Abstract
It is known that plants detoxify several compounds with several modifications such as hydroxylation or glutathionation, and accumulate them in the cells. We report here the metabolism of exogenously added harmful compound naphthols in tobacco cells. Most of added naphthols were accumulated in the cell as glucosides with further modification. The glucosylation activities against naphthols increased in proportion to the concentration of naphthols in the culture medium.
To investigate further, the metabolite of naphthol was purified from the naphthol-treated tobacco cells, and determined the structure as malonylglucoside. Strong malonylation activity was detected in the cell-free extract of tobacco cells using naphtholglucoside as a substrate. Furthermore, when naphthol was added to cell cultures of Sophora and Lithospermum, the added naphthol was accumulated as malonylglucoside in the cells. These results suggested the existence of the metabolizing system that accumulates such xenobiotic compounds as malonylglucoside in plant.
