Chiral recognition in aggregates formed by chiral bola-amphiphiles

The aggregates of three new isomeric chiral bola-amphiphiles have been taken into consideration as models for investigating chiral recognition in biological membranes. The recognition capabilities of the aggregates were explored following (by CD and HPLC experiments) the shift in the equilibrium between the inter-converting enantiomers of a biphenylic derivative and bilirubin, used as markers of chirality. The chiral recognition experiments were performed under different pH and concentration conditions. The results were compared with those relative to the aggregates formed by an equimolar mixture of single head/single chain amphiphiles that mimic the structure of the bola surfactant devoid of a covalent link.

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(2S)-1-[12-(2-{12-[(2S)-2-Carboxypyrrolidine-1-yl]dodecyloxy}phenoxy)dodecyl]pyrrolidine-2-carboxylic acidC40H68N2O6[α]D = −23.7 (c 1.38, MeOH)Absolute configuration: (2S)Soure of chirality: l-Proline

(2S)-1-[12-(3-{12-[(2S)-2-Carboxypyrrolidine-1-yl]dodecyloxy}phenoxy)dodecyl]pyrrolidine-2-carboxylic acidC40H68N2O6[α]D = −24.0 (c 1.76, MeOH)Absolute configuration: (2S)Soure of chirality: l-Proline

(2S)-1-[12-(4-{12-[(2S)-2-Carboxypyrrolidine-1-yl]dodecyloxy}phenoxy)dodecyl]pyrrolidine-2-carboxylic acidC40H68N2O6[α]D = −24.7 (c 2.25, MeOH)Absolute configuration: (2S)Soure of chirality: l-Proline

(2S)-1-(12-Phenoxydodecyl)-pyrrolidine-2-carboxylic acidC23H37NO3[α]D = −23.8 (c 1.56, MeOH)Absolute configuration: (2S)Soure of chirality: l-Proline