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Polysaccharides are ideal natural resources for supplements and pharmaceuticals that have received more and more attention over the years. Natural polysaccharides have been shown to have fewer side effects, but because of their inherently physicochemical properties, their bioactivities were difficult to compare with those of synthetic drugs. Thus, researchers have modified the structures and properties of natural polysaccharides based on structure-activity relationships and have obtained better functionally improved polysaccharides. This review focuses on the major modification methods of polysaccharides, and discusses the effect of molecular modification on their physicochemical properties and bioactivities. Molecular modification methods mainly include chemical, physical, and biological changes. Chemical modification is the most widely used method; it can significantly increase the water solubility and bioactivities of polysaccharides by grafting onto other groups. Physical and biological modifications only change the molecular weight of a polysaccharide, and thereby change its physicochemical properties and bioactivities. Most of the molecular modifications bring about an increase in the antioxidant activity of polysaccharides, and among these, sulfated and acetylated modifications are very common. Furthermore, phosphorylation modification is the most common application to increase antitumor activity, and modified polysaccharides have been shown to have anti-HIV activity as the result of sulfated modification. [ABSTRACT FROM AUTHOR]

[Objective] To explore the identification methods of FRUCTUS AMOMI in different production areas, to detect the infrared absorption spectra of FRUCTUS AMOMI in different production areas by FTIR, to switch the spectra by derivative spectra; and to find out the characteristic difference absorption of FRUCTUS AMOMI in different production areas. [Results] There were no significant differences in the infrared spectra of FRUCTUS AMOMI in different production areas. Some characteristic peaks showed up in the wavelengths of 600 - 750 and 1 300 - 1 400 cm-1 after the fourth-order derivave spectra. Peak differences appeared in eight samples in the wavelengths of 1 000 - 1 300, 1 400 - 1 500, 2 800 - 3 000 and 3 500 - 3 800 cm-1. [Conclusions] There were significant differences in the FTIR spectra of FRUCTUS AMOMI in different production areas after processed by derivative spectra. This method could better identify the FRUCTUS AMOMI in different production areas. [ABSTRACT FROM AUTHOR]

Electrochemiluminescence (ECL) is one of the most powerful techniques that meet the needs of analysis and detection in a variety of scenarios, because of its highly analytical sensitivity and excellent spatiotemporal controllability. ECL combined with microscopy (ECLM) offers a promising approach for quantifying and mapping a wide range of analytes. To date, ECLM has been widely used to image biological entities and processes, such as cells, subcellular structures, proteins and membrane transport properties. In this review, we first introduced the mechanisms of several classic ECL systems, then highlighted the progress of visual biosensing and bioimaging by ECLM in the last decade. Finally, the characteristics of ECLM were summarized, as well as some of the current challenges. The future research interests and potential directions for the application of ECLM were also outlooked., (© 2024 Wiley-VCH GmbH.)