Continuing the separation of the combined alkaloids from the epigeal part of Haplophyllum perforatum [1], the neutral fraction was chromatographed on alumina. The substances were eluted with ether, yielding an optically inactive base with the composition C₁₈H₁₉NO₄ (I), mp 105-106°C (from ethyl acetate), mol. wt. 313 (mass spectrometry), readily soluble in organic solvents and dilute acids but insoluble in water and alkali. The UV spectrum of the base [λmax 251, 322, 335 nm (log ε 4.99, 3.91, 3.89)] resembles that of the furanoquinoline alkaloids of the skimmianine type [2]. The IR spectrum had maxima at 3120 and 3160 cm⁻¹ (furan rings); absorption bands of a hydroxy group were absent. The NMR spectrum (taken in CCl₄) showed the signals of protons with the following values of τ: 2.33 and 3.04 (doublets, 1H each, J = 9 Hz, ortho-aromatic protons); 2.61 and 3.19 (doublets, 1H each, J = 3 Hz, the α- and β-protons of a furan ring); 5.72 and 5.99 (singlets, 3H each, 2 OCH₃); 4.54 (triplet, 1H, J = 6.5 Hz, =CH-CH₂); 5.38 (doublet, 2H, J = 6.5 Hz, =CH-CH₂-O-); 8.26 and 8.30 (singlets, 3H each). The mass spectrum of (I) showed m/e 313 (M⁺, 4%), 245 (100%), 230 (21%), 227 (97%), 216 (22%). These facts suggested the base is a dictanmine derivative with ortho-alkoxy substituents in the benzene ring. Hydrogenation of the base over a platinum catalyst yielded a hexahydro derivative (II) with mp 235-236°C (from ethanol) [mass spectrum: m/e 219 (M⁺, 0.4%), 249 (98%), 234 (100%)] and a substance with mp 163-164°C (from ethanol) identical to authentic tetrahydrohaplopine (IV) obtained by hydrogenation of haplopine (III). Consequently, the alkaloid has structure (I). Partial synthesis of (I) by condensing haplopine with 4-chloro-2-methylbut-2-ene in dry acetone with anhydrous potassium carbonate confirmed identity with the isolated base. Literature reports a substance from Ptelea aptera Parry (mp 101-103°C) proposed as 7-isopentenyloxyfagarine [3], whose UV and NMR data match (I).