Flavanone glucosides in callus and phloem of Prunus avium: Identification and stimulation of their synthesis

The flavanone glucosides dihydrowogonin-7-glucoside, eriodictyol-7-giucoside and prunin (naringenin-7-glucoside) were isolated, identified and quantitatively determined in callus cultures and phloem of Prunus avium L. cvs. Sam and Schneiders. These substances were isolated from callus tissue, where they were most abundant. The identification included TLC, HPLC and spectrophotometry in conjunction with hydroxylation and benzoylation. Elevation of sucrose concentrations in the media from 1 to 4% (w/w) resulted in a 3- to 4-fold increase in prunin. A similar response, although much less pronounced, was observed for eriodictyol-7-glucoside, while dihydrowogonin-7-glucoside was not enhanced under these conditions. Addition of benzyladenine to media of tissue cultures also caused an increase in prunin and eriodictyol-7-glucoside levels. Both of these flavanones also increased in phloem above and below a constriction of Prunus stems. Administration of benzyladenine into Prunus stems resulted in a 4-fold increase of prunin in the phloem.