1-[[4-[(3,4-dichlorophenyl)thio]-3-pyridinyl]sulfonyl]-3-propylurea

1-[[4-[(3,4-dichlorophenyl)thio]-3-pyridinyl]sulfonyl]-3-propylurea, also known as **L-735,524**, is a potent and selective **inhibitor of the enzyme carbonic anhydrase IX (CA IX)**.

**Carbonic anhydrase IX (CA IX)** is an enzyme that plays a crucial role in the growth and survival of tumor cells. It is overexpressed in various types of cancers, particularly those that are hypoxic (low oxygen levels). CA IX helps tumor cells adapt to these harsh conditions by regulating the pH of the tumor microenvironment.

**Why is L-735,524 important for research?**

* **Anti-cancer drug development:** L-735,524 has shown promising anti-cancer activity in preclinical studies. By inhibiting CA IX, it can slow down tumor growth and potentially improve the efficacy of other cancer therapies.
* **Understanding the role of CA IX in cancer:** L-735,524 acts as a valuable tool to investigate the role of CA IX in cancer progression and metastasis.
* **Development of new CA IX inhibitors:** Understanding the mechanism of action of L-735,524 can guide the development of more potent and selective CA IX inhibitors for future therapeutic applications.

**Key features of L-735,524:**

* **High potency:** It exhibits strong inhibition of CA IX with a Ki value in the nanomolar range.
* **Selectivity:** It is highly selective for CA IX over other isoforms of carbonic anhydrase.
* **Good pharmacokinetic properties:** It has favorable bioavailability and pharmacokinetic profile, making it suitable for in vivo studies.

**However, it is important to note that L-735,524 is not currently used clinically. Further research is needed to assess its safety and efficacy in human patients.**