Optimization of ionic liquid-based microwave-assisted extraction of polyphenolic content from Peperomia pellucida (L) kunth using response surface methodology

Valorization of pawpaw (Carica papaya L.) leaves as a source of polyphenols by ionic liquid-based microwave-assisted extraction: Comparison with other extraction methods and bioactivity evaluation

This study aimed to valorize pawpaw (Carica papaya L.) leaves as a rich source of polyphenols through the application of ionic liquid-based microwave-assisted extraction (ILMAE). Initially, the ILMAE process was optimized using response surface methodology (RSM), resulting in a total polyphenols yield of 27.84 ± 0.33 mg GAE/g DW under the optimal conditions: [BMIM]Br concentration of 0.57 mol/L, extraction time of 14 min, microwave power of 460 W, extraction temperature of 77 °C, solvent-to-material ratio of 30 mL/g, and three extraction cycles. Compared to conventional methods such as maceration extraction (ME), heat reflux extraction (HRE), and microwave-assisted extraction (MAE), the ILMAE method exhibited a significantly higher PLTP yield. Furthermore, the PLTP extracts demonstrated strong antioxidant activity against DPPH• and ABTS+• radicals, as well as a significant inhibitory effect on α-glucosidase activity. This work demonstrates that ILMAE is a green and efficient strategy for the valorization of pawpaw leaves.

Phaleria macrocarpa (Scheff.) Boerl.: An updated review of pharmacological effects, toxicity studies, and separation techniques

Phaleria macrocarpa (Scheff.) Boerl. is geographically distributed around Papua Island, Indonesia. Traditionally, P. macrocarpa is exercised to reduce pain, stomachache, diarrhea, tumor problems, blood glucose, cholesterol, and blood pressure. A growing interest in the medicinal values of P. macrocarpa especially in Asia reflects the usage of diverse extraction techniques, particularly modern approaches. In this review article, the extraction methods and solvents relevant to P. macrocarpa were discussed, with the extent of its pharmacological activities. Recent bibliographic databases such as Google Scholar, PubMed, and Elsevier between 2010 and 2022 were assessed. Based on the findings, the pharmacological studies of P. macrocarpa are still pertinent to its traditional uses but primarily emphasise anti-proliferative activity especially colon and breast cancer cells with low toxicity and fruit as the most studied plant part. The utilization of modern separation techniques has predominantly been aimed at extracting mangiferin and phenolic-rich compounds and evaluating their antioxidant capacity. However, the isolation of bioactive compounds remains a challenge, leading to the extensive utilization of the extracts in in vivo studies. This review endeavors to highlight modern extraction methods that could potentially be used as a point of reference in the future for exploring novel bioactive compounds and drug discovery on a multi-scale extraction level.

Optimization of microwave-assisted extraction on polyphenol metabolite from Eleutherine bulbosa (Mill.) urb. bulbs using response surface methodology

Eleutherine bulbosa bulbs, an endemic plant in Indonesia, have enormous potential as raw materials for pharmaceutical products. Therefore, it is necessary to strengthen and develop extraction methods that are easy, rapid, and efficient to enrich targeted secondary metabolites. This study aims to optimize the microwave-assisted extraction (MAE) method conditions for polyphenol metabolite from E. bulbosa bulbs. The MAE method (with different conditions) was applied to extract total polyphenol content (TPC) from E. bulbosa bulbs. TPC values were determined using a 96-well microplate reader spectrophotometry method and Folin-Ciocalteu reagent. The variables of MAE, as an experimental design-independent variable, were involved. The MAE method condition was optimized using response surface methodology (RSM) and Box-Behnken design based on the TPC value. The MAE condition was optimized with 60% ethanol, sample-solvent ratio of 1:10 g/mL, and 50% Watts of microwave power for 10 min. The quadratic regression analysis was achieved to predict the TPC value using the equation: TPC value = 28.63-5.545A +2.211B -0.741C +1.995D - 4.045AB +0.856AC -7.541BC +1.961CD -8.342A2-0.071B2 +1.840C2-1.535D2. For the scale-up confirmation test, a 50-g sample was used to prove the validity of the equation to predict the TPC value, yielding 35.33 ± 2.13 mg gallic acid equivalent/g samples. The optimum of the MAE condition recommended based on the results of RSM analysis can be applied directly to the enrichment of polyphenols metabolite constituent of E. bulbosa easily, cheaply, quickly, and efficiently.

Advances of Imidazolium Ionic Liquids for the Extraction of Phytochemicals from Plants

In this review, we present the research from 2013 to 2022 about the character of ionic liquids, the categories of phytochemicals, and the reasons for selecting imidazolium ionic liquids for phytochemical extraction. Then we introduce the structural formulae of the imidazolium ionic liquids commonly used in the extraction of phytochemicals, the methods used to prepare imidazolium ionic liquids, and a comprehensive introduction of how imidazolium ionic liquids are applied to extract phytochemicals from plants. Importantly, we discuss the strategies for studying the extraction mechanisms of imidazolium ionic liquids to extract phytochemicals, and the recovery methods regarding imidazolium ionic liquids and their recyclability are analyzed. Then the toxicity in imidazolium ionic liquids is pointed out. Finally, the challenges and prospects of extracting phytochemicals by imidazolium ionic liquids are summarized, and they are expected to provide some references for researchers.

Green approach for the recovery of secondary metabolites from the roots of Nardostachys Jatamansi (D. Don) DC using microwave radiations: Process optimization and anti-alzheimer evaluation

Nardostachys jatamansi (D. Don) DC is a highly valued medicinal herb that has been used in traditional medicinal systems for its remedial effects. Owing to the over-exploitation and unethical trade of N. jatamansi, the accelerating global demand of herbal products from this plant cannot be satisfied by the conventional extraction approach. In view of the progressive demand and incredible biological potential of herb, the present research was designed to optimize various extraction parameters for microwave-assisted extraction (MAE). The extracts obtained from the traditional and green approach were also assessed for the recovery of secondary metabolites and anti-Alzheimer's potential. Various parameters like microwave power, temperature, and time of irradiation were optimized for MAE using Box Behkhen Design (BBD) The scanning electron microscopy of different plant samples was also done to observe the effect of microwave radiations. Further, the metabolite profiling of different extracts was also done by gas chromatography-mass spectrometry (GC-MS) analysis. Also the different behavioral and biochemical parameters along with acetylcholinesterase (AChE) inhibitory potential were assessed to evaluate the anti-Alzheimer's potential. Optimized parameters for MAE were found to be as microwave power 187.04 W, temperature 90°C, and irradiation time 20 min. The extract yield in MAE was significantly enhanced as compared to the conventional method. Also, the total phenolic content and total flavonoid content (TFC) were improved pointedly from 32.13 ± 0.55 to 72.83 ± 1.1 mg of GAE/g of extract and 21.7 ± 0.85 to 39.21 ± 0.7 mg of RUE/g of extract respectively. Later, the GC-MS analysis of various extracts confirmed the enhancement in the concentration of various sesquiterpenes like jatamansone, spirojatamol, valerenal, valeric acid, globulol, nootkatone and steroidal compounds such as sitosterol, ergosterol, stigmastanone, etc. in the optimized extract. A significant improvement in anti-Alzheimer's potential was also observed owing to the better concentration of secondary metabolites in the optimized microwave extract. From the current findings, it could be concluded that the MAE could be a successful and green alternative for the extraction and recovery of secondary metabolites from the selected medicinal herb.

Application of Green Technologies in Design-Based Extraction of Celastrus paniculatus (Jyotishmati) Seeds, SEM, GC-MS Analysis, and Evaluation for Memory Enhancing Potential

Background

The Celastrus paniculatus (CP), commonly known as Jyotishmati, is considered as “elixir of life” by Indian people for the prevention or management of many ailments. The seed powder and its extract have widely used commercially for the preparation of various Ayurvedic formulations for the improvement of memory. CP seeds were generally extracted by conventional extraction methods (CEMs) which are assumed to impact environment burden and also produce low extract yield. Green extraction with possible improvement in extract yield has always been the need of hour for selected medicinal plant.

Objective

In the present research, we aimed to optimize the different extraction factors in microwave and ultrasound-based extraction. The various extracts obtained in conventional and green methods are also evaluated for the possible improvement in memory enhancing potential.

Materials and Methods

The selected medicinal herb was extracted by CEM (maceration and percolation). In green methods such microwave-assisted extraction (MAE) and ultrasound assisted-extraction (UAE), various parameters were optimized using Box-Behnken design coupled with response surface methodology. The scanning electron microscopy (SEM) and gas chromatography–mass spectroscopy (GC-MS) analyses were also done to confirm the possible improvement in concentration of plant actives. The Swiss albino mice were used to evaluate memory enhancing potential of different extracts.

Results

At the optimized conditions MAE and UAE the extraction yield, total phenolic content (TPC) and Total flavonoid content (TFC) are significantly improved. The GC-MS analysis further confirms the improvement in concentration of certain fatty acid esters, pilocarpine, and steroidal compounds in optimized extracts. The optimized extracts also exhibited the significant improvement in behavioral parameters, oxidative stress-induced parameters, and acetylcholinesterase inhibitory potential.

Discussion and Conclusion

From the results, we can say that the application of green technologies in design-based extraction of selected herb not only significantly reduces the extraction time but also improves the extract yield and concentration of plant actives. In nutshell, it can be concluded that the green approaches for extraction of seeds of Celastrus paniculatus could be scale up at a commercial level to meet the rising demand for herbal extract.

Generation and characterization of nanobubbles in ionic liquid for a green extraction of polyphenols from Carya cathayensis Sarg

Nanobubbles (NBs) generated-nanojets membrane poration have gained enormous attention. In this study, NBs were fabricated as a novel green approach to assist ionic liquid (IL) [C₄C₁im][BF₄] extraction of polyphenols from Carya cathayensis Sarg. husk. NBs were successfully generated with mean size of 85.47 ± 5 nm, zeta potential of +39 ± 2.24 mV, and concentration of 21.15 ± 0.75 × 10⁸ particles/mL (stable for over 48 h in IL solution). Compared to common solutions extract, IL-NBs extract showed significantly higher (p < 0.05) antioxidant activity and polyphenols yields with a total polyphenol, total flavonoid, and total tannins contents of 85.67 ± 2.05 mg GAE/g DW, 42.44 ± 1.17 mg CE/g DW, and 8.2 ± 0.05 mg TAE/g DW, respectively. The SEM results confirmed that NBs' nanojets caused morphological destruction of the husk powder. Overall, IL-NBs solution showed better extraction efficiency of polyphenols than other solutions, giving insight into a new "green" nanotechnology-based extraction method.