防已科植物アルカロイド研究 (第150報)

ハスノハカズラStephania japonica MIERSのアルカロイド (補遺4) 一新第四級塩基Steponineの構造 その1

抄録

Examinations were made on quaternary bases in Stephania japonica MIERS (Japanese name “Hasunoha-kazura”) and a new crystalline base was isolated. This base, named steponine, agrees with the molecular formula C₂₀H₂₄O₄N⁺, possessing two methoxyls, two phenolic hydroxyls, and one N-methyl group. Its chloride, C₂₀H₂₄O₄NCl⋅H₂O, m.p. 235° (decomp.), shows following constants: [α]_D²¹-129.89°(H₂O); U.V. λ_max^MeOH mμ (logε): 234 (4.12), 282 (3.85); λ_min^MeOH 256mμ (logε 2.76). It colors slightly greenish with ferric chloride and deep blue with the Gibbs reagent.
Recently, Tomita and Kikuchi isolated a new quaternary base, cyclanoline, from Cyclea insularis (MAKINO) DIELS and determined its structure as l-α-N-methylscoulerine (IV). Cyclanoline chloride, C₂₀H₂₄O₄NCl⋅H₂O, m.p. 214-215°(decomp.); [α]_D⁸-115.8° (MeOH); U.V. λ_max^MeOH mμ (log ε): 233 (4.13), 286 (3.88); λ_min^MeOH 255mμ (log ε 2.79). It was described as giving almost no change with ferric chloride and coloring deep blue with Gibbs reagent. Although steponine and cyclanoline (IV) are extremely alike, the infrared spectra of the two chlorides were not identical. Since the infrared spectra of their respective O, O-dimethyl-methine (VI) were completely identical, it was assumed that steponine might be α, β-steric isomer of the N-methyl group in cyclanoline or position isomers of the substituents (two methoxyls and two phenolic hydroxyls) in the protoberberine skeleton.