A one-pot ultrasound-assisted water extraction/cyclodextrin encapsulation of resveratrol from Polygonum cuspidatum

Characterization and bioactivities of coffee husks extract encapsulated with polyvinylpyrrolidone

Coffee processing generates large amounts of residues of which a portion still has bioactive properties due to their richness in phenolic compounds. This study aimed to obtain a coffee husks extract (CHE) and to encapsulate it (ECHE) with polyvinylpyrrolidone using a one-step procedure of solid dispersion. The extraction and encapsulation yields were 9.1% and 92%, respectively. Thermal analyses revealed that the encapsulation increased the thermal stability of CHE and dynamic light scattering analyses showed a bimodal distribution of size with 81% of the ECHE particles measuring approximately 711 nm. Trigonelline and caffeine were the main alkaloids and quercetin the main phenolic compound in CHE, and the encapsulation tripled quercetin extraction. The total phenolics content and the antioxidant activity of ECHE, assayed with three different procedures, were higher than those of CHE. The antioxidant activity and the bioaccessibility of the phenolic compounds of ECHE were also higher than those of CHE following simulated gastrointestinal digestion (SGID). Both CHE and ECHE were not toxic against Alliumcepa cells and showed similar capacities for inhibiting the pancreatic α-amylase in vitro. After SGID, however, ECHE became a 1.9-times stronger inhibitor of the α-amylase activity in vitro (IC50 = 8.5 mg/mL) when compared to CHE. Kinetic analysis revealed a non-competitive mechanism of inhibition and in silico docking simulation suggests that quercetin could be contributing significantly to the inhibitory action of both ECHE and CHE. In addition, ECHE (400 mg/kg) was able to delay by 50% the increases of blood glucose in vivo after oral administration of starch to rats. This finding shows that ECHE may be a candidate ingredient in dietary supplements used as an adjuvant for the treatment of diabetes.

Ultrasound-Assisted Encapsulation of Phytochemicals for Food Applications: A Review

The use of phytochemicals as natural food additives is a topic of interest for both academic and food industry communities. However, many of these substances are sensitive to environmental conditions. For this reason, encapsulation is usually performed prior to incorporation into food products. In this sense, ultrasound-assisted encapsulation is an emerging technique that has been gaining attention in this field, bringing important advantages for the production of functional food products. This review article covered applications published in the last five years (from 2019 to 2023) on the use of ultrasound to encapsulate phytochemicals for further incorporation into food. The ultrasound mechanisms for encapsulation, its parameters, such as reactor configuration, frequency, and power, and the use of ultrasound technology, along with conventional encapsulation techniques, were all discussed. Additionally, the main challenges of existing methods and future possibilities were discussed. In general, ultrasound-assisted encapsulation has been considered a great tool for the production of smaller capsules with a lower polydispersity index. Encapsulated materials also present a higher bioavailability. However, there is still room for further developments regarding process scale-up for industrial applications. Future studies should also focus on incorporating produced capsules in model food products to further assess their stability and sensory properties.

Polygonum cuspidatum Loaded Nanostructured Lipid Carriers for Dual Inhibition of TNF-α- and IL-6 Cytokines and Free Radical Species

The main objective of this study was the testing of natural compounds, such as Polygonum cuspidatum (PgnC) loaded into nanostructured lipid carriers (NLC), which can act as a "double-edged sword" aimed at simultaneously combating dangerous free radicals and inhibiting pro-inflammatory cytokines. Resveratrol-rich PgnC extract was paired with another phytochemical, Diosgenin (DSG), in NLC. The lipid nanocarriers carrying both herbals (NLC-DSG-PgnC) had spherical diameters (100 ± 2 50 nm), a polydispersity index of ~0.15, and electrokinetic potentials greater than -46.5 mV. Entrapment efficiencies of 65% for PgnC and 87% for DSG were determined by chromatographic and UV-Vis spectroscopy assays. Cell cytotoxicity analysis proved that 50 µg/mL of NLC-PgnC and dual-NLC ensured a biocompatible effect like the untreated cells. The dual-NLC assured a much slower in vitro release of DSG and PgnC (67% PgnC and 48% DSG) than the individual-NLC (78% PgnC and 47% DSG) after 4 h of experiments. NLC encapsulating PgnC presented a superior ability to capture cationic radicals: 74.5 and 77.9%. The chemiluminescence results pointed out the non-involvement of DSG in stopping oxygenated free radicals, while the antioxidant activity was maintained at a level higher than 97% for dual-NLC. NLC-DSG-PgnC ensured a promising capacity for inhibition of pro-inflammatory cytokine IL-6, ranging from 91.9 to 94.9%.

Water as Green Solvent: Methods of Solubilisation and Extraction of Natural Products-Past, Present and Future Solutions

Water is considered the greenest solvent. Nonetheless, the water solubility of natural products is still an incredibly challenging issue. Indeed, it is nearly impossible to solubilize or to extract many natural products properly using solely water due to their low solubility in this solvent. To address this issue, researchers have tried for decades to tune water properties to enhance its solvent potential in order to be able to solubilise or extract low-water solubility compounds. A few methods involving the use of solubilisers were described in the early 2000s. Since then, and particularly in recent years, additional methods have been described as useful to ensure the effective green extraction but also solubilisation of natural products using water as a solvent. Notably, combinations of these green methods unlock even higher extraction performances. This review aims to present, compare and analyse all promising methods and their relevant combinations to extract natural products from bioresources with water as solvent enhanced by green solubilisers and/or processes.

Resveratrol biosynthesis, optimization, induction, bio-transformation and bio-degradation in mycoendophytes

Resveratrol (3,4,5-trihydroxystilbene) is a naturally occurring polyphenolic stilbene compound produced by certain plant species in response to biotic and abiotic factors. Resveratrol has sparked a lot of interest due to its unique structure and approved therapeutic properties for the prevention and treatment of many diseases such as neurological disease, cardiovascular disease, diabetes, inflammation, cancer, and Alzheimer's disease. Over the last few decades, many studies have focused on the production of resveratrol from various natural sources and the optimization of large-scale production. Endophytic fungi isolated from various types of grapevines and Polygonum cuspidatum, the primary plant sources of resveratrol, demonstrated intriguing resveratrol-producing ability. Due to the increasing demand for resveratrol, one active area of research is the use of endophytic fungi and metabolic engineering techniques for resveratrol's large-scale production. The current review addresses an overview of endophytic fungi as a source for production, as well as biosynthesis pathways and relevant genes incorporated in resveratrol biosynthesis. Various approaches for optimizing resveratrol production from endophytic fungi, as well as their bio-transformation and bio-degradation, are explained in detail.

Ultrasound-Assisted Extraction of Nannochloropsis oculata with Ethanol and Betaine: 1,2-Propanediol Eutectic Solvent for Antioxidant Pigment-Rich Extracts Retaining Nutritious the Residual Biomass

The aim of this study was the development of an efficient “green” extraction method of Nannochloropsis oculata to produce antioxidant extracts and nutritious residual biomass. Twenty-one extraction methods were evaluated by measuring the reactivity with the Folin–Ciocalteu reagent: ultrasonication or maceration at different temperatures with different organic solvents, extraction at different pH values, enzyme-assisted extraction, encapsulation with β-cyclodextrin, and the use of natural deep eutectic solvents. Ultrasound-assisted extraction with ethanol or betaine: 1,2-propanediol in a molar ratio of 2:5 (BP) had optimal extractive capacity. Both extracts were evaluated with antioxidant assays and the ethanol extract exhibited significantly higher (at least twofold) values. The determination of carotenoids by LC-MS and HPLC-DAD revealed the dominance of violaxanthin and antheraxanthin and their fourfold higher concentrations in the ethanol extract. The ¹H-NMR characterization of the ethanol extract confirmed the results of the colorimetric and chromatographic assays. The microalgal biomass was characterized before and after the extraction in terms of humidity, ash, carbohydrates, proteins, chlorophyll-a, carotenoids, and lipids; the identity and content of the latter were determined with gas chromatography. BP caused a smaller depletion of the lipids from the biomass compared to ethanol, but proteins, carbohydrates, and ash were at a higher content in the biomass obtained after ethanol extraction, whereas the biomass was dry and easy to handle. Although further optimization may take place for the scale-up of those procedures, our study paves the way for a green strategy for the valorization of microalgae in cosmetics without generating waste, since the remaining biomass can be used for aquafeed.

Cyclodextrin as Functional Carrier in Development of Mucoadhesive Tablets Containing Polygoni cuspidati Extract with Potential for Dental Applications

Polygoni cuspidati root is a resveratrol-rich source with anti-inflammatory, angiogenic and neuroprotective effects. The raw material was standardized for the content of resveratrol, for which there is a special justification for administration within the oral mucosa. To improve the solubility of resveratrol and to assure its high content in plant material, an ultrasound-assisted extraction method was applied. The addition of cyclodextrin was found to increase the extraction efficiency of resveratrol (from 13 to 297 µg per 1 g of plant material in case of 50% ethanol extracts) and enhanced its antioxidant activity as compared to pure Polygoni cuspidati extract/resveratrol. Cyclodextrin plays the role of a functional extract regarding technological properties (increasing the extraction of resveratrol from the extract, improving mucoadhesive properties). Therefore, the aim of this study was to develop mucoadhesive tablets containing combinations of the Polygoni cuspidati extract with a cyclodextrin carrier for buccal delivery. The tests sequentially included extract preparation and characterization of its physical and biological properties and then formulation studies with a broad description of the prototype properties. The test results indicate that cyclodextrin increases the efficiency of resveratrol extraction from Polygoni cuspidati rhizome, which is a rich source of resveratrol, and its extract enclosed in a mucoadhesive tablet guarantees prolonged action at the site of administration.

Strategies to increase the shelf life of meat and meat products with phenolic compounds

Oxidative reactions and microbial growth are the main processes involved in the loss of quality in meat products. Although the use of additives to improve the shelf life is a common practice in the meat industry, the current trends among consumers are pushing the researchers and professionals of the meat industry to reformulate meat products. Polyphenols are compounds with antioxidant and antimicrobial activity naturally found in several plants, fruits, and vegetables that can be used in the production of extracts and components in active packaging to improve the shelf life of meat products. This chapter aims to discuss the advances in terms of (1) encapsulation techniques to protect phenolic compounds; (2) production of active and edible packages rich on phenolic compounds; (3) use of phenolic-rich additives (free or encapsulated form) with non-thermal technologies to improve the shelf life of meat products; and (4) use of active packaging rich on phenolic compounds on meat products. Innovative strategies to encapsulated polyphenols and produce films are mainly centered in the use of innovative and emerging technologies (such as ultrasound and supercritical fluids). Moreover, the combined use of polyphenols and non-thermal technologies is a relevant approach to improve the shelf life of meat products, especially using high pressure processing. In terms of application of innovative films, nanomaterials have been largely explored and indicated as relevant strategy to preserve meat and meat products.

Integrated Green Process for the Extraction of Red Grape Pomace Antioxidant Polyphenols Using Ultrasound-Assisted Pretreatment and β-Cyclodextrin

Winemaking is a process that generates a large volume of solid waste biomass, which is currently under extensive investigation as a bioresource of precious polyphenolic compounds. These substances are retrieved from vinification side streams principally by deploying solid–liquid extraction methods. In this frame, the present investigation had as objective the development of an alternative, green extraction process for polyphenols, through integration of ultrasonication as a pretreatment stage, and subsequent extraction with aqueous β-cyclodextrin. Polyphenol recovery from red grape pomace (RGP) was shown to be significantly enhanced by ultrasonication pretreatment, and the use of β-cyclodextrin effectively boosted the aqueous extraction. Under optimized conditions, established by response surface methodology, the maximum yield in total polyphenols was 57.47 mg GAE g−1 dm, at 80 °C, requiring a barrier of 10.95 kJ mol−1. The extract produced was significantly enriched in catechin and quercetin, compared to the aqueous extract, exhibiting also increased antiradical activity. These findings highlighted the value of the process developed for targeted recovery of certain polyphenols and the preparation of task-specific extracts.

One-pot method based on deep eutectic solvent for extraction and conversion of polydatin to resveratrol from Polygonum cuspidatum

The acquisition of resveratrol from Polygonum cuspidatum is complicated and costs organic solvents due to extraction and hydrolysis of its corresponding glycoside (polydatin). In this work, a novel one-pot method based on deep eutectic solvent (DES) was developed for simultaneous extraction and conversion of polydatin to resveratrol from Polygonum cuspidatum for the first time. The extraction yield of resveratrol by DES-based one-pot method were significantly higher than that of water, methanol and ethanol. After optimization by One-Variable-at-a-Time and response surface methodology, the extraction yield of resveratrol reached 12.26 ± 0.14 mg/g within 80 min. The conversation efficiency of polydatin to resveratrol in Polygonum cuspidatum from five different origins was more than 96.3%. Scanning electron microscope results indicated the selected DES disrupted plant cell walls to enhance the yield of resveratrol. The results indicated that one green method was successfully established for efficient extraction and conversion of polydatin to resveratrol from Polygonum cuspidatum.

Purification of total flavonoids from Rhizoma Smilacis Glabrae through cyclodextrin-assisted extraction and resin adsorption

Flavonoids are the main bioactive components responded for the health promoting effects of Rhizoma Smilacis Glabrae (RSG), an herbal material used in many functional food of China. An eco-friendly method with β-cyclodextrin (β-CD)-assisted extraction and resin adsorption/desorption was developed for total flavonoids purification from RSG. Because of complexes formation between flavonoids and β-CD, aqueous solution was used for extraction instead of ethanol. The CD-assisted extraction was optimized through defining optimal CD species, concentration, extraction temperature, and time. The adsorption property of eight macroporous resins on astilbin was compared by adsorption kinetics and capacity. All resins could reach the adsorption equilibrium within 2 hr. Further analyzed by Langmuir and Freundlich models, H103 resin with the best adsorption capacity was selected. The desorption property of different ethanol-water solution was compared. Results showed that by using 75% ethanol, astilbin could be well desorbed from the resin with the recovery of 96.3%. Because of complexes formation, the presence of β-CD would slightly decrease the adsorption rate and capacity of H103 with concentration dependent. In dynamic adsorption, decreasing the flow rate could minish the effects of β-CD. The developed method was successfully used for total flavonoids purified from RSG. The yield of purified product was 8.78%, with astilbin and total flavonoids content of 363.8 and 505.7 mg/g, respectively. The purity was 1.74 times increased with the recovery of 94.38% compared with the extract obtained directly through 50% ethanol extraction.

HPLC Analysis and Skin Whitening Effects of Umbelliprenin-containing Extracts of Anethum Graveolens, Pimpinella Anisum, and Ferulago Campestris

Umbelliprenin has recently been shown to have great potential as a skin whitening agent. Wishing to investigate the same effect in plant species known to biosynthesize this coumarin, three plants belonging to the Apiaceae family, namely Anethum graveolens L. (dill), Pimpinella anisum L. (anise), and Ferulago campestris (Besser) Grecescu (field ferula) were screened by HPLC analysis for their respective content of umbelliprenin in extracts obtained with different solvent mixtures and by maceration and ultrasound-assisted processes. EtOH was shown to be the best solvent, providing umbelliprenin yields ranging from 1.7% to 14.4% (with respect to the total amount of extract obtained). Extracts with the highest content of this farnesyloxycoumarin were then assayed as modulators of melanogenesis in cultured murine Melan A cells employing the same umbelliprenin obtained by chemical synthesis as the reference. A parallelism between the content of the coumarin and the recorded depigmenting effect (60% for the EtOH extract of F. campestris as the best value) was revealed for all plants extracts when applied at a dose of 100 μg/mL. Our results demonstrate that the same potential of umbelliprenin can be ascribed also to umbelliprenin-enriched plant extracts which reinforces enforce the widespread use of phyto-preparations for cosmetic purposes (e.g., A. graveolens).

Advances in ultrasound assisted extraction of bioactive compounds from cash crops - A review

Bioactive compounds in cash crops can be obtained from horticulture, oil and medicinal crops sources. Conventional extraction methods have disadvantages such as low extraction rate, large solvent consumption, high energy consumption and long production cycle. Ultrasonic-assisted extraction is a novel, green and rapid developing technology, which is suitable for up scaling and improving the extraction efficiency of bioactive compounds. Ultrasound mainly acts by producing cavitation bubbles in biological matrix. It has inclusively been reported for achieving high yields and extraction rates of bioactive compounds. Moreover, it can bring remarkable economic and environmental benefits, and has great potential for development and application. This review summarizes the mechanisms, effects of ultrasonic-assisted extraction, ultrasonic devices, and their application in bioactive compounds extraction from cash crops. The future perspective of ultrasound technology is also discussed, which will help to better understand the complex mechanism of ultrasonic-assisted extraction and further guide its application in cash crops.

Chemical modifications of Tonda Gentile Trilobata hazelnut and derived processing products under different infrared and hot-air roasting conditions: a combined analytical study

BACKGROUND

For the processing industry, it is crucial to know what effect the roasting process and conditions have on hazelnut quality. The present study investigates, for the first time, the effects of hot-air and infrared (IR) roasting at different time-temperature combinations on Tonda Gentile Trilobata hazelnut: whole kernels and derived processing products (paste and oil).

RESULTS

The nutritional and physical characteristics of hazelnuts and processing products were investigated to determine the influence of the different roasting conditions as a function of intended use. The antioxidant profile (2.2-diphenyl-1-picrylhydrazyl radical, oxygen radical absorbance capacity and total phenolic content) were analyzed on roasted hazelnut and paste extracts. For a comprehensive understanding of the complex biochemical phenomena occurring during roasting, E-nose and near-IR spectroscopy were also applied. All analytical data were processed using univariate and multivariate data analyses. Hazelnuts derived from IR roasting at higher temperatures (195 °C) showed a richer antioxidant profile and a more intense flavour. On the other hand, the yield associated with the oil extraction under the same conditions was unsatisfactory, making this process completely inadequate for oil production. Oil obtained by hot-air roasting and IR roasting at lower temperature (135 °C) was found to be of good quality, showing rather similar acidity grade, peroxide number and acidic composition. In particular, a slightly but significantly lower acidity was related to lower roasting temperatures (0.21-0.22% versus 0.27% for higher temperatures). All roasting conditions tested allowed the quantitative homogeneous hazelnut paste to be obtained and, from a rheological point of view, a higher roasting temperatures resulted in pastes characterized by higher density and viscosity values.

CONCLUSION

The use of IR was found to be a promising alternative method for hazelnut roasting, as a result of its capability with respect to preserving nutritional values and enhancing organoleptic quality. © 2018 Society of Chemical Industry.

Preparation and biological activity studies of resveratrol loaded ionically cross-linked chitosan-TPP nanoparticles

Nanoparticles with size range of 10-500nm can be efficiently delivered into cancer cells by the Enhanced Permeability and Retention (EPR) effect. Here, we prepared resveratrol (Res) loaded chitosan (CS) nanoparticles with the size of 172-217nm by an ionic cross-linking method, with sodium tripolyphosphate (TPP) as the cross-linking agent, to improve the stability, solubility and tumors targeting of the natural anti-cancer drug Res. The prepared Res loaded CS-TPP nanoparticles presented long-term storage stability and UV light stability. The cumulative drug release from nanoparticles in mimetic tumor tissue condition (pH 6.5) was higher than that in physiological condition (pH 7.4). Further, Res-loaded CS-TPP nanoparticles maintained the antioxidant activity of Res even after UV light irradiation. Cell viability study shows that the as prepared drug loaded nanoparticles had similar antiproliferative activity on hepatocellular carcinoma cells SMMC 7721 and lower cytotoxicity on normal hepatocyte cells L02 compared with free Res. Fluorescence microscopy observation revealed that the nanoparticles were efficiently taken in by SMMC 7721 cells. This work indicates the potential use of drug loaded CS-TPP nanoparticles for the efficient delivery of bioactive Res for chemotherapy.

Cyclodextrins in Food Technology and Human Nutrition: Benefits and Limitations

Cyclodextrins are tasteless, odorless, nondigestible, noncaloric, noncariogenic saccharides, which reduce the digestion of carbohydrates and lipids. They have low glycemic index and decrease the glycemic index of the food. They are either non- or only partly digestible by the enzymes of the human gastrointestinal (GI) tract and fermented by the gut microflora. Based on these properties, cyclodextrins are dietary fibers useful for controlling the body weight and blood lipid profile. They are prebiotics, improve the intestinal microflora by selective proliferation of bifidobacteria. These antiobesity and anti-diabetic effects make them bioactive food supplements and nutraceuticals. In this review, these features are evaluated for α-, β- and γ-cyclodextrins, which are the cyclodextrin variants approved by authorities for food applications. The mechanisms behind these effects are reviewed together with the applications as solubilizers, stabilizers of dietary lipids, such as unsaturated fatty acids, phytosterols, vitamins, flavonoids, carotenoids and other nutraceuticals. The recent applications of cyclodextrins for reducing unwanted components, such as trans-fats, allergens, mycotoxins, acrylamides, bitter compounds, as well as in smart active packaging of foods are also overviewed.

Novel Methods to Generate Active Ingredients-Enriched Ashwagandha Leaves and Extracts

Ashwagandha (Withania somnifera) is an Ayurvedic herb commonly used in world-renowned traditional Indian home medicine system. Roots of Ashwagandha have been traditionally known to possess a variety of therapeutic and health promoting potentials that have not been sufficiently supported by laboratory studies. Nevertheless, most, if not all, of the preventive and therapeutic potentials have been assigned to its bioactive components, steroidal alkaloids and lactones. In contrast to the traditional use of roots, we have been exploring bioactivities in leaves of Ashwagandha. Here, we report that the leaves possess higher content of active Withanolides, Withaferin-A (Wi-A) and Withanone (Wi-N), as compared to the roots. We also established, for the first time, hydroponic cultivation of Ashwagandha and investigated the effect of various cultivation conditions on the content of Wi-A and Wi-N by chemical analysis and bioassays. We report that the Withanone/Withaferin A-rich leaves could be obtained by manipulating light condition during hydroponic cultivation. Furthermore, we recruited cyclodextrins to prepare extracts with desired ratio of Wi-N and Wi-A. Hydroponically grown Ashwagandha and its extracts with high ratio of withanolides are valuable for cancer treatment.

Combination of counterpropagation artificial neural networks and antioxidant activities for comprehensive evaluation of associated-extraction efficiency of various cyclodextrins in the traditional Chinese formula Xue-Zhi-Ning

Xue-Zhi-Ning (XZN) is a widely used traditional Chinese medicine formula to treat hyperlipidemia. Recently, cyclodextrins (CDs) have been extensively used to minimize problems relative to medicine bioavailability, such as low solubility and poor stability. The objective of this study was to determine the associated-extraction efficiency of various CDs in XZN. Three various type CDs were evaluated, including native CDs (α-CD, β-CD), hydrophilic CD derivatives (HP-β-CD and Me-β-CD), and ionic CD derivatives (SBE-β-CD and CM-β-CD). An ultra high-performance liquid chromatography (UHPLC) fingerprint was applied to determine the components in CD extracts and original aqueous extract (OAE). A counterpropagation artificial neural network (CP-ANN) was used to analyze the components in different extracts and compare the selective extraction of various CDs. Extraction efficiencies of the various CDs in terms of extracted components follow the ranking, ionic CD derivatives>hydrophilic CD derivatives>native CDs>OAE. Besides, different types of CDs have their own selective extraction and ionic CD derivatives present the strongest associated-extraction efficiency. Antioxidant potentials of various extracts were evaluated by determining the inhibition of spontaneous, H2O2-induced, CCl4-induced and Fe(2+)/ascorbic acid-induced lipid peroxidation (LPO) and analyzing the scavenging capacity for DPPH and hydroxyl radicals. The order of extraction efficiencies of the various CDs relative to antioxidant activities is as follows: SBE-β-CD>CM-β-CD>HP-β-CD>Me-β-CD>β-CD>α-CD. It can be demonstrated that all of the CDs studied increase the extraction efficiency and that ionic CD derivatives (SBE-β-CD and CM-β-CD) present the highest extraction capability in terms of amount extracted and antioxidant activities of extracts.

One-pot β-cyclodextrin-assisted extraction of active ingredients from Xue-Zhi-Ning basing its encapsulated ability

Xue-Zhi-Ning (XZN) is a traditional Chinese medicine formula, containing active ingredients with poor solubility in water, which has been demonstrated to be helpful for patients with hyperlipidemia. One-pot β-cyclodextrin (β-CD)-assisted extraction of active ingredients from XZN has been carried out to develop an efficient and eco-friendly extraction process. Five active compounds--rubrofusarin gentiobioside, 2,3,5,4'-tetrahydroxy-stilbene-2-O-β-D-glucoside, emodin, nuciferine and quercetin--were identified by UPLC/DAD/MS and used as indexes to evaluate the process optimized by an orthogonal test. The results showed that addition of β-CD significantly enhanced the extraction ratios of all five components. The enhancement of extraction ratios was positively correlated with the apparent formation constants between β-CD and the compounds. The study also showed that the stabilities and dissolution rates of the active ingredients were improved in the presence of β-CD. This one-pot β-cyclodextrin-assisted extraction has the potential to be applied in pharmaceutical preparations directly.

Efficient mechanochemical complexation of various steroid compounds with α-, β- and γ-cyclodextrin

Mechanochemical technology enables solvent-free micronized solid dispersions and efficient molecular host-guest inclusion complexes to be formed in matrices which contain cyclodextrins (CDs). This type of complexation has been studied using α-, β- and γ-cyclodextrin with the dual aims of improving overall solubility and enhancing the bioavailability of common steroid compounds, such as cholic acids and β-sitosterols or lowering cholesterol content in products of animal origin. Several parameters have been studied and optimized: CD/compound molar ratio (1:1, 1:2, 2:1 and 3:1) in function of the cavity sizes of the three different CDs, milling time (from 5 to 40 min) and rotation speed (from 100 to 300 rpm). DSC (differential scanning calorimetry) analyses have revealed that inclusion complexes were efficiently formed after 40 min milling (200 rpm) for β-CD/cholesterol and β-CD/ugrsodeoxycholic acid (encapsulation efficiency 96% and 77% respectively). Besides steroid encapsulation/vehiculation, the mechanochemical technique may pave the way for new ideas in solventless steroid extraction from vegetal matrices with CDs.

Characterization of the Supermolecular Structure of Polydatin/6-O-α-Maltosyl-β-cyclodextrin Inclusion Complex

Polydatin is the main bioactive ingredient in many medicinal plants, such as Hu-zhang (Polygonum cuspidatum), with many bioactivities. However, its poor aqueous solubility restricts its application in functional food. In this work, 6-O-α-Maltosyl-β-cyclodextrin (Malt-β-CD), a new kind of β-CD derivative was used to enhance the aqueous solubility and stability of polydatin by forming the inclusion complex. The phase solubility study showed that polydatin and Malt-β-CD could form the complex with the stoichiometric ratio of 1:1. The supermolecular structure of the polydatin/Malt-β-CD complex was characterized by ultraviolet-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), thermogravimetric/differential scanning calorimetry (TG/DSC), and proton nuclear magnetic resonance ((1) H-NMR) spectroscopy. The changes of the characteristic spectral and thermal properties of polydatin suggested that polydatin could entrap inside the cavity of Malt-β-CD. Furthermore, to reasonably understand the complexation mode, the supermolecular structure of polydatin/Malt-β-CD inclusion complex was postulated by a molecular docking method based on Autodock 4.2.3. It was clearly observed that the ring B of polydatin oriented toward the narrow rim of Malt-β-CD with ring A and glucosyl group practically exposed to the wide rim by hydrogen bonding, which was in a good agreement with the spectral data.

β-Cyclodextrin-assisted extraction of polyphenols from vine shoot cultivars

This work optimized the β-cyclodextrin (β-CD)-assisted extraction process of polyphenols from vine shoots. The efficiency of β-CD was compared to that of ethanol in terms of the quantity and antioxidant capacity (AC) of the extracted polyphenols. Response surface methodology permitted the optimization of the β-CD concentration, time, and temperature. The optimal polyphenol content (PC) [5.8 mg of gallic acid equivalent (GAE)/g of dry matter (DM)] and AC [3146 micromolar trolox equivalent per milliliter (μMTE)] were initially obtained with Syrah cultivar after an extraction of 48 h at 66.6 °C with a 37.7 mg/mL aqueous β-CD solvent. The same PC (5.8 mg of GAE/g of DM) was reached with 50% ethanol/water solvent after 1.65 h. However, a lower AC was found with ethanol (2000 μMTE) compared to β-CD. A comparison of the PC and AC of four different vine shoot cultivars was realized. Our results clearly show the capacity of β-CD to amplify polyphenol extraction from vine shoots.