THE BIOSYNTHESIS OF TROPIC ACID IN PLANTS - EVIDENCE FOR THE DIRECT REARRANGEMENT OF 3-PHENYLLACTATE TO TROPATE

• Published in: Journal of the Chemical Society, Perkin Transactions 1 no. 9; pp. 1159 - 1162
• Main Authors: CHESTERS, NCJE, OHAGAN, D, ROBINS, RJ
• Format: Journal Article
• Language: English
• Published: CAMBRIDGE Royal Soc Chemistry 1994; Royal Society of Chemistry
• Subjects: Alcaloids; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Chemistry; Chemistry, Organic; Fundamental and applied biological sciences. Psychology; Heterocyclic compounds, pigments; Other biological molecules; Physical Sciences; Science & Technology; TRANSFORMED ROOT CULTURES; 1,2-MIGRATION; CHEMISTRY; PHENYLALANINE; PRECURSORS; DATURA-STRAMONIUM L; ALKALOIDS; Datura stramonium; Biosynthesis; NMR spectrometry; Mechanism; Gas chromatography; Alkaloid; Carboxylic acid; Dicotyledones; Angiospermae; Spermatophyta; Biosynthesis precursor; Solanaceae; Mass spectrometry
• ISSN: 0300-922X; 2050-8255; 1364-5463
• DOI: 10.1039/p19940001159

Dual labelled sodium (RS)-3-phenyl[2-C-13,2-H-2]lactate was incubated with transformed root cultures of Datura stramonium and the incorporation of the label into the tropic acid ester moiety of hyoscyamine was assessed by C-13{H-1} and C-13{H-1,H-2} NMR spectroscopy and by GC-MS analysis. It is demonstrated that the C-13-H-2 bond of sodium (RS)-3-phenyl[2-C-13,2-H-2]lactate is incorporated (GC-MS, M + 2, 17%) intact into the hydroxymethyl group at C-3' of the (S)-tropoyl moiety. This result demonstrates unambiguously that 3-phenyllactate is a closer precursor to the tropate ester than phenylpyruvate or phenylalanine.