Polysaccharides are polymerized from monosaccharides, and the molecular weight of polysaccharides is tens of thousands or even millions. They are composed of long-chain monosaccharide units bound together by glycosidic bonds and produce monosaccharides or oligosaccharides upon hydrolysis. If all the monosaccharides in the polysaccharide are of the same type, the polysaccharide is called a homopolysaccharide or a homopolysaccharide. But when more than one type of monosaccharide is present, they are referred to as heteropolysaccharides. Natural saccharide is mostly simple carbohydrate with the formula (CH 2 O)n, where n is 3 or greater than 3. Examples of monosaccharides are glucose, fructose and glyceraldehyde.
Polysaccharide is a natural macromolecular compound from the cell membrane of high animals and plants and the cell wall of microorganisms, and it is one of the basic substances that constitute the energy of life activities. Polysaccharides are an important class of biopolymers, and their function in organisms is usually related to the structure or storage. At present, there are hundreds of active polysaccharides, which can be classified into Plant-derived polysaccharide, Animal-derived polysaccharide, Algae-derived polysaccharides, and microbial-derived polysaccharide according to their different sources. This article describes the following classification of polysaccharides:
Plant-derived polysaccharide
Plant-derived polysaccharides are present in various organs of plants, and there are many studies on the extraction and determination of polysaccharides from fruits and seed kernels (herbal medicines are mostly whole grasses). There is less in-depth research on the medicinal mechanism of such polysaccharides, and most of the research in this area stays at the primary level.
Animal-derived polysaccharide
Animal polysaccharides include glycogen, chitin, heparin, chondroitin sulfate, hyaluronic acid, keratan sulfate, acid mucopolysaccharide or glycosaminoglycan. Heparin, chondroitin sulfate, hyaluronic acid, and keratan sulfate are glycosaminoglycans, which are commonly referred to as proteoglycans because they are often present in a protein-binding state in the body. In animals, structurally similar glucose polymers are more dense branched glycogen, sometimes referred to as "animal starch." The properties of glycogen make it metabolize faster and are suitable for the active life of moving animals.
Algae-derived polysaccharide
The polysaccharide extracted from the seaweed mostly contains sulfate, so it has been recognized as an antithrombotic drug. It has been found that these polysaccharides have antiviral effects in addition to immunostimulating and antitumor effects. For example, one kind of polysaccharide obtained from red algae has a good effect on the treatment of colds. A valuable anti-AIDS polysaccharide drug can also be obtained from seaweed. Some algae polysaccharides can also be used as plant system resistance inducer, and their role in the clean production of agricultural products is also worthy of attention.
Microbial-derived polysaccharide
Microbial-derived polysaccharides can be further divided into bacterial polysaccharides and fungal polysaccharides. Such polysaccharides have been extensively studied up to date, and a wide variety of polysaccharides have been utilized, and bacterial capsular polysaccharides have been used as vaccines in medicine for a long time.
Polysaccharides have a variety of biological activities and are closely related to the maintenance of biological functions. In recent years, plant polysaccharides have been increasingly studied due to their various biological activities such as immune regulation, anti-tumor and anti-aging.
