Solubility-Improved 10-O-Substituted SN-38 Derivatives with Antitumor Activity

Area of Science:

• Medicinal Chemistry
• Organic Synthesis
• Pharmacology

Background:

• SN-38 is a potent antitumor agent with poor water solubility, limiting its clinical application.
• Developing strategies to enhance SN-38's solubility is crucial for improving its therapeutic potential.

Purpose of the Study:

• To synthesize novel 10-O-substituted SN-38 derivatives to improve water solubility.
• To evaluate the solubility, cytotoxicity, and in vivo antitumor activity of these new derivatives.

Main Methods:

• Synthesis of SN-38 derivatives with fluoroalkyl, fluorobenzoyl, or bromobenzoyl groups at the 10-O position.
• Solubility assessment in phosphate-buffered saline.
• In vitro cytotoxicity assays using the PC-3 prostate cancer cell line.
• In vivo antitumor studies in PC-3 tumor-bearing mice.

Main Results:

• The 10-O-fluoropropyl derivative (compound 2) exhibited a 17-fold increase in solubility compared to SN-38.
• Compound 2 demonstrated approximately 50% of SN-38's biological activity in vitro but superior in vivo antitumor efficacy.
• Other derivatives showed modest solubility improvements with comparable in vitro activity to SN-38.

Conclusions:

• 10-O-modifications represent a viable strategy to enhance SN-38's solubility and therapeutic efficacy.
• The developed synthetic route allows for the potential creation of radiolabeled SN-38 derivatives for PET imaging.
• These findings support the medicinal chemistry applications of SN-38 modifications and re-establish its therapeutic potential.