Comparison of different extraction methods of active ingredients of Chinese medicine and natural products.

Like other traditional medicine in the world, Chinese traditional medicine (CTM) has a long history, which is a treasure of the combination of medicine and Chinese classical culture even more than 5000 years. For thousands of years, CTM has made great contributions to the reproduction and health of the Chinese people. It was an efficient therapeutic tool under the guidance of Chinese traditional medical theory, its source is generally natural products, but there are also a small number of it are natural products after some processing methods. In fact, the definition of Chinese medicine (CM) includes both traditional and new CM developed by modern technology. It is well known that the chemical composition of most CM and natural products is very complex, for example, a single herb may contain hundreds of different chemicals, including active ingredients, side effects, and even toxic ingredients. Therefore, the extraction process is particularly crucial for the quality and clinical efficacy of CM and natural products. In this work, a new classification method was proposed to divide the extraction technologies of CM and natural products into 21 kinds in recent years and analyze their status, advantages, and disadvantages. Then put forward a new technical route based on ultra-high-pressure extraction technology for rapid extraction else while removing harmful impurities and making higher utilization of CM and natural products. It is a useful exploration for the extraction industry of medicinal materials and natural products in the world.

Surface-imprinted ß-cyclodextrin-functionalized carbon nitride nanosheets for fluorometric determination of sterigmatomycin.

ß-Cyclodextrin-functionalized carbon nitride nanosheets were modified with a molecularly imprinted polymer to obtain a fluorescent probe of type MIP@ß-CD/CNNS which is shown to enable fluorometric determination of sterigmatocystin (STG). The material was characterized by transmission electron microscopy, infrared spectra, powder X-ray diffraction, X-ray photoelectron spectroscopy, and by absorption and emission spectra. The modified CNNSs have a good fluorescence quantum yield (13%), high sorption capacity for STG (86 mg·g-1), fast adsorption rate (25 min), and superior adsorption selectivity (with an imprint factor 2.56). When used as an optical probe for STG, the CNNSs act as the chromophore, while ß-CD and MIP act as the recognition groups. The blue fluorescence of MIP@ß-CD/CNNS (with excitation/emission maxima at 368/432 nm) is quenched by STG. Fluorescence drops linearly in the 0.15 to 3.1 µM STG concentration range. The lower detection limit is 74 nM. The method was successfully applied to the determination of STG in spiked wheat extract. Conceivably, this detection scheme based on a combination of ß-CD inclusion and molecular imprinting may be extended to the detection of various other organic compounds. Graphical abstractSchematic representation of the preparation of surface-imprinted ß-cyclodextrin-functionalized carbon nitride nanosheets. These are used, along with a molecularly imprinted polymer, for fluorometric determination of sterigmatomycin.

The effect of structure and preparation method on the bioactivity of polysaccharides from plants and fungi.

Polysaccharides are not only the main components in the cell walls of plants and fungi, but also a structure that supports and protects cells. In the process of obtaining polysaccharides from raw materials containing cell walls, the polysaccharides on the cell walls are the products and also a factor that affects the extraction rate. Polysaccharides derived from plants and fungi have mild characteristics and exhibit various biological activities. The biological activity of polysaccharides is related to their chemical structure. This review summarizes the effects of the physicochemical properties and structure of polysaccharides, from cell walls in raw materials, that have an impact on their biological activities, including molecular weight, monosaccharide composition, chain structure, and uronic acid content. Also, the structure of certain natural polysaccharides limits their biological activity. Chemical modification and degradation of these structures can enhance the pharmacological properties of natural polysaccharides to a certain extent. At the same time, the processing method affects the structure and yield of polysaccharides on the cell wall and in the cell. The extraction and purification methods are summarized, and the effects of preparation methods on the structure and physiological effects of polysaccharides from plants and fungi are discussed.