8-(1,1-Dimethyl-2-propenyl)-3'-methoxykaempferol is an isoprenylated kaempferol derivative extracted from fresh pak choi buds with anticancer and antitumor activity.8-(1,1-Dimethyl-2-propenyl)-3'- 8-(1,1-Dimethyl-2-propenyl)-3'- methoxykaempferol showed antiproliferative activity and cytotoxicity in human breast cancer (MCF-7) and human hepatocellular carcinoma (Hep-G2) cell lines.