Characterization and antioxidant activity of the complexes of tertiary butylhydroquinone with β-cyclodextrin and its derivatives

PCL/Locust bean gum nanofibers loaded with HP-β-CD/Epicatechin clathrate compounds for fruit packaging

In this work, the hydroxypropyl-β-cyclodextrin (HP-β-CD)/Epicatechin (EC) clathrate compounds were rapidly prepared based on an ultrasound-mediated method, and Polycaprolactone (PCL)/Locust bean gum (LBG) nanofibers loaded clathrate compounds were fabricated by electrostatic spinning (ELS) for fruit packaging. The results of infrared spectrum and crystal type analysis proved that clathrate compounds were successfully prepared. With the addition of clathrate compounds, the diameter of fibers increased from 553.43 to 1273.47 nm, and hydrogen bonds were formed between clathrate compounds and fibrous membranes, which improved the thermal stability, reduced the crystallinity, and enhanced the hydrophilicity and gas permeability of fibrous membranes. The fibrous membranes indicated sustained release of EC for 240 h, retaining the activity of EC and demonstrating good bacteriostatic ability in vitro and in vivo. The test results showed that the antibacterial fibrous membranes prepared in this work have a positive application prospect for fruit packaging.

Enzymatic and ultrasound assisted β-cyclodextrin extraction of active ingredients from Forsythia suspensa and their antioxidant and anti-inflammatory activities

With the proposal of the 2030 Agenda for Sustainable Development, the Chinese medicine extraction technology has been innovatively improved to prioritize low energy consumption, sustainability, and minimized organic solvent utilization. Forsythia suspensa (FS) possesses favorable pharmacological properties and is extensively utilized in traditional Chinese medicine. However, due to the limitations of the composition and extraction methods, its potential has not been fully developed. Thus, a combination of ultrasound-assisted extraction (UAE), enzyme-assisted extraction (EAE), and β-cyclodextrin extraction (β-CDE) was employed to isolate and purify rutin, phillyrin, and forsythoside A from FS. The results demonstrated that the efficiency of extracting enzymatic and ultrasound assisted β-cyclodextrin extraction (EUA-β-CDE) was highly influenced by the temperature and duration of hydrolysis, as well as the duration of the extraction process. According to the results of the single-factor experiment, Box-Behnken design (BBD) in Response surface method (RSM) was used to optimize the experimental parameters to achieve the maximum comprehensive evaluation value (CEV) value. The EUA-β-CDE compared with other extraction methods, has good extraction effect and low energy consumption by high performance liquid chromatography (HPLC), scanning electron microscopy (SEM), calculation of power consumption and CO2 emission The EUA-β-CDE compared with other extraction methods, has good extraction effect and low energy consumption by HPLC, SEM, calculation of power consumption and CO2 emission. Then, the structural characteristics of EUA-β-CDE of FS extract had significant interaction with β-CD by Fourier infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). In addition, EUA-β-CDE extract has good antioxidant and anti-inflammatory activities. The establishment of EUA-β-CDE of FS provides a new idea for the development and application of other sustainable extraction methods of traditional Chinese medicine.

Preparation of β-Cyclodextrin(CD)/Flavour CD Powder and Its Application on Flavour Improvement of Regular Coffee

To improve the overall sensory evaluation of regular coffee, a mixture of β-CD/flavour CD powder was prepared by a freeze-drying method. Cyclodextrin inclusion complexes consist of eight compounds that are naturally present in coffee, specifically: 2,5-dimethylpyrazine, benzaldehyde, citral, linalool, limonene, phenethyl acetate, furfural, and ethyl acetate. These eight compounds naturally occur in coffee, making them safer than using other compounds. Moreover, these eight compounds are the primary active ingredients in coffee, significantly influencing its flavour profile. Therefore, choosing to complex these eight compounds with cyclodextrins can effectively enhance the taste of the coffee. XRD, FT-IR, and SDE-GC-FID were presented to study the formation of inclusion CD powder, the storage stability, chemical composition changes, and safety. Results show that by the cyclodextrin method of freeze-drying, the CD powder showed a stable encapsulated structure and increased stability of flavour compounds. Based on the coffee aroma analysis results, prepared CD powder can enhance the coffee's aroma score by 3.0-4.0 points and increase the flavour score by 2.1-3.5 points, and it can achieve preservation for a minimum of 181 days at 25 °C. Furthermore, under the requirements of the China national standard for additives, the mixture of β-CD/flavour CD powder was used for the cup testing with four regular coffees to obtain improved coffees. With the full score is 10, improved coffees could score extra 3.0-4.0 points on aroma and 2.1-3.5 on flavour compared to regular coffee. In addition, the CD powder also improves the quality of the coffee in terms of aftertaste, body, and sweetness. Overall, β-CD/flavour CD powders provide several advantages over the currently popular coffee bean processing methods, including improved reproducibility, enhanced controllability, and increased flexibility, while prioritizing safety. And it should be explored further with appropriate compounds given its potential for coffee aroma modulation.

β-cyclodextrin inclusion complexes with short-chain phenolipids: An effective formulation for the dual sustained-release of phenolic compounds

The β-cyclodextrin and short-chain alkyl gallates (A-GAs), which are representative of phenolipids, such as butyl, propyl, ethyl, and methyl gallates, were chosen to form inclusion complexes by the use of the freeze-drying process. In the everted rat gut sac model, HPLC-UV analysis demonstrated that the released A-GAs from inclusion complexes were degraded to yield free gallic acid (GA) (sustained-release function 1). The small intestine membrane may be crossed by both the GA and the A-GAs. A-GAs may also undergo hydrolysis to provide GA (sustained-release function 2) following transmembrane transfer. Clearly, a helpful technique for the dual sustained-release of phenolic compounds is to produce β-cyclodextrin inclusion complexes with short-chain phenolipids. This will increase the bioactivities of phenolic compounds and prolong their in vivo residence length. Moreover, changing the carbon-chain length of these β-cyclodextrin inclusion complexes would readily modify the dual sustained-release behavior of the phenolic compounds. Thus, our work effectively established a theoretical foundation for the use of β-cyclodextrin inclusion complexes containing short-chain phenolipids as new source of functional food components to provide the body with phenolic compounds more efficiently.

Nanozyme-integrated alcogel colorimetric sensor for rapid and on-site detection of tert-butyl hydroquinone

Tert-butyl hydroquinone (TBHQ) stand as one of the most widely used antioxidants in food and daily chemical products. Rapid and sensitive monitoring of TBHQ holds considerable importance in safeguarding human health due to its potential risks. In this study, we devised an alcogel-based colorimetric sensor enabling the portable and visual detection of TBHQ. The Ce-UiO-66 nanozyme exhibiting remarkable oxidase-like activity, was synthesized and characterized, facilitating the catalysis of TBHQ oxidation to 2-tert-butyl-1,4-benzoquinone (TBBQ). The ensuing chromogenic reaction between TBBQ and ethylenediamine produced a stable and colored product, serving as a reliable indicator for the rapid and specific detection of TBHQ. Building upon this discovery, a portable and low-cost colorimetric sensor was fashioned by integrating the nanozyme into κ-carrageenan alcogel, thereby enabling on-site TBHQ detection via a smartphone-based sensing platform. The colorimetric sensor exhibited a detection limit of 0.8 μg mL-1, demonstrating robust performance across various matrices such as edible oils, cosmetics, and surface water. Recoveries ranged from 84.9 to 95.5%, with the sensor's accuracy further validated through gas chromatography-mass spectrometry. Our study presents an effective approach to rapid and convenient monitoring of TBHQ, exhibiting good extensibility and practicability.

Probing the interaction between encapsulated ethoxyquin and its β-cyclodextrin inclusion complex with bovine serum albumin

Ethoxyquin (EQ) is a synthetic antioxidant that is derived from quinolines and found in many meat products. EQ is strictly regulated in feed due to its potential health implications. An investigation of the interaction mechanism between EQ and transporter protein before and after β-cyclodextrin (β-CD) encapsulation was conducted with the use of multi-spectroscopy, cyclic voltammetry, and molecular docking. EQ formed complexes with bovine serum albumin (BSA), and affected secondary structure and microenvironment polarity of BSA. However, at 298 K, EQ's fluorescence quenching constants decreased from (9.81 ± 0.05) × 103 L mol-1 to (4.94 ± 0.09) × 103 L mol-1, binding constants decreased from (10.28 ± 0.02) × 103 L mol-1 to (2.08 ± 0.07) × 103 L mol-1, after encapsulation in β-CD as well as the binding distance increased. β-CD contains part of EQ in its hydrophobic cavity, inhibiting its binding to BSA. β-CD inclusion complex prevented adverse effects of EQ on BSA conformation. However, β-CD encapsulation had no effect on EQ's antioxidant activity.

In Vitro Wound Healing Potential of a Fibroin Film Incorporating a Cannabidiol/2-Hydroxypropyl-β-cyclodextrin Complex

This study aimed to develop a film dressing prepared by incorporating a complex of cannabidiol and 2-hydroxypropyl-β-cyclodextrin (CBD/HP-β-CD) into a fibroin-based film and to investigate its wound healing capabilities. The fibroin from silkworm cocoons exhibited a total protein content of 96.34 ± 0.14% w/w and a molecular weight range of 25 to 245 kDa. Fourier-transform infrared spectroscopy (FTIR) revealed the presence of characteristic amide peaks (I, II, and III) in the isolated fibroin. The CBD/HP-β-CD complex, prepared with a molar ratio of 1:2 (CBD to HP-β-CD), had 81.5 ± 1.2% w/w CBD content, as determined by high-performance liquid chromatography (HPLC). X-ray diffraction (XRD) and FTIR analyses demonstrated successful encapsulation of CBD's hydrophobic aromatic rings by HP-β-CD. Blending the fibroin solution with the CBD/HP-β-CD complex produced a transparent, slightly yellowish film. Mechanical testing revealed a tensile strength of 48.67 ± 2.57 MPa and a % elongation at a break of 1.71 ± 0.21%. XRD and FTIR analyses showed distinctive crystalline and chemical structures of the film. In subsequent in vitro experiments with normal human dermal fibroblasts, the film demonstrated potential for wound healing. An increase in cell division (G2/M phase) was observed compared to the fibroin film without the CBD/HP-β-CD complex. Additionally, fibroblasts treated with the film exhibited enhanced cell migration in a scratch assay and increased expression of vascular endothelial growth factor protein compared to the control group. Overall, these findings underscore the film's potential for enhancing wound healing outcomes.

Microwave-Assisted Formation of Ternary Inclusion Complex of Pterostilbene

Pterostilbene (PTS) is a naturally occurring phytoalexin. PTS displays limited water solubility, which consequently results in its diminished oral bioavailability. Therefore, a ternary inclusion complex (TIC) of PTS with β-cyclodextrin (βCD) in the presence of ternary substance Pluronic® F-127 (PLF) was prepared using microwave technology. The PTS-TIC was characterized by dissolution performance. Further, the prepared TIC was characterized by DSC, FTIR, NMR, XRD, and SEM analysis. Additionally, the antioxidant activity of PTS and PTS-TIC was also evaluated. Phase-solubility studies revealed that PTS's solubility in water was increased by 6.72 times when βCD/PLF was present. In comparison with PTS, prepared PTS-TIC produced a considerable improvement in PTS release. After 1 h, 74.03 ± 4.47% of PTS was released from PTS-TIC. Outcomes of DSC, FTIR, NMR, XRD, and SEM analysis revealed that the PTS was enclosed in the βCD cavity. In terms of antioxidant properties, the PTS-TIC formulation demonstrated superior activity compared to PTS, possibly attributed to the improved solubility of PTS resulting from the formation of TIC using microwave technology. It was concluded that microwave technology proved to be an extremely beneficial means of interacting PTS with βCD. In addition to increasing the solubility of PTS, the findings are also expected to improve its bioavailability by increasing its solubility. As a result, this study could provide insight into potential methods for enhancing the solubility of polyphenolic substances like PTS.

Encapsulation and Biological Activity of Hesperetin Derivatives with HP-β-CD

The encapsulation of insoluble compounds can help improve their solubility and activity. The effects of cyclodextrin encapsulation on hesperetin's derivatives (HHSB, HIN, and HTSC) and the physicochemical properties of the formed complexes were determined using various analytical techniques. The antioxidant (DPPH•, ABTS•+ scavenging, and Fe2+-chelating ability), cytotoxic, and antibacterial activities were also investigated. The inclusion systems were prepared using mechanical and co-evaporation methods using a molar ratio compound: HP-β-CD = 1:1. The identification of solid systems confirmed the formation of two inclusion complexes at hesperetin (CV) and HHSB (mech). The identification of systems of hesperetin and its derivatives with HP-β-CD in solutions at pHs 3.6, 6.5, and 8.5 and at various temperatures (25, 37 and 60 °C) confirmed the effect of cyclodextrin on their solubility. In the DPPH• and ABTS•+ assay, pure compounds were characterized by higher antioxidant activity than the complexes. In the FRAP study, all hesperetin and HHSB complexes and HTSC-HP-β-CD (mech) were characterized by higher values of antioxidant activity than pure compounds. The results obtained from cytotoxic activity tests show that for most of the systems tested, cytotoxicity increased with the concentration of the chemical, with the exception of HP-β-CD. All systems inhibited Escherichia coli and Staphylococcus aureus.

Green Synthesis of Magnetic Supramolecules β-Cyclodextrin/Iron Oxide Nanoparticles for Photocatalytic and Antibacterial Applications

Iron oxide nanoparticles (Fe3O4NPs) are a fascinating field of study due to their wide range of practical applications in environmental and medical contexts. This study presents a straightforward, environmentally friendly method for producing Fe3O4NPs utilizing β-cyclodextrin (β-CD) as a reducing and capping agent. This approach results in the rapid and effective eco-friendly synthesis of β-CD/Fe3O4NPs. The properties and characteristics of β-CD/Fe3O4NPs were investigated using various methods, including ultraviolet-visible (UV/vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetry analysis (TGA), and vibrating-sample magnetometry (VSM). The absorption of β-CD/Fe3O4NPs caused a distinct peak at 349 nm, as evidenced by the results of UV/vis studies. This peak was attributed to the absorption of surface plasmon resonance. The crystalline nature of β-CD/Fe3O4NPs was confirmed through XRD analysis. The SEM and TEM analyses have verified the geometry and structural characteristics of β-CD/Fe3O4NPs. The β-CD/Fe3O4NPs exhibited remarkable effectiveness in the decomposing efficiency (%) of methylene blue (MB) dye with 52.2, 94.1, and 100% for 0.2, 0.4, and 0.6 g β-CD/Fe3O4NPs, respectively. In addition, the highest efficiency in hunting radicals was observed (347.2 ± 8.2 mg/g) at 100 mg/mL β-CD/Fe3O4NPs; the combination of β-CD/Fe3O4NPs exhibited remarkable effectiveness in inhibiting the growth of some bacteria that cause infections. The capabilities of β-CD/Fe3O4NPs for various applications showed that these materials could be used in photocatalytic, antioxidants, and antibacterial. Additionally, the eco-friendly synthesis of these materials makes them a promising option for the remediation of harmful pollutants and microbes.

Ternary Inclusion Complex of Sinapic Acid with Hydroxypropyl-β-cyclodextrin and Hydrophilic Polymer Prepared by Microwave Technology

Sinapic acid (SA) is a poorly water-soluble substance which could result in poor bioavailability. The aim of this study was to determine the “hydroxypropyl β-cyclodextrin (HPβCD)” solubilization of SA in the presence of the auxiliary substance hydroxypropyl methylcellulose (HPMC) and to evaluate the ternary inclusion complex prepared by microwave technology. Phase-solubility profiles showed that HPβCD exhibited the greatest solubilizing effect on SA in the presence of HPMC. The enhanced rate of SA dissolution was exhibited by a ternary complex. Outcomes of analyses such as “DSC, FTIR, NMR, and SEM” confirmed the embedding of SA into the cavity of the HPβCD and the formation of a ternary inclusion complex. The outcomes of antioxidant activity (ABTS and nitric oxide scavenging activity) demonstrated that SA ternary inclusion complex (TIC) presented strong antioxidant activity, which might be a result of the enhanced solubility of SA in the TIC prepared by microwave technology. Hence, SA-TIC formulation could be a better dosage form which may protect the body from free radical damage and oxidative stress. Microwave technology greatly boosted the interaction of SA with HPβCD and HPMC, and such findings are expected to contribute to raising the solubility of SA, thereby improving the bioavailability of SA.

Hydroxypropyl-β-Cyclodextrin for Delivery of Sinapic Acid via Inclusion Complex Prepared by Solvent Evaporation Method

The goal of this study was to increase the aqueous solubility and dissolution rate of sinapic acid (SA) by formulating binary inclusion complex (BIC) of SA with hydroxypropyl-β-cyclodextrin (HPβCD) using solvent evaporation (SE) technology. The phase solubility and dissolution studies were conducted to determine the solubility and in vitro release rate of SA. In addition, the prepared inclusion complex was characterized for solid state characterization using techniques such as DSC, PXRD, SEM, and FTIR. Moreover, the prepared SA-BIC was evaluated for its antioxidant activity. Results revealed that the SA solubility can be shown to improve with a change in HPβCD concentration. About 2.59 times higher solubility of SA in water was noticed in the presence of HPβCD (10 mM). Dissolution study demonstrated that the 34.11 ± 4.51% of SA was released from binary physical mixture (BPM), while the maximum release of 46.27 ± 2.79% of SA was observed for SA-BIC prepared by SE method. The prepared SA-BIC demonstrated distinctive properties when compared to pure SA, which was demonstrated by different analytical methods, such as DSC, PXRD, SEM, and FTIR, as evidence of SA inclusion into HPβCD cavity. Further, it was observed that SA-BIC displayed stronger DPPH radical scavenging activity than SA. In conclusion, SE technology considerably enhanced the complexity of SA with HPβCD, and these observations could help to heighten the SA solubility, which may lead to a better bioavailability.

Rhodamine B functionalized luminescent metal-organic frameworks for ratiometric fluorescence sensing of hydroquinone

The development of sensitive and selective detection methods for hydroquinone (HQ), a phenolic organic compound with high toxicity and low degradability, is of extraordinary importance. In this work, a fluorescent sensor based on functionalized luminescent metal-organic frameworks (LMOFs) was designed and applied for the ratiometric fluorescence sensing of HQ. The sensor was prepared by the functionalization of IRMOF-3 with rhodamine B (RhB), possessing dual-emission fluorescence properties. After the addition of HQ, the blue fluorescence of the IRMOF-3 framework was gradually weakened, while the red fluorescence of RhB remained unchanged, resulting in the continuous fluorescence change of RhB@IRMOF-3 with HQ concentrations. The sensing mechanism demonstrates that HQ changes the fluorescence of the sensor via electron transfer between benzoquinone and RhB@IRMOF-3. The RhB@IRMOF-3 sensor has the advantages of a wide linear range, quick response speed, and strong specificity for HQ detection. This work is the first attempt focusing on functionalized LMOFs for HQ fluorescence detection, which has superb potential for the application to real environmental water samples.

Alarming impact of the excessive use of tert-butylhydroquinone in food products: A narrative review

Tert-butyl hydroquinone (TBHQ) is a food additive commonly used as a more effective protectant in the food, cosmetic and pharmaceutical industries. However, the long-term exposure to TBHQ at higher doses (0.7 mg/kg) results in substantial danger to public health and brings a series of side effects, including cytotoxic, genotoxic, carcinogenic, and mutagenic effects. As a result, the global burden of chronic diseases has fascinated consumers and governments regarding the safety assessment of food additives. Regarding contradictory reports of various research about the application of food additives, the accurate monitoring of food additives is urgent. Notwithstanding, there are reports of the therapeutic effects of TBHQ under pathologic conditions through activation of nuclear factor erythroid 2-related factor 2. Thus, further investigations are required to investigate the impact of TBHQ on public health and evaluate its mechanism of action on various organs and cells. Therefore, this review aimed to investigate TBHQ safety through an overview of its impacts on different tissues, cells, and biological macromolecules as well as its therapeutic effects under pathologic conditions.

Recent advances in cyclodextrin-based films for food packaging

Cyclodextrins are garnering increasing attention because they offer several benefits. For instance, cyclodextrins can form several complexes and supramolecular structures not only for food packaging but also for applications in other fields of science. In this review, we discussed the physical and chemical properties of cyclodextrins and the mechanism of their inclusion complex formation. The use of cyclodextrins in various types of food packaging is elaborated upon. We also explain the effects of cyclodextrins on the packaging of fruits, vegetables, meat, fish, and processed foods. Furthermore, some feasible suggestions for future applications are provided. In addition to the positive attributes of cyclodextrins, there are some limitations and drawbacks, which are discussed briefly in this review. In summary, this review can serve as a guide for researchers exploring cyclodextrins for the development of various packaging films.

Characterization of the physicochemical properties, antioxidant activity, and antiproliferative activity of natural melanin from S. reiliana

This study aimed to characterize the physicochemical properties and stability of L-25 melanin extracted from Sporisorium reilianum (S. reiliana). The results showed that the maximum absorption wavelength of melanin was 215 nm. Reducing agents, heat, light, microwaving, oxidants, and common food additives did not affect the melanin. Additionally, it has a good metal stability except Mn²⁺. The IR spectra revealed the presence of O–H, N–H, C=O, and C=C bonds as well as carboxyl, alcohol hydroxyl, and phenolic hydroxyl groups and a pyran ring. L-25 melanin could be defined as DL-hydroxy phenylalanine (DOPA)-melanin. The antioxidant and antiproliferative were also measured. The melanin has a specific stability and high antioxidant activity, including a strong DPPH free radical scavenging ability, and protected damaged HepG2 cells by reducing reactive oxygen species, malondialdehyde, and lactate dehydrogenase content. In conclusion, S. reilianum represents a novel source of melanin, that could be applied to health food or food additives. Our results show that melanin from S. reilianum is a natural pigment with good stability that has a great prospect of development and application, providing a theoretical basis and methods for its further processing and development as a functional food.

Enhanced antibacterial efficacy and mechanism of octyl gallate/beta-cyclodextrins against Pseudomonas fluorescens and Vibrio parahaemolyticus and incorporated electrospun nanofibers for Chinese giant salamander fillets preservation

A series of alkyl gallates were evaluated for the antibacterial activity against two common Gram-negative foodborne bacteria (Pseudomonas fluorescens and Vibrio parahaemolyticus) associated with seafood. The length of the alkyl chain plays a pivotal role in eliciting their antibacterial activities and octyl gallate (OG) exerted an excellent inhibitory efficacy. To extend the aqueous solubility, stability, and bactericidal properties of octyl gallate (OG), an inclusion complex between OG and β-cyclodextrin (βCD), OG/βCD, was prepared and identified with various methods including X-ray diffraction (XRD), differential scanning calorimeter (DSC) and Fourier transform infrared spectroscopy (FTIR). Furthermore, the enhanced inhibitory effect and potential antibacterial mechanism of OG/βCD against two Gram-negative and Gram-positive foodborne bacteria were comprehensively investigated. The results show that OG/βCD could function against bacteria through effectively damaging the membrane, permeating into cells, and then disturbing the activity of the respiratory electron transport chain to cause the production of high-level intracellular hydroxyl radicals. Moreover, the reinforced OG/βCD-incorporated polylactic acid (PLA) nanofibers were fabricated using the electrospinning technique as food packaging to extend the Chinese giant salamander fillet's shelf life at 4 °C. This research highlights the antibacterial effectiveness of OG/βCD in aqueous media, which can be used as a safe multi-functionalized food additive combined with the benefits of electrospun nanofibers to extend the Chinese giant salamander fillets shelf life by 15 d at 4 °C.

Application of molecular docking in elaborating molecular mechanisms and interactions of supramolecular cyclodextrin

The cyclodextrin (CD)-based supramolecular nanomedicines have attracted growing interest because of their superior characteristics, including desirable biocompatibility, low toxicity, unique molecular structure and easy functionalization. The smart structures of CD impart host-guest interaction for meeting the multifunctional needs of disease therapy. However, it faces challenges in formulation design and inclusion mechanism clarification of the functional supramolecular assemblies owing to the complicated structures and mechanisms. Fortunately, molecular docking helps the researchers to comprehend the interaction between the drug and the target molecule for achieving high-through screening from the database. In this review, we summarized the category and characteristics of molecular docking along with the properties and applications of CD. Significantly, we highlighted the application of molecular docking in elaborating molecular mechanisms and simulating complex structures at molecular levels. The issues and development of CD and molecular docking were also presented to provide beneficial reference and new insights for supramolecular nano-systems.

Cannabidiol/hydroxypropyl-β-cyclodextrin inclusion complex: structure analysis, release behavior, permeability, and bioactivity under in vitro digestion

The inclusion complex of CBD greatly improved its release performance and bioactivity.

New Horizons in Microbiological Food Safety: Ultraefficient Photodynamic Inactivation Based on a Gallic Acid Derivative and UV-A Light and Its Application with Electrospun Cyclodextrin Nanofibers

An excellent bactericidal effect of octyl gallate (OG)-mediated photodynamic inactivation (PDI) against foodborne pathogens (Escherichia coli and Staphylococcus aureus) was evaluated in relation to the mode of action. UV-A irradiation (wavelength, 365 nm; irradiance, 8.254 ± 0.18 mW/cm²) of the bacterial suspension containing 0.15 mM OG could lead to a >5-log reduction of viable cell counts within 30 min for E. coli and only 5 min for S. aureus. Reactive oxygen species (ROS) formation was considered the main reason for the bactericidal effect of OG + UV-A light treatment because toxic ROS induced by OG-mediated PDI could attack the cellular wall, proteins, and DNA of microbes. Moreover, the bactericidal effect, as well as the yields of ROS, depended on OG concentrations, irradiation time, and laser output power. Furthermore, we prepared an edible photodynamic antimicrobial membrane comprising electrospun cyclodextrin nanofibers (NFs) by embedding OG. The resultant OG/HPβCD NFs (273.6 μg/mL) under UV-A irradiation for 30 min (14.58 J/cm) could cause a great reduction (>5-log) of viable bacterial counts of E. coli. The in situ photodynamic antibacterial activity of OG/HPβCD NF-based packaging was evaluated during the Chinese giant salamander storage. Overall, this research highlights the dual functionalities (antibacterial and photodynamic properties) of OG as both an antibacterial agent and photosensitizer and the effectiveness of electrospun NFs containing OG as an active antibacterial packaging material for food preservation upon UV light illumination.

Release Characteristics of an Essential Oil Component Encapsulated with Cyclodextrin Shell Matrices

BACKGROUND

Essential oils are poor aqueous solubility and high volatility compounds. The encapsulation of essential oils with Cyclodextrins (CDs) can protect them from adverse environmental conditions and improve their stability. Therefore, increasing the functional capabilities of essential oils when they were used as additives in pharmaceutical and food systems. Additionally, the release of active compounds is an important issue. However, there were few studies about the effect of different CDs on the release of drugs after encapsulation. Therefore, the information on the study of release models is considerably limited.

OBJECTIVE

This study aimed to (i) characterize the physico-chemical properties and release behavior of myrcene encapsulated in the four different shell matrices of α-CD, β-CD, γ-CD and 2-hydroxypropyl-β- cyclodextrin (HP-β-CD), which were selected from the perspective of stability, and (ii) determine the release mechanism of myrcene in Inclusion Complexes (ICs).

METHODS

ICs of myrcene and four CDs were prepared by freeze-drying. The physico-chemical properties of ICs were fully characterized by laser diffraction particle size analyzer, Scanning Electron Microscope (SEM), Fourier-Transform Infrared spectroscopy (FT-IR) and Differential Scanning Calorimeter (DSC). The release behaviors of ICs at 50, 60, 70 and 80 °C were determined and described by zeroorder or first-order kinetics with the Henderson-Pabis, Peppas, Avrami and Page mathematical models. Moreover, the possible binding modes of ICs were identified with molecular modelling technique.

RESULTS

Firstly, the structure of Particle Size Distribution (PSD), FT-IR, DSC and SEM showed that (i) CDs could effectively encapsulate the myrcene molecules, and (ii) the release kinetics were well simulated by Avrami and Page models. Secondly, the release rates of the ICs experienced an unsteady state in the early stage, and gradually became almost constants period after 20 hours. Except that the release of myrcene in γ-CD/myrcene belonged to the first-order kinetic, the release models of the remaining three ICs belonged to diffusion mode. Thirdly, the calculated binding energies of the optimized structures for α-CD/myrcene, β-CD/myrcene, γ-CD/myrcene, and HP-β-CD/myrcene ICs were -4.28, -3.82, -4.04, and -3.72 kcal/mol, respectively. Finally, the encapsulation of myrcene with α-CD and β-CD was preferable according to the stability and release characteristics.

CONCLUSION

The encapsulation of myrcene was profoundly affected by the type of CDs, and the stability could be improved by complexation with suitable CDs. The binding behavior between guest and CD molecules, and the release profile of the guest molecules could be effectively explained by the kinetics parameters and molecular modelling. This study can provide an effective basis and guide for screening suitable shell matrices.

In vitro and in vivo evaluation of didymin cyclodextrin inclusion complexes: characterization and chemosensitization activity

Didymin is a dietary flavonoid that first found in citrus fruits, and possesses antioxidant properties. Our preliminary experiments first discovered that didymin was able to sensitize the resistant cancer cells against chemotherapeutics and combat multidrug resistance. However, its poor aqueous solubility and resultant low bioavailability limit its potentials as an adjuvant phytochemical drug for chemotherapy. Thus, this study prepared the inclusion complex of didymin with β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin to improve its bioavailability and then evaluate their chemosensitization effects. The didymin inclusion complexes formulation was prepared and their host-guest structure was characterized by FT-IR, PXRD, DSC, and SEM techniques. In vitro/in vivo results demonstrated that didymin inclusion complex enhanced its water solubility and orally bioavailability. Furthermore, didymin inclusion complex exerted considerable chemosensitivity potency, and improve the anti-tumor effects of chemotherapeutics in vivo. Therefore, didymin inclusion complex could provide a safe, effective, economical, and adjuvant drug for future treatment of chemoresistant cancers.

A double carbon dot system composed of N, Cl-doped carbon dots and N, Cu-doped carbon dots as peroxidase mimics and as fluorescent probes for the determination of hydroquinone by fluorescence

A fluorescence method is described for the determination of hydroquinone based on the double carbon dot system as peroxide mimic enzymes and fluorescent probes. Deep eutectic solvent (DES)-based fluorescent carbon dots (N/Cl-CDs) and copper-doped carbon dots (N/Cu-CDs) were prepared by the hydrothermal method. Both carbon dots were characterized with transmission electron microscopy (TEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet-visible (UV-Vis) spectroscopy, X-ray photoelectron spectrometry (XPS), Fourier transform infrared (FT-IR) spectroscopy, and fluorescence spectroscopy. N/Cl-CDs displayed intrinsic peroxidase-like activity and were able to catalyze the oxidation of hydroquinone (H₂Q) to p-benzoquinone (BQ) along with an intermediate. The intermediate (BQ) did quench the N/Cu-CD photoluminescence (PL) at 450 nm using an excitation wavelength of 347 nm. Based on the results, a fluorescent platform is proposed for the determination of hydroquinone with a promising determination limit of 0.04 μM (linear range, 1.0-75 μM). The recoveries of spiked water samples were in the range 89.5-105.1%, with relative standard deviations (RSDs) of 1.5-2.9%. This method was applied to determination of H₂Q in environmental water samples. Graphical abstract A fluorescence method was established for the determination of hydroquinone based on the double carbon dot system as peroxide-mimic enzymes and fluorescent probes. Chlorine-doped carbon dots (N/Cl-CDs) derived from deep eutectic solvent (DES) displayed intrinsic peroxidase-like activity, and were able to catalyze the oxidation of hydroquinone (H2Q) to p-benzoquinone (BQ) along with an intermediate. The intermediate (BQ) did quench the N/Cu-CD photoluminescence (PL). This method was applied to H2Q in environmental water samples.

The pivotal role of nuclear factor erythroid 2-related factor 2 in diabetes-induced endothelial dysfunction

Endothelial dysfunction (ED) is a key event in the onset and progression of vascular complications associated with diabetes. Regulation of endothelial function and the underlying signaling mechanisms in the progression of diabetes-induced vascular complications have been well established. Recent studies indicate that increased oxidative stress is an important determinant of endothelial injury and patients with hypertension display ED mediated by impaired Nitric Oxide (NO) availability. Further, oxidative stress is known to be associated with inflammation and ED in vascular remodeling and diabetes-associated hypertension. Numerous strategies have been developed to improve the function of endothelial cells and increasing number of evidences highlight the indispensable role of antioxidants in modulation of endothelium-dependent vasodilation responses. Nuclear factor Erythroid 2-related factor 2 (Nrf2), is the principal transcriptional regulator, that is central in mediating oxidative stress signal response. Having unequivocally established the relationship between type 2 diabetes mellitus (T2DM) and oxidative stress, the pivotal role of Nrf2/Keap1/ARE network, has taken the center stage as target for developing therapies towards maintaining the cellular redox environment. Several activators of Nrf2 are known to combat diabetes-induced ED and few are currently in clinical trials. Focusing on their therapeutic value in diabetes-induced ED, this review highlights some natural and synthetic molecules that are involved in the modulation of the Nrf2/Keap1/ARE network and its underlying molecular mechanisms in the regulation of ED. Further emphasis is also laid on the therapeutic benefits of directly up-regulating Nrf2-mediated antioxidant defences in regulating endothelial redox homeostasis for countering diabetes-induced ED.

Preparation and Characterisation of Polyphenol-HP-β-Cyclodextrin Inclusion Complex that Protects Lamb Tripe Protein against Oxidation

Grape seed extract (GSE) displays strong antioxidant activity, but its instability creates barriers to its applications. Herein, three HP-β-CD/GSE inclusion complexes with host-guest ratios of 1:0.5, 1:1, and 1:2 were successfully prepared by co-precipitation method to improve stability. Successful embedding of GSE in the HP-β-CD cavity was confirmed by fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) analyses. The Autodock Tools 1.5.6 was used to simulate the three-dimensional supramolecular structure of the inclusion complex of 2-hydroxypropyl-β-cyclodextrin and grape seed extract (HP-β-CD/GSE) by molecular docking. The MALDI-TOF-MS technology and chemical database Pubchem, and structural database PDB were combined to reconstitute the three-dimensional structure of target protein. The binding mode of the HP-β-CD/GSE inclusion complex to target protein was studied at the molecular level, and the antioxidant ability of the resulting HP-β-CD/GSE inclusion complexes was investigated by measuring 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. The effects of HP-β-CD/GSE on myofibrillar protein from lamb tripe were also investigated under oxidative conditions. The positions and interactions of the binding sites of HP-β-CD/GSE inclusion complexes and target protein receptors were simulated by molecular docking. The results showed that HP-β-CD/GSE inclusion complexes were successfully prepared, optimally at a molar ratio of 1:2. At low (5 μmol/g) to medium (105 μmol/g) concentrations, HP-β-CD/GSE inclusion complexes decreased the carbonyl content, hydrophobicity, and protein aggregation of myofibrillar protein from lamb tripe, and increased the sulphydryl content. Furthermore, high concentration (155 μmol/g) of HP-β-CD/GSE inclusion complexes promoted protein oxidation.

Development of Starch-Based Antifungal Coatings by Incorporation of Natamycin/Methyl-β-Cyclodextrin Inclusion Complex for Postharvest Treatments on Cherry Tomato against Botrytis cinerea

The application of natamycin as a natural fungicide in edible coatings is challenging because of its low aqueous solubility. In this study, the natamycin/methyl-β-cyclodextrin (N/ME-β-CD) inclusion complex was fabricated and incorporated into waxy corn starch-based coatings for postharvest treatments. The phase solubility of natamycin in the presence of ME-β-CD at 293.2 K, 303.2 K, and 313.2 K is determined and used to calculate the process thermodynamic parameters. The N/ME-β-CD inclusion complex was confirmed and characterized by FTIR and 1H NMR spectroscopy. The results indicated that the inclusion complex was formed and the hydrophobic part (C16-C26) of natamycin might be partially inserted into the cavity of ME-β-CD form the wide rim. The effects of N/ME-β-CD incorporated starch-based coatings (N/ME-β-CD S coatings) on postharvest treatments of cherry tomatoes were evaluated in vivo. The N/ME-β-CD S coatings could reduce weight loss, delay fruit ripening, and inhibit fruit decay caused by Botrytis cinerea in tomato fruit during storage.

[6]-Shogaol/β-CDs inclusion complex: preparation, characterisation, in vivo pharmacokinetics, and in situ intestinal perfusion study

Aims: The aim was to improve the absorption and bioavailability of [6]-shogaol with β-cyclodextrin (β-CD) prior to in vitro and in vivo evaluation. Methods: [6]-Shogaol/β-CDs inclusion complexes (6-S-β-CDs) were developed using saturated aqueous solution method and characterised with appropriate techniques. The absorption and bioavailability potential of [6]-shogaol was evaluated via in vivo pharmacokinetics and in situ intestinal perfusion. Results: The results of characterisation showed that 6-S-β-CDs (drug loading, 7.15%) were successfully formulated. In vitro release study indicated significantly improved [6]-shogaol release. Pharmacokinetic parameters such as Cmax, AUC0-36 h, and oral relative bioavailability (about 685.36%) were substantially enhanced. The in situ intestinal perfusion study revealed that [6]-shogaol was markedly absorbed via passive diffusion in the intestinal segments, and duodenum followed by ileum and jejunum. Conclusions: Cyclodextrin inclusion technology could enhance the intestinal absorption and oral bioavailability of hydrophobic drugs like [6]-shogaol.

The mechanism of bensulfuron-methyl complexation with β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin and effect on soil adsorption and bio-activity

In this work, the inclusion complexes of hydrophobic herbicide bensulfuron-methyl (BSM) with β-cyclodextrin (β-CD) and (2-hydroxypropyl)-β-CD (2-HP-β-CD) were prepared and characterized. Phase solubility study showed that both β-CD and 2-HP-β-CD increased the solubility of BSM. Three-dimensional structures of the inclusion complexes were simulated by the molecular docking method. The docking results indicated that guest BSM could enter into the cavities of host CDs, folded, and centrally aligned inside the inclusion complexes. The benzene ring of the guest molecule was close to the wide rim of the host molecules; the pyrimidine ring and side chains of the guest molecule were oriented toward the narrow rim of the host molecule. The inclusion complexes were successfully prepared by the coprecipitation method. The physiochemical characterization data of 1H NMR, FT-IR, XRD, and DSC showed that the guest and host molecules were well included. BSM had lower soil adsorption and higher herbicidal activity in the complexation form with β-CD or 2-HP-β-CD than in the pure form. The present study provides an approach to develop a novel CDs-based formulation for hydrophobic herbicides.

Host-Guest Inclusion Systems of Morin Hydrate and Quercetin with Two Bis(β-cyclodextrin)s: Preparation, Characterization, and Antioxidant Activity

The inclusion complexation behaviour of morin hydrate (MH) and quercetin (QCT) with the two amide-bridged bis(β-cyclodextrin (β-CD))s, 1 and 2, was investigated in both solution and the solid state. The inclusion complexations were characterised by proton nuclear magnetic resonance, 2D rotating-frame Overhauser effect spectroscopy, X-ray powder diffraction, infrared spectroscopy and scanning electron microscopy. Ultraviolet titration analysis indicated that 1 and 2 form 1:1 molar stoichiometry inclusion complexes with MH and QCT, and the data obtained showed that 2 with two guests has a higher complex stability constant (KS) when compared with that of 1. Moreover, 1 and 2 were able to solubilize MH and QCT to high levels, up to ~200-fold. Furthermore, the antioxidant activity of MH, QCT and their inclusion compounds were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. Together, these results showed that the inclusion complexes exhibited a more effective antioxidant activity when compared with free MH. The satisfactory antioxidant activity and high water solubility of the bis(β-CD)s/flavonoid complexes may have potential use as healthcare products and herbal medicine.

An aspirated in-syringe device fixed with ionic liquid and β-cyclodextrin-functionalized CNTs/TiO2 for rapid adsorption and visible-light-induced photocatalytic activity

Dual-functional photocatalyst, IL–CD-CNTs/TiO₂, was fabricated through a facile one-pot solvothermal strategy coupled with an aspirated in-syringe device.

Preparation and Characterization of Butachlor/(2-Hydroxypropyl)-β-cyclodextrin Inclusion Complex: Improve Soil Mobility and Herbicidal Activity and Decrease Fish Toxicity

A water-soluble inclusion complex for butachlor was prepared by complexation with (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD). Phase solubility results indicated a 1:1 stoichiometric ratio with an apparent stability constant of 864.3 M^-1 in the obtained solid complex. The formation of the complex was confirmed by ¹H nuclear magnetic resonance, Fourier transform infrared, and differential scanning calorimetry spectra. Coupled with the molecular docking results, butachlor was considered to be completely included in HP-β-CD cavity. Butachlor complexation with HP-β-CD decreased its adsorption capacity and enhanced its mobility in soil. The inclusion complex displayed better herbicidal activities than free butachlor. The 96 h median lethal concentration values of the inclusion complex and free butachlor was 2.30 and 0.65 mg L^-1, respectively, for zebrafish, indicating that the complexation could significantly reduce toxicity to fishes. The present study provides an approach to develop environment-friendly formulations using CDs for herbicides.