Phenolic constituents of Hypericum triquetrifolium Turra (Guttiferae) growing in Turkey: variation among populations and plant parts

Hypericum triquetrifolium Turra (Guttiferae) has received considerable scientifi c interest in recent years, as it is a source of a variety of biologically active compounds including phenolics. Th e present study was conducted to determine the variation in the content of several phenolics, namely phenylpropane chlorogenic acid and fl avonoids such as rutin, hyperoside, apigenin-7-O-glucoside, kaempferol, quercitrin, quercetin and amentofl avone among four H. triquetrifolium populations from the Central Black Sea Region of Turkey. Th e aerial parts representing a total of 30 shoots were collected at full fl owering in each population. Aft er drying at room temperature, they were dissected into fl oral, leaf and stem tissues and subsequently assayed for phenolic compounds by HPLC. Th e populations varied signifi cantly in phenolic content. Among diff erent plant parts, the fl owers were found to be the principle organ for chlorogenic acid, hyperoside, apigenin-7-O-glucoside, kaempferol, quercetin and amentofl avone accumulations, while rutin and quercitrin were accumulated mainly in the leaves. Th e presence of apigenin-7-O-glucoside and amentofl avone in H. triquetrifolium is reported by us for the fi rst time. Th e chemical variation among the populations and plant parts is discussed as being possibly the result of diff erent genetic, environmental and morphological factors.