5503-03-7Relevant academic research and scientific papers
Linolenate 9R-dioxygenase and allene oxide synthase activities of lasiodiplodia theobromae
Jerneren, Fredrik,Eng, Felipe,Hamberg, Mats,Oliw, Ernst H.
, p. 65 - 73 (2012)
Jasmonic acid (JA) is synthesized from linolenic acid (18:3n-3) by sequential action of 13-lipoxygenase, allene oxide synthase (AOS), and allene oxide cyclase. The fungus Lasiodiplodia theobromae can produce large amounts of JA and was recently reported to form the JA precursor 12-oxophytodienoic acid. The objective of our study was to characterize the fatty acid dioxygenase activities of this fungus. Two strains of L. theobromae with low JA secretion (～0.2 mg/L medium) oxygenated 18:3n- 3 to 5,8-dihydroxy-9Z,12Z,15Z- octadecatrienoic acid as well as 9R-hydroperoxy-10E,12Z,15Z-octadecatrienoic acid, which was metabolized by an AOS activity into 9-hydroxy-10-oxo-12Z,15Z- octadecadienoic acid. Analogous conversions were observed with linoleic acid (18:2n-6). Studies using [11S-2H]18:2n-6 revealed that the putative 9R-dioxygenase catalyzed stereospecific removal of the 11R hydrogen followed by suprafacial attack of dioxygen at C-9. Mycelia from these strains of L. theobromae contained 18:2n-6 as the major polyunsaturated acid but lacked 18:3n-3. A third strain with a high secretion of JA (～200 mg/L) contained 18:3n-3 as a major fatty acid and produced 5,8-dihydroxy-9Z,12Z,15Z- octadecatrienoic acid from added 18:3n-3. This strain also lacked the JA biosynthetic enzymes present in higher plants.
Allene Oxide Synthase Pathway in Cereal Roots: Detection of Novel Oxylipin Graminoxins
Grechkin, Alexander N.,Ogorodnikova, Anna V.,Egorova, Alevtina M.,Mukhitova, Fakhima K.,Ilyina, Tatiana M.,Khairutdinov, Bulat I.
, p. 336 - 343 (2018/06/04)
Young roots of wheat, barley, and sorghum, as well as methyl jasmonate pretreated rice seedlings, undergo an unprecedented allene oxide synthase pathway targeted to previously unknown oxylipins 1–3. These Favorskii-type products, (4Z)-2-pentyl-4-tridecene-1,13-dioic acid (1), (2′Z)-2-(2′-octenyl)-decane-1,10-dioic acid (2), and (2′Z,5′Z)-2-(2′,5′-octadienyl)-decane-1,10-dioic acid (3), have a carboxy function at the side chain, as revealed by their MS and NMR spectral data. Compounds 1–3 were the major oxylipins detected, along with the related α-ketols. Products 1–3 were biosynthesized from (9Z,11E,13S)-13-hydroperoxy-9,11-octadecadienoic acid, (9S,10E,12Z)-9-hydroperoxy-10,12-octadecadienoic acid (9-HPOD), and (9S,10E,12Z,15Z)-9-hydroperoxy-10,12,15-octadecatrienoic acid, respectively, via the corresponding allene oxides and cyclopropanones. The data indicate that conversion of the allene oxide into the cyclopropanone is controlled by soluble cyclase. The short-lived cyclopropanones are hydrolyzed to products 1–3. The collective name “graminoxins” has been ascribed to oxylipins 1–3.
Detection of divinyl ether synthase in Lily-of-the-Valley (Convallaria majalis) roots
Ogorodnikova, Anna V.,Latypova, Larisa R.,Mukhitova, Fahima K.,Mukhtarova, Lucia S.,Grechkin, Alexander N.
experimental part, p. 2793 - 2798 (2009/04/11)
Incubations of linoleic acid with cell-free preparations from Lily-of-the-Valley (Convallaria majalis L., Ruscaceae) roots revealed the presence of 13-lipoxygenase and divinyl ether synthase (DES) activities. Exogenous linoleic acid was metabolized predominantly into (9Z,11E,1′E)-12-(1′-hexenyloxy)-9,11-dodecadienoic (etheroleic) acid. Its identification was confirmed by the data of ultraviolet spectroscopy, mass spectra, 1H NMR, COSY, catalytic hydrogenation. The isomeric divinyl ether (8E,1′E,3′Z)-12-(1′,3′-nonadienyloxy)-8-nonenoic (colneleic) acid was detected as a minor product. Incubations with linoleic acid hydroperoxides revealed that 13-hydroperoxide was a preferential substrate, while the 9-hydroperoxide was utilized with lesser efficiency.
