Separation of Enantiomers of a Phospholipid in Langmuir Monolayers by a New Selector

Abstract

Chiral discrimination in a racemic mixture of dipalmitoylphosphatidylcholine (DPPC) is induced by a new selector at the water-air interface: L-DPPC is segregated in the condensed phase of a Langmuir monolayer upon interactions with an enantiopure amphiphilic compound.

Enantiomers of phospholipids and cholesterol: A key to decipher lipid‐lipid interplay in membrane

“…Brewster angle microscopy images at the water‐air interface for Langmuir monolayers D‐DPPC (A) and D,L ( racemic )‐DPPC (B) . D‐DPPC enantiomer forms multilobar patterns (A), the shape of which is directly correlated with the absolute configuration, while racemic DPPC does not exhibit a chiral pattern (B).…”

“…A Brewster angle microscopy study revealed that the monolayer membrane of DPPC enantiomers (Figure ) forms multilobar or rosette assemblages in a stereochemistry‐dependent manner . Different domain shapes were observed depending on the compression rate.…”

“…Different domain shapes were observed depending on the compression rate. Actually, the slow formation of the homophilic assemblage comprising L‐DPPC or D‐DPPC exhibited polarities with the formation of counterclockwise or clockwise lobes (Figure A), while the lobes from the racemic mixture lost polarity (Figure B) . The formation of such multilobar domains with chirality‐specific polarity was assumed to be related to the balance between the electrostatic repulsion of the oriented head groups and the line tension to compact the domain .…”

“…A Brewster angle microscopy study revealed that the monolayer membrane of DPPC enantiomers ( Figure 12) forms multilobar or rosette assemblages in a stereochemistry-dependent manner. 57 Different domain shapes were observed depending on the compression rate. Actually, the slow formation of the homophilic assemblage comprising L-DPPC or D-DPPC exhibited polarities with the formation of counterclockwise or clockwise lobes ( Figure 13A), while the lobes from the racemic mixture lost polarity ( Figure 13B).…”

“…[57][58][59][60] The formation of such multilobar domains with chirality-specific polarity was assumed to be related to the balance between the electrostatic repulsion of the oriented head groups and the line tension to compact the domain. 57 In terms of the head group orientation, recent MD simulations suggested that the choline moiety of PC (Cβ-Cα-O-P-O) assumes four consecutive +gauche conformations and mirror image −gauche conformations in an almost similar ratio. 61 Therefore, the stereoselective head group repulsion unlikely lead to the charity-dependent head group conformation.…”