Hypericin and pseudohypericin contents in some Hypericum species growing in Turkey
Hypericin and pseudohypericin content in stems, leaves, and flowers of some Hypericum species growing in Turkey, namely, H. heterophyllum Vent, H. hyssopifolium L., H. linarioides Bosse, H. monbretii Spach, H. orientale L., H. origanifolium Willd., H. perforatum L., H. scabrum L., and H. triquetrifolium Turra, was determined by HPLC. Hypericin and pseudohypericin were detected in all species tested except for H. heterophyllum, and the presence in H. orientale and H. scabrum was reported by us for the first time in the current study. Hypericin and pseudohypericin contents observed in the study varied greatly depending on species and plant tissues. The lowest levels of hypericin and pseudohypericin were detected in leaves of H. hyssopifolium [0.030 and 0.051 mg/g dry weight (DW), respectively] whereas flowers of H. montbretii produced the highest levels of both hypericin forms (2.52 mg/g DW hypericin and 3.58 mg/g DW pseudohypericin). H. montbretti and H. triquetrifolium were found to be superior over H. perforatum with regard to hypericin and pseudohypericin content, encouraging the cultivation and biological evaluation of these species in Turkey.