Biotransformation of gentian violet to leucogentian violet by human, rat, and chicken intestinal microflora.

Cellular suspensions of microflora isolated from human feces and from intestinal contents of rat and chicken transformed the triphenylmethane dye gentian violet under anaerobic conditions. Pure cultures of nine genera of strict and facultative anaerobes were also active. All pure cultures and mixed intestinal microflora were found to convert the dye to leucogentian violet. Leucogentian violet was identified by HPLC retention time in a reverse phase system, and by mass spectral comparison with authentic compound. Leucogentian violet was extracted from the supernatants of the microfloral cultures, but the major portion of the metabolite was often bound to the cells (up to 87% of the metabolite produced by human microflora). Metabolites were quantitatively extracted from cell-free supernatants with 1-butanol/hexane, and from cellular pellets with trichloracetic acid. Leucogentian violet, amounting to 11% of the total radioactivity, was also detected by HPLC in ether extracts of feces collected from a female Fischer 344 rat dosed orally for 4 days with 14C-labeled gentian violet.