From methanolic extract of aerial parts of Peucedanum ruthenicum M. Bieb (Apiaceae) collected from Mazandaran province of Iran, four flavonoids namely Isorhamnetin 3-0-rutinoside 1, rutin 2, quercetin 3, morin 4 and two phenolic acids namely caffeic acid 5 and p-coumaric acid 6 have been isolated by Paper Chromatography (PC) and crystallization. Their structures were elucidated by MS, 1H, 13C N...