A tricatecholic receptor for carbohydrate recognition: synthesis and binding studies

Area of Science:

• Organic Chemistry
• Supramolecular Chemistry
• Carbohydrate Chemistry

Background:

• Tripodal receptors are crucial in supramolecular chemistry for molecular recognition.
• Catechol and ureidic moieties serve as key hydrogen-bonding units in host-guest interactions.
• Understanding monosaccharide binding is vital for biological and chemical applications.

Purpose of the Study:

• To synthesize and characterize a new tripodal receptor with catechol subunits.
• To investigate the binding affinities and selectivities of this receptor towards various monosaccharides.
• To compare its performance with a structurally analogous ureidic receptor.

Main Methods:

• Multi-step organic synthesis starting from 1,3,5-triethylbenzene and pyrogallol.
• 1H NMR titrations in CDCl3 to determine association constants.
• Utilizing the BC50 parameter to quantify binding affinities in multi-equilibrium systems.

Main Results:

• The tripodal catechol receptor was successfully synthesized.
• Binding affinities for octyl glycosides ranged from 0.87 to 5.2 mM.
• A 6-fold selectivity was observed for alpha-mannoside over beta-glucoside.
• Affinity was comparable to the ureidic analog, but selectivity significantly improved.

Conclusions:

• The tripodal catechol receptor demonstrates effective binding and selectivity for monosaccharides.
• Replacement of ureidic groups with catecholic ones significantly alters binding selectivity.
• This receptor design offers a platform for developing selective carbohydrate sensors.