( 14 ) c-labelled alkaloid precursors ( arginine , putrescine , spermidine ) fed to senecio vulgaris plants via the root system were rapidly taken up and efficiently incorporated into the pyrrolizidine alkaloid senecionine n-oxide ( sen-nox ) with total incorporations of 3-6 % .
C0002062
alkaloid
C0034335
pyrrolizidine alkaloid