Extraction Improvement of the Bioactive Blue-Green Pigment "Marennine" from Diatom 's Blue Water: A Solid-Phase Method Based on Graphitic Matrices.
William Bélanger, Alexandre A Arnold, François Turcotte, Richard Saint-Louis, Jean-Sébastien Deschênes, Bertrand Genard, Isabelle Marcotte, Réjean Tremblay
Author Information
William Bélanger: Institut des Sciences de la mer, Université du Québec à Rimouski, 310 des Ursulines, Rimouski, QC G5L 3A1, Canada.
Alexandre A Arnold: Department of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Downtown Station, Montreal, QC H3C 3P8, Canada.
François Turcotte: Institut des Sciences de la mer, Université du Québec à Rimouski, 310 des Ursulines, Rimouski, QC G5L 3A1, Canada.
Richard Saint-Louis: Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, 300 des Ursulines, Rimouski, QC G5L 3A1, Canada.
Jean-Sébastien Deschênes: Département de Mathématiques, Informatique et Génie, Université du Québec à Rimouski, 300 des Ursulines, Rimouski, QC G5L 3A1, Canada.
The compound "marennine" is a blue-green pigment produced by the benthic microalgae , with pathogenicity reduction activities against some bacteria and promising potential as a natural pigment in seafood industries. After decades of research, the chemical family of this compound still remains unclear, mainly because structural studies were impaired by the presence of co-extracted compounds in marennine isolates. To improve the purity of marennine extract, we developed a novel extraction method using a graphitic stationary phase, which provides various advantages over the previous procedure using tandem ultrafiltration. Our method is faster, more versatile, provides a better crude yield (66%, compared to 57% for ultrafiltration) and is amenable to upscaling with continuous photobioreactor cultivation. Our goal was to take advantage of the modulable surface properties of the graphitic matrix by optimizing its interactions with marennine. As such, the effects of organic modifiers, pH and reducing agents were studied. With this improvement on marennine purification, we achieved altogether the isolation of a fucoidan-related, sulfated polysaccharide from blue water. Characterization of the polysaccharides fraction suggests that roughly half of UV-absorbing compounds could be isolated from the marennine crude extracts. The identification of sulfated polysaccharides could be a major breakthrough for marennine purification, providing targeted isolation techniques. Likewise, the added value of and the role of polysaccharides in previous marennine chemical characterization and bioactivity studies remain to be determined.
