Vacuoles were isolated by osmotic rupture of mesophyll protoplasts from the primary leaves of 4-d- and 7-d-old plants of rye (Secale cereale L.). Their content of two flavones, luteolin 7-O-[β-D-glucuronosyl-(1→2)β-D-glucuronide] (R2) and luteolin 7-O-[β-D-glucuronosy 1 (1→2)