Polysaccharides, also known as polysaccharides, can be divided into two categories. Polysaccharides containing only one monosaccharide unit, such as starch, are called homopolysaccharides; Polysaccharides containing two or more monosaccharide units are called heteropolysaccharides, such as hyaluronic acid. Generally, polysaccharides have no exact molecular weight, and monosaccharide units in them can be increased or decreased due to the metabolic needs of cells. Polysaccharides are not reducible and sweet, most of them are insoluble in water, and some of them form colloidal solutions with water. Polysaccharides are widely distributed in nature, and their functions are varied. Some polysaccharides are stored forms of monosaccharides; Many polysaccharides are structural units of single-celled microorganisms, cell walls of higher plants and external surfaces of animal cells. Other polysaccharides are components of vertebrate connective tissue and arthropod exoskeleton. Structural polysaccharide has the function of protection and support. The most important stored polysaccharides are starch and glycogen.
The use of polysaccharides in the field of life science research, glycobiology has always been the research preface and hot spot in this field. The development of modern medical cell biology and molecular biology has made people realize that the disorder of immune system not only produces many diseases, but also is closely related to human aging and the occurrence of frequently-occurring diseases of the elderly, such as tumors, hypertension, diabetes and even mental illness. Since the 1980s, scientists have been interested in plant polysaccharides, In particular, I have developed a strong interest in the study of polysaccharides in traditional Chinese medicine. So far, 100 has been reported one after another, which has many physiological activities such as immunomodulation, anti-tumor, anti-virus, anti-infection and hypoglycemic, and some of them have been used in clinical adjuvant treatment and rehabilitation of tumor, hepatitis and cardiovascular diseases, among which the most important pharmacological function is to promote immunity. A large number of pharmacological and clinical applications have shown that these polysaccharides have definite functions. Most of its original crude drugs belong to tonic traditional Chinese medicines. Recent pharmacological research and clinical application have shown that it has obvious immune enhancement effect, and its effective component is polysaccharide or glycoconjugates, including glycopeptides, proteoglycans and other different glycopeptides, which have different forms of immune activity, some show strong cellular immune function, some show strong humoral immune function, and some also have obvious anti-lipid peroxidation effect. The structural analysis of these glycopeptides that inhibit LDL oxidation shows that their * * * features are high polysaccharide content, some of which can be as high as 90. The polysaccharide structure has its * * * characteristics, that is, they all end in Ara, but they also have their own personalities. Some main chains are linked by 1 6, and some are linked by 1 4. Some of them are combined with the pharmacological research results of pigments, and the results also show that not only the whole molecule in these glycopeptides has immune activity, but also the polysaccharide chain in the molecule has immune activity, and some of them are stronger than the whole molecule. Polysaccharides are used as antitumor drugs because people are dissatisfied with the current cancer chemotherapy drugs. Although chemists have synthesized countless compounds with quite strong killing effect on cancer cells, However, while killing cancer cells, it also damages normal cells, which shows many side effects in clinic, especially when chemotherapy drugs damage the immune system of patients. Therefore, polysaccharide immunomodulators are very attractive in the treatment of tumors, especially when they can be combined with some anticancer drugs such as 5 FU cyclophosphamide, which can restore the immune function caused by chemotherapy and enhance the anti-tumor effect. Chemists have obtained a variety of polysaccharide compounds from traditional Chinese medicines, which can not only promote the immune function of the body, but also prove that some polysaccharides do have the function of anti-aging and prolonging life. The development of immunomodulators of traditional Chinese medicine will have the following trends: from the research of polysaccharide of single traditional Chinese medicine to the research of compound polysaccharide system of traditional Chinese medicine, from the research of single immune system to the research of neuroendocrine immune network, from medicine to food, from treatment to health care.