Preparation of Magnetic Nano-Catalyst Containing Schiff Base Unit and Its Application in the Chemical Fixation of CO₂ into Cyclic Carbonates

The development of a catalyst for the conversion of CO2 and epoxides to the corresponding cyclic carbonates is still a very attractive topic. Magnetic nano-catalysts are widely used in various organic reactions due to their magnetic separation and recycling properties. Here, a magnetic nano-catalyst containing a Schiff base unit was designed, synthesized and used as a heterogeneous catalyst to catalyze CO2 and epoxides to form cyclic carbonates without solvents and co-catalysts. The catalyst was characterized using Fourier transform infrared (FTIR), X-ray diffraction (XRD), thermogravimetric (TG), VSM, SEM, TEM and BET. The results show that the magnetic nano-catalyst containing the Schiff base unit has a high activity in the solvent-free cycloaddition reaction of CO2 with epoxide under mild conditions, and is easily separated from the reaction mixture driven by external magnetic force. The recovered catalyst maintains a high performance after five cycles

Liquid Metal-Based Epidermal Flexible Sensor for Wireless Breath Monitoring and Diagnosis Enabled by Highly Sensitive SnS2 Nanosheets

Real-time wireless respiratory monitoring and biomarker analysis provide an attractive vision for noninvasive telemedicine such as the timely prevention of respiratory arrest or for early diagnoses of chronic diseases. Lightweight, wearable respiratory sensors are in high demand as they meet the requirement of portability in digital healthcare management. Meanwhile, high-performance sensing material plays a crucial role for the precise sensing of specific markers in exhaled air, which represents a complex and rather humid environment. Here, we present a liquid metal-based flexible electrode coupled with SnS2 nanomaterials as a wearable gas-sensing device, with added Bluetooth capabilities for remote respiratory monitoring and diagnoses. The flexible epidermal device exhibits superior skin compatibility and high responsiveness (1092%/ppm), ultralow detection limits (1.32 ppb), and a good selectivity of NO gas at ppb-level concentrations. Taking advantage of the fast recovery kinetics of SnS2 responding to H2O molecules, it is possible to accurately distinguish between different respiratory patterns based on the amount of water vapor in the exhaled air. Furthermore, based on the different redox types of H2O and NO molecules, the electric signal is reversed once the exhaled NO concentration exceeds a certain threshold that may indicate the onset of conditions like asthma, thus providing an early warning system for potential lung diseases. Finally, by integrating the wearable device into a wireless cloud-based multichannel interface, we provide a proof-of-concept that our device could be used for the simultaneous remote monitoring of several patients with respiratory diseases, a crucial field in future digital healthcare management

Knoevenagel reaction promoted by functional ionic liquids with primary and tertiary amines

Functional ionic liquids have been widely used in the fields of synthetic chemistry, analytical chemistry, electrochemistry and material chemistry owing to their excellent properties such as easy structure modification and adjustable properties. In this work, a series of basic functionalized ionic liquids were prepared from 1, 4-diazabicyclo [2.2.2] octane (DABCO) or hexamethylenetetramine (HMTA) with various halogenated hydrocarbons, then these functional ionic liquids and water were used as solvent-catalyst system in the Knoevenagel reaction of various aldehydes with ethyl cyanoacetate or malononitrile, the influence of the structure of the ionic liquid and the content of water was investigated. The results showed that the composite solvent-catalyst system mixed by the functional ionic liquid N-(3-aminopropyl)-1,4-diazabicyclo [2.2.2] octane bromide with water can effectively promote the Knoevenagel reaction and the alkalinity of amine and hydrogen bond play an important role. Aromatic aldehydes with electron-donating or electron-withdrawing groups can obtain the target product at an excellent yield (79-99%). It is worth noting that the polycyclic aromatic aldehydes with high steric hindrance, 86%-95% yields of the object products were also obtained after 15 h-25 h. Furthermore, the catalyst could be reused for 6 times without any loss in its catalytic activity. The composite solvent-catalyst system mixed by the Functional ionic liquid N-(3-aminopropyl)-1,4-diazabicyclo[2.2.2]octane bromide with water can effectively promote the Knoevenagel reaction, even for the electron-rich aromatic aldehydes with poor reactivity, high yields of the target products and fast reaction rate were also obtained at room temperature.</p

Dynamic changes in chemical composition and microbial community characteristics during pile-fermentation process of Phyllanthus emblica Linn. fruit

Pile-fermentation is a common processing step for Phyllanthus emblica L. fruit (PEF) in its producing area. This process enhances its flavor, reduces astringency, and increases its health benefits. However, the mechanism behind pile-fermentation and the key factors impacting PEF quality remain unknown, becoming an urgent challenge that limits its further application. To address this issue, 87 volatile compounds were analyzed by HS-SPME/GC-QQQ-MS/MS and identified acetic acid and ethyl acetate as distinguishing markers before and after fermentation. The results found that 2-methoxy-3-isobutylpyrazine contributes to the differences in odor after fermentation based on the odor intensity characteristic spectrum. Illumina Miseq sequencing of ITS1 region and 16SrDNA V4 region was performed to investigate the microbial succession during the pile-fermentation. A total of 4 phyla 34 genera of fungi and 15 phyla 61 genera of bacteria were detected in all samples. The results showed that the dominant bacteria had significant differences due to different habitats before fermentation, and the diversity increased after fermentation, while the fungal diversity exhibited the opposite trend. Aspergillus and the Unclassified_f_Necriaceae genus emerged as dominant genera after fermentation. Additionally, through UPLC-QTOF-MS analysis, we identified 18 differential components before and after fermentation. Among these, 5 compounds, such as 2-O-galloyl-1,4-galactolactone and 1-methyl-2-gallate galactose ester, showed a downward trend, whereas 13 compounds, including corilagin and chebulitic acid, exhibited an upward trend. These changes weakened astringency while improving sourness and aftertaste sweetness. The results of this study hold significant importance in clarifying the fermentation mechanism and improving the quality standards of PEF

Thermal treatment enhances the resisting exercise fatigue effect of Phyllanthus emblica L.: novel evidence from tannin conversion in vitro, metabolomics, and gut microbiota community analysis

Abstract Polyphenols are the main component of Phyllanthus emblica (PE). However, polyphenols are so easy to transform that it is unknown that how drying methods driven by heating affect the anti-fatigue effect of PE. This manuscript investigated the effects of five drying methods on the chemical composition transformation and anti-fatigue of PE, and discussed the action mechanism. The results suggested that the anti-fatigue effect of PE with hot-air-dried at 100 °C was the best, which was as 1.63 times as that with freeze-drying. Ellagic acid (EA) may be a key component of PE in anti-fatigue, and its mechanism of action may be related to regulating intestinal microbiota, protecting mitochondria, and regulating energy metabolism. This study first revealed the thermal transformation of polyphenols in PE, found the most effective strategy for enhancing the anti-fatigue function, and explores its action mechanism

High or low temperature extraction, which is more conducive to Triphala against chronic pharyngitis?

Objective: Explore the effects of high-temperature reflux extraction and low-temperature decompressing inner ebullition on Triphala's chemical composition and anti-chronic pharyngitis activity. Methods: The network pharmacology was used to analyze the material basis, targets and pathways of Triphala for chronic pharyngitis. HPLC were used to compare the fingerprint profile and content of components between the two extracts. The antioxidant and anti-chronic pharyngitis activities of the two extracts were compared by DPPH assay and ammonia induced chronic pharyngitis model in rats. Results: The network pharmacology results showed that the active ingredients of Triphala for chronic pharyngitis are epigallocatechin-3-gallate, (+)-catechin, epicatechin, epicatechin gallate, (+)-gallocatechin, quercetin, luteolin, leucodelphinidin and other flavonoids; phenolic acids such as gallic acid and ellagic acid; alkaloids such as ellipticine, cheilanthifoline; hydrolyzed tannins such as corilagin and chebulic acid. The high-temperature reflux extract and the low-temperature decompressing inner ebullition extract have extremely significant differences in the fingerprint profile. Among them, the content of gallic acid, ellagic acid, chebulic acid, catechin, epicatechin, corilagin, quercetin, and epicatechin gallate in the reflux extract is 1.1–5.3 times as much as decompressing inner ebullition extract. The free radical scavenging ability of reflux extract is significantly stronger than that of decompression extract (p < 0.01), and it has a repairing effect on pharyngeal mucosal damage (reducing keratinization or hyperplasia of mucosal epithelium, reducing inflammatory cell infiltration and bleeding), and reducing IL-1β (P＜0.05), IL-6 (p＜0.05), TNF-α overexpression ability is stronger than the decompressing inner ebullition extract. Conclusions: gallic acid, ellagic acid, chebulic acid, catechin, epicatechin, corilagin and epicatechin gallate are the basic aglycones or oligomers of tannin. High temperature reflux extraction can significantly promote the occurrence of the hydrolysis of tannins and significantly increases the content of these components.Therefore, its anti-chronic pharyngitis activity is enhanced. It is suggested that high temperature reflux extraction should be used in the treatment of chronic pharyngitis