Nitric oxide release from a cucurbituril encapsulated NO-donor

Area of Science:

• Supramolecular Chemistry
• Chemical Biology
• Materials Science

Background:

• Controlling the decomposition of S-nitrosothiols and the subsequent release of nitric oxide (NO) is crucial for various applications.
• Nitric oxide plays vital roles in physiological processes and is a target for therapeutic interventions.

Purpose of the Study:

• To investigate the effect of cucurbituril encapsulation on the stability and reactivity of S-nitrosothiols.
• To develop a method for controlled nitric oxide release using host-guest complexation.

Main Methods:

• Synthesis and characterization of nitrosomercaptopyridine (SNO+).
• Complexation of SNO+ within the cucurbit[7]uril (CB7) macrocycle.
• Kinetic studies to determine denitrosation rate constants.
• Measurement of nitric oxide release using a selective electrode.

Main Results:

• Encapsulation of SNO+ within the CB7 cavity significantly increased its nitrosation equilibrium constant.
• Host-guest complexation drastically reduced the denitrosation rate constant of SNO+.
• SNO+ encapsulation prevented its decomposition into disulfide and nitric oxide.
• Controlled nitric oxide release was achieved by chemically inducing the expulsion of SNO+ from the CB7 cavity.

Conclusions:

• Cucurbit[7]uril acts as a stabilizing host for S-nitrosothiols, modulating their reactivity.
• This host-guest system provides a platform for the controlled release of nitric oxide.
• The findings have implications for developing NO-releasing agents for therapeutic and research purposes.