The production of polyphenols by two-year-old callus cultures from flo
ral buds of Crataegus monogyna has been studied in relation to growth
variation within a subculture period. Calli produce mainly proanthocya
nidins (1074-2959 mg 100 g(-1) dry wt), B2 dimer (86-321 mg 100 g(-1)
dry wt), (-)-epicatechin (468-807 mg 100 g(-1) dry wt), chlorogenic ac
id (213-769 mg 100 g(-1) dry wt), and a major flavonoid hyperoside (61
-143 mg 100 g(-1) dry wt). Optimum production of polyphenols seems to
be generally attained when maximal growth is reached.