Search Results (15)

In this study, an orthogonal array design was employed to optimize total flavonoid extraction conditions. The results showed that the optimal conditions were an ethanol concentration of 70%, an ultrasonic power of 250 W, a solid–liquid ratio of 1:30 g/mL, and an ultrasonic time of 25 min. Under these optimal extraction conditions, the total flavonoid yield was 169.3 mg/g plant material. The purification effects of LX-38, LX-60, LS-46, LS-306, XDA-8, AB-8, and D101 macroporous resins on the total flavonoids of Eucommia ulmoides leaves were also investigated. The parameters of the process using XDA-8 macroporous resin for the purification of the crude extract of total flavonoids from Eucommia ulmoides leaves were investigated. The adsorption conditions of the XDA-8 resin consisted of an initial sample concentration of 2.0 mg/mL, a sample pH value of 5.0, an adsorption flow rate of 1.5 mL/min, and a temperature of 25 °C. The desorption conditions of the XDA-8 resin consisted of 60% ethanol used as a desorption solution and a 2.0 mL/min desorption flow rate of the eluent. The total flavonoids from the Eucommia ulmoides leaves were purified under these conditions, and, afterward, the flavonoid content was 51.5%. The main components of the purified flavonoids from the Eucommia ulmoides leaves were isolated using high-performance liquid chromatography (HPLC), and they included chlorogenic acid, rutin, isoquercetin, kaempferol-3-O-rutinoside, quercetin 3-rhamnoside, hyperoside, and quercetin. The antioxidant activities were measured, and those of the purified total flavonoids from the Eucommia ulmoides leaves were higher than those of dibutylhydroxytoluene (BHT) and lower than those of ascorbic acid (Vc). Additionally, the purified total flavonoids from the Eucommia ulmoides leaves exhibited significant antioxidant activities. Full article

Macroporous silicon is a promising substrate in the field of optics, electronics, etc. In this paper, highly ordered macropore arrays were fabricated in p-type silicon wafers by electrochemical etching using a double-tank cell. The effect of the silicon resistivity, etching voltage and etching time on the pore morphology was investigated and the influence mechanism was analyzed. The pore diameter would decrease with the increase in the silicon resistivity and the decrease in the etching voltage, due to the increase in the space charge region width (SCRL). The pore depth would increase with the resistivity and the voltage. However, too high resistivity would cause insufficiency at the pore tips and too high voltage would cause pore splitting, which may cause a decrease in the pore depth. Then, the aspect ratio of 21 can be obtained on the silicon wafer with a resistivity of 50–80 Ω·cm at the etching voltage of 5 V with a maximum etching rate of about 0.92 μm/min. Full article

A two-dimensional array of microfluidic ports with remote-controlled valve actuation is of great interest for applications involving localized chemical stimulation. Herein, a macroporous silicon-based platform where each pore contains an independently controllable valve made from poly(N-isopropylacrylamide) (PNIPAM) brushes is proposed. These valves are coated with silica-encapsulated gold nanorods (GNRs) for NIR-actuated switching capability. The layer-by-layer (LBL) electrostatic deposition technique was used to attach the GNRs to the PNIPAM brushes. The deposition of GNRs was confirmed by dark-field optical microscopy, and the localized surface plasmon resonance (LSPR) of the deposited GNRs was analyzed using UV-Vis spectra. To evaluate the chemical release behaviors, fluorescein dye was employed as a model substance. The chemical release properties, like OFF-state diffusion through the valve, the ratio between ON-state and OFF-state chemical release, and the rapidness of chemical modulation of the valve, were investigated, varying the PNIPAM brush thickness. The results indicate that enhancing the thickness of the PNIPAM brush in our platform improves control over the chemical modulation properties. However, excessive increases in brush length may lead to entanglement, which negatively impacts the chemical modulation efficiency. Full article

The orthogonal array design method was used to optimize ultrasonic-assisted extraction of resveratrol from peanut sprouts. The results showed that the highest extraction yield of resveratrol using ultrasonic-assisted extraction could be up to 1.1%. The optimal extraction conditions were liquid to solid ratio of 30:1 (mL/g) and ethanol concentration of 80% (v/v) as solvent for 40 min at the temperature of 70 °C. AB-8 macroporous adsorption resin was used to purify the crude extract and the resveratrol content increased to 47.5% after one treatment run. The optimal adsorption parameters were initial concentrations in the sample solution of 2 mg/mL, a pH of 5.0, a flow rate of 2 mL/min, and a temperature of 25 °C. The optimal desorption parameters were 60% ethanol and a flow rate of 1 mL/min. The chemical composition of the peanut sprout’s resveratrol sample was investigated via HPLC, and the predominant constituents were found to be protocatechuic acid, catechins, caffeic acid, epicatechuic acid, resveratrol, and rutin. The antioxidant activities of the resveratrol were measured via the following different analytical methods: reducing power, 2,2-diphenyl-1-picrylhdrazyl (DPPH), hydroxyl radical-scavenger activity, superoxide radical-scavenger activity, the β-carotene bleaching test, and the scavenging nitrite test. The results indicated that the resveratrol in peanut sprouts have significant antioxidant activities and can be used as a source of potential antioxidant. And peanut sprout’s resveratrol has the potential and valuable application to be used as a new type of resveratrol resource. The finding of this study can provide some theoretical reference for the comprehensive utilization of peanut resources in the development of antioxidant health foods. Full article

In this work, ordered macropore arrays in n-type silicon wafers were fabricated by anodic etching using a double-tank electrochemical cell. The effects of the wafer thickness, etching time and voltage on the quality of macropore arrays were investigated. Homogeneous macropore arrays could be achieved in 200 μm thick silicon wafers, but could not be obtained from 300 and 400 μm thick silicon wafers. Highly ordered macropore arrays with an aspect ratio of 19 were fabricated in 200 μm thick n-type silicon at 4.5 V. The etching current decreases in 200 μm thick silicon but increases in thicker silicon with an increase in time. It demonstrates that the minority carrier transportation capability from the illuminated surface to the reactive surface is different for silicon wafers with different thicknesses. The minority carrier concentration at the illuminated surface for stable macropore formation and the current under different etching voltages were calculated based on a hole transport model. The results show that appropriately decreasing wafer thickness and increasing voltage can help stable macropore array fabrication in the illumination-limited double-tank cell. Full article

Hydrogenolysis via targeted depolymerization of C–O linkages is a techno-economic beneficial process for converting lignin into highly valuable chemicals and clean fuels. In this work, a macroporous silicalite-1 (S-1) array-supported Ru-Ni metallic phosphide composite (Ru-Ni₁₂P₅/S-1₅) was prepared as a catalyst and hydrogenolysis activity under relative mild conditions was investigated using a series of compounds containing ether linkages as lignin-related model compounds. The Lewis acid sites originating from the unreduced Ru species and the macroporous geometry of S-1 significantly influenced hydrogenolysis activity and product selectivity. Analysis of the mechanism demonstrated that both the aryl ether and aliphatic ether linkages were directly hydrogenated over Ru-Ni₁₂P₅/S-1₅. 2D-HSQC-NMR spectroscopy demonstrated that the ether linkages of lignin were efficiently cleaved by Ru-Ni₁₂P₅/S-1₅. Furthermore, the obtained liquid hydrogenolysis products are high value-added chemicals used for pharmaceutical production and can be facilely tuned via the reaction conditions. Full article

Red Malus ‘Royalty’ fruits are rich in anthocyanins. This study aimed to obtain the optimal parameters for the extraction and separation of anthocyanins from Malus ‘Royalty’ fruits and to evaluate the inhibitory effect of the enriched anthocyanin fraction on gastric cancer cells. Ultrasonic-assisted extraction was used for the extraction of the anthocyanins of Malus ‘Royalty’ fruit, and the extraction results showed that the optimum parameters were an extraction temperature of 20 °C, a solid–liquid ratio of 1:6 (g/mL), ethanol and formic acid contents of 70% and 0.4%, respectively, an extraction time of 40 min, and an ultrasonic power of 300 W. The optimum extraction parameters to achieve the highest anthocyanin yield by a single-factor experiment coupled with response surface methodology were identified. The separation results showed that the AB-8 macroporous resin was a better purifying material, with 60% ethanol as an adsorbent, and the adsorption–desorption equilibrium times were 6 h and 1 h, respectively. Cyanidin-3-galactoside was the main body composition separation of anthocyanins by a high-performance liquid chromatography-diode array detector. The antitumor activity results showed that the anthocyanins of Malus ‘Royalty’ fruits have a significant inhibitory effect on the gastric cancer cell line BGC-803. The in vitro cell viability test of CCK-8 showed that the inhibitory effect on tumor cells was more significant with the increased anthocyanin concentration, with a half maximal inhibitory concentration (IC₅₀) value of 105.5 μg/mL. The cell morphology was observed by an inverted microscope, and it was found that the backbone of BGC-803 treated with a high concentration of anthocyanins was disintegrated and the nucleoplasm was concentrated. The mechanism of apoptosis was analyzed by Western blotting, and the results showed that with increasing anthocyanin concentration in the medium, the expression levels of the proapoptotic proteins Bax and Bak increased, and the expression levels of the antiapoptotic proteins Bcl-2 and Bcl-xL decreased, which coordinated the regulation of cell apoptosis. This research suggests that the enriched anthocyanin fraction from Malus ‘Royalty’ fruits have potential antitumor and adjuvant therapeutic effects on gastric cancer. Full article

Hazelnut skin is a rich source of polyphenols but is generally discarded during the roasting process of hazelnuts. Previous studies reported the extraction and identification of these compounds using different solvents and procedures; however, there are few reports on their enrichment and purification. In this study, three types of Amberlite macroporous resins (XAD 16, XAD 4, and XAD 7) were compared to evaluate the enrichment of polyphenols via adsorption and desorption mechanisms. The operating condition parameters for polyphenol adsorption/desorption of each resin were determined, the kinetics of adsorption were examined, and a method for polyphenol recovery was developed using static and dynamic adsorption/desorption. Antioxidant activity and high-performance liquid chromatography-diode array detection were used to confirm the increase in polyphenols obtained using the adsorption/desorption technique. XAD16 showed the highest adsorption capacity, with a recovery of 87.7%, and the adsorption kinetics fit well with a pseudo-second-order model. The highest poly-phenol desorption ratio was observed using an ethanol/water solution (70% v/v) at a flow rate of 1.5 bed volume/h. Full article

The Zuojin Pill consists of Coptidis Rhizoma (CR) and Euodiae Fructus (EF). It has been a classic prescription for the treatment of gastrointestinal diseases in China since ancient times. Alkaloids are considered to be its main pharmacologically active substances. The authors of the present study investigated the feasibility of preparing high purity total alkaloids (TAs) from CR and EF extracts separately and evaluated the effect for the treatment of bile reflux gastritis (BRG). Coptis chinensis Franch. and Evodia rutaecarpa (Juss.) Benth. were used in the study. An optimized method for the enrichment and purification of TAs with macroporous resin was established. Furthermore, qualitative analysis by using ultra-high performance liquid chromatography coupled with electrospray ionization and quadrupole-time of flight mass spectrometry (UHPLC–ESI–QTOF-MS) was explored to identify the components of purified TAs. Thirty-one compounds, thirty alkaloids and one phenolic compound, were identified or tentatively assigned by comparison with reference standards or literature data. A method of ultra-high performance liquid chromatography coupled with diode array detector (UHPLC–DAD) for quantitative analysis was also developed. The contents of nine alkaloids were determined. Moreover, a rat model of BRG was used to investigate the therapeutic effect of the combination of purified TAs from CR and EF. Gastric pathologic examination suggested that the alkaloids’ combination could markedly attenuate the pathological changes of gastric mucosa. Full article

For the full development and utilization of Sophora tonkinensis Gagnep., this study was primarily intended to established a simple and efficient approach for the preparative purification of total flavonoids from S. tonkinensis by macroporous resin column chromatography (MRCC). The adsorption and desorption characteristics of the total flavonoids on ten macroporous resins were first studied, and AB-8 resin was chosen as the most suitable, and the adsorption data were best fitted to the pseudo-second-order kinetics model and Langmuir isotherm model. Furthermore, the technological parameters for the purification of the total flavonoids were optimized using column chromatography. After a sample one-step purification procedure, the content of the total flavonoids increased by about 4.76-fold from 12.14% to 57.82%, with a recovery yield of 84.93%. In addition, the comparative analysis of the flavonoid extracts before and after purification was performed by high-performance liquid chromatography coupled with photodiode-array detection (HPLC-PAD). The results showed that the contents of six major flavonoids in the purified product were all higher than before the purification. Therefore, the AB-8 MRCC established in this work was a promising method for the industrial-scale purification of the total flavonoids from S. tonkinensis. Full article

Three-dimensional ordered macroporous (3-DOM) IrO₂ material was prepared using PMMA as a template and ammonia as a chelator. These 3-DOM IrO₂ honeycomb arrays showed a large surface area and ordered macropores (155 nm in diameter) cross-linked by secondary mesopores. Internal structures of 3-DOM IrO₂ material were observed microscopically through these secondary pores. According to the X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) spectra, 3-DOM IrO₂ has a rutile crystal structure and is mainly composed of iridium dioxide. In acidic electrolytes, the overpotential of 3-DOM IrO₂ material at 0.5 mV cm⁻² was only 0.22 V. Accelerated durability tests demonstrated excellent durability of 3-DOM IrO₂ as an oxygen evolution reaction (OER) catalyst. Full article

Socially responsible technologies are designed while taking into consideration the socioeconomic, geopolitical and environmental limitations of regions in which they will be implemented. In the medical context, this involves making therapeutic platforms more accessible and affordable to patients in poor regions of the world wherein a given disease is endemic. This often necessitates going against the reigning trend of making therapeutic nanoparticles ever more structurally complex and expensive. However, studies aimed at simplifying materials and formulations while maintaining the functionality and therapeutic response of their more complex counterparts seldom provoke a significant interest in the scientific community. In this review we demonstrate that such compositional simplifications are meaningful when it comes to the design of a solution for osteomyelitis, a disease that is in its natural, non-postoperative form particularly prevalent in the underdeveloped parts of the world wherein poverty, poor sanitary conditions, and chronically compromised defense lines of the immune system are the norm. We show that calcium phosphate nanoparticles, which are inexpensive to make, could be chemically designed to possess the same functionality as a hypothetic mixture additionally composed of: (a) a bone growth factor; (b) an antibiotic for prophylactic or anti-infective purposes; (c) a bisphosphonate as an antiresorptive compound; (d) a viral vector to enable the intracellular delivery of therapeutics; (e) a luminescent dye; (f) a radiographic component; (g) an imaging contrast agent; (h) a magnetic domain; and (i) polymers as viscous components enabling the injectability of the material and acting as carriers for the sustained release of a drug. In particular, calcium phosphates could: (a) produce tunable drug release profiles; (b) take the form of viscous and injectable, self-setting pastes; (c) be naturally osteo-inductive and inhibitory for osteoclastogenesis; (d) intracellularly deliver bioactive compounds; (e) accommodate an array of functional ions; (f) be processed into macroporous constructs for tissue engineering; and (g) be naturally antimicrobial. All in all, we see in calcium phosphates the presence of a protean nature whose therapeutic potentials have been barely tapped into. Full article

Duchesnea indica (D. indica) is an important traditional Chinese medicine, and has long been clinically used to treat cancer in Asian countries. It has been described previously as a rich source of phenolic compounds with a broad array of diversified structures, which are the major active ingredients. However, an accurate and complete phenolic profiling has not been determined yet. In the present work, the total phenolic compounds in crude extracts from D. indica were enriched and fractionated over a macroporous resin column, then identified by HPLC-ESI-MS/MS and ESI-IT-MS (ion trap MS). A total of 27 phenolic compounds were identified in D. indica, of which 21 compounds were identified for the first time. These 27 phenolic compounds encompassing four phenolic groups, including ellagitannins, ellagic acid and ellagic acid glycosides, hydroxybenzoic acid and hydroxycinnamic acid derivatives, and flavonols, were then successfully quantified using peak areas against those of the corresponding standards with good linearity (R² > 0.998) in the range of the tested concentrations. As a result, the contents of individual phenolic compounds varied from 6.69 mg per 100 g dry weight (DW) for ellagic acid to 71.36 mg per 100 g DW for brevifolin carboxylate. Not only did this study provide the first phenolic profiling of D. indica, but both the qualitative identification and the subsequent quantitative analysis of 27 phenolic compounds from D. indica should provide a good basis for future exploration of this valuable medicinal plant. Full article

In present study, the anthocyanin composition and content of the fruit of B. heteropoda Schrenk were determined for the first time. The total anthocyanins were extracted from the fruit of B. heteropoda Schrenk using 0.5% HCl in 80% methanol and were then purified using an AB-8 macroporous resin column. The purified anthocyanin extract (PAE) was evaluated by high-performance liquid chromatography with a diode array detector (HPLC-DAD) and HPLC-high resolution-electrospray ionization-mass spectrometry (HPLC-HR-ESI-MS) under the same experimental conditions. The results revealed the presence of seven different anthocyanins. The major anthocyanins purified by preparative HPLC were confirmed to be delphinidin-3-O-glucopyranoside (30.3%), cyanidin-3-O-glucopyranoside (33.5%), petunidin-3-Ο-glucopyranoside (10.5%), peonidin-3-O-glucopyranoside (8.5%) and malvidin-3-O-glucopyranoside (13.8%) using HPLC-HR-ESI-MS and NMR spectroscopy. The total anthocyanin content was 2036.6 ± 2.2 mg/100 g of the fresh weight of B. heteropoda Schrenk fruit. In terms of its total reducing capacity assay, DPPH radical-scavenging activity assay, ferric-reducing antioxidant power (FRAP) assay and ABTS radical cation-scavenging activity assay, the PAE also showed potent antioxidant activity. The results are valuable for illuminating anthocyanins composition of B. heteropoda Schrenk and for further utilising them as a promising anthocyanin pigment source. This research enriched the chemical information of B. heteropoda Schrenk. Full article

An innovative fabrication method to produce a macroporous Si surface by employing an anodic aluminium oxide (AAO) nanopore array layer as an etching template is presented. Combining AAO with a reactive ion etching (RIE) processes, a homogeneous and macroporous silicon surface can be effectively configured by modulating AAO process parameters and alumina film thickness, thus hopefully replacing conventional photolithography and electrochemical etch methods. The hybrid process integration is considered fully CMOS compatible thanks to the low-temperature AAO and CMOS processes. The gas-sensing characteristics of 50 nm TiO₂ nanofilms deposited on the macroporous surface are compared with those of conventional plain (or non-porous) nanofilms to verify reduced response noise and improved sensitivity as a result of their macroporosity. Our experimental results reveal that macroporous geometry of the TiO₂ chemoresistive gas sensor demonstrates 2-fold higher (~33%) improved sensitivity than a non-porous sensor at different levels of oxygen exposure. In addition, the macroporous device exhibits excellent discrimination capability and significantly lessened response noise at 500 °C. Experimental results indicate that the hybrid process of such miniature and macroporous devices are compatible as well as applicable to integrated next generation bio-chemical sensors. Full article