- Toxic effects of Gymnodinium cf. mikimotoi unsaturated fatty acids to gametes and embryos of the sea urchin Paracentrotus lividus
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The toxicity of the main Gymnodinium cf. mikimotoi polyunsaturated fatty acid, has been investigated using the sea urchin gamete and embryo bioassays. The 18:5n3 fatty acid delays or inhibits first cleavage of Paracentrotus lividus eggs and provokes abnormalities in the embryonic development. These effects were compared with those of other polyunsaturated fatty acids, 18:4n3, 20:5n3 and 22:6n3, which are also present in this alga. A classification of the different fatty acids, based on their effects on sea urchin egg cleavage and the determination of the half inhibiting concentrations (IC50) is proposed. Copyright (C) 1999 Elsevier Science Ltd. The toxicity of the main Gymnodinium cf. mikitomoi polyunsaturated fatty acid, has been investigated using the sea urchin gamete and embryo bioassays. The 18:5n3 fatty acid delays or inhibits first cleavage of Paracentrotus lividus eggs and provokes abnormalities in the embryonic development. These effects were compared with those of other polyunsaturated fatty acids, 18:4n3, 20:5n3 and 22:6n3, which are also present in this alga. A classification of the different fatty acids, based on their effects on sea urchin egg cleavage and the determination of the half inhibiting concentrations (IC50) is proposed.
- Sellem, Fériel,Pesando, Danielle,Bodennec, Guy,El Abed, Amor,Girard, Jean-Pierre
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- Control Mechanism for Carbon-Chain Length in Polyunsaturated Fatty-Acid Synthases
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Polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are essential fatty acids. PUFA synthases are composed of three to four subunits and each create a specific PUFA without undesirable byproducts. However, detailed biosynthetic mechanisms for controlling final product profiles have been obscure. Here, the bacterial DHA and EPA synthases were carefully dissected by in vivo and in vitro experiments. In vitro analysis with two KS domains (KSA and KSC) and acyl-acyl carrier protein (ACP) substrates showed that KSA accepted short- to medium-chain substrates while KSC accepted medium- to long-chain substrates. Unexpectedly, condensation from C18 to C20, the last elongation step in EPA biosynthesis, was catalyzed by KSA domains in both EPA and DHA synthases. Conversely, condensation from C20 to C22, the last elongation step for DHA biosynthesis, was catalyzed by the KSC domain in DHA synthase. KSC domains therefore determine the chain lengths.
- Hayashi, Shohei,Naka, Mai,Ikeuchi, Kenshin,Ohtsuka, Makoto,Kobayashi, Kota,Satoh, Yasuharu,Ogasawara, Yasushi,Maruyama, Chitose,Hamano, Yoshimitsu,Ujihara, Tetsuro,Dairi, Tohru
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p. 6605 - 6610
(2019/04/17)
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- ALL-CIS-3,6,9,12,15-OCTADECAPENTAENOIC ACID FROM THE UNICELLULAR ALGA GYMNODINIUM KOWALEVSKII
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All-cis-3,6,9,12,15-octadecapentaenoic acid (18:5n-3) was isolated from total lipids of the cultivated microalga Gymnodinium kowalevskii.Its structure was confirmed by GC-MS, 1HNMR, IR and synthesis using a modified method of iodolactonization from 22:6n-3. Key Word Index - Gymnodinium kowalevskii; Gymnodiniaceae; unicellular algae; marine lipids; octadecapentaenoic acid; synthesis.
- Kuklev, D. V.,Aizdaicher, N. A.,Imbs, A. B.,Bezuglov, V. V.,Latyshev, N. A.
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p. 2401 - 2404
(2007/10/02)
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