Extraction And Separation Of The Total Pigment In The Seaweed And Brown Algae Flavin And Its Biological Activity Study

Pigment is closely related to human life, and the use of it is becoming more and more widespread. But in recent years, with the medical toxicology and biological experiments of synthetic colorings studied, people found that synthetic colorings can produce toxic effects in the human metabolic process and potentially carcinogenic and other toxic side effects. This made the application species of synthetic colorings rapidly declined and the scope of application strictly limited. At the same time, natural pigment industry is rebounding, showing a new strong development momentum; natural pigments instead of synthetic colorings in the food, cosmetics and pharmaceuticals as a coloring agent has now become the inevitable trend of development.For the current, the research and development of natural pigments mainly concentrate in the terrestrial plants, while the applications of pigments in seaweed are much less. China has a rich resources of Laminaria japonica, so this paper took Laminaria japonica as the material for the study of total pigments extraction , the separation of fucoxanthin, and the biological activity of total pigments.The Pigments in Laminaria japonica was extracted with six organic solvents and analyzed in spectroscopy analysis. The extractions conditions were screened by an orthogonal test and the quantity of extracted pigments were determined spectroscopically. The results show that: (1) among the six organic solvents, acetone was the most effective one for the extraction; (2) the optimum extraction conditions were as follows: the ratio of S/M (solvent volume/ material weight) was 30ml/g; fresh seaweed was extracted 2 times in 2 hours; (3) the average total content of pigments was 1.85 mg/g (calculated with dry L. japonica).The separation of fucoxanthin was carried out by the method of silica gel column chromatography. The pigment extraction was loaded into a silica gel column and purified twice with the mobile phase of hexane/ethyl acetate (1:2, v/v) and chloroform/acetone (12:1, v/v) separately. One of the bright yellow pigment was presumed to be fucoxanthin based on its typical UV-vis spectrum.The radical scavenging activity of Laminaria japonica pigments was studied by the DPPH(2,2-Diphenyl^-1-picrylhydrazyl)assay. The total pigments showed a strong DPPH radical scavenging activity of 65.819% with the concentration of 0.52mg.ml^-1 . The DPPH radical scavenging activity of fucoxanthin was 19.85% with the concentration of 0.27mg.ml^-1.The antimicrobial activity of pigment in Laminaria japonica was studied by the method of round paper. The results showed that the pigment extracts have activity against Escherichia coli, Pseudomonas aeruginosa, Saricina flava and Saccharomyes cerevisia. The antibacterial activity of total pigments for Saccharomyes cerevisia was the strongest with an inhibition diameter of 18.9 mm; and the antibacterial activity of fucoxanthin for Saricina flava was also much significant with an inhibition diameter of 10.2 mm. In the same concentration, the antibacterial activity of total pigment was much more significantly than fucoxanthin. It seemed that there were also other kind of pigments with much stronger antibacterial activity in Laminaria japonica.