Asymmetrical, Symmetrical, Divalent, and Y-Shaped (Bola)amphiphiles: The Relationship between the Molecular Structure and Self-Assembly in Amino Derivatives of Sophorolipid Biosurfactants

Abstract : Conventional head-chain but also more exotic divalent, gemini or bolaform amphiphiles have in common well-defined hydrophilic and hydrophobic blocks with often a predictable self-assembly behaviour. However, new categories of amphiphiles, like microbial biosurfactants, challenge such conventional understanding, because of the poorly-defined boundaries between the hydrophilic and hydrophobic portions. Microbial glycolipids, like sophorolipids, rhamnolipids or cellobioselipids, interesting biodegradable, nontoxic, alternatives to synthetic surfactants, all represent interesting examples of atypical amphiphiles with partially predictable self-assembly properties. However, their limited molecular diversity strongly limits their application potential. For this reason, we used them as ready-made platform to prepare a whole class of new derivatives. In particular, a broad range of amino derivatives of sophorolipid biosurfactant was recently prepared with the goal of producing biobased antimicrobial and transfection agents, of which the efficiency strongly depends on their molecular structure and unpredictable self-assembly behavior. The new compounds contain a set of asymmetrical and symmetrical bolaamphiphiles, the latter with three or four hydrophilic centers, divalent amphiphiles with asymmetric polar headgroups and even a Y-shaped amphiphiles, bearing two sophorose groups connected to one nitrogen atom. In this contribution we employ small angle x-ray scattering (SAXS) to establish a relationship between their peculiar molecular structures and the self-assembly properties in water. We find that all divalent and Y- shaped compounds form micelles, of which the hydrophilic shell is composed of a bulky sophorose-C x (x= 8,11)-amine moiety, with aggregation numbers between 30 and 100. On the contrary, most symmetrical and asymmetrical bolaamphiphiles display poor self-assembly properties, generally showing aggregation numbers below 20, especially in the presence of either short spacers or large spacers containing hydrophilic centers.
Document type :
Journal articles
Complete list of metadatas

https://hal.sorbonne-universite.fr/hal-02128241
Contributor : Guillaume Laurent <>
Submitted on : Tuesday, May 14, 2019 - 5:17:31 PM
Last modification on : Friday, July 12, 2019 - 5:42:01 PM

File

 Restricted access
To satisfy the distribution rights of the publisher, the document is embargoed until : 2019-10-19

Please log in to resquest access to the document

Identifiers

Citation

Niki Baccile, Elisabeth I. P. Delbeke, Martha Brennich, Chloé Seyrig, Jonas Everaert, et al.. Asymmetrical, Symmetrical, Divalent, and Y-Shaped (Bola)amphiphiles: The Relationship between the Molecular Structure and Self-Assembly in Amino Derivatives of Sophorolipid Biosurfactants. Journal of Physical Chemistry B, American Chemical Society, 2019, 123 (17), pp.3841-3858. ⟨10.1021/acs.jpcb.9b01013⟩. ⟨hal-02128241⟩

Share

Metrics

Record views

49