| Biofouling, which causes large problems during the exploration of the ocean, is the accumulation of living organisms by adhesion, growth and reproduction. The traditional antifouling agents such as tributyltin and cuprous oxide was widely used, but at the same time they bring serious calamity to marine ecological environment. Due to the environmental pressure caused by TBT, in 2008 the International Maritime Organization (IMO) banned the use of triorganotin-based paints worldwide. So it is an agent problem to develop the low toxicity, environmental friendly antifouling agent. Among these investigations, marine natural products have been highlighted as promising environmental friendly antifoulants.Marine algae which have been widely used in food, medicine and other fields are the primary producers in the ocean. Now people attach much important to the marine antifouling research of marine algae. In this paper we selected laminaria and Kjellmaniella crassifolia. belonging to Phaeophyceae, as the raw materials. We first extract and separate the bioactive substance from the tow algae respectively. And then we evaluated their antifouling properties against diatom Skeletonema costatum and barnacle larval Chthamalus challengeri. At last those antifouling substances’ structures were identified. The main conclusions of this paper were listed as follows:The laminaria "sanhai", belonging to Phaeophyceae, Laminariales, Laminariaceae, Saccharina, was achieved by artificial breeding with excellent qualities, and it was widely planted in China and commercially available. Firstly, ethanol, methylene chloride and other organic solvent were used in the crude extraction (crude extract A and B). And then solid-phase extraction and liquid-liquid extraction were used in the next separation and purification (purification C and D). Anti-alga test was followed after every crude extraction and purification in order to find out the best antifoulant of the laminaria. At last the best antifouling substances were crude extract B and purification D. The 96h-EC50 and 24h-LC50 values of crude extract B of laminaria "sanhai" against diatom (Skeletonema costatum) and barnacle larval (Chthamalus challengeri) were 8.9μg·mL-1 and 12.0μg·mL-1 respectively. The antialgal and antilarval activities of purified fraction D was improved with the 96h-EC50 value of 7.4μg·mL-1 against S.costatum and 24h-LC50 value of 9.7μg·mL-1 against C.challengeri larvae. Identification by IR, Q-TOFMS and GC-MS of the isolated bioactive substances revealed the abundance of fatty acids, such as hexadecanoic acid, octadecanoic acid, octadecenoic acid and so on.Kjellmaniella crassifolia belonging to Phaeophyceae, Laminariales, Laminariaceae, was achieved by artificial breeding with excellent qualities, and it distributed in southern Japan Hokkaido hakodate and muroran coastal area. The application value of Kjellmaniella crassifolia is very high, but until now the study about its antifouling is little. So in this paper, we first make crude extraction of Kjellmaniella crassifolia to get crude extraction A and B. Then we used column chromatography to make further separation to get 9 kinds of chromatographic components. Anti-alga test was throughout the whole experiment. At last we find out the crude extract B and chromatographic components F of Kjellmaniella crassifolia have the best antifouling abulities. The 96h-EC50 and 24h-LC50 values of crude extract B of Kjellmaniella crassifolia against S. costatum and C. challenger larvae were 17.3μg·mL-1 and 16.1μg·mL-1 respectively. The antialgal and antilarval activities of chromatographic components F was better with the 96h-EC50 value of 10.3μg·mL-1 against S.costatum and 24h-LC50 value of 11.9μg·mL-1 against C.challengeri larvae. Those antifouling substances were finally identified as fatty acids compounds, including myristic acid, hexadecanoic acid, octadecenoic acid etc.The results of the investigation showed that both the laminaria and Kjellmaniella crassifolia have secondary metabolite with antifouling abilities. Those bioactive substances were identified as a serious of fatty acids compounds, such as myristic acid, hexadecanoic acid, octadecenoic acid. Those antifouling substances are expected to be environmental friendly antifouling agent. |
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