The present invention is directed to compounds which are conjugates of two non-toxic natural products, noscapine (and various noscapine analogs) and folic acid (and various folic acid analogs), where the folic acid is conjugated to noscapine or the noscapine analog at the 9-position on the isoquinoline ring on the noscapine framework. Pharmaceutical compositions including the compounds, and methods of treating various tumors using the compounds and compositions, are also disclosed. The conjugates are particularly useful for treating cancers which overexpress the Folate Receptor α (FRa) receptor.
