scholarly journals Extracts of medicinal plants with natural deep eutectic solvents: enhanced antimicrobial activity and low genotoxicity

BMC Chemistry ◽  
2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Tsvetinka Grozdanova ◽  
Boryana Trusheva ◽  
Kalina Alipieva ◽  
Milena Popova ◽  
Lyudmila Dimitrova ◽  
...  

AbstractNatural deep eutectic solvents (NADES) are a new alternative to toxic organic solvents. Their constituents are primary metabolites, non-toxic, biocompatible and sustainable. In this study four selected NADES were applied for the extraction of two medicinal plants: Sideritis scardica, and Plantago major as an alternative to water-alcohol mixtures, and the antimicrobial and genotoxic potential of the extracts were studied. The extraction efficiency was evaluated by measuring the extracted total phenolics, and total flavonoids. Best extraction results for total phenolics for the studied plants were obtained with choline chloride-glucose 5:2 plus 30% water; but surprisingly these extracts were inactive against all tested microorganisms. Extracts with citric acid-1,2-propanediol 1:4 and choline chloride-glycerol 1:2 showed good activity against S. pyogenes, E. coli, S. aureus, and C. albicans. Low genotoxicity and cytotoxicity were observed for all four NADES and the extracts with antimicrobial activity. Our results confirm the potential of NADESs for extraction of bioactive constituents of medicinal plants and further suggest that NADES can improve the effects of bioactive extracts. Further studies are needed to clarify the influence of the studied NADES on the bioactivity of dissolved substances, and the possibility to use such extracts in the pharmaceutical and food industry.

2022 ◽  
Vol 19 ◽  
Author(s):  
Melita Lončarić ◽  
MAJA MOLNAR

Abstract: Recently, more and more researchers are resorting to green methods and techniques to avoid environmental pollution. Accordingly, many researchers have been working on the development of new green synthetic procedures trying to avoid the use of toxic organic solvents. A sustainable concept of green and environmentally friendly solvents in chemical synthesis nowadays encompasses a relatively new generation of solvents called deep eutectic solvents (DESs). DESs often have a dual role in the synthesis, acting as both, solvents and catalysts. In this study, DESs are used in the Knoevenagel synthesis of rhodanine derivatives, with no addition of conventional catalysts. A model reaction of rhodanine and salicylaldehyde was performed in 20 different DESs at 80 °C, in order to find the best solvent, which was further used for the synthesis of the series of desired compounds. A series of rhodanines was synthesized in choline chloride: acetamide (ChCl:acetamide) DES with good to excellent yields (51.4 – 99.7 %).


Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 242 ◽  
Author(s):  
Jeniffer Torres-Vega ◽  
Sergio Gómez-Alonso ◽  
José Pérez-Navarro ◽  
Edgar Pastene-Navarrete

Peumus boldus Mol., is a Chilean medicinal tree used for gastrointestinal and liver diseases. Such medicinal properties are associated with the presence of bioactive flavonoids and aporphine alkaloids. In this study, a new green and efficient extraction method used seven natural deep eutectic solvents (NADES) as extraction media. The extraction efficiency of these NADES was assessed, determining the contents of boldine and total phenolic compounds (TPC). Chemical profiling of P. boldus was done by high-performance liquid chromatography coupled to photo diode array detector and electrospray ion-trap mass spectrometry (HPLC-PDA-ESI-IT/MS) and electrospray ionization quadrupole time-of-flight high-resolution mass spectrometry (HPLC-ESI-QTOF-MS). Among the NADES tested, NADES4 (choline chloride-lactic acid) and NADES6 (proline-oxalic acid) enable better extraction of boldine with 0.427 ± 0.018 and 2.362 ± 0.055 mg of boldine g−1 of plant, respectively. Extraction of boldine with NADES4 and NADES6 was more efficient than extractions performed with methanol and water. On the other hand, the highest TPC were obtained using NADES6, 179.442 ± 3.79 mg of gallic acid equivalents (GAE g−1). Moreover, TPC in extracts obtained with methanol does not show significant differences with NADES6. The HPLC-PAD-MS/MS analysis enable the tentative identification of 9 alkaloids and 22 phenolic compounds. The results of this study demonstrate that NADES are a promising green extraction media to extract P. boldus bioactive compounds and could be a valuable alternative to classic organic solvents.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 18 ◽  
Author(s):  
Lele Yang ◽  
Ling Li ◽  
Hao Hu ◽  
Jianbo Wan ◽  
Peng Li

Natural deep eutectic solvents (NADESs), composed of natural primary metabolites, are now widely used as green and sustainable extraction solvents of bioactive components. In the present study, various NADESs were prepared to extract multi-components from different preparations of an herbal formula (Chinese name: Jinqi Jiangtang, JQJT) using ultrasound-assisted extraction (UAE). Results showed that most prepared NADESs provided more effective extraction of phenolic acids and alkaloids from JQJT preparations than conventional solvents. Among the tested NADESs, the solvent formed by choline chloride and laevulinic acid was selected to optimize the operational parameters using response surface methodology. The optimized extraction method was successfully applied to extract six major components in four commercial JQJT products, and quantification analysis was performed by the validated high-performance liquid chromatography with ultraviolet detection (HPLC-UV) method. The quantitative results indicated that preparations from different manufacturers showed different chemical profiles. In conclusion, NADESs-based UAE shows considerable potential as an efficient and green method for extraction of multi-bioactive components from commercial herbal preparations.


2019 ◽  
Vol 9 (1) ◽  
pp. 13-25 ◽  
Author(s):  
Bojana Bradić ◽  
Uroš Novak ◽  
Blaž Likozar

AbstractThis study provides a complete evaluation of a sustainable zero-waste process for the recovery of added value biomaterials from the abundant shrimp shell biomass waste using natural deep eutectic solvents (NADES). The process parameters for the fractionation of α-chitin, minerals and protein was followed using on-line measurements. Furthermore, the quantitative analysis of isolated chitin, minerals and solvent waste streams were examined. The dominant fractionation mechanisms are explained through the analysis of the liquid and solid fractions. Four of the most promising, and commercially available, NADES consisting on mixtures of Choline Chloride-Lactic Acid (CCLA), Choline Chloride-Malonic Acid (CCMA), Choline Chloride-Urea (CCUR) and Choline Chloride-Citric Acid (CCCA), were tested. The highest chitin extraction yield obtained was < 90% using CCLA, leading to purity higher than 98%. Moreover, it is possible to recycle this particular NADES several times, while having no loss in the shrimp shell fractionation capability.


Chemosphere ◽  
2018 ◽  
Vol 209 ◽  
pp. 831-838 ◽  
Author(s):  
Raheleh Ahmadi ◽  
Bahram Hemmateenejad ◽  
Afsaneh Safavi ◽  
Zahra Shojaeifard ◽  
Maryam Mohabbati ◽  
...  

SynOpen ◽  
2018 ◽  
Vol 02 (04) ◽  
pp. 0306-0311 ◽  
Author(s):  
Pierre-Olivier Delaye ◽  
Mélanie Pénichon ◽  
Leslie Boudesocque-Delaye ◽  
Cécile Enguehard-Gueiffier ◽  
Alain Gueiffier

Herein, we present the first Suzuki–Miyaura cross-coupling in a sustainable natural deep eutectic solvent (NaDES) applied to biologically relevant imidazo-fused scaffolds imidazo[1,2-a]pyridine and imidazo[1,2-b]pyridazine. The choline chloride/glycerol (1:2, mol/mol) NaDES allowed the functionalisation of diverse positions on the heterocycles with various boronic acids, by using 2.5 mol% of readily available Pd(OAc)2. Notably, the catalytic system proceeds without any ligands or additives, without protection from the atmosphere.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1781
Author(s):  
Sofia Chanioti ◽  
Maria Katsouli ◽  
Constantina Tzia

Olive pomace, the solid by-product derived from olive oil production consists of a high concentration of bioactive compounds with antioxidant activity, such as phenolic compounds, and their recovery by applying innovative techniques is a great opportunity and challenge for the olive oil industry. This study aimed to point out a new approach for the integrated valorization of olive pomace by extracting the phenolic compounds and protecting them by encapsulation or incorporation in nanoemulsions. Innovative assisted extraction methods were evaluated such as microwave (MAE), homogenization (HAE), ultrasound (UAE), and high hydrostatic pressure (HHPAE) using various solvent systems including ethanol, methanol, and natural deep eutectic solvents (NADESs). The best extraction efficiency of phenolic compounds was achieved by using NADES as extraction solvent and in particular the mixture choline chloride-caffeic acid (CCA) and choline chloride-lactic acid (CLA); by HAE at 60 °C/12,000 rpm and UAE at 60 °C, the total phenolic content (TPC) of extracts was 34.08 mg gallic acid (GA)/g dw and 20.14 mg GA/g dw for CCA, and by MAE at 60 °C and HHPAE at 600 MPa/10 min, the TPC was 29.57 mg GA/g dw and 25.96 mg GA/g dw for CLA. HAE proved to be the best method for the extraction of phenolic compounds from olive pomace. Microencapsulation and nanoemulsion formulations were also reviewed for the protection of the phenolic compounds extracted from olive pomace. Both encapsulation techniques exhibited satisfactory results in terms of encapsulation stability. Thus, they can be proposed as an excellent technique to incorporate phenolic compounds into food products in order to enhance both their antioxidative stability and nutritional value.


Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2079
Author(s):  
Gui-Ya Yang ◽  
Jun-Na Song ◽  
Ya-Qing Chang ◽  
Lei Wang ◽  
Yu-Guang Zheng ◽  
...  

In the present study, a simple and environmentally friendly extraction method based on natural deep eutectic solvents (NADESs) was established to extract four bioactive steroidal saponins from Dioscoreae Nipponicae Rhizoma (DNR). A total of twenty-one types of choline chloride, betaine, and L-proline based NADESs were tailored, and the NADES composed of 1:1 molar ratio of choline chloride and malonic acid showed the best extraction efficiency for the four steroidal saponins compared with other NADESs. Then, the extraction parameters for extraction of steroidal saponins by selected tailor-made NADES were optimized using response surface methodology and the optimal extraction conditions are extraction time, 23.5 min; liquid–solid ratio, 57.5 mL/g; and water content, 54%. The microstructure of the DNR powder before and after ultrasonic extraction by conventional solvents (water and methanol) and the selected NADES were observed using field emission scanning electron microscope. In addition, the four steroidal saponins were recovered from NADESs by D101 macroporous resin with a satisfactory recovery yield between 67.27% and 79.90%. The present research demonstrates that NADESs are a suitable green media for the extraction of the bioactive steroidal saponins from DNR, and have a great potential as possible alternatives to organic solvents for efficiently extracting bioactive compounds from natural products.


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