Alstonia scholaris (Apocynaceae) has so far furnished only two indole alkaloids, echitamine and echitamidine. This communication reports the structure of another indole base, alkaloid A, isolated from the leaves of this plant. Alkaloid A (C₂₀H₂₅N₂O₃, m.p. 223-225°C dec., [α]ᴅ -47° (CHCl₃)) is a tertiary weak base with pKa 5.72 (ethanol-water), forming a methiodide (C₂₁H₂₈N₂O₃I, m.p. 235-237°C dec.) and a yellow picrate (C₂₆H₂₈N₅O₉, m.p. 172-174°C dec.). Functional group analysis indicated a carbomethoxyl group (IR: 5.78 μ; NMR: 3.74 δ singlet, 3H), an -NH group (IR: 2.9 μ, active hydrogen), and one C-methyl. Ozonolysis yielding acetaldehyde (as DNPR derivative) and NMR (methylene quartet at 5.44 δ, methyl doublet at 1.58 δ, J=14 c.p.s.) confirmed an ethylidene group. UV spectra (ethanol: λmax 237, 287 nm, logε 3.90, 3.51; concentrated HClO₄: λmax 239, 244, 305 nm, logε 3.65, 3.64, 3.67) suggested a dihydroindole system changing to 3H-indolium in acid, indicating the third oxygen is a carbinolemine ether at the indoline A-position (as in picraline and pseudoakuammigine). NMR (4.025 δ singlet, 1H) supported the ether bridge between oxygen and nitrogen-adjacent carbon. Based on these data and biogenetic considerations, alkaloid A was proposed to have structure (I), identical to desacetyldesformylpicraline. This was confirmed by: (1) superimposable NMR spectra with picraline; (2) mass spectrometry (molecular ion at m/z 336, consistent with C₂₀H₂₅N₂O₃; LAH reduction product (M=296, desformylpicralinol) showing expected fragmentation; deuteride reduction product fragments shifting to m/z 131, 145, 146, 169, 253); (3) superimposable IR spectra and undepressed mixed melting point with picrinine (desacetyldesformylpicraline). The isolation of picrinine from A. scholaris has biogenetic significance as it may be an intermediate in the formation of echitamine and echitamidine skeletons.