セリ科植物成分の研究 (第3報)

ししうど根の成分その1

抄録

In addition to the two components reported previously, another substance was isolated from the root of Angelica pubescens MAXIM. (Umbelliferae) as white microneedles, m. p. 256-257°, C₁₁H₈O₄; U. V. λ_max^EtOH 257, 309, 332 mμ; I. R. λ_max^Nujol 5.7, 5.95μ. Oxime, m. p. 225°, C₁₁H₉O₄N. The substance (II) obtained on opening of the lactone ring formed a 2, 4-dinitrophenylhydrazone, m. p. 275° (decomp.). The substance possesses one methoxyl but no hydroxyl. (I) is a new substance as a plant component but is similar to the substance obtained by Späth as the decomposition intermediate product of ostruthin methyl ether. The structure of (I) was established in a different manner. Clemmensen-Martin reduction of (I) afforded white needles (III), m. p. 134-134.5°, C₁₁H₁₀O₃, and a substance, C₁₁H₁₂O₃, of m. p. 93-94°. The lactone ring in (III) was opened to afford a substance (IV) which was decomposed with potassium permanganate, yielding white needles, m. p. 119-121°, C₁₀H₁₂O₃. This substance was found to be identical with 2, 4-dimethoxy-5-methylbenzaldehyde, which was synthesized by another route from cresorcinol. Therefore, (II) is 6-methyl-7-methoxycoumarin and (I) would be 7-methoxy-6-coumarinaldehyde, which was named angelical. The glabra-lactone obtained earlier from Angelica glabra MAKINO was not obtained from the present material.