The P-gp, MRP1 and BCRP inhibitory properties of 11 were detected, measured and quantified by calcein AM accumulation and cell flow cytometry based (accumulation or efflux) assays against human colon cancer (SW620 and SW620 Ad300), ovarian carcinoma (2008 and 2008/MRP1) and non-small cell lung (NCI-H460 and NCI-460/MX20) cells, respectively, with further validation of P-gp inhibitory properties measured in Hoechst 33342 accumulation and efflux, and doxorubicin drug resistance reversal assays, and of BCRP inhibitory properties in [3H]-mitoxantrone drug accumulation and efflux assays. The gene discussed is PGP; the disease is malignant colon neoplasm.