56410-34-5Relevant articles and documents
LICHEN ACIDS, PLANT GROWTH INHIBITORS FROM USNEA LONGISSIMA
Nishitoba, Yukiko,Nishimura, Hiroyuki,Nishiyama, Tohru,Mizutani, Junya
, p. 3181 - 3186 (1987)
Eight components, depsides and orcinol derivatives which exhibit growth-inhibitory activity against lettuce seedlings were isolated from Usnea longissima and identified from their physicochemical data.Key Word Index - Usnea longissima; depside; β-orcinol;
BIOSYNTHESIS OF CANESCIN, A METABOLITE OF ASPERGILLUS MALIGNUS : INCORPORATION OF METHIONINE, ACETATE, SUCCINATE, AND ISOCOUMARIN PRECURSORS, LABELLED WITH DEUTERIUM AND CARBON-13
Lewis, Christopher N.,Staunton, James,Sunter, David C.
, p. 747 - 754 (2007/10/02)
The biosynthesis of canescin (1), a metabolite of Aspergillus malignus, has been studied using methionine, sodium- and acetate, and sodium- and -succinate as simple precursors, and deuterium labelled isocoumarins as potential advanced precursors.Analysis of the labelled products by both n.m.r. and mass spectrometry suggests that 6,8-dihydroxy-3,7-dimethylisocoumarin (13) is the first enzyme-free intermediate produced by the polyketide synthase, and the 7-formyl-6,8-dihydroxy-3-methylisocoumarin (16) is a later intermediate on the pathway.Incorporation into canescin of (13)C together with one deuterium atom from methionine proves that the formyl group of (16) is derived from this source and that it is not oxidised to the level of a carboxylic acid in subsequent steps.The (13)C labels in the succinate units are incorporated into the γ-lactone carbons (C-11 to C-13) of canescin, but with complete loss of the neighbouring deuterium label.