This study was undertaken to determine the total quantity of phenolic and
flavonoids, as well as to find out about the HPLC quantification of some
individual phenolic compounds (i.e. chlorogenic acid, vitexin 2”-O-rhamnoside,
vitexin, rutin, hyperoside, quercetin, and isoquercetin) in flowers and
leaves of 56 samples of different hawthorn species (Crataegus spp.) collected
from different geographical regions of Iran. The amount of total
phenolics ranges from 7.21 to 87.73 mg GAE/g in dry weight of the plant,
and the total amount of flavonoids varied amongst species and in different
plant organs ranging from 2.27 to 17.40 mg/g dry weight. Chlorogenic acid,
vitexin, and vitexin 2”-O-rhamnoside were found to be the most abundant
phenolic compounds in the extracts of hawthorn leaves. Meanwhile, chlorogenic
acid, hyperoside, and rutin were the most abundant phenolic compounds
in the extracts of hawthorn flowers in most genotypes. The
antioxidant activity widely varied in species and in different organs of
each individual plant, ranging from 0.9 to 4.65 mmol Fe++/g DW plant,
calculated through the ferric-reducing antioxidant power (FRAP) method.
Thus, this could provide valuable data for developing breeding strategies
and plans; it can also help us in selecting genotypes with high phenolic
contents for producing natural antioxidants and other bioactive compounds
beneficial for food or the pharmaceutical industries.