Biotransformation of Pyrene by Cell Cultures of Soybean (Glycine max L.), Wheat (Triticum aestivum L.), Jimsonweed (Datura stramonium L.), and Purple Foxglove (Digitalis purpurea L.)

The metabolism of the four-ringed polycyclic aromatic hydrocarbon (PAH) pyrene was investigated using cell suspension cultures of soybean, wheat, purple foxglove, and jimsonweed and callus cultures of soybean and foxglove. In all species, nonextractable residues were found (soybean, jimsonweed, and foxglove suspensions, <10% of applied ¹⁴C; soybean and foxglove callus cultures, 20-25%; wheat, 30-40%); soluble metabolites were detected in only foxglove and wheat. About 90% of applied pyrene was transformed in wheat. Corresponding data from soybean and foxglove callus cultures were about 30% and those from soybean, jimsonweed, and foxglove suspensions about 7%. In foxglove, 1-hydroxypyrene methyl ether was identified as the main metabolite, whereas a complex mixture of carbohydrate conjugates of 1-hydroxypyrene was found in wheat. Due to the present results, crop and wild plants may be metabolic sinks for PAHs in the environment. Concentrations and toxicological implications of 1-hydroxypyrene, its derivatives, and analogous metabolites of other PAHs should be investigated.