Camptothecin-7-yl-methanthiole: semisynthesis and biological evaluation.

The introduction of a methylenthiol group at position 7 of camptothecin was carried out in four steps. This preparation also yielded the corresponding disulfide, which behaves as a prodrug due to its reactivity with glutathione. Assessment of their antiproliferative activities, investigations of their mechanism of action, and molecular modeling analysis indicated that the 7-modified camptothecin derivatives described herein maintain the biological activity and drug–target interactions of the parent compound.