• 2004

Lectin activities and chemical characteristics of Escherichia coli, Lactobacillus spp. and Bifidobacterium spp. originating from the porcine cecal mucosal layer were studied based on hemagglutination assay (HA) and hemagglutination inhibition assay (HIA). Although all the bacterial strains were able to agglutinate erythrocytes of porcine or rabbit origin, much higher HA titers were consistently observed for Lactobacillus spp. than for E. coli or for Bifidobacterium spp. A remarkable reduction in HA titers occurred by the treatment of E. coli and Lactobacillus spp. with protease or trypsin and of Bifidobacterium spp. with protease, trypsin or periodate. There were no significant effects on the HA titers of the three groups of bacteria after the treatment with lipase. Hemagglutination of E. coli was strongly inhibited by D (+)-mannose and D (+)-galactose; Lactobacillus spp. by $\alpha$-L-rhamnose and methyl-$\beta$-galactopyranoside; Bifidobacterium spp. by D (+)-alactose, $\alpha$-L-rhamnose, $\alpha$-L-fucose, L (+)-arabinose, D (+)-mannose, D (-)-fructose at a relatively low concentration (1.43 to 3.75 mg/ml). These results, combined with the enhanced HA activities of the three bacterial strains by modification of rabbit erythrocytes with neuraminidase and abolished HA activity of E. coli after treatment with $\beta$-galactosidase, indicate that it might be the glycoproteinous substances surrounding the surface of the bacterial cells that are responsible for the adhesions of these microorganisms by recognizing the specific receptors on the red blood cell.