Objective:To study and establish a high-throughput and rapid detection method for fluorine ion content in water based on 96-well plate and microplate reader, and to evaluate its performance.Methods:According to the principle of blue ternary complex formed by reaction of fluorine ion with fluorine reagent and lanthanum nitrate, the absorbance of the complex at the wavelength of 650 nm was proportional to the concentration of fluoride ion, and the content of fluoride ion in water samples was quantitatively determined by microplate reader. The accuracy, precision and detection limit of the method were evaluated by the standard recovery rate method and the reference material method.Results:The linear correlation coefficient of the standard curve of this method was > 0.999; the standard recovery rates of different concentrations were 99.00% - 103.33% in the accuracy experiment of this method, and the average recovery rate was 101.08%. In the standard material method, the measured values are all within the calibration range of the standard solution. The relative standard deviation of water samples with different concentrations was ≤10% in the precision experiment and the detection limit was 0.06 mg/L.Conclusion:The method has good accuracy and precision, low detection limit and small sample consumption, and this method can greatly improve the detection efficiency.

Hyperaldosteronism is a common disease that is closely related to endocrine hypertension and other cardiovascular diseases. Cytochrome P450 11B2 (CYP11B2), an important enzyme in aldosterone (ALD) synthesis, is a promising target for the treatment of hyperaldosteronism. However, selective inhibitors targeting CYP11B2 are still lacking due to the high similarity with CYP11B1. In this study, atractylenolide-I (AT-I) was found to significantly reduce the production of ALD but had no effect on cortisol synthesis, which is catalyzed by CYP11B1. Chemical biology studies revealed that due to the presence of Ala320, AT-I is selectively bound to the catalytic pocket of CYP11B2, and the C8/C9 double bond of AT-I can be epoxidized, which then undergoes nucleophilic addition with the sulfhydryl group of Cys450 in CYP11B2. The covalent binding of AT-I disrupts the interaction between heme and CYP11B2 and inactivates CYP11B2, leading to the suppression of ALD synthesis; AT-I shows a significant therapeutic effect for improving hyperaldosteronism.