Evaluation of Phylloquinone Content in 42 Species Algae Inhabiting the Japanese Coast and Relationship between Phylloquinone and Chlorophyll Contents

Terrestrial green plants are rich in phylloquinone (PK), and their PK content is highly correlated with the chlorophyll content. However, there are few studies on the PK content of algae and its correlation with chlorophyll content. To evaluate the PK content in algae and its correlation with chlorophyll, the PK and chlorophyll contents in algae, including Phaeophyta (18 species), Rhodophyta (17 species), and Chlorophyta (seven species), were determined. Algae, particularly Phaeophyta, contain more functional components than do other green terrestrial plants. Therefore, other components such as carotenoids, polyphenols, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability were analyzed to confirm their correlation with PK. Furthermore, terrestrial plants such as leafy vegetables, other vegetables, and tea powder were evaluated for the same components and compared with the experimental results for algae. This results showed that PK was abundant in Phaeophyta and almost all samples contained more than 100 μg/100 g of dry samples. In particular, Sargassum muticum contained 514.11±11.29 μg/100 g. However, almost all of the Rhodophyta and Chlorophyta contained a little PK. The results also confirmed a positive correlation between the PK and chlorophyll content in Rhodophyta (R²=0.7085), Chlorophyta (R²=0.7264), and terrestrial plants (R²=0.8436). However, no correlation was observed between the PK and chlorophyll content in Phaeophyta (R²=0.1013). In addition, the principal component analysis results showed no correlation between PK and other components, such as carotenoids and polyphenols, and DPPH radical scavenging ability in algae. However, Phaeophyta also contained more functional components, such as carotenoids, polyphenols, and DPPH radical scavenging ability than the other algal groups.