摘要:Objective: to evaluated the antiproliferative activity of natural coumarin from Calophyllum incrasaptum M.R Henderson-Wytt Smith against human breast cancer cells MCF-7. Methode : Coumarin from ethyl acetate fraction of C. incrasaptum M.R Henderson-Wyatt Smith was isolated by coloumn chromatographyic and structure elucidated by using spectroscopic methods and isolate compound was evaluated for their antiproliferative activities in the alamar blue assay. Result: Coumarin have antiproliferative activity against MCF-7 cancer cell lines through alamar blue assay for 4 h after treatment. Conclusions: coumarin showed good activity against cancer cell lines with IC50 value of 2.23 μg/mL.