Zur Biosynthese des Apigenins und Chrysoeriols in der Petersilie

Abstract

The aglykon of a second flavoneglycoside present in parsley plants and fruits has been identified as Chrysoeriol (5.7.4′-trihydroxy-3′-methoxyflavone). According to its hydrolytic and spectral properties the glycoside is the 7-apiosyl-glucoside of chrysoeriol. 4.2′.4′.6′-Tetrahydroxychalcone-2′-glucoside- [β-14C] is incorporated into apigenin (5.7.4′-trihydroxyflavone) in parsley without randomization of the label. When a mixture of 5.7.4′-trihydroxyflavanone-[2-14C] with either trans-3.5.7.4′-tetrahydroxyflavanone- [T] or 3.5.7.4′-tetrahydroxyflavone- [T] was fed to two month old parsley shoots, the incorporation of the trihydroxyflavanone into apigenin or chrysoeriol was higher by a factor of 67 to 400 than that of the tetrahydroxyflavanone or tetrahydroxyflavone. These results prove that the flavones are formed by dehydrogenation of flavanones and not by dehydration of dihydroflavonols.