Isolation and structure determination of algicidal compounds from Ulva fasciata.
Thirty-seven species of seaweeds including 10 Chlorophyta, 13 Phaeophyta, and 14 Rhodophyta collected from the coast of Nagasaki Prefecture, Japan, were screened for algicidal activity against the red-tide phytoplankton Heterosigma akashiwo. The green alga Ulva fasciata (Ulvaceae, Chlorophyta) showed the strongest algicidal activity among the seaweeds tested. Bioassay-guided fractionation of the methanol extract of U. fasciata led to isolation of three algicidal compounds whose structures were determined to be hexadeca-4,7,10,13-tetraenoic acid (HDTA), octadeca-6,9,12,15-tetraenoic acid (ODTA), and alpha-linolenic acid on the basis of spectroscopic information. These polyunsaturated fatty acids (PUFAs) showed potent algicidal activity against H. akashiwo (LC(50) 1.35 microg/ml, 0.83 microg/ml, and 1.13 microg/ml for HDTA, ODTA, and alpha-linolenic acid, respectively), and the result demonstrated the potential of these PUFAs for practical harmful algal bloom control.
Alamsjah
Mochammad Amin
MA
Graduate School of Science and Technology, Nagasaki University, Japan.
Hirao
Shotaro
S
Ishibashi
Fumito
F
Fujita
Yuji
Y
D000460:Chlorophyta / Q000737:chemistry; D005231:Fatty Acids, Unsaturated / Q000302:isolation & purification* / Q000494:pharmacology*; D010839:Phytoplankton / Q000187:drug effects*; D012624:Seaweed / Q000737:chemistry; D044445:Ulva / Q000737:chemistry*; D017962:alpha-Linolenic Acid / Q000302:isolation & purification / Q000494:pharmacology
D005231:Fatty Acids, Unsaturated; C114465:hexadecatetraenoic acid; D017962:alpha-Linolenic Acid; C013641:parinaric acid