In addition to myristicin [1, 2], an aromatic aldehyde not previously described in the literature (named equisetin) was isolated from the total extractive substances of the roots of Ferula equisetacea by adsorption chromatography on neutral alumina (activity grade IV). Equisetin has a molecular formula corresponding to m/e 208 (M⁺), mp 133-134°C (ethanol), and Rf 0.48. Its IR spectrum shows absorption bands at (cm⁻¹) 3040, 1665, 1650, 1640, 1615, 970 (trans -CH=CH-), 2810, 2730, 2705, 1680 (α,β-unsaturated -CHO), 1595, 1515, 1500 (aromatic ring), and 1050 and 922 (-O-CH₂-O-). The NMR spectrum (Varian JNM-4H-100 MHz, CDCl₃, TMS, δ scale) exhibits proton signals at (ppm) 3.95 (-OCH₃, 3H), 6.02 (-O-CH₂-O-, 2H, singlet), 6.55 (-CH=CH-CHO, 1H, quartet, J=7.5 Hz and 15.3 Hz), 6.74 and 6.76 (meta-position benzene ring protons, two superposed doublets, 1H each, J=1.5 Hz), 7.35 (-CH=CH-CHO, 1H, doublet, J=15.3 Hz), and 9.62 (-CH=CH-CHO, 1H, doublet, J=7.5 Hz). The chemical shift and coupling constants of H-7 and H-8 protons indicate the trans configuration of olefinic protons conjugated with the carbonyl group. Based on the spectral data, the structure of equisetin was proposed.