Synthesis of Uniform, Monodisperse, Sophorolipid Twisted Ribbons

Cuvier, Anne-Sophie; Babonneau, Florence; Berton, Jan; Stevens, Christian V.; Fadda, G. C.; Génois, Isabelle; Griel, Patrick Le; Péhau‐Arnaudet, Gérard; Baccile, Niki

doi:10.1002/asia.201500693

Cited by 23 publications

(44 citation statements)

References 35 publications

(84 reference statements)

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“…Eventually, midsized fibrillar pellets indefinitely grow by both fibrillation and aggregation into very large aggregates ( Figure 8E). The presence of large spherical fibrous pellets has been demonstrated before in cryo-TEM experiments collected on assynthesized SL-C18:0 sample at acidic pH, 43 thus indicating that the observation method preferred in this work does not influence the formation mechanism of the fibers.…”

Section: Langmuirsupporting

confidence: 61%

“…In addition, it was shown that the effect of NaCl in these systems only influences aggregation: NaCl only affects the aspect ratio of SL-C18:1 micelles, 41 while it impacts fiber aggregation, but not their chirality, on SL-C18:0 sophorolipids. 43 Additional arguments supporting the low impact of NaCl will be discussed in the text.…”

Section: ■ Materials and Methodsmentioning

confidence: 97%

“…This operation allows one single grid to contain all objects formed at different stages of their growth, from the precursor micellar/platelet 38 to the twisted ribbon 42 state. Previous experiments 43 have shown that, for this particular system, conventional TEM observation does not affect the fibrillar structure and morphology; for this reason, we use it here in a qualitative way to observe the intermediates of the twisted ribbon formation.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

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Self-Assembly Mechanism of pH-Responsive Glycolipids: Micelles, Fibers, Vesicles, and Bilayers

et al. 2016

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A set of four structurally related glycolipids are described: two of them have one glucose unit connected to either stearic or oleic acid, and two other ones have a diglucose headgroup (sophorose) similarly connected to either stearic or oleic acid. The self-assembly properties of these compounds, poorly known, are important to know due to their use in various fields of application from cleaning to cosmetics to medical. At basic pH, they all form mainly small micellar aggregates. At acidic pH, the oleic and stearic derivatives of the monoglucose form, respectively, vesicles and bilayer, while the same derivatives of the sophorose headgroup form micelles and twisted ribbons. We use pH-resolved in situ small angle X-ray scattering (SAXS) under synchrotron radiation to characterize the pH-dependent mechanism of evolution from micelles to the more complex aggregates at acidic pH. By pointing out the importance of the COO − /COOH ratio, the melting temperature, T m , of the lipid moieties, hydration of the glycosidic headgroup, the packing parameter, membrane rigidity, and edge stabilization, we are now able to draw a precise picture of the full self-assembly mechanism. This work is a didactical illustration of the complexity of the self-assembly process of a stimuli-responsive amphiphile during which many concomitant parameters play a key role at different stages of the process.

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Section: Langmuirsupporting

confidence: 61%

Section: ■ Materials and Methodsmentioning

confidence: 97%

Section: ■ Materials and Methodsmentioning

confidence: 99%

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Self-Assembly Mechanism of pH-Responsive Glycolipids: Micelles, Fibers, Vesicles, and Bilayers

et al. 2016

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“…Secondly, we have demonstrated that NaCl has no effect at all on the nature of the self-assembled structure in similar systems, but it only affects aggregation: on micellar-forming monounsaturated sophorolipids, NaCl only affects the degree of ellipticity of the micelles, 28 while on chiral-fiber forming saturated sophorolipids, NaCl only affects fiber aggregation but not their chirality. 36 Aliquots of the sample are then taken and analyzed by cryo-TEM and SAXS. in-situ experiments (see SAXS section) are performed during the synthesis process while ex-situ experiments, to reduce at best the aging time, are performed within a few hours after synthesis.…”

Section: Hydrolysis Of Cellobioselipids (Clh)mentioning

confidence: 99%

pH-Driven Self-Assembly of Acidic Microbial Glycolipids

et al. 2016

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Microbial glycolipids are a class of well-known compounds, but their self-assembly behavior is still not well understood. While the free carboxylic acid end group makes some of them interesting stimuli-responsive compounds, the sugar hydrophilic group and the nature of the fatty acid chain make the understanding of their self-assembly behavior in water not easy and highly unpredictable. Using cryo-transmission electron microscopy (cryo-TEM) and both pH-dependent in situ and ex situ small angle X-ray scattering (SAXS), we demonstrate that the aqueous self-assembly at room temperature (RT) of a family of β-d-glucose microbial glycolipids bearing a saturated and monounsaturated C18 fatty acid chain cannot be explained on the simple basis of the well-known packing parameter. Using the “pH-jump” process, we find that the molecules bearing a monosaturated fatty acid forms vesicles below pH 6.2, as expected, but the derivative with a saturated fatty acid forms infinite bilayer sheets below pH 7.8, instead of vesicles. We show that this behavior can be explained on the different bilayer membrane elasticity as a function of temperature. Membranes are either flexible or stiff for experiments performed at a temperature respectively above or below the typical melting point, T M, of the lipidic part of each compound. Finally, we also show that the disaccharide-containing acidic cellobioselipid forms a majority of chiral fibers, instead of the expected micelles.

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“…[17][18][19][20][21][22][23][24][25][26][27][28][29][30] Due to their amphiphilic character, sophorolipids possess selfassembly properties which results in the formation of nanostructures with supramolecular chirality. [31][32][33][34][35][36][37] Being low foaming surfactants, natural sophorolipid mixtures were already commercialized by companies like Ecover, Saraya, Soliance and MG Intobio in their hard surface cleaning, automatic dishwashing rinse aid, laundry and cosmetic products. 13,16,38 However, application of sophorolipids in the detergent sector has as main drawback the higher production cost compared to conventional and alternative environmentally friendly surfactants such as alkyl-polyglucosides.…”

Section: Introductionmentioning

confidence: 99%

Sophorolipid Amine Oxide Production by a Combination of Fermentation Scale-up and Chemical Modification

Delbeke

Roelants

Matthijs

et al. 2016

Ind. Eng. Chem. Res.

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Production scale-up of high purity diacetylated C18:1 sophorolipid lactone was demonstrated from lab to pilot scale with the Starmerella bombicola lactone esterase overexpression strain (oe sble) as production organism. The 150 L fermentation using oleic acid and yeast extract, characterized by a titer of 199 g/L and a volumetric productivity of 0.9 g/L·h, was most successful to obtain a highly pure (>98%) and uniform (96% C18:1 SL lactone) sophorolipid product suitable for chemical derivatization. The fermentation product was subsequently modified to produce sophorolipid amine oxides, which cannot be produced enzymatically. First, the fermentation product was transformed into an intermediate sophorolipid aldehyde via methanolysis, protection of the sugar head through acetylation and ozonolysis. This aldehyde intermediate was then used for the synthesis of the sophorolipid amine oxides via reductive amination, oxidation and deprotection of the sugar head. The total yield of this synthetic pathway amounts to 18-30%. These compounds constitute a class of innovative sophorolipid derivatives with potential for high added-value applications. The sophorolipid amine oxides have been evaluated for their antimicrobial activity against the Gram-negative bacteria Escherichia coli LMG 8063, Klebsiella pneumoniae LMG 2095 and Pseudomonas aeruginosa PAO1, and the Gram-positive bacteria Staphylococcus aureus ATCC 6538 and Staphylococcus aureus Mu50. The present approach of combining of large-scale fermentation and subsequent chemical modification facilitates the creation of a platform of innovative sophorolipid derivatives in adequate quantities, opening the door for novel applications.

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Synthesis of Uniform, Monodisperse, Sophorolipid Twisted Ribbons

Cited by 23 publications

References 35 publications

Self-Assembly Mechanism of pH-Responsive Glycolipids: Micelles, Fibers, Vesicles, and Bilayers

Self-Assembly Mechanism of pH-Responsive Glycolipids: Micelles, Fibers, Vesicles, and Bilayers

pH-Driven Self-Assembly of Acidic Microbial Glycolipids

Sophorolipid Amine Oxide Production by a Combination of Fermentation Scale-up and Chemical Modification

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