Table 1.

Calculation of curcuminoid concentration based on spectral analysis. Different concentrations of our curcuminoid preparation were analyzed in a SpectraMax M2e spectrophotometer in a volume of 200 µL (pathlength 0.56 cm). The calculated values were in good agreement with the estimated values, indicating a high degree of purity in our curcuminoid preparation.

Estimated Concentration (µM)	A427 Pathlength 0.56 cm	Observed Concentration (µM)
1.25	0.0477	1.4
2.5	0.0915	2.6
5	0.1787	5.2
10	0.3366	9.7
20	0.663	19.1