110567-68-5Relevant articles and documents
Algicidal hydroxylated C18 unsaturated fatty acids from the red alga Tricleocarpa jejuensis: Identification, synthesis and biological activity
Ishibashi, Fumito,Kuwano, Kazuyoshi,Shibahara, Tomohiro,Zha, Shijiao
, (2020/06/05)
Bioassay-guided separation of a methanol extract of Tricleocarpa jejuensis by monitoring algicidal activity against the red tide phytoplankton Chattonella antiqua led to the isolation of an active fraction consisting of a mixture of four isomeric compounds. The active compounds were identified as (E)-9-hydroxyoctadec-10-enoic acid (1), (E)-10-hydroxyoctadec-8-enoic acid (2), (E)-11-hydroxyoctadec-12-enoic acid (3) and (E)-12-hydroxyoctadec-10-enoic acid (4) by NMR, IR and mass spectral data. The structures were confirmed by comparison of the NMR and MS data with those of authentic samples of 1–4 obtained by unambiguous syntheses. Synthesized hydroxy acids 1–4 and related compounds were assessed for algicidal activity against C. antiqua and it was found that all of 1–4 had high activity (>80% mortality at 24 h) at a concentration of 20 μg/mL. A structure–activity relationship study using 11 related compounds revealed that the presence of the hydroxyl group is important for the activity and the double bond may be replaced with a triple bond.
Allylic Mono- and Di-hydroxylation of Isolated Double Bonds with Selenium Dioxide-tert-Butyl Hydroperoxide. NMR Characterization of Long-chain Enols, Allylic and Saturated 1,4-Diols, and Enones
Knothe, Gerhard,Bagby, Marvin O.,Weisleder, David,Peterson, Robert E.
, p. 1661 - 1670 (2007/10/02)
Selenium dioxide with tert-butyl hydroperoxide as re-oxidant was used in the allylic hydroxylation of isolated double bonds in straight-chain hydrocarbons.This was shown for mono-unsaturated fatty acids, esters and alcohols.Either allylic position was hydroxylated individually or both positions reacted to give dihydroxy isomers, affording numerous novel hydroxy compounds.Yields of monohydroxy compounds in which the OH group is between the double bond and C-1 were usually higher than those in which the OH group is between the double bond and the methyl terminus.Monohydroxy products were used as starting material in subsequent allylic hydroxylation reactions to increase the yield of dihydroxy product, although this reaction is slow.Coinciding with the known mechanism, cis double bonds of starting materials isomerized nearly quantitatively to trans double bonds in the products while trans double bonds did not isomerize.Resonance differences of the olefinic carbons in 13C NMR of the unsaturated monohydroxy compounds show on which side of the double bond the hydroxy group is located.The magnitude of these differences depends on the nature of the group at C-1 and the distance of the double bond from C-1.Corresponding saturated hydroxy fatty acids were synthesized with the hydrazine-air system. 13C-NMR of the saturated compounds showed that the dihydroxy products were erythro/threo diastereoisomers.With this assignment, 1H NMR of the unsaturated allylic dihydroxy compounds may be used to distinguish these diastereoisomers.The olefinic protons of the erythro dihydroxy diastereoisomer resonate downfield from those of the threo form.The threo diastereoisomers are formed in higher yields than theirerythro counterparts.Compounds with allylic keto group (enones) analogous to the monohydroxy products arose as side products.The 13C NMR spectra of these enones are discussed.
