Extraction of Synadenium grantii Hook f. using conventional solvents and supercritical CO2 + ethanol

Extraction of High Value Products from Zingiber officinale Roscoe (Ginger) and Utilization of Residual Biomass

Zingiber officinale Roscoe (ginger) is a plant from the Zingiberaceae family, and its extracts have been found to contain several compounds with beneficial bioactivities. Nowadays, the use of environmentally friendly and sustainable extraction methods has attracted considerable interest. The main objective of this study was to evaluate subcritical propane (scPropane), supercritical CO2 (scCO2), and supercritical CO2 with ethanol (scCO2 + EtOH) as co-solvent methods for the extraction of high value products from ginger. In addition, the reuse/recycling of the secondary biomass in a second extraction as a part of the circular economy was evaluated. Both the primary and the secondary biomass led to high yield percentages, ranging from 1.23% to 6.42%. The highest yield was observed in the scCO2 + EtOH, with biomass prior used to scCO2 extraction. All extracts presented with high similarities as far as their total phenolic contents, antioxidant capacity, and chemical composition. The most abundant compounds, identified by the two different gas chromatography-mass spectrometry (GC-MS) systems present, were a-zingiberene, β- sesquiphellandrene, a-farnesene, β-bisabolene, zingerone, gingerol, a-curcumene, and γ-muurolene. Interestingly, the reuse/recycling of the secondary biomass was found to be promising, as the extracts showed high antioxidant capacity and consisted of significant amounts of compounds with beneficial properties.

Phytochemical Analysis and Genotoxicological Evaluation of Prickly Pear Peel Extracts

This study investigated the beneficial properties of prickly pear peel (PPP) extracts from Opuntia ficus-indica (L.) Mill. Extracts were obtained via the Soxhlet extraction method using methanol (P1), ethanol (P2) and ethanol-water (P3) as extraction solvents. Their total phenolic and flavonoid content (TPC and TFC, respectively) and their antioxidant activity (AA) were determined. The PPP extracts were characterized in detail using mass spectrometry techniques. Their cyto-genotoxic effect and antigenotoxic potential against mitomycin C were evaluated via the cytokinesis block micronucleus (CBMN) assay on human lymphocytes. Enhanced TPC, TFC and AA values were recorded for all the extracts. Moreover, P1 and P2 were cytotoxic only at the highest concentrations, whereas P3 was found to be cytotoxic in all cases. No significant micronucleus induction was observed in the tested extracts. The PPP extracts contain bioactive compounds such as flavonoids, carboxylic acids, alkaloids, fatty acids and minerals (mainly K, Si, Mg, Ca, P and Zn). The results showed that all three extracts exerted high antigenotoxic activity. Our findings confirm the beneficial and genoprotective properties of PPP extracts and further studies on the bioactive compounds of Opuntia ficus-indica (L.) Mill. are recommended, as it constitutes a promising plant in pharmaceutical applications.

Bioactive Secondary Plant Metabolites from Euphorbia umbellata (PAX) BRUYNS (Euphorbiaceae)

The species Euphorbia umbellata has been used to treat inflammatory diseases, cancer, and ulcers. Biological activities reported in the literature, including antiproliferative, cytotoxic and anti-inflammatory, are attributed to the chemical constituents present in its composition as terpenes and polyphenolic compounds. The most recurrently verified metabolites in the Euphorbiaceae family plant species are terpenes, of which euphol is a major constituent with broadly reported cytotoxic, antinociceptive and anti-inflammatory effects; it frequently appears in various extracts obtained from the plant. Euphol has a documented inhibitory effect on neutrophil chemotaxis and can modulate the complement system. Since complement system activation is intimately intertwined with autoimmune and inflammatory diseases, tumor growth promotion and metastasis, plant metabolites from Euphorbia umbellata might influence the outcomes of inflammatory processes. We believe that this is the first review presenting the current knowledge on Euphorbia umbellata secondary metabolites and their biological activities.

Multifactor assessments to determine the overall performance of supercritical fluid extraction from Gynura procumbens essential oil

Gynura procumbens is a medicinal herb that contains bioactive compounds that can relieve coughs and prevent liver cancer. Supercritical fluid extraction (SFE) was suggested as one of the techniques that can be used to extract the valuable compounds from the G. procumbens. SFE was widely applied in extracting medicinal ingredients from herbs. However, most of them were performed only at the laboratory scale. Moreover, study to increase the yield performance, economic studies and safety assessments of the SFE process were also performed; however, these tests were conducted individually. Moreover, to date, there is no integration study between all the factors stated for determining the overall performance of SFE with herbs specifically G. procumbens. The integration between all the factors is beneficial because the data on the overall performance can assist in developing the SFE process with G. procumbens at the pilot or industrial scale. Therefore, this study incorporated a multifactor approach to measure the overall performance of the SFE process towards G. procumbens by using a rating and index approach. A summary of factors, such as the solubility of G. procumbens in CO₂, operational cost and safety assessment elements, were taken into consideration as the main influences that determine the overall performance index of this study. I_performance or overall performance of SFE from G. procumbens was successfully assessed and compared with response surface methodology (RSM). Overall, the results from I_performance exhibit satisfactory solubility values when compared to the optimized value from RSM when considering the lowest operational costs in the safest SFE environment.

Investigation of the Genotoxic, Antigenotoxic and Antioxidant Profile of Different Extracts from Equisetum arvense L

The present study investigated the cyto-genotoxic and antigenotoxic effects of four different extracts of Equisetum arvense L. (common name: field horsetail) on human lymphocytes. Specifically, Soxhlet’s prepared extracts from E. arvense L., using different solvents (S1: methanol (MeOH)-, S2: ethanol (EtOH)-, S3: water-, and S4: ethanol/water (EtOH-W)-) were analyzed for (a) their total phenolic and flavonoid content (TPC and TFC, respectively), (b) their antioxidant activity (AA), via the DPPH, FRAP and ABTS assays, and (c) their cyto-genotoxic and/or protective efficiency against the mutagenic agent mitomycin C, via the Cytokinesis Block MicroNucleus assay. All extracts showed increased TPC, TFC, and AA values in almost all cases. S1, S3 and S4 demonstrated no cytotoxic potential, whereas S2 was cytotoxic only at the highest concentrations. Genotoxicity was not observed in the tested extracts. The highest antigenotoxic activity was observed for EtOH-W (S4) extract, which was found to be rich in flavonoids, flavonoid-O-glycosides, phytosterols, phenolic and fatty acids as well as in minerals and mainly in K, Ca, Mg, Si and P, as assessed by using various mass spectrometry techniques. Those findings confirm that E. arvense L. extracts could be valuable candidates for medicinal applications and pharmaceutical products, thus alleviating the effects of more conventional drugs.

Optimization of supercritical-CO2 extraction and pharmacokinetics in SD rats of alkaloids form Sophora moorcroftiana seed

The total alkaloids extracted from the seeds of Sophora moorcroftiana (TAs-SM) have the potential to treat alveolar echinococcosis, a disease included by the WHO in a list of 17 key neglected diseases world-wide. The aims of the current study were first to develop a supercritical fluid extraction (SFE) method for optimizing TAs-SM extraction, and second, to develop an optimized method for evaluating TAs-SM pharmacokinetics in vivo. The Box–Behnken response surface method was used to optimize the extraction process, and ultra-high liquid chromatography coupled with high resolution electrospray mass spectrometry (UPLC-HR-ESI-MS) was used to determine the pharmacokinetics of TAs-SM in SD rats. The results indicated the following optimal SFE extraction conditions: pressure = 31 MPa, temperature = 70 °C, time = 162.18 min. With these parameters, total alkaloids could be extracted from each gram of S. moorcroftiana, with the total content being 68.88 μg. The linear range of UPLC-HR-ESI-MS is 0.78–200.00 ng/ml, R² > 0.99, and the sample recovery is 99–113%. The precision, accuracy, selectivity and stability of the method meet the requirements of US FDA guidelines. To our knowledge this study is the first to establish an SFE method for extracting TAs-SM and the first to employ UPLC-HR-ESI-MS for measuring TAs-SM in rats. These findings provide important contributions for using TAs-SM in further drug development and clinical applications.

Extraction of Phenolic Compounds with Antioxidant Activity from Strawberries: Modelling with Artificial Neural Networks (ANNs)

This research study focuses on the evaluation of the total phenolic compounds (TPC) and antioxidant activity (AOA) of strawberries according to different experimental extraction conditions by applying the Artificial Neural Networks (ANNs) technique. The experimental data were applied to train ANNs using feed- and cascade-forward backpropagation models with Levenberg-Marquardt (LM) and Bayesian Regulation (BR) algorithms. Three independent variables (solvent concentration, volume/mass ratio and extraction time) were used as ANN inputs, whereas the three variables of total phenolic compounds, DPPH and ABTS antioxidant activities were considered as ANN outputs. The results demonstrate that the best cascade- and feed-forward backpropagation topologies of ANNs for the prediction of total phenolic compounds and DPPH and ABTS antioxidant activity factors were the 3-9-1, 3-4-4-1 and 3-13-10-1 structures, with the training algorithms of trainlm, trainbr, trainlm and threshold functions of tansig-purelin, tansig-tansig-tansig and purelin-tansig-tansig, respectively. The best R² values for the predication of total phenolic compounds and DPPH and ABTS antioxidant activity factors were 0.9806 (MSE = 0.0047), 0.9651 (MSE = 0.0035) and 0.9756 (MSE = 0.00286), respectively. According to the comparison of ANNs, the results showed that the cascade-forward backpropagation network showed better performance than the feed-forward backpropagation network for predicting the TPC, and the FFBP network, in predicting the DPPH and ABTS antioxidant activity factors, had more precision than the cascade-forward backpropagation network. The ANN technique is a potential method for estimating targeted total phenolic compounds and the antioxidant activity of strawberries.

Evaluation of antioxidant capacity, fatty acid profile, and bioactive compounds from buritirana (Mauritiella armata Mart.) oil: A little-explored native Brazilian fruit

Buritirana (Mauritiella armata Mart.) is a fruit species native to the Amazon and Cerrado region, belonging to the Arecaceae family. It has high nutritional and functional potential, yet little explored. In this study, we evaluated for the first time the overall yield, behavior of total carotenoids in the extraction kinetics, fatty acid profile, bioactive compounds, and the antioxidant capacity of the oil from buritirana fractions obtained by supercritical CO₂. The highest extraction yield was found in the pulp and whole without seed at 60 °C (18.06 ± 0.40 and 14.55 ± 1.10 g 100 g^-1 of the freeze-dried sample (fdw), respectively), and in the peel at 40 °C (8.31 ± 0.73 g 100 g^-1 fdw). During the extraction kinetics, the pulp had the highest yields of oil (41.57%) and total carotenoids (8.34 mg g^-1) after 61 min at 40 °C. The antioxidant potential, fatty acid profile, and α-tocopherol content were dependent on both fraction and temperature, with oleic acid being the main fatty acid. The oil from the whole fraction without seed had the largest number (20) of identified phenolic compounds. The extraction at 60 °C reduced the relative intensity of most compounds in the whole without seed and pulp. Moreover, it increased the intensity of the compounds in the peel. These results suggest that buritirana is a good oil source with great bioactive potential to produce new products with functional claims.

Wheat straw components fractionation, with efficient delignification, by hydrothermal treatment followed by facilitated ethanol extraction

Lignocellulosic biomass fractionaion into its three major components is critically important for efficient feedstock utilization. The hydrothermal-ethanol method has broad application as its first step, hydrothermal treatment, provides high hemicellulose separation efficiency. However, it severely inhibits the delignification on the subsequent ethanol extraction. In this study, the second step, ethanol extraction, was facilitated by the addition of 3% NaOH and 3% H₂O₂, resulting in a significant improvement of lignin separation (by 48.2%). SEM, AFM, XPS, and XRD were used to characterize the surface composition of the remaining solids (crude cellulose) while the structure of isolated lignin was characterized by FT-IR, CP/MAS 13C NMR, GPC and TGA. The lignin samples isolated with both facilitated and non-facilitated ethanol extraction were compared to elucidate the lignin removal mechanism. The results showed that lignin degradation and crosslinking/polymerization occur in parallel during both the hydrothermal treatment and ethanol extraction.

Supercritical Extraction of Red Propolis: Operational Conditions and Chemical Characterization

The objective of this study was to determine the best operational conditions for obtaining red propolis extract with high antioxidant potential through supercritical fluid extraction (SFE) technology, using carbon dioxide (CO₂) as the supercritical fluid and ethanol as the cosolvent. The following parameters were studied: overall extraction curve, S/F (mass of CO₂/mass of sample), cosolvent percentage (0, 1, 2 and 4%) and global yield isotherms as a function of different pressures (250, 350 and 450 bar) and temperatures (31.7, 40 and 50 °C). Within the investigated parameters, the best conditions found were an S/F of 131 and the use of ethanol at the highest concentration (4% w/w), which resulted in higher extract yields and higher content of antioxidant compounds. Formononetin, the main biomarker of red propolis, was the compound found at the highest amounts in the extracts. As expected, the temperature and pressure conditions also influenced the process yield, with 350 bar and 40 °C being the best conditions for obtaining bioactive compounds from a sample of red propolis. The novel results for red propolis found in this study show that it is possible to obtain extracts with high antioxidant potential using a clean technology under the defined conditions.

Comparative antidandruff efficacy of plant extracts prepared from conventional and supercritical fluid extraction method and chemical profiling using GCMS

BACKGROUND

To combat dandruff associated pathogens, supercritical fluid extraction (SFE) can be used as an alternative eco-friendly technique to obtain antimicrobial plant extracts over conventional methods.

OBJECTIVES

The purpose of the study was to compare the yield and antimicrobial potential of extracts obtained by different extraction methods.

METHODS

Extraction was carried out by cold percolation method using ethyl acetate (EA) and SFE using CO₂. Antimicrobial activity was studied against dandruff causing microbes; Malassezia furfur, Propionibacterium acne, and Staphylococcus epidermidis by agar well diffusion and micro broth dilution method. Statistical evaluation was done by principal component analysis (PCA).

RESULTS

The yield was found higher in the ethyl acetate extracts. PCA indicated that among the sixteen extracts, SFE extract of Azadirachta indica leaves was the most influential with the highest F1 score and maximum antimicrobial activity. Cinnamomum zeylanicum SFE extract demonstrated the lowest MIC against P. acne and M. furfur. GC-MS analysis of A. indica extract inferred that ganoderic acid, 13,14-epoxyoleanan-3-ol acetate, henicosanal, 2-heptadecycloxirane were the major phytoconstituents whereas cinnamaldehyde, α- muurolene and caffeic acid were primarily found in cinnamon.

CONCLUSION

Bioactive compounds identified in the extracts of A. indica and C. zeylanicum can be used in natural antidandruff products.