Comparison of Vibrational Spectroscopic Techniques for Quantification of Water in Natural Deep Eutectic Solvents

peer reviewedVibrational spectroscopic techniques, i.e., attenuated total reflectance infrared (ATR-IR), near infrared spectroscopy (NIRS) and Raman spectroscopy (RS), coupled with Partial Least Squares Regression (PLSR), were evaluated as cost-effective label-free and reagent-free tools to monitor water content in Levulinic Acid/L-Proline (LALP) (2:1, mol/mol) Natural Deep Eutectic Solvent (NADES). ATR-IR delivered the best outcome of Root Mean Squared Error (RMSE) of Cross-Validation (CV) = 0.27% added water concentration, RMSE of Prediction (P) = 0.27% added water concentration and mean % relative error = 2.59%. Two NIRS instruments (benchtop and handheld) were also compared during the study, respectively yielding RMSECV = 0.35% added water concentration, RMSEP = 0.56% added water concentration and mean % relative error = 5.13% added water concentration, and RMECV = 0.36% added water concentration, RMSEP = 0.68% added water concentration and mean % relative error = 6.23%. RS analysis performed in quartz cuvettes enabled accurate water quantification with RMECV = 0.43% added water concentration, RMSEP = 0.67% added water concentration and mean % relative error = 6.75%. While the vibrational spectroscopic techniques studied have shown high performance in relation to reliable determination of water concentration, their accuracy is most likely related to their sensitivity to detect the LALP compounds in the NADES. For instance, whereas ATR-IR spectra display strong features from water, Levulinic Acid and L-Proline that contribute to the PLSR predictive models constructed, NIRS and RS spectra are respectively dominated by either water or LALP compounds, representing partial molecular information and moderate accuracy compared to ATR-IR. However, while ATR-IR instruments are common in chemistry and physics laboratories, making the technique readily transferable to water quantification in NADES, Raman spectroscopy offers promising potential for future development for in situ, sample withdrawal-free analysis for high throughput and online monitoring

Solid/liquid extraction as key step for quality assessment of commercial cranberry products usingHPTLC-densitometry

Poster Session F : Innovative Approaches in polyphenol researchIncreasing number of dietary supplement containing cranberry polyphenols are commercialized every year. The composition of cranberry ingredients varies from whole fruit powder to cranberry extract or mixture with blueberry.In order to analyze the quality of cranberry based commercial products, researchers proceed to quality control based on BL-DMAC analysis after one step extraction. In our previous work, we demonstrated that BL-DMAC analysis is not sufficient alone to assess the quality of cranberry ingredients. BL-DMAC as quality control couple to High Performance Thin Layer Chromatography -densitometry bring complementary information, especially rate of epicatechin, PAC-A2and PAC-B2.In this work, different extraction solvents were screened for extraction of PACs from a range of commercial dietary supplements. Thus, solid / liquid extraction step was repeated until total extraction of polyphenols was achieved, i.e no coloration of the residue in contact with DMAC reagent. If the solvent nature was found to have a minor impact, the number of required extraction steps varied significantly between commercial products. This step was then demonstrated to be a key factor to control for meaningful comparison between various food supplements.Quality assessment of cranberry extracts was then conducted using both BL-DMAC and HPTLC-densitometry protocols, in order to obtain global PACs content and metabolic profile. A large diversity of PACs global content and profile was observed[br/] This work highlighted the need of new standardization protocols to control and asses the quality of cranberry ingredients, to guarantee biological effect

Biomass Valorization Using Natural Deep Eutectic Solvents: What’s New in France?

International audienceWith the growing interest in more environmentally friendly solvents and processes, the introduction of Natural Deep Eutectic Solvents (NaDES) as low cost, non-toxic and biodegradable solvents represent a new opportunity for green and sustainable chemistry. Thanks to their remarkable advantages, NaDES are now arousing growing interest in many fields of research such as food, health, cosmetics and biofuels. Around the world, NaDES are seen as a promising alternative to commonly used petrochemical solvents. The objective of this review is to draw up a panorama of the existing skills on NaDES in French laboratories and industries for the valuation of natural products. This review therefore focuses on current applications, skills and perspectives, in order to analyze the place of French research in the use of NaDES for the valorization of biomass since 2015

Natural Deep Eutectic Solvents as sustainable solvent for Suzuki-Miyaura cross- coupling reactions applied to imidazo-fused heterocycles

International audienc

Glycerol-based NaDES as green solvents for ultrasound-assisted extraction of phycocyanin from Arthrospira platensis—RSM optimization and ANN modelling

International audienc

Solid/liquid extraction as key step for quality assessment of commercial cranberry products using HPTLC-densitometry

Poster Session Wednesday : Theme 5: Production and regulatory aspects of herbal preparationsSolid/liquid extraction as key step for quality assessment of commercial cranberry products using HPTLC-densitometry. 9. Joint Natural Products Conference 201

Quality control of commercial cranberry products: HPTLC-densitometry a new deal

International audienceA fast quality control protocol based on reference BL-DMAC assay and High-performance thin-layer chromatography (HPTLC)-Densitometry was optimized for routine quality control of cranberry (Vaccinium macrocarpon) products. The sample preparation appeared as a key step to ensure a relevant comparison of products quality and biological data. Sequential solid/liquid extractions were required to fully extract polyphenols, regardless the extraction solvent chosen. The HPTLC-densitometry herein protocol used epicatechin, PAC-A2 and PAC-B2 as quality markers and densitometric measurements at 200 nm. The PAC-A2/Epicatechin ratio, obtained using HPTLC, appeared as an appropriate indicator of the quality of cranberry ingredient. Only two products, among the tested panel, exhibited a high quality cranberry-based ingredient using this criteria. UPLC-MS analyses coupled to multivariate analyses confirmed HPTLC-densitometry conclusions. This work highlighted the plural PAC composition of commercial products and the lack of standardization for cranberry-based products on the market, explaining the non-reproducibility of clinical trials

Purification of dirucotide, a synthetic 17-aminoacid peptide, by ion exchange centrifugal partition chromatography

International audienceDirucotide is a synthetic drug candidate for the treatment of multiple sclerosis. This 17-aminoacid peptide was successfully purified by ion exchange centrifugal partition chromatography. The optimized conditions involved the biphasic methyl tert-butyl ether/acetonitrile/n-butanol/water (2:1:2:5, v/v) solvent system in the descending mode, the di(2-ethylhexyl)phosphoric acid cation-exchanger with an exchanger (di(2-ethylhexyl)phosphoric acid)/dirucotide mole ratio of 100 and Ca2+ ions in aqueous solution as displacer. Critical impurities were efficiently eliminated and dirucotide was recovered in high yield and purity (69% and 98%, respectively) and with a productivity of 2.29 g per liter of stationary phase per hour

Alternative Solvents for the Biorefinery of Spirulina: Impact of Pretreatment on Free Fatty Acids with High Added Value

The growing demand for molecules of interest from microalgal biomass, such as phycobiliproteins, has led to an accumulation of unused by-products. For example, phycocyanin, obtained by the extraction of Spirulina, generated cakes rich in non-polar molecules of interest, such as free fatty acids (FFAs). These FFAs were generally considered as markers of lipidome degradation, but represented a relevant alternative to topical antibiotics, based on a biomimetic approach. In order to develop a sustainable Spirulina biorefinery scheme, different pretreatments and alternative solvents were screened to identify the best combination for the valorization of FFAs. Thus, five pre-treatments were studied including a phycocyanin extraction by-product. The following three biobased solvents were selected: ethyl acetate (EtOAc), dimethyl carbonate (DMC) and a fatty acid-based natural deep eutectic solvent (NaDES). The pigment and fatty acid profiles were established by spectroscopic and chromatographic approaches. NaDES demonstrated superior extraction capacity and selectivity compared to other biobased solvents, regardless of pretreatment. In contrast, EtOAc and DMC showed a greater diversity of FFAs, with a predominance of polyunsaturated fatty acids (PUFAs). The by-product has also been highlighted as a relevant raw material facilitating the recovery of FFAs. These results pave the way for a green biorefinery of the lipid fraction and phycobiliproteins of microalgae