Biomimetic Metal-Organic Nanotubular Host for Straight-Chain Fatty Acids Recognition

Area of Science:

• Supramolecular Chemistry
• Biomimetic Chemistry

Background:

• Fatty acids have diverse biological roles, but their recognition by molecular receptors is challenging due to their flexible hydrocarbon chains.
• Natural fatty acid-binding proteins (FABPs) offer a model for selective fatty acid recognition.

Purpose of the Study:

• To design and synthesize artificial receptors capable of selective fatty acid recognition, inspired by FABPs.
• To investigate the binding mechanisms and selectivity of these artificial receptors for different fatty acid structures.

Main Methods:

• Coordination-driven assembly of pillararene-derived ligands with silver(I) salts to form nanotubular metallo-cavitands (metal-organic pillars).
• Characterization of the host-guest interactions using structural and binding studies.
• Evaluation of selectivity based on fatty acid conformation (linear vs. coiled).

Main Results:

• Successfully synthesized metal-organic pillars with internal channels >2.6 nm.
• Demonstrated selective binding of linear saturated and trans fatty acids via C-H···π and van der Waals interactions.
• Showed exclusion of coiled cis-polyunsaturated fatty acids, like DHA, due to structural incompatibility.

Conclusions:

• Artificial receptors can effectively emulate the molecular recognition capabilities of natural proteins.
• Metal-organic pillars provide a platform for selective binding of specific fatty acid conformations.
• This approach enables the targeting of "bad" fatty acids linked to adverse health effects.