tailieunhanh - Báo cáo khoa học: Unprecedented pathogen-inducible complex oxylipins from flax – linolipins A and B

Oxylipins constitute a large family of bioregulators, biosynthesized via unsaturated fatty acid oxidation. This study reports the detection of an unprecedented family of complex oxylipins from flax leaves. Two major members of this family, compounds1and2, were isolated and purified. Their structures were evaluated using NMR and MS analyses. | ỊFEBS Journal Unprecedented pathogen-inducible complex oxylipins from flax - linolipins A and B Ivan R. Chechetkin Fakhima K. Mukhitova Alexander S. Blufard Andrey Y. Yarin Larisa L. Antsygina and Alexander N. Grechkin Kazan Institute of Biochemistry and Biophysics Russian Academy of Sciences Russia Keywords divinylether synthase flax lipoxygenase cascade oxylipins pathogenesis Correspondence A. N. Grechkin Kazan Institute of Biochemistry and Biophysics Russian Academy of Sciences . Box 30 420111 Kazan Russia Fax 7 843 292 7347 Tel 7 843 231 9022 E-mail grechkin@ Website http eng Received 28 April2009 revised 28 May 2009 accepted 12 June 2009 Oxylipins constitute a large family of bioregulators biosynthesized via unsaturated fatty acid oxidation. This study reports the detection of an unprecedented family of complex oxylipins from flax leaves. Two major members of this family compounds 1 and 2 were isolated and purified. Their structures were evaluated using NMR and MS analyses. Both compounds were identified as monogalactosyldiacylglycerol species. Compound 1 contains one a-linolenoyl residue and one residue of 9Z 11E 1 Z 3 Z -12- 1 3 -hexadienyloxy -9 11-dodecadienoic ro5Z -etherolenic acid at positions sn-1 and sn-2 respectively. Compound 2 possesses ro5Z -etherolenic acid residues at both position sn-1 and position sn-2. We suggest the trivial names linolipin A and linolipin B for compounds 1 and 2 respectively and the collective name linolipins for this new family of complex oxylipins. The linolipin content of flax leaves increased significantly in response to pathogenesis. Thus accumulation of esterified antimicrobial divinyl ethers may be of relevance to plant defense. doi Introduction The lipoxygenase cascade and its product the oxylipins 1 2 including jasmonates 3-7 play important roles in plant signaling and defense. The primary lipoxygenase products fatty acid hydroperoxides .