Carthmin,the red coloring matter of the flowers of Carthamus tinctorius L.(Safflower), is one of the representative old Japanese natural dyestuff with shikonin and indigo. The existence of yellow carthamin precursor in the extracts of the florets of safflower has hitherto been known, however, the structure has not been elucidated yet by reason of its instability. The yellow precursor was isolated from the fresh florets of Safflower, as micro needles through many purifying method, mainly column chromato-graphy. This pigment was unstable and immediately changed to red carthamin on spraying peroxidase-H_2O_2 solution. The ^1H- and ^<13>C-NMR spectra of this compound exhibited the existence of>CH-COOH moiety instead of-CH=moiety on carthamin. From these results along with mass spectral data, we propose the structure (1) for the precursor of carthamin. Further, the chemical and the spectral evidences of synthetic modet compound (3) were similar to those of precursor.
