Figure 2

Cluster analysis of growth inhibition of 88 curcuminoids. The IC50 values are graded by coloring from red (0 μM) to cyan (50 μM). Eighty eight analogs are lined in perpendicular, and 16 cancer cell lines are lined in horizontal. Group a is composed of the analogs with the high IC₅₀ values, and Group b composed of analogs with the low IC₅₀ values, and Group c includes the analogs with the lowest IC₅₀ values. The analogs enclosed with red rectangle are DOPs, and the analogs attached with closed circle are non-DOPs. Acyclic DOPs are indicated by open circle. Blue arrows indicate the analogs of which predictive values of solubility are better than curcumin.