モクレン科植物アルカロイド研究 (第28報)

タイワンオガタマノキMichelia compressa MAXIM. var. Formosana KANEHIRAのアルカロイド その1

抄録

Alkaloids contained in Michelia compressa MAXIM. var. formosana KANEHIRA (Japanes name “Taiwan-Ogatamanoki”), a plant of the Magnoliaceae family indigenous to Formosa, were examined. From the heartwood of this tree, tertiary non-phenolic beses were isolated as colorless prisms, m.p. 180-181°, and pale yellow needles, m.p. 279-281°(decomp.). The main alkaloid of m.p. 180-181° was named “ushinsunine.” This base corresponds to the molcular formula of C₁₈H₁₇O₃N, [α]_D -113.6° (EtOH), it is positive to the Gaebel and Labat's color reaction for methylenedioxy group, and does not contain methoxyl group. It easily forms a basic monoacetate of colorless prisms, m.p. 202-203°, C₁₈H₁₆O₂N(OCOCH₃). Infrared spectrum of ushinsunine revealed the presence of alcoholic hydroxyl and methylenedioxy groups (Chart 1) and its ultraviolet spectrum suggested the structure of an aporphine-type base (Fig. 1). It was thereby assumed that ushinsunine is an aporphine-type base represented by the experimental formula of C₁₈H₁₇O₃N=C₁₆H₁₁(OH)(O₂CH₂)(NCH₃).
The other base of m.p. 279-281° (decomp.) was proved to be the identical with oxoushinsunine, m.p. 280-281°(decomp.), obtained by oxidation of ushinsunine with pyridine and chromium trioxide, as will be described in a later report.
Water-soluble quaternary bases were obtained in the form of magnoflorine (I) and a minute amount of a new base as a picrate.