The new alkaloid muricatisine has been isolated from the epigeal parts of the plants Oxytropis muricata (Pall.) DC. (Mongolia) and O. puberula Boriss. (Kazakhstan), which belong to the Fabaceae family. Continuing a study of alkaloids of plants of the genus Oxytropis, muricatisine was first isolated from O. muricata but due to its small amount, its structure was established after isolation from O. puberula. It is an optically inactive alkaloid with mp 124-125°C (from acetone), composition C₁₅H₁₃NO₂ (M⁺ 239), readily soluble in chloroform, sparingly soluble in methanol, and insoluble in water and alkalis. Its structure was established as N-benzoyl-2-oxo-2-phenylethylamine on the basis of spectral characteristics (UV maxima at 202 and 242 nm; IR absorption bands of active hydrogen at 3359 cm⁻¹ and conjugated/amide carbonyls at 1694 and 1635 cm⁻¹; mass spectrum with molecular ion at m/z 239 and characteristic ions at m/z 135, 134, 105, and 77; PMR signals of a methylene group bound to nitrogen, a NH group, and 10 aromatic protons) and confirmed by a partial synthesis via oxidation of N-benzoyl-2-hydroxy-2-phenylethylamine with the Jones reagent, where the synthetic product was identical to natural muricatisine according to TLC, mixed melting point, and IR spectrum. Muricatisine was previously known as a synthetic product with matching melting point and mass spectrum.