Chemical modification of curcumin: Solubility and antioxidant capacity

Figures & data

Figure 1. NMR spectra of curcumin, curcumin-HBr and curcumin-choline chloride.

Table 1. Antioxidant effect of curcumin and treated curcumin on DPPH and ABTS radical scavenging and formation of phosphomolybdenum complex (PM).

Sample	DPPH	ABTS	PM
	IC50	IC50	EC50
Curcumin	16.4 ± 0.82	0.91 ± 0.031	114 ±5.8
Curcumin-HBr	7.4 ± 0.43	0.42 ± 0.022	41 ± 3.6
Curcumin-choline chloride	11.0 ± 0.54	0.74 ± 0.033	30 ± 2.3

IC₅₀ (µg) is the inhibition concentration of the test sample that decreases 50% initial radical.

EC₅₀ (µg) is the efficient concentration of the test sample that increases O.D 0.5.

Each value is expressed as means ± SD (n = 3).

Figure 2. Correlation between the concentrations of (1) curcumin, (2) curcumin-HBr, and (3) curcumin-choline chloride, and their antioxidant capacity as determined by DPPH assay.

Figure 3. Correlation between the concentrations of (1) curcumin, (2) curcumin-HBr, and (3) curcumin-choline chloride and their antioxidant capacity as determined by ABTS assay.

Figure 4. Correlation between the concentrations of (1) curcumin, (2) curcumin-HBr, and (3) curcumin-choline chloride and their antioxidant capacity as determined by formation of phosphomolybdenum complex assay.