Reversibility of the oleanolic acid monoglycosides transport across the tonoplast in vacuoles isolated from Calendula officinalis leaves.

The possibility of the reversible tonoplast transport of oleanolic acid monoglycosides was investigated in vacuoles isolated from Calendula officinalis leaf protoplasts. The obtained results point to the reversibility of the transport of monoglucoside I, whereas monoglucuronide F seems to be definitely stored in the vacuolar space.