title: Highly asymmetrical glycerol diether bolalipids: synthesis and temperature-dependent aggregation behavior.
abstract: In the present work, we describe the synthesis and temperature-dependent aggregation behavior of two examples of a new class of highly asymmetrical glycerol diether bolaphospholipids. The bolalipids contain a long alkyl chain (C32) bound to glycerol in the sn-3 position, carrying a hydroxyl group at the ω position. The C16 alkyl chain in the sn-2 position either possesses a racemic methyl branch at the 10 position of the short alkyl chain (lipid II) or does not (lipid I). The sn-1 position of the glycerol is linked to a zwitterionic phosphocholine moiety. The temperature-dependent aggregation behavior of both bolalipids was studied using differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy, and X-ray scattering. Aggregate structures were visualized by transmission electron microscopy (TEM). We show that both bolalipids self-assemble into large lamellar sheetlike aggregates. Closed lipid vesicles or other aggregate structures such as tubes or nanofibers, as usually found for diglycerol tetraether lipids, were not observed. Within the lamellae the bolalipid molecules are arranged in an antiparallel (interdigitated) orientation. Lipid I, without an additional methyl moiety in the short alkyl chain, shows a lamellar phase with high crystallinity up to a temperature of 34 °C, which was not observed before for other phospholipids.
authors.affiliation: Institute of Pharmacy, Martin Luther University (MLU) Halle-Wittenberg , Wolfgang-Langenbeck-Str. 4, 06120 Halle (Saale), Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Markowski
authors.affiliation: Institute of Pharmacy, Martin Luther University (MLU) Halle-Wittenberg , Wolfgang-Langenbeck-Str. 4, 06120 Halle (Saale), Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Drescher
authors.affiliation: Institute of Chemistry, MLU Halle-Wittenberg , von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
authors.forename: Günter
authors.initials: G
authors.lastname: Förster
authors.affiliation: Institute of Chemistry, MLU Halle-Wittenberg , von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
authors.forename: Bob-Dan
authors.initials: BD
authors.lastname: Lechner
authors.affiliation: Center for Structure and Dynamics of Proteins (MZP), MLU Halle-Wittenberg, Biocenter , Weinbergweg 22, 06120 Halle (Saale), Germany.
authors.forename: Annette
authors.initials: A
authors.lastname: Meister
authors.affiliation: Institute of Chemistry, MLU Halle-Wittenberg , von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany.
authors.forename: Alfred
authors.initials: A
authors.lastname: Blume
authors.affiliation: Institute of Pharmacy, Martin Luther University (MLU) Halle-Wittenberg , Wolfgang-Langenbeck-Str. 4, 06120 Halle (Saale), Germany.
authors.forename: Bodo
authors.initials: B
authors.lastname: Dobner
mesh_terms: D002152:Calorimetry, Differential Scanning; D005995:Glyceryl Ethers / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010743:Phospholipids / Q000138:chemical synthesis* / Q000737:chemistry; D013696:Temperature
chemical_list: D005995:Glyceryl Ethers; D010743:Phospholipids