sepharose and 3-6-anhydrogalactose

Agarose is a linear polysaccharide composed of D-galactose and 3,6-anhydro-L-galactose (AHG). It is a major component of the red algal cell wall and is gaining attention as an abundant marine biomass. However, the inability to ferment AHG is considered an obstacle in the large-scale use of agarose and could be addressed by understanding AHG catabolism in agarolytic microorganisms. Since AHG catabolism was uniquely confirmed in

Topics: Aldehydes; Bacterial Proteins; Galactose; Hydrogen-Ion Concentration; Iron; Metabolic Networks and Pathways; NADPH Dehydrogenase; Racemases and Epimerases; Recombinant Proteins; Rhodophyta; Sepharose; Streptomyces coelicolor; Substrate Specificity; Temperature

3,6-Anhydro-l-galactose (l-AHG), a major component of agarose derived from red macroalgae, has excellent potential for industrial applications based on its physiological activities such as skin whitening, moisturizing, anticariogenicity, and anti-inflammation. However, l-AHG is not yet commercially available due to the complexity, inefficiency, and high cost of the current processes for producing l-AHG. Currently, l-AHG production depends on a multistep process requiring several enzymes. Here, we designed and tested a novel two-step process for obtaining high-titer l-AHG by using a single enzyme. First, to depolymerize agarose preferentially into agarobiose (AB) at a high titer, the agarose prehydrolysis using phosphoric acid as a catalyst was optimized at a 30.7% (w/v) agarose loading, which is the highest agarose or agar loading reported so far. Then AB produced by the prehydrolysis was hydrolyzed into l-AHG and d-galactose (d-Gal) by using a recently discovered enzyme, Bgl1B. We suggest that this simple and efficient process could be a feasible solution for the commercialization and mass production of l-AHG.

Topics: Bacterial Proteins; Biocatalysis; Biotechnology; Disaccharides; Galactose; Gammaproteobacteria; Glycoside Hydrolases; Molecular Conformation; Plant Extracts; Rhodophyta; Seaweed; Sepharose

Topics: Animals; Cell Line, Tumor; Cell Proliferation; Disaccharidases; Epidermal Cells; Epidermis; Galactose; Galactosides; Glycoside Hydrolases; Humans; Melanins; Melanocytes; Mice; Oligosaccharides; Rhodophyta; Seaweed; Sepharose; Skin Lightening Preparations; Skin Pigmentation; Structure-Activity Relationship

Commercial kappa- and iota carrageenans were cationized with 3-chloro-2-hydroxypropyltrimethylammonium chloride in aqueous sodium hydroxide solution. For kappa-carrageenan three derivatives with different degrees of substitution were obtained. Native and amphoteric kappa-carrageenans were characterized by NMR and infrared spectroscopy, scanning electron and atomic force microscopy; methanolysis products were studied by electrospray ionization mass spectrometry. Young moduli and the strain at break of films, differential scanning calorimetry, rheological and flocculation behavior were also evaluated; the native and the amphoteric derivatives showed different and interesting properties. Cationization of iota-carrageenan was more difficult, indicating as it was previously observed for agarose, that substitution starts preferentially on the 2-position of 3,6-anhydrogalactose residues; in iota-carrageenan this latter unit is sulfated.

Topics: Carrageenan; Cations; Elastic Modulus; Galactose; Magnetic Resonance Spectroscopy; Microscopy, Atomic Force; Polysaccharides; Propanols; Quaternary Ammonium Compounds; Rheology; Sepharose; Spectrometry, Mass, Electrospray Ionization

3,6-Anhydro-L-galactose (L-AHG) constitutes 50% of agarose, which is the main component of red macroalgae. No information is currently available on the mass production, metabolic fate, or physiological effects of L-AHG. Here, agarose was converted to L-AHG in the following three steps: pre-hydrolysis of agarose into agaro-oligosaccharides by using acetic acid, hydrolysis of the agaro-oligosaccharides into neoagarobiose by an exo-agarase, and hydrolysis of neoagarobiose into L-AHG and galactose by a neoagarobiose hydrolase. After these three steps, L-AHG was purified by adsorption and gel permeation chromatographies. The final product obtained was 95.6% pure L-AHG at a final yield of 4.0% based on the initial agarose. In a cell proliferation assay, L-AHG at a concentration of 100 or 200 μg/ mL did not exhibit any significant cytotoxicity. In a skin whitening assay, 100 μg/ mL of L-AHG showed significantly lower melanin production compared to arbutin. L-AHG at 100 and 200 μg/ mL showed strong anti-inflammatory activity, indicating the significant suppression of nitrite production. This is the first report on the production of high-purity L-AHG and its physiological activities.

Topics: Acetic Acid; Animals; Anti-Inflammatory Agents; Cell Line; Cell Proliferation; Cell Survival; Disaccharidases; Galactose; Glycoside Hydrolases; Hydrolysis; Macrophages; Melanins; Melanocytes; Mice; Sepharose; Skin Lightening Preparations