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Incheon, South Korea

Seo Y.C.,Kangwon National University | Choi W.S.,Kangwon National University | Park J.H.,Daebong LS Ltd | Park J.O.,Daebong LS Ltd | And 2 more authors.
International Journal of Molecular Sciences | Year: 2013

A method for stably purifying a functional dye, phycocyanin from Spirulina platensis was developed by a hexane extraction process combined with high pressure. This was necessary because this dye is known to be very unstable during normal extraction processes. The purification yield of this method was estimated as 10.2%, whose value is 3%-5% higher than is the case from another conventional separation method using phosphate buffer. The isolated phycocyanin from this process also showed the highest purity of 0.909 based on absorbance of 2.104 at 280 nm and 1.912 at 620 nm. Two subunits of phycocyanin namely α-phycocyanin (18.4 kDa) and β-phycocyanin (21.3 kDa) were found to remain from the original mixtures after being extracted, based on SDS-PAGE analysis, clearly demonstrating that this process can stably extract phycocyanin and is not affected by extraction solvent, temperature, etc. The stability of the extracted phycocyanin was also confirmed by comparing its DPPH (α,α-diphenyl-β-picrylhydrazyl) scavenging activity, showing 83% removal of oxygen free radicals. This activity was about 15% higher than that of commercially available standard phycocyanin, which implies that the combined extraction method can yield relatively intact chromoprotein through absence of degradation. The results were achieved because the low temperature and high pressure extraction effectively disrupted the cell membrane of Spirulina platensis and degraded less the polypeptide subunits of phycocyanin (which is a temperature/pH-sensitive chromoprotein) as well as increasing the extraction yield. © 2013 by the authors; licensee MDPI, Basel, Switzerland. Source

Bae J.Y.,Seoul National University of Science and Technology | Jang H.N.,Seoul National University of Science and Technology | Ha J.H.,Seoul National University of Science and Technology | Park J.-H.,Daebong LS Ltd | And 2 more authors.
Korean Journal of Microbiology and Biotechnology | Year: 2014

In this study, Glycyrrhiza uralensis and Glycyrrhiza glabra extracts, with their countries of origin as Korea (Jecheon), Uzbekistan and China, were prepared under various extraction conditions. There were 8 extraction conditions which the licorice were subjected to, and all conditions had different extraction solvents, temperatures and times. Antimicrobial activity on skin flora was evaluated comparatively by a disc diffusion assay, broth macrodilution assay, and kill time curve assay Based on the antimicrobial activity of their extract confirmed by disc diffusion assay, we established optimal extraction conditions The Korean licorice extract (85% ethanol, 40°C, 12 h) showed the best activity amongst the samples examined. In particular, its antimicrobial activity against Propionibacterium acnes was the highest Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of the licorice extracts revealed that the Korean licorice (156 |ug/ml and 1,250 ng/ml) had better antimicrobial activity than that of the Uzbekistani licorice (625 ng/ml and 2,500 ng/ml) and the Chinese licorice (625 ng/ml and 5,000 ng/ml) Taken together, it was shown that Korean licorice extracted in group F (85% ethanol, 40°C, 12 h) had the highest antimicrobial activity amongst the licorices from the other countries of origin. These results also suggest that the optimal extraction conditions are 85% ethanol, 40°C, 12 h, and that licorice has a potential application as a natural preservative in cosmetics products, thereby replacing synthetic preservatives. © 2014, The Korean Society for Microbiology and Biotechnology. Source

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