6) were evaluated for anticancer potential using cell cycle progression markers. No effect on MCF-7 cell viability or apoptosis was seen with these derivatives at concentrations of up to 100?μM after 72?h of incubation. At 100?μM, sarcophine and its derivatives 2-strong class="a-plus-plus">5 arrested the MCF-7 cells in G0/G1 phase, with concomitant decrease in the cell populations at S and G2+M phases. MDA-MB-231 cells were not responsive to any of the derivatives. Our preliminary results suggest that the sulfur-containing derivatives of sarcophine, especially 2 and 3, show potent and cell-specific antiproliferative activity." />