Enzymological Aspects of Flavonoid Catabolism in Plant Cell Cultures

Abstract

Flavonoids are mainly stored as glycosides in vacuoles of plant cells. Thus, in chick pea plants (Cicer arietinum L.), isoflavones occur as 7--0-glycosides and flavonols as the 3-glycosides (7). Removal of the sugar part by specific glycosidases is generally considered to be the first step of catabolic pathways for these particular metabolically active compounds. According to this hypothesis a specific $β$-glucosidase for isoflavone 7-glucosides could be demonstrated in chick pea plants (8). The enzyme appears in all organs of chick pea plants at the same time as the isoflavones (6) and the cellular distribution of the enzyme is well correlated with the isoflavone content (5).