Notice of RetractionQuantification of Tetrandrine and Fangchinoline in Water Extract of Stephania tetrandra and Their Effects on Chlorella pyrenoidosa

Notice of Retraction

After careful and considered review of the content of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE´s Publication Principles.

We hereby retract the content of this paper. Reasonable effort should be made to remove all past references to this paper.

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The quantification of fangchinoline and tetrandrine in water extract of Stephania tetrandra and their effects on Chlorella pyrenoidosa were performed. The result showed that the fangchinoline content varied from 59.2-71.6 g kg^-1 dry weight in water-extracted solution of Stephania tetrandra. The content of tetrandrine were between 40.7and 46.3 g kg^-1 dry weight. Exogenously added fangchinoline and tetrandrine inhibited the growth of Chlorella pyrenoidosa respectively, with EC_50,6d of 12.44 mg L^-1 and 9.90 mg L^-1 (6 days). The EC_50,7d of Stephania tetrandra extract on Chlorella pyrenoidosa was 10.02 mg L^-1 (7 days). Furthermore, the extract of Stephania tetrandra did not change pH, turbidity, electrical conductivity and chlorophyll a obviously, indicating that Stephania tetrandra, as a kind of algicides, did not remarkably impact the safety of aquatic ecosystem. Therefore, we concluded that Stephania tetrandra might be a potential effective method in control and mitigation of harmful algal bloom.