Aspergillus versicolorの代謝生産物に関する研究

(第2報) Sterigmatocystinの理化学的性質及び化学構造(その2)

抄録

Sterigmatocystin was pale yellow needle, m.p. 244_??_5°. It was soluble in acetone, benzene, ethyl acetate and chloroform, sparingly soluble in alcohol, methanol and ether, insoluble in petroleum ether and water. It gave a dark blue violet color with FeCl₃. Its molecular formula, C₁₅H₁₂O₅, was proposed from the results of elementary analysis and molecular weight determination. It had one hydroxyl, one methoxyl, and one methylene dioxyl group.
On decomposition with concentrated hydroiodic acid, or AlCl₃, it gave 1, 3, 8-trihydroxyxanthone. And when the substance obtained from sterigmatocystin by oxidation using KMnO₄ was heated at 220_??_300°, it gave 1-methoxy-3, 8-dihydroxyxanthone.
In an infra-red absorption spectrum of sterigmatocystin, such absorption of carbonyl group as could be seen in xanthone was not observed. And it was comparatively stable in alkaline, but unstable in mineral acid. Thus methylene dioxyl group was considered to be at 8 and 9 positions, or peri-position in xanthone nuleus.
Summarizing the facts above mentioned, the authors advanced the following structure for sterigmatocystin.