Analytical method to evaluate chelating capacity of constituents in decoction of Chinese materia medica with free iron ions / 中草药

ABSTRACT

Objective: To establish the in vitro screening method for determining what kinds of Chinese materia medica (CMM) and which main constituents in the medicine used for the treatment of Alzheimer's disease, Parkinson's disease, and osteoporosis can chelate with free iron ions (Fe3+) and evaluating the chelating strength. Methods: Based on the catalytic effect of Fe3+ on the spirolactam (nonfluorescence) to ring-open amide reaction (fluorescence), the catalytic spectrophotometric method was established to determine the free Fe3+ in the decoction of CMM, by adding a certain amount of iron ion and determinig the chelating level to evaluate the chelating strength of the constituents in CMM. Results: The chelating strength of kidney-tonifying CMM is stronger. The catalytic spectrophotometric method could be used to determine the free Fe3+ in the decoction of CMM and the linearity was good in the range of 1.68-22.4 mg/L, r = 0.999 0. The average recovery was between 90.45% and 104.11% with RSD < 5%. Conclusion: This method can be used to evaluate the chelating capacity of constituents in CMM with Fe3+.