Stabilization of Black Locust Flower Extract via Encapsulation Using Alginate and Alginate-Chitosan Microparticles.

Black locust flower extract contains various polyphenols and their glucosides contribute to the potential health benefits. After intake of these bioactive compounds and passage through the gastrointestinal tract, their degradation can occur and lead to a loss of biological activity. To overcome this problem, the bioactive compounds should be protected from environmental conditions. This study aimed to encapsulate the black flower extract in the microparticles based on biodegradable polysaccharides, alginate, and chitosan. In the extract, the total antioxidant content was found to be 3.18 ± 0.01 g gallic acid equivalent per 100 g of dry weight. Also, the presence of lipids (16), phenolics (27), organic acids (4), L-aspartic acid derivative, questinol, gibberellic acid, sterol, and saponins (2) was confirmed using the UHPLC-ESI-MS analysis. In vitro assays showed that the extract has weak anti-α-glucosidase activity and moderate antioxidant and cytotoxic activity against the HeLa cell line. The extrusion method with secondary air flow enabled the preparation of microparticles (about 270 µm) encapsulated with extract. An encapsulation efficiency of over 92% was achieved in the alginate and alginate-chitosan microparticles. The swelling study confirmed a lower permeability of alginate-chitosan microparticles compared with alginate microparticles. For both types of microparticles, the release profile of antioxidants in the simulated gastrointestinal fluids at 37 °C followed the Korsmeyer-Peppas model. A lower diffusion coefficient than 0.5 indicated the simple Fick diffusion of antioxidants. The alginate-chitosan microparticles enabled a more sustained release of antioxidants from extract compared to the alginate microparticles. The obtained results indicated an improvement in the antioxidant activity of bioactive compounds from the extract and their protection from degradation in the simulated gastric conditions via encapsulation in the polymer matrixes. Alginate-chitosan showed slightly slower cumulative antioxidant release from microparticles and better antioxidant activity of the extract compared to the alginate system. According to these results, alginate-chitosan microparticles are more suitable for further application in the encapsulation of black locust flower extract. Also, the proposed polymer matrix as a drug delivery system is safe for human use due to its biodegradability and non-toxicity.

Chemical Profile and Antioxidant and Antimicrobial Activity of Rosa canina L. Dried Fruit Commercially Available in Serbia.

The aim of this work was to give as much information as possible on Rosa canina dried fruit that is commercially available in Serbia. In order to provide the chemical composition, the UHPLC-DAD-ESI-MS method was employed for both polar and non-polar extracts of samples obtained with a solvent mixture consisting of hexane, acetone, and ethanol in a volume ratio of 2:1:1, respectively, and 0.05% (w/v) butylated hydroxytoluene. In addition, the total content levels of lycopene, ß-carotene, total polyphenols, and flavonoids were determined by means of UV-vis spectrophotometry. The antioxidant activity was tested by applying four different methods: ABTS, DPPH, FRAP, and CUPRAC. Overall, nine compounds were identified. The results of chemical composition analysis were used as the basis for the interpretation of the calculated results for the antioxidant and antimicrobial activity. The obtained results for R. canina dried fruit extract are as follows: ß-carotene-7.25 [mg/100 g fruit weight]; lycopene-2.34 (mg/100 g FW); total polyphenol content (TPC)-2980 [mg GAE/kg FW]; total flavonoid content (TFC)-1454 [mg CE/kg FW]; antioxidant activity-ABTS 12.3 [µmol/100 g FW], DPPH 6.84, FRAP 52.04, and CUPRAC 15,425; and antimicrobial activity-Staphylococcus aureus MIC/MMC 4/0 [mg∙mL-1], Enterococcus faecalis 4/0, Bacillus cereus 4/0, Escherichia coli 4/0, Salmonella enteritidis 4/4, Enteroabacter aerogenes 4/0, Pseudomonas aeruginosa 2/0, and Candida albicans 2/0.

Modified Sulfanilamide Release from Intelligent Poly(N-isopropylacrylamide) Hydrogels.

The aim of this study was to examine homopolymeric poly(N-isopropylacrylamide), p(NIPAM), hydrogels cross-linked with ethylene glycol dimethacrylate as carriers for sulfanilamide. Using FTIR, XRD and SEM methods, structural characterization of synthesized hydrogels before and after sulfanilamide incorporation was performed. The residual reactants content was analyzed using the HPLC method. The swelling behavior of p(NIPAM) hydrogels of different crosslinking degrees was monitored in relation to the temperature and pH values of the surrounding medium. The effect of temperature, pH, and crosslinker content on the sulfanilamide release from hydrogels was also examined. The results of the FTIR, XRD, and SEM analysis showed that sulfanilamide is incorporated into the p(NIPAM) hydrogels. The swelling of p(NIPAM) hydrogels depended on the temperature and crosslinker content while pH had no significant effect. The sulfanilamide loading efficiency increased with increasing hydrogel crosslinking degree, ranging from 87.36% to 95.29%. The sulfanilamide release from hydrogels was consistent with the swelling results-the increase of crosslinker content reduced the amount of released sulfanilamide. After 24 h, 73.3-93.5% of incorporated sulfanilamide was released from the hydrogels. Considering the thermosensitivity of hydrogels, volume phase transition temperature close to the physiological temperature, and the satisfactory results achieved for sulfanilamide incorporation and release, it can be concluded that p(NIPAM) based hydrogels are promising carriers for sulfanilamide.

Preparation and Characterization of Alginate Hydrogels with High Water-Retaining Capacity.

Hydrogels are very attractive materials due to their multifunctional properties. Many natural polymers, such as polysaccharides, are used for the preparation of hydrogels. The most important and commonly used polysaccharide is alginate because of its biodegradability, biocompatibility, and non-toxicity. Since the properties of alginate hydrogel and its application depend on numerous factors, this study aimed to optimize the gel composition to enable the growth of inoculated cyanobacterial crusts for suppressing the desertification process. The influence of alginate concentration (0.1-2.9%, m/v) and CaCl2 concentration (0.4-4.6%, m/v) on the water-retaining capacity was analyzed using the response surface methodology. According to the design matrix, 13 formulations of different compositions were prepared. The water-retaining capacity was defined as the system response maximized in optimization studies. The optimal composition of hydrogel with a water-retaining capacity of about 76% was obtained using 2.7% (m/v) alginate solution and 0.9% (m/v) CaCl2 solution. Fourier transform infrared spectroscopy was used for the structural characterization of the prepared hydrogels, while the water content and swelling ratio of hydrogels were determined using gravimetric methods. It was concluded that alginate and CaCl2 concentrations play the most important role regarding the gelation time, homogeneity, water content, and swelling ratio of the hydrogel.

Osage orange (Maclura pomifera (Raf.) Schneid) fruit extracts: UHPLC-DAD-ESI-MS/MS analysis, antioxidant activity and in vivo skin tests.

This work aimed to evaluate chemical profile, antioxidant activity and topical application safety of the raw Osage orange (Maclura pomifera (Raf.) Schneid) fruit extracts obtained by maceration using ethanol and acetone. Out of eighteen different compounds registered in the extracts, fifteen were identified by ultra-high-performance liquid chromatography-tandem mass spectrometry. Pomiferin and osajin were characteristic and representative compounds in both ethanolic and acetone extracts of the Osage orange fruit. Both extracts showed good antioxidant activity (EC50 = 0.03 mg/cm3) after 20 min of incubation. The topical administration safety of the extracts was evaluated in vivo by measuring skin biophysical parameters: electrical capacitance and erythema index, as indicators of stratum corneum hydration and irritation, respectively. Based on the results of the in vivo skin tests, it can be concluded that both of the Osage orange fruit extracts are safe for topical administration - they increased skin hydration and reduced skin irritation under the occlusion.

The role of acute rehabilitation in COVID-19 patients.

BACKGROUND: In the published literature there is scarce data on the importance of acute rehabilitation in patients suffering from COVID-19 disease. AIM: Evaluation of the feasibility of respiratory and neuromuscular rehabilitation treatment in stable acute COVID-19 inpatients. DESIGN: The study was designed as an observational prospective investigation of two cohorts respectively identified as Mild/Moderate and Stable Severe COVID-19 disease. All patients received a rehabilitation treatment consisting of breathing exercises, range of motion exercises and strengthening exercises, with the main difference in intensity and progression of treatment, depending on individual capacity of patient. SETTING: Inpatients with diagnosed mild to moderate, or stable severe COVID-19 infection were included in the study. POPULATION: Acute COVID-19 inpatients. METHODS: Patients were divided into two groups depending on the severity of disease: "mild to moderate group" (MMG) and "stable severe group" (SSG). Functional outcomes included the Barthel Index (BI), Six Minute Walk Test (6MWT), Borg Scale for dyspnea, "Time Up and Go" Test (TUG), "Sit To Stand" test (STS), "One Leg Stance Test" (OLST) and Beck Depression Inventory (BDI) were evaluated at baseline and after rehabilitative treatment, on discharge. RESULTS: We included 147 acute COVID-19 inpatients (75 male and 72 female), mean aged 63.90±13.76 years. There were noticeable statistically significant improvements in all observed measurements in both groups. Comparison between groups showed significant difference in MMG compared to SSG in all functional outcomes: TUG (P<0.001), STS (P<0.001), OLST (P<0.001), BDI (P=0.008), BI (P<0.001), and Borg scale for dyspnea (P<0.001). Despite the significant improvements of BI in SSG, the obtained values showed that the patients were still not functionally independent. CONCLUSIONS: Acute respiratory and neuromuscular rehabilitation program is a feasibile, but also effective and safe method for improving functional status in patients with COVID-19 infection. CLINICAL REHABILITATION IMPACT: Results of the present study implicate that a supervised early rehabilitation program, implemented in the treatment of patients with COVID-19 disease in the acute phasis a feasible way for significant improvement of patient's functional outcomes. Early rehabilitation should be included into clinical protocols for the treatment of patients with COVID-19.

The Formulation of Curcumin: 2-Hydroxypropyl-ß-cyclodextrin Complex with Smart Hydrogel for Prolonged Release of Curcumin.

Curcumin comes from the plant species Curcuma longa and shows numerous pharmacological activities. There are numerous curcumin formulations with gels or cyclodextrins in order to increase its solubility and bioavailability. This paper presents the formulation of complex of curcumin with 2-hydroxypropyl-ß-cyclodextrin in a thermosensitive hydrogel, based on N-isopropylmethacrylamide and N-isopropylacrylamide with ethylene glycol dimethacrylate as a crosslinker. The product was characterized by chemical methods and also by FTIR, HPLC, DSC, SEM, XRD. The results show that synthesis was successfully done. With an increase in the quantity of crosslinker in the hydrogels, the starting release and the release rate of curcumin from the formulation of the complex with hydrogels decreases. The release rate of curcumin from the gel complex formulation is constant over time. It is possible to design a formulation that will release curcumin for more than 60 days. In order to determine the mechanism and kinetics of curcumin release, various mathematical models were applied by using the DDSolver package for Microsoft Excel application. The Korsmeyer-Peppas model best describes the release of curcumin from the gel formulation of the complex, while the values for the diffusion exponent (0.063-0.074) shows that mechanism of the release rate is based on diffusion.

Sustainable Dyeing and Functionalization of Different Fibers Using Orange Peel Extract's Antioxidants.

A diluted ethanol orange peel extract was used for sustainable dyeing and functionalization of different fabrics. The extract analysis was performed using UPLC-ESI-MS/MS; its total flavonoid (0.67 g RE/100 g d.w.) and antioxidant (2.81 g GAE/100 g d.w.) contents and antioxidant activity (IC50 of 65.5 µg/mL) were also determined. The extract dyeing performance at various dyebath pH values was evaluated using multifiber fabric. Among six fabrics, extract possessed the ability for dyeing wool, polyamide, and cellulose acetate (at pH 4.5), which color strength (K/S) values increased after washing (9.7-19.8 vs. 11.6-23.2). Extract:water ratio of 20:35 (v/v) was found to be sufficient for achieving satisfactory K/S values (i.e., 20.17, 12.56, and 10.38 for wool, polyamide, and cellulose acetate, respectively) that were slightly changed after washing. The optimal dyeing temperatures for wool, polyamide, and cellulose acetate are 55, 35, and 25 °C, while the equilibrium dye exhaustion at those temperatures was achieved after 45, 120, and 90 min, respectively. The color coordinate measurements revealed that wool and polyamide fabrics are yellower than cellulose acetate, while, compared to polyamide and cellulose acetate, wool is redder. Possible interactions between selected fabrics and extract compounds are suggested. All fabrics possessed excellent antioxidant activity (88.6-99.6%) both before and after washing. Cellulose acetate provided maximum bacterial reduction (99.99%) for Escherichia coli, and Staphylococcus aureus, which in the case of Staphylococcus aureus remained unchanged after washing. Orange peel extract could be used for simultaneous dyeing and functionalization of wool and polyamide (excellent antioxidant activity) and cellulose acetate (excellent antioxidant and antibacterial activity) fabrics.

Ten-year single-center experience with treatment of primary diffuse malignant peritoneal mesothelioma (DMPM) by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

PURPOSE: This single-center study evaluated cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) for diffuse malignant peritoneal mesothelioma (DMPM). METHODS: Prospectively collected data from a single institution data registry was retrospectively investigated. Eighty-four patients with primary malignant peritoneal mesothelioma underwent CRS and HIPEC with cisplatin and doxorubicin either for 60 min or 90 min of duration from 2011 to 2021. The primary endpoint was overall survival. The secondary endpoint was the evaluation of prognostic factors for overall survival. The tertiary endpoint was to assess the effect of neoadjuvant chemotherapy on survival. RESULTS: The median follow-up was 5.0 years (95%-CI 4.6-5.5). The median age was 59.2 years (IQR: 47-66). Eighty-two patients (97.6%) had epithelioid tumors. The median peritoneal cancer index was 18.0 (IQR: 13-27). Sixty-six patients (78.6%) had complete or near-complete cytoreduction (CCR 0 or CCR 1). Seventy patients (83.3%) received HIPEC for 60 min and 14 patients (16.7%) received it for 90 min. Twenty-two patients (26.2%) had grade 3 to 4 complications. Acute kidney injury (AKI) stage I-III occurred in 30 (35.7%) patients. Three patients (3.6%) died perioperatively. The overall median survival was 38.4 months (95%-CI 23.6-54.3), and the 5-year survival rate was 42%. Survival was independently associated with age, female gender, and thrombocytosis. Preoperative chemotherapy did not emerge as an adverse prognostic factor. CONCLUSION: In well-selected patients with DMPM, prolonged survival is achievable with CRS and HIPEC in specialized centers.

Electrospun Poly(lactide) Fibers as Carriers for Controlled Release of Biochanin A.

The aim of this study is to investigate the possibility of using electrospun polylactide (PLA) fibers as a carrier of the phytoestrogen biochanin A. Polylactide fibers were prepared with different contents of biochanin A by using an electrospinning method at specific process parameters. The obtained electrospun polylactide fibers, as carriers of biochanin A, were characterized by means of different methods. The presented results showed that the mechanical properties of PLA have not changed significantly in the presence of biochanin A. Scanning electron microscopy showed that the fine fiber structure is retained without visible deformations and biochanin A crystals on the surface of the fibres. The analysis by infrared spectroscopy showed that there are no strong interactions between polylactide and biochanin A molecules, which is a good prerequisite for the diffusion release of biochanin A from PLA fibers.The release of biochanin A from PLA fibers in buffer solution pH 7.4 at 37 °C was monitored by applying the HPLC method. The rate and time of the release of biochanin A from PLA fibers is in correlation with the amount of the active ingredient in the matrix of the carrier and follows zero-order kinetics. PLA fibers with biochanin A exhibit concentration-dependent activity on proliferation and migration of L929 fibroblasts in direct culture system in vitro, and proved to be suitable for a potential formulation for use in wound healing.

Curcumin: Biological Activities and Modern Pharmaceutical Forms.

Curcumin (1,7-bis-(4-hydroxy-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione) is a natural lipophilic polyphenol that exhibits significant pharmacological effects in vitro and in vivo through various mechanisms of action. Numerous studies have identified and characterised the pharmacokinetic, pharmacodynamic, and clinical properties of curcumin. Curcumin has an anti-inflammatory, antioxidative, antinociceptive, antiparasitic, antimalarial effect, and it is used as a wound-healing agent. However, poor curcumin absorption in the small intestine, fast metabolism, and fast systemic elimination cause poor bioavailability of curcumin in human beings. In order to overcome these problems, a number of curcumin formulations have been developed. The aim of this paper is to provide an overview of recent research in biological and pharmaceutical aspects of curcumin, methods of sample preparation for its isolation (Soxhlet extraction, ultrasound extraction, pressurised fluid extraction, microwave extraction, enzyme-assisted aided extraction), analytical methods (FTIR, NIR, FT-Raman, UV-VIS, NMR, XRD, DSC, TLC, HPLC, HPTLC, LC-MS, UPLC/Q-TOF-MS) for identification and quantification of curcumin in different matrices, and different techniques for developing formulations. The optimal sample preparation and use of an appropriate analytical method will significantly improve the evaluation of formulations and the biological activity of curcumin.

Optimization of Ultrasound-Assisted Extraction and Encapsulation of Antioxidants from Orange Peels in Alginate-Chitosan Microparticles.

The recovery of bioactive compounds from waste and modification of their properties by encapsulation are the main challenges today. In this study, the ultrasound-assisted extraction of antioxidants from orange peels was optimized using a central composite design. Ethanol (50%, v/v) was the solvent of choice for their extraction. The obtained total antioxidant contents were fitted using the second-order polynomial equation. The optimal conditions were the extraction time of 30 min, temperature of 60 °C, and the liquid-to-solid ratio of 15 mL/g. After that, the optimal extract was encapsulated in alginate-chitosan beads to modify the release of antioxidants under gastrointestinal tract conditions. The average size of beads was 252 µm, while the encapsulation efficiency was 89.2%. The results of the FTIR analysis indicated that there are no interactions between compounds of the extract and alginate-chitosan. In vitro release studies showed an initial rapid and then slow release of antioxidants. This release followed the simple Fickian diffusion. The encapsulation of orange peel extract provided improvement in the delivery of antioxidants after gastrointestinal digestion. The obtained encapsulated beads can be applied as the natural active ingredient of food, cosmetics, and pharmaceutical products.

Waste Materials as a Resource for Production of CMC Superabsorbent Hydrogel for Sustainable Agriculture.

Waste materials are receiving more attention as concerns about the future of our planet increase. Cellulose is the most common substance in agricultural waste. Agricultural wastes containing cellulose are misplaced resources that could be reused in various fields for both environmental and economic benefits. In this work, 32 different kinds of waste are investigated for chemical modification in order to obtain carboxymethyl cellulose for the production of a superabsorbent hydrogel that can be applied in agriculture. A brief literature review is provided to help researchers wishing to obtain carboxymethyl cellulose by carboxymethylation starting with waste materials. We also provide details about methods to obtain as well as verify carboxymethylation. Carboxymethyl cellulose (CMC), as a constituent of cellulosic water and superabsorbent hydrogels with applications in agriculture, is described. Superabsorbent hydrogels with CMC are able to absorb huge amounts of water and are biodegradable.

Ultrasound-Assisted Extraction of Carotenoids from Orange Peel Using Olive Oil and Its Encapsulation in Ca-Alginate Beads.

The paper was aimed at developing an ultrasound-assisted extraction of carotenoids from orange peel using olive oil as a solvent. A central composite design was used to define the optimal conditions for their extraction. Under the optimal conditions (extraction time of 35 min, extraction temperature of 42 ℃, and a liquid-to-solid ratio of 15 mL/g), the experimental and predicted values of carotenoid content were 1.85 and 1.83 mg/100 g dry weight, respectively. The agreement of these values indicated the adequacy of the proposed regression model. The extraction temperature only had a negative influence on carotenoid content. The impact of extraction parameters on the carotenoid content was decreased according to the following order: extraction time, liquid-to-solid ratio, and extraction temperature. Ca-alginate beads were prepared using the extrusion process to increase the stability and protect the antioxidant activity of olive oil enriched with carotenoids. The encapsulation efficiency and particle mean diameter were 89.5% and 0.78 mm, respectively. The presence of oil extract in Ca-alginate beads was confirmed by Fourier-transform infrared spectroscopy. The antioxidant activity of the oil enriched with carotenoids before and after encapsulation in the alginate beads was determined according to the DPPH assay.

Modified Biochanin A Release from Dual pH- and Thermo-Responsive Copolymer Hydrogels.

The temperature- and pH-responsive poly(N-isopropylacrylamide-co-acrylic acid), p(NIPAM-co-AA), copolymer was synthesized by free radical polymerization and examined as a carrier for modified release of biochanin A. Biochanin A is a biologically active methoxylated isoflavone which exhibits estrogenic and other pharmacological activities. Due to its poor aqueous solubility and extensive first-pass metabolism, biochanin A has low bioavailability. The aim of this work was to incorporate biochanin A into the synthesized p(NIPAM-co-AA) copolymer and to examine its release at the body temperature and pH values that correspond to pH values of vaginal and rectal cavities. The amount of released biochanin A was monitored by the ultra-visible spectroscopy (UV-Vis) method. The structure of synthesized p(NIPAM-co-AA) copolymer and copolymer with incorporated biochanin A were characterized by using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) methods. The content of residual monomers in the synthesized copolymer was analyzed by using the high-pressure liquid chromatography (HPLC) method. The swelling behavior of p(NIPAM-co-AA) copolymer was monitored in relation to the temperature and pH values of the surrounding medium. For modelling the process of p(NIPAM-co-AA) copolymer swelling, the full three-level factorial design was applied.

Optimization of ultrasound-assisted extraction of polyphenols from wheatgrass (Triticum aestivum L.).

Conventional extraction techniques require high consumption of available resources and thus are ineffective and expensive, especially at an industrial scale. The aim of the study was to optimize the ultrasound-assisted extraction of polyphenols from fresh wheatgrass (Triticum aestivum L.). The effects of different extraction techniques and solvents were investigated on the yield of extractive substances and antioxidant activity. The ultrasound-assisted extraction technique and ethanol gave the highest yield of extractive substances so that they were used in the optimization studies. The central composite design was employed to find the optimal levels of ethanol concentration, extraction temperature, and extraction time. The total phenolic content was varied in the range of 10.50-15.50 grams of gallic acid equivalents per 100 g of dry weight of plant material (g GAE 100 g-1 dw). The optimal conditions for ultrasound-assisted extraction were: (1) 56% (v/v) ethanol, (2) temperature of 59 °C, and (3) extraction time of 28 min. The results of ANOVA indicated that the highest impact had the extraction temperature on the total phenolic content. The toxic solvents were not used in the developed extraction procedure. The consumption of energy and raw plant material is estimated to be lower by at least 10% compared to conventional techniques.

Physico-Chemical Properties and Oxidative Stability of Fixed Oil from Plum Seeds (Prunus domestica Linn.).

Storage of a great amount of plum kernel waste becomes a challenge for food industry. In this work, the plum seed was used as a source of fixed oil that can be an ingredient of commercial products. Soxhlet extraction was carried out using the different solvents, such as n-hexane, n-heptane, ethyl acetate, acetone, or chloroform:methanol mixture (2:1 v/v). The highest yield of oil (about 30%) was obtained using n-heptane and n-hexane, while the lowest yield was obtained using ethyl acetate. The analysis of physico-chemical parameters indicated that all samples of plum seed oil have an exceptional quality. Schaal oven test indicated that the fixed oil of plum seed exhibited satisfactory oxidative stability at moderate storage temperatures (up to 65 °C). The composition of phenolic compounds in the oil samples was determined using HPLC method. The most abundant compound of seven identified and quantified phenolic compounds was vanillic acid. The highest content of ß-carotene (1.67 mg 100 g-1 fixed oil) spectrophotometrically determined was in the oil extracted with n-hexane. The lowest content of ß-carotene (1.26 mg 100 g-1 fixed oil) was determined in the oil extracted with a mixture of chloroform:methanol (2:1 v/v). This oil had the highest antioxidant activity (IC50 value of 4.35 mg mL-1) compared to other oil samples. The antioxidant activity was probably caused by the presence of phenolic compounds. The investigated physico-chemical properties demonstrated that the plum seed oil has a potential for application in the food, cosmetics, and pharmaceutical industry.

Drug design strategies with metal-hydroxyquinoline complexes.

Introduction: 8-hydroxyquinoline derivatives and their complexes with transition metals are the subject of many studies due to their anticancer, anti-inflammatory, anti-infective, and antidiabetic activities.Areas covered: Within this article, the authors review the synthesis and current applications of metal-8-hydroxyquinoline complexes in drug design with a critical overview of the latest advancements in the field.Expert opinion: Metal-8-hydroxyquinoline complexes are especially interesting because of their simple synthesis procedures and possible applications in modern medicine. The complexation between transition metal ions and 8-hydroxyquinoline or its derivatives is achieved via their O and N atoms. The main problem with their application is lipophilicity. This particular property has an impact on their solubility, biological activity, transport through the cell membrane, construction of the complex with a receptor, and development of drugs. Furthermore, in the treatment of neurodegenerative diseases and brain cancers, the passage of the complexes through the blood-brain barrier can only be ensured through novel drug design.

Optimization of Ultrasound-Assisted Extraction of Phenolic Compounds from Black Locust (Robiniae Pseudoacaciae) Flowers and Comparison with Conventional Methods.

The aim of this study was to optimize the ultrasound-assisted extraction of phenolic compounds from black locust (Robiniae pseudoacaciae) flowers using central composite design. The ethanol concentration (33-67%), extraction temperature (33-67 °C), and extraction time (17-33 min) were analyzed as the factors that impact the total phenolic content. The liquid-to-solid ratio of 10 cm3 g-1 was the same during extractions. The optimal conditions were found to be 59 °C, 60% (v/v) ethanol, and extraction time of 30 min. The total phenolic content (TPC = 3.12 gGAE 100 g-1 dry plant material) and antioxidant activity (IC50 = 120.5 µg cm-3) of the extract obtained by ultrasound-assisted extraction were compared with those obtained by maceration (TPC = 2.54 gGAE 100 g-1 dry plant material, IC50 = 150.6 µg cm-3) and Soxhlet extraction (TPC = 3.22 gGAE 100 g-1 dry plant material, IC50 = 204.2 µg cm-3). The ultrasound-assisted extraction gave higher total phenolic content and better antioxidant activity for shorter extraction time so that it represents the technique of choice for the extraction of phenolic compounds. The obtained extract, as the source of antioxidants, can be applied in the pharmaceutical and food industries.

The effect of complexation with cyclodextrins on the antioxidant and antimicrobial activity of ellagic acid.

PURPOSE: The aim of the paper was to develop the simple procedures for preparation of inclusion complexes of ellagic acid (EA) with cyclodextrins (CDs) and to investigate their antioxidant and antimicrobial activity. METHODS: The structural characterization was carried out using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) methods. The phase solubility technique was used to investigate the interactions between 'host' and 'guest' molecules and to estimate the molar ratio between them. The antioxidant and antimicrobial activity of EA and inclusion complexes were determined. RESULTS: The apparent stability constants were found to be 117 dm3 mol-1 for the complex with ß-CD and 161 dm3 mol-1 for the complex with (2-hydroxypropyl)-ß-cyclodextrin (HP-ß-CD). The results of phase-solubility studies showed that EA formed the inclusion complexes with CDs in the molar ratio of 1:1. The calculated half-maximal inhibitory concentration was 41.18 µg cm-3 for butyl hydroxy toluene, 1.96 µg cm-3 for EA, 0.88 µg cm-3 for inclusion complex with HP-ß-CD, and 1.27 µg cm-3 for inclusion complex with ß-CD. CONCLUSION: The stability constants indicated the rapid release of EA from the inclusion complexes in the aqueous medium at 25 °C. The antioxidant activity of EA was increased, while the antimicrobial activity was preserved after complexation with CDs.