BIOSYNTHESIS OF MUSTARD OIL GLUCOSIDES: V. FORMATION OF GLUCONASTURTIIN FROM L-GAMMAPHENYLBUTYRINE-C(14)-N(15) IN WATERCRESS,
Abstract
C(14)-Labelled compounds were fed to watercress (Nasturtium officinale R. Br.) and their efficiency as precursors of the aglycone portion of gluconasturtiin compared. Phenylalanine-2- and -3-C(14) and sodium acetate-2-C(14) were efficient precursors of the aglycone but neither compound was as efficient a precursor as gamma-phenylbutyrine (2-amino-4-phenylbutyric acid). Approximately 40% of the C(14) from gamma-phenylbutyrine-2- or -3-C(14) was incorporated into the aglycone side chain. Results of studies with doubly labelled L-gamma-phenylbutyrine-C(14)-N(15) show that theamine nitrogen is incorporated directly into the thioglucoside. Evidence that indicates that D-gamma-phenylbutyrine is converted to its L-isomer by the plant is also presented. The results of an isotope competition experiment provide some evidence for the existence of a chain-lengthening pathway (analogous to the formation of leucine from valine) for the biosynthesis of gamma-phenylbutyrine from phenylalanine and acetate in watercress. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 12, 1964
- Accession Number
- AD0614508
Entities
People
- E. W. Underhill
Organizations
- National Research Council Canada