Investigation of functional constituents derived from seaweeds around Hokkaido and establishment of their analytical methods × SDGs
In order to utilize marine products as food and chemical products, it is necessary to search for unknown components with human health-beneficial functions and establish new simple and versatile methods for analysis of functional components. Especially, establishment of the methods lead to innovate industrial quality control of food and chemical products. I hope to contribute to the SDGs (9 INDUSTRY, INNOVATION AND INFRASTRUCTURE and 12 RESPONSIBLE CONSUMPTION AND PRODUCTION).
The research is conducted on chemical constituents of seaweeds around Hokkaido, one of the world‘s leading area of seaweed species and biomass. In the concrete, my group searches functional constituents expected to be good for human health and seafood safety, and determines their structures and functions. In addition, my group establishes new analytical methods for quantification of functional constituents in order to develop useful methods for human and seafood industries.
Functional Constituents derived from seaweeds
My research group has investigated to obtain and identify enzyme inhibitors derived from low-available seaweeds collected around Hokkaido, as functional constituents. We separate pure functional compounds by using various techniques and determine their structures by instrumental analyses. Seaweeds do not move by themselves like land plants and microorganisms. So they synthesize and use various compounds as self-protection and communication tools. Among these compounds, we aim to find new compounds that are useful for humans and seafood industry.
The enzymes targeted for research include α-glucosidase related to postprandial hyperglycemia, β-glucuronidase related to delayed excretion of xenobiotics, glucosidase 6-phosphate dehydrogenase related to production of bioreductants and nucleic acid constituent sugars, xanthine oxidase related to uric acid production, lipoxygenase related to inflammation, and tyrosinase involved in blackening of shrimp and crabs. We are searching for substances that inhibit their function.
We collect seaweeds by ourselves in various areas of Hokkaido. Return to the lab and create an extraction product (extraction) using organic solvent. The extract is screened by enzyme inhibition tests. The inhibitors are separated by various chromatographic techniques to obtain pure inhibitors. They are analyzed by various instruments to determine the structure.
A series of bromophenols were obtained from the seaweeds belonging to red algae of the family Rhodomelaceae. In addition, phlolotannins, alkapolyenes, and chlorophyll-related compounds were obtained from the seaweeds as lipoxygenase inhibitors.
You can collect seaweeds yourself in the future and disclose new compounds
Development of quantification methods for seaweed polysaccharides, especially fucoidan
Among seaweeds, brown algae, including Kombu (sea tangle) and Wakame (sea mustard), contain laminaran, fucoidan, and alginic acid as polysaccharides. These polysaccharides have already been reported for various functions and are known as health-benefitial effects for humans. However, while it says, "How much of these polysaccharides are in seaweed?" there is no easy way to determine how much they are in the seaweed. This is partly due to the complex structure of fucoidan, which shows chemical variety of fucoidan depending on the type of seaweed.
For this purpose, we are developing a new method to easily measure the amount of laminaran, fucoidan, and alginic acid extracted from seaweeds. This method aims to establish a measurement method that can be used anywhere by using inexpensive measurement devices.
Since it is difficult to extract laminaran, fucoidan, and alginic acid separately from brown algae, we have studied a simple method to separate polysaccharides from seaweeds after extracting polysaccharide mixtures from seaweeds. Subsequently, we are developing a simple method for measuring the amount of polysaccharides in each polysaccharide fractions.
We have established a simple method for separation of polysaccharides by ion exchange. Research is currently underway to establish a method for easily measuring polysaccharides in separate segments.
Since we are not researching functions of polysaccharides, we are aiming to establish important analytical methods before use of their functions