Antialgal Activity of Glycoglycerolipids Derived from a Green Macroalgae <i>Ulva prolifera</i> on Six Species of Red Tide Microalgae

Abstract

1-O-palmitoyl -3-O-β-D-galactopyranosyl glycerol, 1-O-octadecanoic acid-3-O-β-D-galactopyranosyl glycerol, and 1-O-palmitoyl-2-O-oleoyl-3-O-β-D-galactopyranosyl glycerol were isolated from Ulva prolifera for the first time in our previous research. There are growth inhibiton of these three glycoglycerolipids against six species of red tide microalgae (Amphidinium carterae, Heterosigma akashiwo, Karenia mikimotoi, Phaeocystis globosa, Prorocentrum donghaiense, and Skeletonema costatum) investigated. Results showed that they have selective antialgal activity against six species of red tide microalgae, and antialgal activities against test red tide microalgae obviously enhanced with the increase of concentration of glycoglycerolipids. Among them, 1-O-octadecanoic acid-3-O-β-D-galactopyranosyl glycerol and 1-O-palmitoyl-2-O-oleoyl-3-O-β-D-galactopyranosyl glycerol exhibited more extensive antialgal activities, and the growth of Phaeocystis globosa, Prorocentrum donghaiense, and Skeletonema costatum (or Karenia mikimotoi, and Skeletonema costatum) was inhibited by these two glycoglycerolipids. Further, EC50-96h values of these three glycoglycerolipids for six red tide microalgae were obtained for the first time. By analyzing and comparing EC50-96h values, it has been determined that 1-O-octadecanoic acid-3-O-β-D-galactopyranosyl glycerol and 1-O-palmitoyl-2-O-oleoyl-3-O-γ-D-galactopyranosyl glycerol showed the superior application potential than potassium dichromate as a characteristic antialgal agent against Phaeocystis globosa; More importantly, 1-O-octadecanoic acid-3-O-β-D-galactopyranosyl glycerol exhibited the superior application potential than potassium dichromate and other reported compounds as a characteristic antialgal agent against Prorocentrum donghaiense.