クロバナヒキオコシ成分の研究 (第1報)

抄録

Two kinds of bitter principle were isolated from the dried leaves of Isodon trichocarpus (MAXIM.) KUDO. The one of m.p. 297-299° (decomp.), C₂₀H₂₆₍₂₈₎O₆, was named enmein (I), and the other melted at 263-265° with decomposition. (I) forms a dihydro compound (II) and a diacetate (III), suggesting the presence of at least one double bond and two hydroxyls, one of which was found to be secondary by chromium trioxide oxidation of (I). Saponification of (III) with oxalic acid afforded monoacetylenmein (IV) while saponification of (III) with hydrochloric acid and ethanol afforded (V), C₂₀H₂₆₍₂₈₎O₆⋅C₂H₅OH. The presence of at least one lactone was presumed from the result of saponification of (I) with ethanol and potassium hydroxide.