BIOSYNTHESIS OF MUSTARD OIL GLUCOSIDES: VII. FORMATION OF SINIGRIN IN HORSERADISH FROM HOMOMETHIONINE-2-14C AND HOMOSERINE-2-14C

Abstract

Five C14-labeled amino acids were administered to horseradish (Armoracia lapathifolia Gilib.) leaves. Three of the amino acids, DL-homoserine- 2-C14, DL-methionine- 2-C14, and DL-homomethionine-2-C14 (2-amino-5-(methylthio)valeric acid), were precursors of the aglycone (allyl isothiocyanate) of sinigrin. The other two, DL-allylglycine-2-C14 (2-amino-4-pentenoic acid) and DL-2-amino-5-hydroxyvaleric acid-2-C14, were incorporated in insignificant amounts. The relationships of the 3 efficient precursors are discussed. The syntheses of 4 C14-labeled amino acids used in this investigation are described.