Search Results (38)

Efficient recovery of phenolic compounds from citrus processing by-products requires optimized solvent systems and reliable frameworks for comparing emerging extraction technologies. In this study, a solvent system was first optimized to maximize phenolic recovery from lemon (Citrus limon (L.) Burm. f.) processing by-products, enabling a standardized comparison of ultrasound-assisted extraction (UAE) and hydrodynamic cavitation (HC). A preliminary solid–liquid extraction screening using different water:ethanol ratios (v/v) identified a 50:50 hydroalcoholic mixture as the optimal solvent system for recovering phenolic compounds. HPLC analysis confirmed the presence of major flavanones (eriocitrin and hesperidin) and hydroxycinnamic acids (caffeic, p-coumaric, sinapic, and ferulic acids). Antioxidant capacity was assessed using complementary assays (Folin–Ciocalteu, DPPH, and ORAC) to provide a comprehensive evaluation of antioxidant activity. Under optimized solvent conditions, UAE significantly improved the recovery of total flavanones (+25.9%), hydroxycinnamic acids (+10.3%), total polyphenols (+20.5%), DPPH activity (+6.0%), and ORAC values (+9.6%) compared with conventional extraction. HC further enhanced extraction performance, increasing flavanone recovery by 12.0%, hydroxycinnamic acids by 7.2%, total polyphenols by 5.2%, and antioxidant activity (DPPH and ORAC) by 11.4% and 2.0%, respectively, relative to UAE. Following ethanol removal and concentration, HC-derived extracts showed the highest phenolic content and antioxidant capacity. These results demonstrate that solvent optimization, combined with a standardized comparison of extraction technologies, enhances phenolic recovery from lemon processing by-products. The findings indicate that HC is a promising, scalable approach for the sustainable recovery of bioactive compounds from citrus side-streams. The novelty of this work lies in the integration of solvent optimization with a systematic and standardized comparison of UAE and HC, providing a reproducible framework for evaluating emerging extraction technologies and highlighting the enhanced performance and scalability potential of HC for phenolic recovery from citrus processing by-products. Full article

Cocoa pod husk (CPH), a major agro-industrial residue, contains valuable bioactive compounds whose recovery can support sustainable waste valorization. This study evaluated the influence of increasing ethanol concentrations on the ultrasound-assisted extraction (UAE) of bioactive compounds from CPH and their antioxidant, antihypertensive, and antihyperglycemic activity. Dried and milled CPH was extracted using ethanol–water mixtures (0–100% ethanol) under fixed ultrasonic conditions. Cocoa pod husk powder characterization and the resulting extracts were analyzed in terms of chemical composition (lignocellulosic compounds, proximate and elemental composition, and bromatological composition), antioxidant capacity, and in vivo antihypertensive and antihyperglycemic effects in Wistar rats. The results showed that solvent polarity strongly modulated extraction efficiency: absolute ethanol yielded the highest phenolic (171.43 mg GAE/g) and flavonoid (132.05 mg QE/g) content, whereas hydroalcoholic mixtures, particularly 50:50, enhanced overall antioxidant performance, especially in FRAP. The chemical analysis results showed the selective recovery of compounds such as quercetin, hesperidin, and theobromine, and FTIR-PCA results revealed distinct solvent-dependent chemical profiles. In vivo assays indicated modest blood pressure stabilization and a more pronounced antihyperglycemic effect after chronic administration. Overall, UAE proved an effective, rapid, and solvent-efficient method for CPH valorization, highlighting its potential for producing natural antioxidants applicable to food, nutraceutical, and cosmetic formulations. Full article

Osteosarcoma is one of the most common malignant tumors that develop in the bone. Currently, surgery is often the best and most used approach, often preceded and followed by chemotherapy, which, however, carries serious short- and long-term side effects. Recently, much attention has been paid to natural compounds capable of inducing tumor cell death, reducing tumor and metastatic activity, and interacting with selective chemotherapy targeting tumor cells. Griffonia simplicifolia, a tropical African plant, has attracted attention because its extracts with bioactive chemicals have demonstrated multiple therapeutic uses. We show the antitumor properties of a Griffonia seed extract, obtained by maceration in a hydroalcoholic mixture (ethanol/water, 70/30, v/v, Gri70), on osteosarcoma cell lines, evaluating cytotoxicity, interaction with a pro-inflammatory signal (interleukin-1β), epigenetic activity of this signal on interleukin-6 gene expression, and interactions with an elective chemotherapeutic agent, doxorubicin. Although the extract did not have strong antiproliferative activity in the cell lines analyzed, we nevertheless observed that it was able to block proliferative and migration signals induced by interleukin-1β, as well as acting epigenetically by blocking the de-methylation of the interleukin-6 promoter and its expression. Furthermore, the extract did not appear to interfere with the antitumor activity of doxorubicin, and the interaction potentiated antimetastatic effects. These results indicate that Gri-70 extract may be useful as adjuvants to enhance the effect of doxorubicin, reducing the adverse effects associated with the increased EMT process of osteosarcoma cells that manage to overcome cell death induction. Indeed, metastasis represents the main cause of poor prognosis. Full article

Type 2 diabetes mellitus (T2DM) remains a global health challenge, necessitating novel therapeutic and dietary strategies. This study optimized hydroalcoholic extraction parameters to maximize α-amylase inhibitory activity from five African medicinal plants: Combretum glutinosum (CG), Ziziphus mauritiana (ZM), Gymnosporia senegalensis (GS), Boscia senegalensis (BS), and Citrullus colocynthis (CC). A central composite design (CCD) modeled the effects of the liquid-to-solid (L/S) ratio (5–15 mL/g) and ethanol concentration (0–100%, v/v), identifying optimal conditions at low L/S ratios (5 mL/g) and moderate-to-high ethanol concentrations (40–100%) for GS, ZM, and CG, where inhibition levels exceeded 80–98% of α-amylase activity. Extracts from CG, ZM, and GS showed the strongest inhibition (IC₅₀ values of 3.67, 9.8, and 2.25 mg/mL, respectively). Antioxidant capacities, evaluated by DPPH and FRAP assays, correlated strongly with total phenolic content (TPC), with ZM exhibiting superior DPPH (IC₅₀ = 1.94 ± 0.16 mg/mL) and FRAP (IC₅₀ = 4.34 ± 0.52 mg/mL) activities. Incorporation of optimized plant powders (3%, w/v) into bread dough significantly influenced textural and colorimetric properties. Mixture design analysis revealed that CG-rich formulations (>2%) yielding hardness exceed 6 N, while ZM–GS blends maintain 3 N, offering targeted firmness control. The addition of medicinal plants significantly increased the total phenolics content by 60% of doughs and thus caused a significant improvement in antioxidant activities. These functional enrichments suggest potential for developing hypoglycemic bakery products with improved sensory attributes. This integrative approach combining extraction optimization and food formulation offers promising avenues for natural antidiabetic agents and functional food development. Full article

The use of antioxidants in the dermatocosmetic industry has become increasingly popular to help protect and stabilize other sensitive active ingredients, prolonging the effectiveness and durability of the cosmetic product. Grape pomace, as the main by-product generated through winemaking, and Polygonum cuspidatum, concentrate bioactive metabolites with high antioxidant activity. Hydroalcoholic extracts obtained from grape pomace (Merlot and Feteasca Neagra varieties) and the root and flower of Japanese knotweed, respectively, alone and in mixtures, were characterized, and preliminary assays were conducted for their incorporation in two gel-based cosmetic formulations. The characterization of the extracts revealed the presence of catechin, vanillic acid, caffeic acid, myricetin, resveratrol, and kaempferol. The hydroalcoholic extract of P. cuspidatum flower and root was found to have the highest content of total phenolic compounds (10.920 ± 0.268 mg GAE/mL, respectively, 4.751 ± 0.072 mg GAE/mL), and the highest antioxidant activity (expressed as DPPH Radical Scavenging Capacity, IC₅₀) by 28.04 ± 1.12 µg GAE/mL and 83.91 ± 1.13 µg GAE/mL, respectively. Catechin was the most abundant polyphenol found in pomace extract (687.87 mg/kg). The type and the concentration of the plant extract used in dermatocosmetic gel formulations influenced their antioxidant activity. Encapsulation of P. cuspidatum flower extract in liposomes prior to their incorporation into the gel formulation demonstrated the role of liposomes in enhancing the stability and modulation of phenolic compound delivery. It is worth noting that this dermatocosmetic formulation, which contains the flower extract of P. cuspidatum, was the subject of a pending patent application. Full article

Horseradish (Armoracia rusticana) is a plant with a long tradition of use and numerous remarkable properties. It is especially appreciated for its antioxidant, antimicrobial, and anti-inflammatory effects. The therapeutic potential of the subject in the management of allergies has received comparatively less attention, despite its composition being rich in bioactive substances. The purpose of this research was to enhance the recovery of bioactive compounds from horseradish by applying an optimized ultrasound-assisted extraction process modelled through Design-Expert software (version 11). Spectrophotometric and chromatographic analyses revealed higher concentrations of polyphenols in extracts obtained with a methanol–water mixture (1:1, v/v) compared to ultrapure water, confirming the efficiency of solvents with lower polarity. The antioxidant activity was found to be significant, with the hydroalcoholic extract achieving 96.93% and the aqueous extract reaching 89.34%. The vitamin C content was determined to be 105.32 mg/100 g and 90.35 mg/100 g, respectively. The polyphenolic profile and fatty acid analysis confirmed the presence of bioactive compounds previously reported as antiallergenic, including protocatechuic, p-hydroxybenzoic, vanillic, caffeic, chlorogenic, p-coumaric, rosmarinic acids, and polyunsaturated fatty acids such as linoleic and linolenic acids, alongside the vitamin C content. The results of the present study confirm that horseradish is a rich natural source of bioactive compounds, particularly antioxidants, which may be of interest for further studies related to functional applications. Full article

The aim of this study was to investigate the suitability of Pressurized Liquid Extraction (PLE) and Supercritical Fluid Extraction (SFE) for Quercus robur bark and Artemisia vulgaris extraction. PLE of Q. robur and A. vulgaris were carried out at different temperatures with water, ethanol and several hydroalcoholic mixtures. SFE of A. vulgaris was performed at different pressures and ethanol concentrations. The anti-inflammatory activity of Q. robur extracts, the antibacterial activity of A. vulgaris extracts and the antioxidant activity of the extracts from both materials were determined. The highest phenolic compound content and antioxidant activity of Q. robur extracts were achieved with water at 100 °C (487.97 mg GAE/g and 3741 µg trolox/g). The highest values for A. vulgaris extracts were obtained with ethanol at 200 °C (149.16 mg/g and 437.13 µmol/g). The ethanolic extract at 150 °C from A. vulgaris had a noticeable anti-inflammatory activity (inhibition of TNF-α and IL-6 secretion near basal values and inhibition of IL-1β higher than 80% at 20 µg/mL). A. vulgaris extracts obtained by SFE exerted antibacterial activity against E. coli (IC₅₀ of 1388 µg/mL with neat SCCO₂ at 15 MPa) and S. aureus (1406 µg/mL using SCCO₂ with 10% ethanol). Full article

Nowadays, several processes to enrich desired bioactive compounds in plant extracts have been developed. The objective of the present study was to assess the performance of bovine serum albumin in increasing the extractive yields of anthraquinones and diarylheptanoids from their respective raw plant powder extracts. Aloe emodin, rhein, emodin, and chrysophanol, from Polygonum cuspidatum, Senna alexandrina, Rhamnus frangula, and Rheum palmatum, and curcumin from Curcuma longa were analyzed in parent dry extracts, solubilized either with water, ethanol, or hydro-alcoholic mixtures, and in ones treated with aqueous solutions of bovine serum albumin by HPLC with UV/Vis detection. The different ratios between the volumes of solvents, powdered plant extracts, and bovine serum albumin were tested. The addition of albumin provided an increase in the yields of aloe emodin in the range 7.8–50.4-fold; of rhein in the range 6.1–14.1-fold; of emodin in the range 19.7–39.7-fold; of chrysophanol in the range 15.1–28.7-fold; and, finally, of curcumin of 32.1-fold. The addition of bovine serum albumin in the processing of plant extracts has been shown to be a novel and a valid alternative, comparing favourably to already reported methodologies. The easy-to-handle procedures, readily accessible facilities, and the employment of cheap substrates and reagents represent the most evident advantages of the methodology described herein. Full article

Antimicrobial resistance (AMR) is one of humanity’s main health problems today. Despite all the breakthroughs and research over the past few years, the number of microbial illnesses that are resistant to the available antibiotics is increasing at an alarming rate. In this article, we estimated the biomedical potential of Portuguese propolis harvested from the Gerês apiary over five years, evaluating the in vitro antimicrobial effect of five hydroalcoholic extracts prepared from five single propolis samples and of a hydroalcoholic extract obtained from the mixture of all samples. The antimicrobial potential was firstly assessed by determining the minimum inhibitory concentration (MIC) of these extracts against a panel of three Gram-positive (Bacillus subtilis, methicillin-sensitive Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus) and one Gram-negative bacteria (Escherichia coli), as well as two yeasts (Candida albicans and Saccharomyces cerevisiae). As MIC values against each bacterium were consistent across all the evaluated propolis extracts, we decided to further conduct a disk diffusion assay, which included three commercial antibiotics—erythromycin, vancomycin, and amoxicillin/clavulanic acid—for comparison purposes. In addition to displaying a concentration-dependent antibacterial effect, the hydroalcoholic extracts prepared with 70% ethanol exhibited stronger antimicrobial capacity than vancomycin against B. subtilis (% of increase ranged between 26 and 59%) and methicillin-sensitive S. aureus (% of increase ranged between 63 and 77%). Moreover, methicillin-resistant S. aureus (MRSA) showed susceptibility to the activity of the same extracts and resistance to all tested antibiotics. These findings support that propolis from Gerês is a promising natural product with promising antimicrobial activity, representing a very stimulating result considering the actual problem with AMR. Full article

Separating hydroalcoholic mixtures remains a significant challenge in engineering. Liquid–liquid extraction has emerged as an appealing alternative method, because it avoids the need for the large energy inputs, volatile organic compounds, and high pressures that are typically required by other separation processes. This study explores the use of hydrophobic deep eutectic solvents (HDESs) composed of terpenes and 10-undecenoic acid as extraction agents for the liquid–liquid separation of hydroalcoholic mixtures composed of alcohols (ethanol, propan-1-ol, and propan-2-ol) and water. The water content in the solvents studied was notably low, reflecting their hydrophobic nature. For the dried HDES samples, the water content ranged from 553 to 4901 ppm. In contrast, the water-saturated samples exhibited higher water contents, ranging from 7250 to 20,864 ppm. The HDES based on thymol, DL-menthol, and L-menthol displayed a eutectic point at an x_terpenes of approximately 0.67. These mixtures maintained a liquid state up to a mole fraction of terpenes around 0.75. In contrast, the HDES composed of carvacrol, fenchyl alcohol, and α-terpineol exhibited their eutectic point at an x_terpenes near 0.5. Notably, these mixtures remained in a liquid state across the entire composition range studied. The 2:1 molar ratio (HBA:HBD) presented the best values for extracting alcohols, reaching 34.04%, 36.59%, and 39.78% for ethanol, propan-2-ol, and propan-1-ol, respectively. These results show that HDES can be applied to overcome issues with existing extraction solvents, increasing the separation efficiency and making the process eco-friendly. Full article

Sulforaphane is a chiral phytochemical with chemopreventive properties. The presence of a stereogenic sulfur atom is responsible for the chirality of the natural isothiocyanate. The key role of sulfur chirality in biological activity is underscored by studies of the efficacy of individual enantiomers as chemoprotective agents. The predominant native (R) enantiomer is active, whereas the (S) antipode is inactive or has little or no biological activity. Here we provide an enantioselective high-performance liquid chromatography (HPLC) protocol for the direct and complete resolution of sulforaphane and its chiral natural homologs with different aliphatic chain lengths between the sulfinyl sulfur and isothiocyanate group, namely iberin, alyssin, and hesperin. The chromatographic separations were carried out on the immobilized-type CHIRALPAK IH-3 chiral stationary phase with amylose tris-[(S)-methylbenzylcarbamate] as a chiral selector. The effects of different mobile phases consisting of pure alcoholic solvents and hydroalcoholic mixtures on enantiomer retention and enantioselectivity were carefully investigated. Simple and environmentally friendly enantioselective conditions for the resolution of all chiral ITCs were found. In particular, pure ethanol and highly aqueous mobile phases gave excellent enantioseparations. The retention factors of the enantiomers were recorded as the water content in the aqueous-organic modifier (methanol, ethanol, or acetonitrile) mobile phases progressively varied. U-shaped retention maps were generated, indicating a dual and competitive hydrophilic interaction liquid chromatography (HILIC) and reversed-phase liquid chromatography retention mechanism on the CHIRALPAK IH-3 chiral stationary phase. Finally, experimental chiroptical studies performed in ethanol solution showed that the (R) enantiomers were eluted before the (S) counterpart under all eluent conditions investigated. Full article

The content of chemical constituents in Eugenia uniflora leaf extracts correlates positively with biological activities. The experimental objective was to carry out the phytochemical screening and purification of the major polyphenols from the leaves of E. uniflora. In addition, the anti-Candida activity of the hydroalcoholic extract, fraction, subfractions and polyphenols purified were evaluated. After partitioning of the extract with ethyl acetate, the fractions were chromatographed on Sephadex^® LH-20 gel followed by RP-flash chromatography and monitored by TLC and RP-HPLC. The samples were characterized by mass spectrometry (LC-ESI-QTOF-MS²) and subjected to the microdilution method in 96-well plates against strains of C. albicans, C. auris, and C. glabrata. Myricitrin (93.89%; w/w; m/z 463.0876), gallic acid (99.9%; w/w; m/z 169.0142), and ellagic acid (94.2%; w/w; m/z 300.9988) were recovered. The polyphenolic fraction (62.67% (w/w) myricitrin) and the ellagic fraction (67.86% (w/w) ellagic acid) showed the best antifungal performance (MIC between 62.50 and 500 μg/mL), suggesting an association between the majority constituents and the antifungal response of E. uniflora derivatives. However, there is a clear dependence on the presence of the complex chemical mixture. In conclusion, chromatographic strategies were effectively employed to recover the major polyphenols from the leaves of the species. Full article

Stevia rebaudiana Bertoni, a no-calorie natural sweetener, contains a plethora of polyphenols that exert antioxidant properties with potential medicinal significance. Due to the variety of functional groups, polyphenols exhibit varying solubility depending on the nature of the extraction solvents (water, organic, or their mixtures, defined further on as hydroalcoholic extracts). In the present study, we performed a systematic review, following PRISMA guidelines, and meta-analysis, synthesizing all available data from 45 articles encompassing 250 different studies. Our results showed that the total phenolic content (TPC) of hydroalcoholic and aqueous extracts presents higher values (64.77 and 63.73 mg GAE/g) compared to organic extracts (33.39). Total flavonoid content (TFC) was also higher in aqueous and hydroalcoholic extracts; meta-regression analysis revealed that outcomes in different measuring units (mg QE/g, mg CE/g, and mg RUE/g) do not present statistically significant differences and can be synthesized in meta-analysis. Using meta-regression analysis, we showed that outcomes from the chemical-based ABTS, FRAP, and ORAC antioxidant assays for the same extract type can be combined in meta-analysis because they do not differ statistically significantly. Meta-analysis of ABTS, FRAP, and ORAC assays outcomes revealed that the antioxidant activity profile of various extract types follows that of their phenolic and flavonoid content. Using regression meta-analysis, we also presented that outcomes from SOD, CAT, and POX enzymatic antioxidant assays are independent of the assay type (p-value = 0.905) and can be combined. Our study constitutes the first effort to quantitatively and statistically synthesize the research results of individual studies using all methods measuring the antioxidant activity of stevia leaf extracts. Our results, in light of evidence-based practice, uncover the need for a broadly accepted, unified, methodological strategy to perform antioxidant tests, and offer documentation that the use of ethanol:water 1:1 mixtures or pure water can more efficiently extract stevia antioxidant compounds. Full article

Phenolic compounds from a hydroalcoholic extract of wet olive pomace were purified and concentrated by an integrated membrane process in organic media. First, UF010104 (Solsep BV) and UP005 (Microdyn Nadir) membranes were tested to be implemented in the ultrafiltration stage, with the aim of purifying the extract and obtaining a permeate enriched in phenolic compounds. Despite the high flux observed with the UF010104 membrane (20.4 ± 0.7 L·h⁻¹·m⁻², at 2 bar), the UP005 membrane was selected because of a more suitable selectivity. Even though some secoiridoids were rejected, the permeate stream obtained with this membrane contained high concentrations of valuable simple phenols and phenolic acids, whereas sugars and macromolecules were retained. Then, the ultrafiltration permeate was subjected to a nanofiltration step employing an NF270 membrane (DuPont) for a further purification and fractionation of the phenolic compounds. The permeate flux was 50.2 ± 0.2 L·h⁻¹·m⁻², working at 15 bar. Hydroxytyrosol and some phenolic acids (such as vanillic acid, caffeic acid, and ferulic acid) were recovered in the permeate, which was later concentrated by reverse osmosis employing an NF90 membrane. The permeate flux obtained with this membrane was 15.3 ± 0.3 L·h⁻¹·m⁻². The concentrated phenolic mixture that was obtained may have important applications as a powerful antioxidant and for the prevention of diabetes and neurodegenerative diseases. Full article

Green chemistry emphasizes the isolation of biologically active compounds from plants and biomass to produce renewable, bio-based products and materials through sustainability and circularity-driven innovation processes. In this work, we have investigated the extraction of rosmarinic acid (RA), a phenolic acid with several biological properties, from aromatic herbs using ultrasounds and low environmental risk natural deep eutectic solvents (NADES). Various solvent mixtures have been investigated, and the parameters influencing the process have been studied by a mixture-process experimental design to identify the optimal RA extraction conditions. The extraction yield has been calculated by HPLC-diode array analysis. The lactic acid:ethylene glycol mixture using an ultrasound-assisted process has been found to be the most versatile solvent system, giving RA yields 127–160% higher than hydroalcoholic extraction (70% ethanol). The deep eutectic solvent nature of lactic acid:ethylene glycol has been demonstrated for the first time by multi-technique characterization (¹H-NMR and ¹³C-NMR, DSC, and W absorption properties). The aqueous raw extract has been directly incorporated into poly(vinyl alcohol) to obtain films with potential antibacterial properties for applications in the field of food and pharmaceutical packaging. Full article