Issue 23, 2020

Synthesis and self-assembly of aminyl and alkynyl substituted sophorolipids

Abstract

Sophorolipids are one of the most important microbial biosurfactants, because of their large-scale production and applications developed so far in the fields of detergency, microbiology, cosmetics or environmental science. However, the structural variety of native sophorolipids is limited/restricted, a limiting fact for the development of new properties and their potential applications. In their open acidic form, C18:1 sophorolipids (SL) are classically composed of a sophorose headgroup and a carboxylic acid (COOH) end-group. The carboxyl group gives them unique pH-responsive properties, but it is a poorly reactive group and its charge can only be negative. To develop a new generation of pH-responsive, positively charged, SL and to improve their reactivity for further functionalization, we develop here SL with an amine (–NH2) or terminal alkyne (–C[triple bond, length as m-dash]CH) end-group analogues. The amine group generates positively charged SL and is more reactive than carboxylic acids, e.g. towards aldehydes; the alkyne group provides access to copper-based click chemistry. In this work, we synthesized (C18:1) and (C18:0) –NH2 and (C18:1) –C[triple bond, length as m-dash]CH sophorolipid derivatives and we study their self-assembly properties in response to pH and/or temperature changes by means of static and dynamic light scattering, small angle (X-ray, neutron) scattering and cryogenic electron microscopy. Monounsaturated aminyl SL-C18:1-NH2 sophorolipids form a micellar phase in their neutral form at high pH and a mixed micellar-bilayer phase in their positively charged form at low pH. Saturated aminyl SL-C18:0-NH2 sophorolipids form a micellar phase in their charged form at low pH and a twisted ribbon phase in their neutral form at high pH and monounsaturated alkynyl SL-C18:1-C[triple bond, length as m-dash]CH sophorolipids form a main micellar phase at T > 51.8 °C and a twisted ribbon phase at T < 51.8 °C.

Graphical abstract: Synthesis and self-assembly of aminyl and alkynyl substituted sophorolipids

Supplementary files

Article information

Article type
Paper
Submitted
08 Қыр. 2020
Accepted
12 Қаз. 2020
First published
10 Қар. 2020

Green Chem., 2020,22, 8323-8336

Synthesis and self-assembly of aminyl and alkynyl substituted sophorolipids

A. A. Ba, J. Everaert, A. Poirier, P. Le Griel, W. Soetaert, S. L. K. W. Roelants, D. Hermida-Merino, C. V. Stevens and N. Baccile, Green Chem., 2020, 22, 8323 DOI: 10.1039/D0GC03053H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements