| Abstract: | The influence of dioxybenzenes and their quinones on Dunaliella salina, Nitella sp. and Elodea canadensis was investigated. It was established that the higher the rate of polyphenol oxidation by the aqueous plants, the higher the toxicity of the compound being studied is and the larger the reduction of the SH-group content due to the incubation of plants in these polyphenol solutions is. Formation of o- and p-benzoquinones by the aquatic plants in the course of dioxybenzene oxidation was proved. Treatment of plants with quinone solutions led to a larger SH-group concentration drop than with phenols. Oxidation products of pyrocatechol, caffeic and chlorogenic acids caused the greatest decrease of the SH-group content directly at the moment of their preparation, i. e., when the o-quinone concentration was at its maximum. The conclusion is drawn that a higher degree of toxicity to the aquatic plants of pyrocatechol and hydroquinone, in comparison with other phenols, is due to their ability to oxidize phenols to quinones. It is suggested that one of the possible biochemical mechanisms for demonstrating the toxic action of the phenol oxidation products is the blocking of SH-groups. |
