Extracting mycotoxins from edible vegetable oils by using green, ecofriendly deep eutectic solvents

In this work, we developed an environmentally friendly liquid-liquid microextraction method using a natural deep eutectic solvent in combination with liquid chromatography for the simultaneous determination of four mycotoxins (deoxynivalenol, alternariol, ochratoxin A and zearalenone) in edible vegetable oils. A chemometric approach assessed the effect of the operational parameters on the mycotoxin extraction efficiency. The extracts were analyzed by HPLC coupled with a diode array and fluorescence detector. The optimum NADES composition resulted in the highest extraction recoveries, and it was applied to coextract the target mycotoxins in several types of edible vegetable oils without using hazardous solvents or requiring further clean-up. The limits of detection ranged from 0.07 to 300 µg kg-1, and recoveries were close to 100%, except for zearalenone (viz. 35%), with relative standard deviations below 9% in all cases. The proposed method was validated following the European Commission 2002/657/EC and 2006/401/EC.

Separation of natural compounds using eutectic solvent-based biphasic systems and centrifugal partition chromatography

A study on the formation of ternary biphasic systems composed of heptane, 1-butanol or ethyl acetate and type III or type V deep eutectic solvents based on levulinic acid and choline chloride or thymol was carried. Binodal curves and densities and phase compositions of phases in equilibrium for seven systems are reported. The partition coefficients of six natural compounds, namely quercetin, apigenin, coumarin, β-ionone, retinol, and α-tocopherol, in these systems were measured. Results show that the influence of choline chloride on the partition coefficients is more significant in systems with 1-butanol or ethyl acetate than previously reported for ethanol, and that the separation of natural compounds is worst when using DES containing thymol instead of choline chloride. Based on these partition coefficients, one system composed of heptane, 1-butanol and the DES choline chloride:levulinic acid at molar ratio 1:3 was selected to be applied in centrifugal partition chromatography, and the results obtained confirmed that it allows a good separation of apigenin, coumarin, β-ionone and α-tocopherol.

Drug delivery of 6-bromoindirubin-3'-glycerol-oxime ether employing poly(D,L-lactide-co-glycolide)-based nanoencapsulation techniques with sustainable solvents

BACKGROUND

Insufficient solubility and stability of bioactive small molecules as well as poor biocompatibility may cause low bioavailability and are common obstacles in drug development. One example of such problematic molecules is 6-bromoindirubin-3'-glycerol-oxime ether (6BIGOE), a hydrophobic indirubin derivative. 6BIGOE potently modulates the release of inflammatory cytokines and lipid mediators from isolated human monocytes through inhibition of glycogen synthase kinase-3 in a favorable fashion. However, 6BIGOE suffers from poor solubility and short half-lives in biological aqueous environment and exerts cytotoxic effects in various mammalian cells. In order to overcome the poor water solubility, instability and cytotoxicity of 6BIGOE, we applied encapsulation into poly(D,L-lactide-co-glycolide) (PLGA)-based nanoparticles by employing formulation methods using the sustainable solvents Cyrene™ or 400 g/mol poly(ethylene glycol) as suitable technology for efficient drug delivery of 6BIGOE.

RESULTS

For all preparation techniques the physicochemical characterization of 6BIGOE-loaded nanoparticles revealed comparable crystallinity, sizes of about 230 nm with low polydispersity, negative zeta potentials around - 15 to - 25 mV, and biphasic release profiles over up to 24 h. Nanoparticles with improved cellular uptake and the ability to mask cytotoxic effects of 6BIGOE were obtained as shown in human monocytes over 48 h as well as in a shell-less hen's egg model. Intriguingly, encapsulation into these nanoparticles fully retains the anti-inflammatory properties of 6BIGOE, that is, favorable modulation of the release of inflammation-relevant cytokines and lipid mediators from human monocytes.

CONCLUSIONS

Our formulation method of PLGA-based nanoparticles by applying sustainable, non-toxic solvents is a feasible nanotechnology that circumvents the poor bioavailability and biocompatibility of the cargo 6BIGOE. This technology yields favorable drug delivery systems for efficient interference with inflammatory processes, with improved pharmacotherapeutic potential.

Predicting Abraham model solvent coefficients

Background

The Abraham general solvation model can be used in a broad set of scenarios involving partitioning and solubility, yet is limited to a set of solvents with measured Abraham coefficients. Here we extend the range of applicability of Abraham’s model by creating open models that can be used to predict the solvent coefficients for all organic solvents.

Results

We created open random forest models for the solvent coefficients e, s, a, b, and v that had out-of-bag R² values of 0.31, 0.77, 0.92, 0.47, and 0.63 respectively. The models were used to suggest sustainable solvent replacements for commonly used solvents. For example, our models predict that propylene glycol may be used as a general sustainable solvent replacement for methanol.

Conclusion

The solvent coefficient models extend the range of applicability of the Abraham general solvation equations to all organic solvents. The models were developed under Open Notebook Science conditions which makes them open, reproducible, and as useful as possible.

Graphical Abstract