PMC-A is the most cytotoxic compound among PMC analogs.

<p>Viabilities of HCT116 cells were analyzed by MTT assay following 24 h treatment with 100 µM of each PMC analog. Wild-type HCT116 cells were assayed colorimetrically following 24 h treatment with PMC analogs. Average absorption values relative to untreated control are displayed after multiplication with 100. The results from at least 3 independent experiments were shown as means ± SD. Difference of mean values between treated and untreated samples were tested using unpaired student’s t-test; <b>**</b>P<0.01. Control cells were treated with solvent only. All tested analogs except the precursor PMC led to significant loss of viability/proliferation while PMC-A and -F proved most cytotoxic to cells.