Angelylalkannin, a naphthoquinone compound isolated from the roots of Alkanna tinctoria, exhibits significant antiproliferative effects on human colon cancer cells HCT-116 and SW-480. The median inhibitory concentration (IC50) of Angelylalkannin is 4.76 mM for HCT-116 cells and 7.03 mM for SW-480 cells. Similar to alkannin, Angelylalkannin induces cell cycle arrest in the G1 phase and cell apoptosis at concentrations ranging from 1-10 mM.