Cocaine detoxification by combinatorially substituted beta-cyclodextrin libraries

Area of Science:

• Supramolecular Chemistry
• Organic Chemistry
• Catalysis

Background:

• Beta-cyclodextrins (beta-CDs) are cyclic oligosaccharides with a hydrophobic cavity and hydrophilic exterior.
• Modified beta-CDs can act as artificial enzymes (zymes) for various chemical transformations.
• Cocaine hydrolysis is a target reaction for developing selective catalytic systems.

Purpose of the Study:

• To synthesize and screen libraries of per-6-substituted and tri-substituted 6-deoxy-beta-cyclodextrins for cocaine hydrolytic activity.
• To identify structure-activity relationships governing the catalytic hydrolysis of cocaine.
• To explore the predictive potential of per-substituted beta-CD libraries for designing active tri-substituted analogs.

Main Methods:

• Solution-phase combinatorial chemistry was employed to generate diverse beta-CD libraries from iodo precursors.
• High-throughput electrospray mass spectrometry (ESMS) was used to screen libraries for cocaine hydrolysis.
• Analysis of cocaine hydrolytic activity and comparison of active library compositions.

Main Results:

• Several per-6-substituted beta-CD libraries demonstrated specific hydrolysis of cocaine's methyl ester.
• The most active library (per-6-substituted beta-CD I) achieved complete cocaine hydrolysis within 24 hours.
• Structure-activity relationships indicated specific interactions between beta-CD amine side chains and cocaine.
• Three common side chains were identified in the most active per-substituted and tri-substituted beta-CD libraries.

Conclusions:

• Modified beta-cyclodextrins can be designed as effective catalysts for cocaine hydrolysis.
• The per-6-substituted beta-CD series provides a valuable platform for predicting the activity of more complex tri-substituted analogs.
• This study highlights the potential of combinatorial chemistry and high-throughput screening in discovering novel catalytic systems.