N-(jasmonoyl)tyrosine-derived compounds from flowers of broad beans (Vicia faba).
Two new amide-linked conjugates of jasmonic acid, N-[(3R,7R)-(-)-jasmonoyl]-(S)-dopa (3) and N-[(3R,7R)-(-)-jasmonoyl]-dopamine (5), were isolated in addition to the known compound N-[(3R,7R)-(-)-jasmonoyl]-(S)-tyrosine (2) from the methanolic extract of flowers of broad bean (Vicia faba). Their structures were proposed on the basis of spectroscopic data (LC-MS/MS) and chromatographic properties on reversed and chiral phases and confirmed by partial syntheses. Furthermore, tyrosine conjugates of two cucurbic acid isomers (7, 8) were detected and characterized by LC-MS. Crude enzyme preparations from flowers of V. faba hydroxylated both (+/-)-2 and N-[(3R,7R/3S,7S)-(-)-jasmonoyl]tyramine [(+/-)-4] to (+/-)-3 and (+/-)-5, respectively, suggesting a possible biosynthetic relationship. In addition, a commercial tyrosinase (mushroom) and a tyrosinase-containing extract from hairy roots of red beet exhibited the same catalytic properties, but with different substrate specificities. The conjugates (+/-)-2, (+/-)-3, (+/-)-4, and (+/-)-5 exhibited in a bioassay low activity to elicit alkaloid formation in comparison to free (+/-)-jasmonic acid [(+/-)-1].
Kramell
Robert
R
Department of Natural Product Biotechnology, Leibniz Institute of Plant Biochemistry, Weinberg 3, D-06120 Halle (Saale), Germany. Robert.Kramell@ipb-halle.de
Schmidt
Jürgen
J
Herrmann
Gabriele
G
Schliemann
Willibald
W
D000363:Agaricales / Q000201:enzymology; D027461:Beta vulgaris / Q000201:enzymology; D003517:Cyclopentanes / Q000737:chemistry / Q000302:isolation & purification*; D035264:Flowers / Q000737:chemistry / Q000201:enzymology; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D054883:Oxylipins; D010946:Plants, Medicinal / Q000737:chemistry*; D013237:Stereoisomerism; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification*; D031307:Vicia faba / Q000737:chemistry* / Q000201:enzymology
D003517:Cyclopentanes; D054883:Oxylipins; D014443:Tyrosine; C011006:jasmonic acid; D014442:Monophenol Monooxygenase