Lack of mutagenicity of a red food colour impurity (1- carboxyl-5,7-dibromo-6-hydroxy-2,3,4-trichloroxanthone) in Phloxine B

Abstract

To evaluate the mutagenicity of 1-carboxyl-5,7-dibromo-6-hydroxy-2,3,4-trichloroxanthone (HXCA), which is an impurity present in Food Red No. 104 (FR104, Phloxine B, the Japanese counterpart of D&C Red No. 28), HXCA was isolated from FR104 using pH-zone-refining counter-current chromatography and preparative HPLC. A large amount of HXCA was synthesized to perform the Ames test, and its identity was confirmed by comparison of its HPLC retention time, UV-Vis, MS and NMR spectra with those of HXCA isolated from FR104. The results of the Ames test using synthetic HXCA showed that it did not possess mutagenic activity. The results of the mutagenicity test for HXCA will provide useful information for the establishment of an upper limit for HXCA in FR104 (or D&C Red No. 28) for use in regulatory considerations.