BIOSYNTHESIS OF AZETIDINE-2-CARBOXYLIC ACID IN CONVALLARIA MAJALIS: STUDIES WITH N-15 LABELLED PRECURSORS

Article abstract of DOI:10.1016/S0031-9422(00)83735-8

Key Word Index - Convallaria majalis; Liliaceae; lily-of-the-valley; biosynthesis; azetidine-2-carboxylic acid; <1-14C, 15N>methionine; <1-14C, 2- and 4-15N>-2,4-diaminobutanoic acid; <1-13C, carboxyl-14C, 15N>-1-aminocyclopropane-1-carboxylic acid. (R,S)-<1-14C, 15N>Methionine, (R,S)-<1-14C, 2-15N>- and (R,S)-<1-14C, 4-15N>-2,4-diaminobutanoic acid, and <1-13C, carboxyl-14C, 15N>-1-aminocycloproprane-1-carboxylic acid were synthesized and fed to Convallaria majalis plants.The labelled methionine was the most efficient precursor of azetidine-2-carboxylic acid (A-2-C), the specific incorporation of the 15N (0.47percent) being essentially the same as that of the 14C (0.45percent).The A-2-C derived from the labelled 2,4-diaminobutanoic acid was radioactive (specific incorporation of 14C: 0.05, 0.06percent); however, a much higher level of activity was found in aspartic and glutamic acid, and 2,4-diaminobutanoic acid is not considered to be a direct precursor of A-2-C in this species.Negligible 14C activity was found in A-2-C after feeding the labelled 1-aminocyclopropane 1-carboxylic acid.