Alkaloids from Veratrum album subsp. lobelianum

I n our preceding paper [1] we reported t h e isolation of a novel, amorphous ester alkaloid from Veratrum album subsp. lobelianum (BERNH.) Suessenguth. This al­ kaloid has been found, together with protoveratrine A, germitetrine and veratroylzygadenine in the ester alkaloid fraction [2]. Acetylveratroylgermine designated originally amorphous alkaloid [1] [a]f) + 6 . 6 ° (chloroform) has, according to ele­ mental analysis, molecular formula C38H53NO12 (M 715.84). The ultraviolet spectrum of this substance displays maxima a t 291 nm (log e 3.75), 260 nm (log E 4.07) and 218 nm (log e 4.35) indicative of substituted benzene ring. The infrared spectrum shows peaks a t 1520 and 1610 c m " 1 (aromatic ring), 1725 c m " 1 (ester of veratric acid) and 1750 c m 1 (ester of acetic acid). Peaks a t 2760, 2780, 2815 and 2840 c m 1 (Bohlman bands) evidence the presence of transquinolicidine skeleton [3] in the molecule of this alkaloid. The NMR spectrum reveals signals at ô 1.00 p.p.m. (singlet, 3H, C(i9) angular metlvyl group), 1.17 (singlet, 3H, Q21) tert-meťhjl group), 1.10 (doublet, J = 7.0 cps, 3H, C(25) «sec-metlryl group in axial position [4], 3.87 (singlet, 6H, two methoxy groups), and 2.05 (singlet, 3H, acetyl group). Upon saponification with methanolic sodium hydroxide acetylveratroylgermine affords acetic acid which was determined as a-naphthylacetamide [1], veratric acid and germine, the latter being identified by its m.p., optical rotation, Rp value and mass spectrum. After standing in aqueous methanol [5] for 24 hours acetylveratroylgermine loses acetic acid t o give veratroylgermine. To the further amorphous alkaloid of [a]f) —2.2° (chloroform) obtained from the ester alkaloid fraction the molecular formula C36H51NO11 (M 673.80) was assigned according to the elemental analysis. The ultraviolet spectrum of this sub­ stance is similar to t h a t of acetylveratroylgermine, the maxima being at 292 nm (log e 3.81), 262 nm (log e 4.13) and 219 nm (log e 4.47) indicating thus the presence of veratric acid in t h e structure of this alkaloid. Similarly, the infrared spectrum