The following species of the family Papaveraceae were used: Chelidonium majus L.,
Dicranostigma lactucoides Hook.f. and Thomson, Macleaya microcarpa (Maxim) Fedde,
Sanguinaria canadensis L. and Stylophorum lasiocarpum (Oliv.) Fedde. The plants were
obtained from the Centre of Medical Plants, Faculty of Medicine, Masaryk University,
Brno, Czech Republic. The seeds were obtained from various botanic gardens. Voucher
specimens have been deposited at the Department of Biochemistry, Faculty of Medicine,
Masaryk University.