A type of tannin usually found in brown algae such as kelps and rockweeds. Unlike the hydrolysable or condensed tannins, these compounds are oligomers of phloroglucinol.
| Member | Definition | Role |
|---|
| 6,6'-bieckol | A phlorotanin that is 1,1'-bioxanthrene substituted by 3,5-dihydroxyphenoxy groups at position 6 and 6' and hydroxy groups at positions 2, 2', 4, 4', 7, 7', 9 and 9' respectively. It is isolated from an edible marine brown alga Ecklonia cava and exhibits antioxidant activity. | 6,6'-bieckol |
| 7-phloroeckol | A phlorotannin that is eckol in which the hydroxy group at position 7 is replaced by a 2,4,6-trihydroxyphenoxy group. Isolated from the marine brown alga, Ecklonia cava, it exhibits antioxidant activity. | 7-phloroeckol |
| dieckol | A phlorotannin isolated from a brown alga Ecklonia cava which exhibits antioxidant, hepatoprotective and anticoagulant activities. | dieckol |
| eckol | A phlorotannin that is oxanthrene-1,3,6,8-tetrol substituted by a 3,5-dihydroxyphenoxy moiety at position 4. Isolated from the marine brown alga, Ecklonia cava, it exhibits antioxidant activity. | eckol |
| eckstolonol | A phlorotannin that is [1,4]benzodioxino[2,3-a]oxanthrene substituted by hydroxy groups at positions 1, 3, 6, 9 and 11. Isolated from the brown alga Ecklonia stolonifera, it exhibits radical scavenging activity. | eckstolonol |