Institute of Botany, Azerbaijan National Academy of Sciences

The roots of Prangos biebersteinii Karjag. collected from Beshbarmak mountains were investigated. Seven crystalline substances of the coumarin nature were isolated from an acetone extract of P. bieber-steinii roots using the method of column chromatography (Al2O3, III-IV degree activity): C16H14O4, m.p. 108.0-109.0ºC (1), C15H16O3, m.p. 84.0-85.0ºC (2), C16H14O5, m.p. 145.0-146.0ºC (3), C16H16O5, m.p. 109.0-110.0ºC (4), C16H14O5, m.p. 141.0-143.0ºC (5), C16H16O6, m.p. 137.0-138.5ºC (6), C11H6O4, m.p. 286.0-279.5ºC (7). On the basis of physical and chemical properties (elemental composition, melt-ing temperature) and spectral (UR- and NMR-spectra) data they were identified as isoimperatorin (1), ostol (2), isooxypeucedanin (3), pranferol (4), peucedanin (5), oxypeucedanin hydrate (6) and bergap-tol, respective (7).