A BLUE PIGMENT DERIVED FROM ROSMARINIC ACID AND FESO4 IS RESPONSIBLE FOR THE BLUE PIGMENT SECRETED INTO THE MEDIUM BY LAVANDULA X INTERMEDIA CELL-CULTURES GROWN IN THE DARK

Rosmarinic acid (alpha-O-caffeoyl-3,4-dihydroxy phenyllactic acid) is the main phenolic constituent (1.0-7.0 mu mol/kg) present in methanolic extracts of the medium from Lavandula x intermedia cell cultures which have been grown on agar gel containing Murashige & Skoog medium. In this medium, the concentration of FeSO4 is 100 mu mol/kg. Since rosmarinic acid yields a blue pigment upon reaction with FeSO4 (lambda(max) = 572 nm and epsilon(572) = 3,820 M(-1) cm(-1) at pH 6.0), this pigment appears to be the main compound responsible for the blue colour which is secreted into the medium by Lavandula x intermedia cell cultures grown in the dark.