Representatives of the genera Aconitum and Delphinium are valuable alkaloid-bearing plants of the Ranunculaceae family. This study analyzed the alkaloid content in the hypogeal organs (rhizomes with roots) of Aconitum chasmanthum Stapf (a Himalayan species grown from Munich-cultured seeds) and Delphinium elatum L. (a naturalized Eurasian species) cultivated in the Polar-Alpine Botanical Garden (Kirovsk). Both plants adapted to the subarctic environment, showing resistance to unfavorable factors and capacity for vegetative and seed reproduction. For A. chasmanthum, air-dry raw material was treated with sodium carbonate, extracted with chloroform, and acid-treated to yield total alkaloids (1.3% of dry weight). Column chromatography on alumina (hexane-ether elution) isolated two alkaloids: I (aconitine, C₃₄H₄₇NO₁₂) and II (isotalatisidine, C₂₃H₃₇NO₅), identified via ¹H/¹³C NMR, comparison with authentic specimens (mixed melting points, TLC, IR), and were first isolated from this plant. For D. elatum, similar extraction methods were used: total alkaloids were 2.5% (complete withering phase) and 2.24% (incipient vegetation phase) of dry weight. Chromatographic separation yielded base III (nudicauline, C₃₈H₅₀N₂O₁₁), identified by HRMS, IR, PMR, MS, saponification to delectinine (comparison with standard), and ¹³C NMR. Nudicauline was previously isolated in small amounts from D. elatum seeds but was here obtained in large amounts from rhizomes and roots. This study reports the first isolation of aconitine and isotalatisidine from A. chasmanthum and the first large-scale isolation of nudicauline from D. elatum rhizomes and roots.