Ultrasound-assisted extraction of polyphenols from Chinese propolis

IntroductionPropolis is a beneficial bioactive food with rich polyphenols content. Nowadays, an increasing interest is attracted to the extraction of polyphenols from raw propolis. This study utilized the novel ultrasound-assisted approach for polyphenol extraction from Chinese propolis, aiming to improve its extraction yield and reveal the relevant mechanisms via extraction kinetic study as well as the compositional and structural analysis.MethodsThe optimum ultrasound-assisted extraction conditions were optimized according to the total phenolic content and total flavonoids content. Compositional and structural analysis were conducted using high performance liquid chromatography-quadrupole-time of flight tandem mass spectrometry, high-performance liquid chromatography, Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM).Results and discussionThe optimum ultrasound-assisted extraction conditions were as follows: ratio of liquid to solid, 60:1; ultrasound power, 135 W; ultrasound duration, 20 min. Under the optimum conditions, the antioxidant activities of the extract were increased by 95.55% and 64.46% by 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability assay and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging ability assay, respectively, compared to those obtained by traditional maceration. The second-order kinetics model was employed to study the extraction process; it was found that ultrasound significantly accelerated the extraction of propolis and increased the maximum extraction volume of phenolic compounds. The qualitative and quantitative analysis of polyphenol compositions showed that ultrasound did not change the polyphenol types in the extract but it significantly improved the contents of various flavonoids and phenolic acids such as galangin, chrysin, pinocembrin, pinobanksin and isoferulic acid. Likewise, the FT-IR analysis indicated that the types of functional groups were similar in the two extracts. The SEM analysis revealed that the ultrasound-assisted extraction enhanced the contact areas between propolis and ethanol by breaking down the propolis particles and eroding the propolis surface

The glycogen synthase kinase MoGsk1, regulated by Mps1 MAP kinase, is required for fungal development and pathogenicity in Magnaporthe oryzae

Magnaporthe oryzae, the causal agent of blast disease, is one of the most destructive plant pathogens, causing significant yield losses on staple crops such as rice and wheat. The fungus infects plants with a specialized cell called an appressorium, whose development is tightly regulated by MAPK signaling pathways following the activation of upstream sensors in response to environmental stimuli. Here, we show the expression of the Glycogen synthase kinase 3 (GSK3) MoGSK1 in M. oryzae is regulated by Mps1 MAP kinase, particularly under the stressed conditions. Thus, MoGSK1 is functionally characterized in this study. MoGsk1 is functionally homologues to the Saccharomyces cerevisiae GSK3 homolog MCK1. Gene replacement of MoGSK1 caused significant delay in mycelial growth, complete loss of conidiation and inability to penetrate the host surface by mycelia-formed appressorium-like structures, consequently resulting in loss of pathogenicity. However, the developmental and pathogenic defects of Delta mogsk1 are recovered via the heterologous expression of Fusarium graminearum GSK3 homolog gene FGK3, whose coding products also shows the similar cytoplasmic localization as MoGsk1 does in M. oryzae. By contrast, overexpression of MoGSK1 produced deformed appressoria in M. oryzae. In summary, our results suggest that MoGsk1, as a highly conservative signal modulator, dictates growth, conidiation and pathogenicity of M. oryzae

A calcium ion-imprinted porous film prepared from a cellulose-alginate composite

An ion-imprinted (IIP) film has been successfully prepared in this work. Firstly, mixture solution of cellulose and alginate was obtained by dissolving those polymers in a NaOH/urea aqueous solution. Then the mixture solution was cast onto glass plate and coagulated in CaCl2 aqueous solution bath to prepare a composite film. The matrix of the film was further fixed by cross-linking. Finally, the chelated Ca2+ in the matrix was removed to obtain the IIP film. The IIP film was characterized to show satisfactory mechanical properties, and to exhibit porous mesh network microstructure. The equilibrium swelling ratio of the IIP film was determined to be 700?%. The IIP film was immersed into Ca2+, Ca2+/Cu2+, Ca2+/Zn2+ and Ca2+/Mg2+ solutions to check the adsorption behavior, respectively. The results indicate that the IIP film displayed highly selective Ca2+ recognition, and the presence of additional cations had little effect on the Ca2+ recognition. Thus prepared Ca2+ imprinted film have potential applications in fields such as hard water softening, and Ca2+ enrichment or recognition

Reforestation in southern China: revisiting soil N mineralization and nitrification after 8 years restoration

Nitrogen availability and tree species selection play important roles in reforestation. However, long-term field studies on the effects and mechanisms of tree species composition on N transformation are very limited. Eight years after tree seedlings were planted in a field experiment, we revisited the site and tested how tree species composition affects the dynamics of N mineralization and nitrification. Both tree species composition and season significantly influenced the soil dissolved organic carbon (DOC) and nitrogen (DON). N-fixing Acacia crassicarpa monoculture had the highest DON, and 10-mixed species plantation had the highest DOC. The lowest DOC and DON concentrations were both observed in Eucalyptus urophylla monoculture. The tree species composition also significantly affected net N mineralization rates. The highest rate of net N mineralization was found in A. crassicarpa monoculture, which was over twice than that in Castanopsis hystrix monoculture. The annual net N mineralization rates of 10-mixed and 30-mixed plantations were similar as that of N-fixing monoculture. Since mixed plantations have good performance in increasing soil DOC, DON, N mineralization and plant biodiversity, we recommend that mixed species plantations should be used as a sustainable approach for the restoration of degraded land in southern China

Real-time tracking and in vivo visualization of β-galactosidase activity in colorectal tumor with a ratiometric near-infrared fluorescent probe

Development of “smart” noninvasive bioimaging probes for trapping specific enzyme activities is highly desirable for cancer therapy in vivo. Given that β-galactosidase (β-gal) is an important biomarker for cell senescence and primary ovarian cancers, we design an enzyme-activatable ratiometric near-infrared (NIR) probe (DCM-βgal) for the real-time fluorescent quantification and trapping of β-gal activity in vivo and in situ. DCM-βgal manifests significantly ratiometric and turn-on NIR fluorescent signals simultaneously in response to β-gal concentration, which makes it favorable for monitoring dynamic β-gal activity in vivo with self-calibration in fluorescent mode. We exemplify DCM-βgal for the ratiometric tracking of endogenously overexpressed β-gal distribution in living 293T cells via the <i>lacZ</i> gene transfection method and OVCAR-3 cells, and further realize real-time in vivo bioimaging of β-gal activity in colorectal tumor-bearing nude mice. Advantages of our system include light-up ratiometric NIR fluorescence with large Stokes shift, high photostability, and pH independency under the physiological range, allowing for the in vivo real-time evaluation of β-gal activity at the tumor site with high-resolution three-dimensional bioimaging for the first time. Our work provides a potential tool for in vivo real-time tracking enzyme activity in preclinical applications

Synthesis of Polyaniline/Graphene Oxide/Azobenzene Composite and Its Adjustable Photoelectric Properties

Azobenzene derivatives have fast light response characteristics; in this paper, a new azobenzene derivative (Azo) was synthesized and to be made a composite (PANI/GO/Azo) with polyaniline/graphene oxide (PANI/GO). Both composites were carefully investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). Moreover, their electrochemical properties were characterized by the electrochemical workstation, including cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), cycling stability, and electrochemical impedance spectroscopy (EIS). The results demonstrated that the PANI/GO/Azo composite has a higher capacitance of 478.3 F g−1 than that of PANI/GO (359.9 F g−1) at a current density of 1 A g−1. PANI/GO/Azo composite showed excellent photosensitive electrochemical properties under UV irradiation, and its rate of capacitance change achieved about 52.57%. Additionally, the PANI/GO/Azo composite also displayed high reversibility, with specific capacitance retention of 92% after 500 cycles. Therefore, the PANI/GO/Azo electrode with a controllable electrochemical performance by UV irradiation had a great potential in the photoresponsive supercapacitor

A Multiaddressable Photochromic Bisthienylethene with Sequence-Dependent Responses: Construction of an INHIBIT Logic Gate and a Keypad Lock

A photochromic bisthienylethene derivative (<b>BIT</b>) containing two imidazole units has been synthesized and fully characterized. When triggered by chemical ions (Ag⁺), protons, and light, <b>BIT</b> can behave as an absorbance switch, leading to a multiaddressable system. <b>BIT</b> exhibits sequence-dependent responses via efficient interaction of the specific imidazole unit with protons and Ag⁺. Furthermore, an INHIBIT logic gate and a keypad lock with three inputs are constructed with the unimolecular platform by employing an absorption mode at different wavelengths as outputs on the basis of an appropriate combination of chemical and photonic stimuli

Potential Role of Quercetin in Polycystic Ovary Syndrome and Its Complications: A Review

Polycystic ovary syndrome (PCOS) is a common multisystem disease with reproductive, metabolic and psychological abnormalities. It is characterized by a high prevalence rate in women of childbearing age and highly heterogeneous clinical manifestations, which seriously harm women&rsquo;s physical and mental health. Quercetin (QUR) is a natural compound of flavonoids found in a variety of foods and medicinal plants. It can intervene with the pathologic process of PCOS from multiple targets and channels and has few adverse reactions. It is mentioned in this review that QUR can improve ovulation disorder, relieve Insulin resistance (IR), reduce androgen, regulate lipid metabolism, regulate gut microbiota and improve vascular endothelial function, which is of great significance in the treatment of PCOS

Near-Infrared Colorimetric and Fluorescent Cu²⁺ Sensors Based on Indoline–Benzothiadiazole Derivatives via Formation of Radical Cations

The donor–acceptor system of indoline–benzothiadiazole is established as the novel and reactive platform for generating amine radical cations with the interaction of Cu²⁺, which has been successfully exploited as the building block to be highly sensitive and selective near infrared (NIR) colorimetric and fluorescent Cu²⁺ sensors. Upon the addition of Cu²⁺, an instantaneous red shift of absorption spectra as well as the quenched NIR fluorescence of the substrates is observed. The feasibility and validity of the radical cation generation are confirmed by cyclic voltammetry and electron paramagnetic resonance spectra. Moreover, the introduction of an aldehyde group extends the electron spin density and changes the charge distribution. Our system demonstrates the large scope and diversity in terms of activation mechanism, response time, and property control in the design of Cu²⁺ sensors

Interaction of Surface Water and Groundwater Influenced by Groundwater Over-Extraction, Waste Water Discharge and Water Transfer in Xiong’an New Area, China

Understanding the interaction of surface water and groundwater affected by anthropogenic activities is of great importance for water resource and water quality management. The Xiong&rsquo;an New Area, located in the North China Plain, has been designated a new building area by China&rsquo;s government. Groundwater has been over pumped and artificial water was transferred to meet the water supply in this region. Therefore, the natural interaction of surface water and groundwater has been greatly changed and there has been a complex impact of the groundwater from anthropogenic activities. In this study, we used water chemical ions and stable isotopes of &delta;2H and &delta;18O to assess the interaction of surface water and groundwater in the Xiong&rsquo;an New Area. We carried out field surveys and water sampling of the Fu River (domestic waste water discharge), Lake Baiyangdian (artificial water transfer), and the underlying groundwater along the water bodies. Results show that the artificial surface water (discharged and transferred) became the major recharge source for the local groundwater due to the decline of groundwater table. We used groundwater table observations, end-member mixing analysis of the stable isotopic composition and chloride tracers to estimate the contributions of different recharge sources to the local groundwater. Due to the over pumping of groundwater, the lateral groundwater recharge was dominant with a contribution ratio ranging from 12% to 78% in the upper reach of the river (Sections 1&ndash;3). However, the contribution of lateral groundwater recharge was estimated to be negligible with respect to the artificial water recharge from Lake Baiyangdian. Seepage from the Fu River contributed a significant amount of water to the connecting aquifer, with a contribution ranging from 14% to 75% along the river. The extent of the river influence into the aquifer ranges as far as 1400 m to the south and 400 m to the north of the Fu River. Estimations based on isotopic fractionation shows that about 25% of Lake Baiyangdian water was lost by evaporation. By using the stable isotopes of oxygen and hydrogen in the lake water, an influencing range of 16 km west of the lake was determined. The interaction of the surface water and groundwater is completely changed by anthropogenic activities, such as groundwater over pumping, waste water discharge and water transfer. The switched interaction of surface water and groundwater has a significant implication on water resources management