Used in cancer treatment, particularly for colorectal, ovarian, and small cell lung cancers. Acts as a topoisomerase I inhibitor, preventing DNA replication in cancer cells, leading to cell death. Serves as the parent compound for synthetic derivatives like irinotecan and topotecan, which are more water-soluble and widely used in chemotherapy. Also investigated for antiviral properties, especially against herpesviruses and hepatitis B. Studied in targeted drug delivery systems, including nanoparticle formulations, to improve tumor specificity and reduce side effects.