Ma. Alnuri et al., EMODIN, A NATURALLY-OCCURRING ANTHRAQUINONE - ITS ISOLATION AND SPECTROPHOTOMETRIC DETERMINATION IN RUMEX CYPRIUS PLANT, Spectroscopy letters, 29(8), 1996, pp. 1539-1543
A new method for isolation and specrophotometric determination of emod
in is presented. Emodin was isolated by thin layer chromatography (tlc
) and column chromatography (cc) techniques, as an orange long crystal
line substance. Emodin exhibits two absorption maxima, at 320 and 520
nm. Stability of the color and the effect of pH were studied. Beer's l
aw is obeyed in the range 2-30 ppm. The method is applied to the deter
mination of emodin in roots, stems, and leaves of Rumex cyprius plant.
[GRAPHICS] on the stereochemistry of the molecule was obtained from 2
D NOESY and NOE-difference techniques.