Changing the Solvent for Iron

In order to evaluate the iron-curcumin complex, solutions of equal molarity were prepared.  The solution of Fe(III) was prepared using water, and the curcumin solution was prepared using ethanol.  When a UV spectrum was run, the usual peaks for the iron-curcumin complex did not appear.  This problem was rectified when a new solution of the same molarity of Fe(III) was prepared using ethanol instead of water.  The difference was immediately apparent.

Both of these solutions contain the exact same ratio of iron to curcumin, but the solution on the left was made with the iron dissolved in water and the solution on the right was made with the iron dissolved in ethanol.  The color change in the solution on the left indicates the formation of the iron-curcumin complex.





The difference seen visually was supported by the UV spectrum results as well.  The following two runs are the results from the solutions in the previous picture.  The orange line represents the solution made with the iron dissolved in water and the black line represents the solution made with iron dissolved in ethanol.  On the black line, the shift of the tallest peak as well as the appearance of the shoulder around 540nm indicates the formation of the iron-curcumin complex.

These results indicate that iron is complexing with water and once this complex occurs, it cannot be removed for use by the curcumin.  This means that in order to prepare a premade complex for biological use, the iron must not come into contact with anything else it can form complexes with.

6/18/18
-Alex Griffith