The significantly quenched luminescence of delaminated SDC/OS-LDH when contacted with Fe ³⁺ can sensitively detect trace amounts of Fe ³⁺ .

In the present study, the extraction technology and preparative separation of 1-deoxynojirimycin from mulberry leaves were systematically investigated. Four extraction parameters (ethanol concentration, extraction temperature, extraction time and ratio of solvent to sample) were explored by response surface methodology (RSM). The results indicated that the maximal yield of 1-deoxynojirimycin was achieved with an ethanol concentration of 55%, extraction temperature of 80 °C, extraction time of 1.2 h and ratio of solvent to sample of 12:1. The extraction yield under these optimum conditions was found to be 256 mg/100 g dry mulberry leaves. A column packed with a selected resin was used to perform dynamic adsorption and desorption tests to optimize the separation process. The results show that the preparative separation of 1-deoxynojirimycin from mulberry leaves can be easily and effectively done by adopting 732 resin. In conclusion, 732 resin is the most appropriate for the separation of 1-deoxynojirimycin from other components in mulberry leaves extracts, and its adsorption behavior can be described with Langmuir isotherms and a two-step adsorption kinetics model. The recovery and purity of 1-deoxynojirimycin in the final product were 90.51% and 15.3%, respectively.

Layered double hydroxides (LDHs), also known as hydrotalcite-like compounds, are widely used in many fields due to their unique structural advantages. Based on LDHs, a wide range of metal catalysts could be synthesized with high metal dispersion, tunable acid-base properties, facile but flexible preparation methods, strong metal-support interaction, and thermal stability. Owing to these outstanding advantages, LDH-derived materials manifest great potential as catalysts, particularly in hydrogenation and hydrogenolysis reactions. More than 200 papers published in the past five years in this field clearly indicated the rapid development of these materials. In this respect, it is imperative and essential to provide a timely review to summarize the current progress and motivate greater research effort on hydrogenation and hydrogenolysis catalysts derived from LDHs. In this review, the applications of LDH-derived materials as heterogeneous catalysts in various hydrogenation and hydrogenolysis reactions were comprehensively discussed. Hydrogenation of unsaturated chemical bonds, hydrodeoxygenation of oxygenated compounds, hydrogenolysis of carbon–carbon bonds and hydrogenation of nitrites and nitriles were described. This review demonstrates the extraordinary potentials of LDH-derived catalysts in hydrogenation and hydrogenolysis reactions, and it is undoubted that LDH-derived catalysts will play an even more significant role in the foreseeable future.

In this study, an ultrasonic-assisted procedure for the extraction of mulberry leaf polysaccharides (MLPs) was investigated using response surface methodology with a 29-run Box–Behnken design. Four factors were investigated, and it was found that the factors influencing the process, in order of significance, were the extraction temperature > liquid-to-material ratio > ultrasonic power. Considering practical conditions, the parameters were adjusted to a liquid-to-material ratio of 16:1 mL/g, extraction time of 58 min, extraction temperature of 65 °C, and ultrasonic power of 500 W. Under these conditions, the yield of MLPs was 14.47%, which is close to the predicted value, indicating that the extraction process optimized by response surface methodology (RSM) is feasible. The separation and purification effects of macroporous resin and activated carbon on MLPs were investigated, with the D152 resin being considered the most suitable choice. The optimal separation conditions were found to be a sample concentration of 0.5 g/mL and an optimal flow rate of 1 mL/min. Thin-layer chromatography and infrared spectroscopy revealed that polysaccharides extracted from mulberry leaves are primarily composed of rhamnose, xylose, and arabinose. In conclusion, this study successfully optimized the ultrasonic-assisted extraction process of MLPs through response surface methodology, determined the optimal parameter combination, and verified its efficiency and stability. Under the optimal conditions obtained for ultrasonic-assisted extraction, the yield of MLPs is significantly higher than that reported in the previous literature. The decolorization process of crude mulberry leaf polysaccharide extract was also investigated, and the purified MLPs have clear monosaccharide composition and structural characteristics, providing a theoretical basis and technical support for their application in functional food or drug development.

In-depth studies on condensate structures during furfural rearrangement to cyclopentanone are presented. Polymeric condensates with high levels of conjugation were the main cause for carbon loss and catalyst deactivation.