This diploma thesis describes the isolation of different biologically important compounds from natural sources and their subsequent transformations. Successfully isolated compounds were: nicotine from tobacco (genus Nicotiana) by extraction, matricin from chamomile (Chamomilla recutita) by extraction and chamazulene from chamomile by distillation. Nicotine obtained from tobbaco was used to form complexes with selected metal ions (Cu2+, Ni2+ in Co2+) and matricin obtained from chamomile was further transformed into chamazulene. Diploma thesis also describes an unsuccessful attempt at the isolation of cannabidiol and cannabidiolic acid from hemp (Cannabis sativa L.). Isolated compounds were characterised using 1H NMR spectroscopy and IR spectroscopy.