ISOLATION AND STRUCTURE OF PHYSIOLOGICALLY ACTIVE SUBSTANCES OF ALGAE.

从褐藻（Cladosiphon okamuranus）甲醇提取物中分离出一种化感物质。采用生物定量法对活性物质的提取和纯化过程进行了监测，测定了活性物质对紫斑卟啉（Porphyra yezoensis）和赤石斑麻（Hetesigma akashhiwo）贝壳孢子的抑制作用。化合物经鉴定为6Z、9Z、12Z、15z -十八十四烯酸，并对36种微藻进行了抑菌活性试验。许多真核生物在5ppm时受到影响，但原核生物在25ppm时不受影响。四不饱和脂肪酸以1ppm的浓度杀灭有毒的红潮浮游生物，如古查通菌。

An allelopathic substance was isolated from the methanol extract of the brown alga, Cladosiphon okamuranus. Extraction and purification of the active substance was monitored by bioassys against the conchospores of Porphyra yezoensis and Hetesigma akashiwo. The compound was identified as 6Z,9Z,12Z,15Z-octadecatetraenoic acid and its activity was then tested against 36 species of microalgae. Many of eukaryotes tested were affected at 5 ppm, but prokaryotes were unaffected at 25 PPM. The tetraunsturated fatty acid exterminated toxic red tide planktons such as Chattonella antiqua at 1 ppm concentration.