Study The Method To Determine The Free State Of Fe³⁺ In Decoction Of Traditional Chinese Medicine And Application

Iron is one of the most important essential elements in the biological systems and plays a key role in many biochemical processes at the cellular level, such as the synthesis of DNA and hemoglobin, electron transfer, ATP production, cellular respiration, cell proliferation and differentiation and regulation of gene expression. The change of the amount of Fe3+is associated with many diseases, including certain cancers and dysfunction of organs. Iron deficiency can lead to the enzyme activity becoming lower and cell function disorder, diminished strength and fatigue. This also can cause abnormity of tissues and organs and so on. However, accumulation of iron can cause many diseases, including diabetes mellitus, arteriosclerosis, Parkinson’s disease, Alzheimer’s disease and Osteoporosis. The absorption, intake, utilization and reserve of iron are regulated by precision mechanism in hunman body, but there is no effective mechanism for the excretion of excess iron. So when too much exogenous iron was taken in which would result in iron overload.Some traditional Chinese medicines (TCMs) are reported that could treat the diseases such as Alzheimer’s disease, Parkinson’s disease and Osteoporosis. It is speculated that the therapeutical effects of TCM for these diseases may have the relationshio with iron excretion by forming complex with constituents in TCM. In order to evaluate the iron chelating ability of constituents in TCM, the contents of free Fe3+in decoction should be determined. If the constituents in decoction have strong chelating ability, the recovery of determined free Fe3+would be much less than expected value after adding a certain amount of Fe3+ion. Because of the addition of Fe3+was used to form complex with the constituents in decoction. Therefore, the adding recovery can be used to reflect the iron chelating ability. A method was proposed to determine free Fe3+in decoction of TCM based on the catalytic effect of Fe3+on the spirolactam (nonfluorescence) of rhodamine B hydrazide derivative (FD1) to ring-open amide (fluorescence).Ethanolic solution of FD1mixing with the decoction of TCM for5min, the reaction was followed spectrophotometrically by measuring the absorbance of colored ring-open amide at 563nm. The contents of free Fe3+could be obtained by comparing with the standard curve. The linearity was good in the range of1.68-22.4mg/L, r=0.9990. The average recovery was between90.45%and104.11%with RSD<5%. The contents of free Fe3+were determined in84TCMs. By adding a certain amount of Fe3+ion to the decoction of each TCM, recovery was used to evaluate the chelating ability. The results show that Cyathula officinalis possesses highest chelating strength. The chelating strength of kidney-tonifying traditional Chinese medicines are also higher than the others.