1954 Volume 74 Issue 10 Pages 1092-1096
The specific new coloration reaction of hydroxyanthrone derivatives was further extended and a micromethod for the separatory determination of 1, 8-dihydroxy-anthrone and -anthraquinone derivatives was established. To the pyridine solution of 1, 8-dihy-droxyanthrone derivatives, 0.1% pyridine solution of p-nitrosodimethylaniline is added and the colored solution thereby obtained is measured with the Beckman spectrophotometer. The detection curve is linear, showing possibility of quantitative determination (5-25γ/cc.). In this case, the presence of excess of the reagent, hydroxyanthraquinones, flavonoids, and sugars does not interfere with the measurement. By the concurrent use of this method and that of determination of hydroxyanthraquinones (Shibata: This Journal, 72, 1311 (1952)), seasonal variation in the content of chrysophanol, chrysophanol anthrone, emodin, and emodin anthrone in the fresh and dried fruits of Rhamnus dahurica Pall. var. nipponica Mak. was examined (cf. Figs. 6-9).
