The composition and antioxidative properties of crude phlorotannins isolated from Japanese Eisenia and Ecklonia species including cultured E. kurome were analyzed. As a result of liquid chromatography mass spectrometry analysis, it was suggested that the phlorotannins were composed of compounds containing 3 - 7 phloroglucinol units for Eisenia species and 3 - 8 phloroglucinol units for Ecklonia species. The antioxidant properties of phlororannins were evaluated using the hydrophilic oxygen radical absorbance capacity (H-ORAC) assay, the measurements of superoxide anion radical scavenging activity (SOSA) with electron spin resonance method, and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reducing power assay. It was clarified that the phlorotannins contained H-ORAC values of 8.9 × 103 - 1.0 × 104 µmol-Trolox equivalents (TE)/g, SOSA of 1.5 × 104 - 2.9 × 104 superoxide dismutase units/g, DPPH radical scavenging activity of 4.7 × 103 - 5.5 × 103 µmol-TE/g, and reducing power of 6.5 × 102 - 7.0 × 102 mg-ascorbic acid equivalents/g, and had excellent antioxidative properties.
Shibata, T., Nagayama, K., Sugiura, S., Makino, S., Ueda, M., & Tamaru, Y. (2015). Analysis on Composition and Antioxidative Properties of Phlorotannins Isolated from Japanese Eisenia and Ecklonia Species. American Journal of Plant Sciences, 06(15), 2510–2521. https://doi.org/10.4236/ajps.2015.615253