MYRIOPHYLLUM SPICATUM-RELEASED ALLELOPATHIC POLYPHENOLS INHIBITING GROWTH OF BLUE-GREEN ALGAE MICROCYSTIS AERUGINOSA

摘要

A culture solution of macrophyte Myriophyllum spicatum was subjected to algal assay- directed fractionation on the basis of polarity and molecular weight. As the water-soluble fraction below molecular weight l000 was the only fraction to inhibit the growth of blue-green algae Microcystis aeruginosa, it was analyzed by analytical high--performance liquid chromatography (HPLC) and atmospheric pressure chemical ionization mass spectrometry (APCl-MS) in order to identify M. spicatum-released growth-inhibiting allelochemicals. Both HPLC and APCl-MS revealed the release of four polyphenols exhibiting growth inhibition effects, i.e., ellagic, gallic and pyrogallic acids and (+)- catechin. A quantitative investigation of their respective inhibitory effects showed that gallic and pyrogallic acids are more inhibitory than (+)--catechin and ellagic acid, and that the autoxidized products of each polyphenol demonstrated growth inhibjtion. Finally, when the collective activity of a mixture of the polyphenols was examined. synergistic growth inhibition of M. aeruginosa occurred.