title: Isolation and structure determination of algicidal compounds from Ulva fasciata.
abstract: 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.
authors.affiliation: Graduate School of Science and Technology, Nagasaki University, Japan.
authors.forename: Mochammad Amin
authors.initials: MA
authors.lastname: Alamsjah
authors.forename: Shotaro
authors.initials: S
authors.lastname: Hirao
authors.forename: Fumito
authors.initials: F
authors.lastname: Ishibashi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Fujita
mesh_terms: 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
chemical_list: D005231:Fatty Acids, Unsaturated; C114465:hexadecatetraenoic acid; D017962:alpha-Linolenic Acid; C013641:parinaric acid