Cytotoxicities, cell cycle and caspase evaluations of 1,6-diaryl-3(Z)-hexen-1,5-diynes, 2-(6-aryl-3(Z)-hexen-1,5-diynyl)anilines and their derivatives.

Compounds 3, 6–7, 9–10, 15–17, and 20–21 showed growth inhibition effects on a full panel of 60 human cancer cell lines, and most of the average IC50 values of the indicated analogues were from <0.01 to 96.6μM, in which analogues 16 and 17 revealed the highest cytotoxic activity with the cancer cell lines at 10−7M concentration range. During the cell cycle analysis, a moderate to high apoptotic progress induction was shown by 3, 9, 16–17, and 20 compared with the control, which 2-(6-(2-thienyl)-3(Z)-hexen-1,5-diynyl)aniline 16 showed the highest apoptotic effect. Structures 16–17 displayed a significant G2/M phase arrest in the cell growth cycle compared with other derivatives, which the proportions of the G2/M phase cells were accumulated to 71.5% and 82.6%, respectively. Moreover, the colorimetric assay of 16–17 also provided advanced evidence to the relationship between the compounds and the caspase-3 enzyme, which was one of the major promoters of apoptotic effect.