A COMPARISON OF THE TOXICITY AND METABOLISM OF PHENOL AND CHLORINATEDPHENOLS BY LEMNA-GIBBA, WITH SPECIAL REFERENCE TO 2,4,5-TRICHLOROPHENOL

The toxicity of a series of chlorinated phenols, from phenol to pentac hlorophenol, was determined using frond reproduction in aseptically gr own Lemna gibba. The toxicities of the phenols tended to increase as t he number of chlorine substituents on the phenol ring increased. The p lants metabolized each of the phenols in the same manner producing met abolites that were more polar than their parent compounds. The metabol ite for 2,4,5-trichlorophenol was isolated and identified by nuclear m agnetic resonance spectroscopy and chemical ionization mass spectrosco py. The structural identity was confirmed by comparison with synthetic material as 2,4,5-trichlorophenyl-beta-D-glucopyranoside. These resul ts, together with previously published results, suggest that conjugati on with D-glucose is a stereotypic response of duckweed to challenge b y phenol and chlorinated phenols.