Cimicifuga属植物の成分研究(第5報) : オオバショウマの成分 その5 : 25-O-Acetylcimigenol, Dehydroxy-15-O-methylcimigenolおよび15-O-Methylcimigenolの構造

抄録

Three new triterpenes, named 25-O-acetylcimigenol (I), dehydroxy-15-O-methyl cimigenol (VI) and 15-O-methylcimigenol (VIII), were obtained from the hypogenous part of Cimicifuga acerina and their structures were determined. I, mp 193-194°, [α]¹⁵_D+39.3°, C₃₂H₅₀O₆, leads to cimigenol (II) and cimigenyl diacetate (V), of which structures were determined, by hydrolysis and acetylation, respectively. I forms a diketo derivative (III), mp 211-212°, C₃₂H₄₆O₆ and a monoketo derivative (IV), mp 175-175.5°, C₃₂H₄₈O₆ by·oxidation. VI, mp 222-223°, [α]⁷_D+38.5°, C₃₁H₄₈O₄ forms an acetate (VII), mp 186-187°, [α]⁷_D+42.6°, C₃₈H₅₀O₅, which is obtained from 15-O-methylcimigenol (VIII), on acetylation and dehydration. VIII, mp 199.5-200.5°, [α]⁵_D+38.9°, C₃₁H₅₀O₅, forms an acetate (IX), mp 124-125°, [α]⁵_D+45.7°, C₃₃H₅₂O₆ and a keto derivative (X), mp 156-157°, C₃₁H₄₈O₅, by acetylation and oxidation, respectively. VIII, also, is synthesized from cimigenyl diacetate II (V) by reaction with dry methanol and conc. H₂SO₄ following hydrolysis.