DNA polymerase-IN-1, a DNA polymerase inhibitor, exhibited antiproliferative activity against tumor cells with a half-inhibitory concentration (IC50) of 20.7 μM. DNA polymerase-IN-1 inhibited Taq DNA polymerase with an IC50 of less than 250 μM. DNA polymerase-IN-1 was shown to inhibit Taq DNA polymerase by RT- DNA polymerase-IN-1 showed antiretroviral activity in vitro by RT-PCR assay and can be used to study oxidative damage and colorectal cancer.