Saccharides, also known as carbohydrates, are widely distributed in living organisms. Saccharides are not only stored nutrients in living organisms, but also precursors for the biosynthesis of other organic compounds. Saccharides are another important class of biological information molecules in organisms, in addition to proteins and nucleic acids. They play a crucial role in fertilization, development, differentiation, and maintaining the balance of the nervous and immune systems; As a surface “recognition marker” of cell molecules, it participates in many physiological and pathological processes in the body, such as adhesion of white blood cells and endothelial cells in inflammatory reactions, infection of host cells by bacteria and viruses, and immune recognition of antigens and antibodies.
According to the number of sugar groups that make up saccharides, they can be divided into three categories: monosaccharides, oligosaccharides, and polysaccharides. Monosaccharides are mostly in crystalline form, have a sweet taste, are easily soluble in water, soluble in dilute alcohols, difficult to dissolve in high concentrations of ethanol, insoluble in low polarity solvents such as ether, chloroform, and benzene, and have optical and reducing properties. Oligosaccharides are typically composed of 2-9 monosaccharide molecules polymerized together. However, currently only oligosaccharides consisting of 2-5 monosaccharide molecules have been discovered, which are called disaccharides or disaccharides (sucrose, maltose), trisaccharides (mannotriose, gentian trisaccharide), tetrasaccharides (stachyose), pentasaccharides (raffinose), etc. The most widely distributed and free oligosaccharides in plants are sucrose.
Oligosaccharides are mostly polymerized from different sugars and can also be polymerized from the same monosaccharides, such as maltose and trehalose. Oligosaccharides have properties similar to monosaccharides: crystallinity, sweetness, easy solubility in water, difficult solubility or insolubility in organic solvents, and are easily hydrolyzed by enzymes or acids into monosaccharides with optical activity. When there are free aldehyde or ketone groups in the molecule, it has reducibility, such as maltose and lactose; When there are no free aldehyde or ketone groups in the molecule, it does not have reducibility, such as sucrose and gentian trisaccharide.
Polysaccharides are composed of more than 10 monosaccharide molecules, typically consisting of hundreds or even thousands of monosaccharide molecules. A polysaccharide composed of a single monosaccharide is called homopolysaccharide, with the general formula (CnHnOn), which can reach several thousand. Polysaccharides composed of two or more different monosaccharides are called heteropolysaccharides. In addition to monosaccharides, polysaccharides also contain uronic acids, deoxysugars, amino sugars, and sugar alcohols, and may have other substituents. Polysaccharides can be divided into two categories based on their functions. One is the support tissue of animals and plants that is insoluble in water, such as fiber ropes in plants and chitin in crustaceans. The other is the storage nutrient of animals and plants, which can be dissolved in hot water to form a gelatinous solution. With the development of science and technology, the biological activities of many polysaccharides have been discovered and used in clinical practice, such as polysaccharides from Acanthopanax senticosus, Ganoderma lucidum, Polygonatum sibiricum, and Astragalus membranaceus, which can promote the immune function of the human body. Lentinan has anti-cancer activity, and deer antler polysaccharides can resist ulcers.
Fungus polysaccharides have complex biological activities and functions, mainly including the following aspects:
1. Activation of macrophages: As macrophages play a major role in resisting various infections and anti-tumor activities, activation of macrophages can enhance the body’s ability to resist diseases. Polysaccharides such as shiitake mushroom polysaccharides and polysaccharides isolated and extracted from fungi such as Ganoderma lucidum, Tremella fuciformis, Auricularia auricula, Hericium erinaceus, Charactylodes macrocephala, and Cordyceps sinensis can significantly enhance the phagocytic function of peritoneal macrophages.
2. Activating lymphocytes: the immune system of cancer and AIDS patients is severely damaged due to chemotherapy and radiotherapy, and polysaccharide compounds can partially restore and strengthen the immune function of patients. Polysaccharides from Cordyceps sinensis, Honeysuckle fungus, Ganoderma lucidum, Tremella fuciformis, Hericium erinaceus, and Tremella fuciformis can all significantly enhance lymphocyte proliferation induced by haptoglobin A in vitro.
3. Promote interferon production: After 12 hours of in vivo administration, shiitake mushroom polysaccharides can promote the peak concentration of interferon in the plasma. Currently, polysaccharides from Ganoderma lucidum, Tremella fuciformis, Ganoderma lucidum, Poria cocos, Poria cocos, Poria cocos, Agaricus bisporus, Flammulina velutipes, Auricularia auricula, Agaricus bisporus, Agaricus bisporus, Cordyceps sinensis, and other polysaccharides have been extensively studied for their polysaccharides.
4. Promote the production of interleukin (IL): Tremella fuciformis polysaccharides can significantly increase the production of IL-2 in normal mouse spleen cells and significantly restore the secretion of IL2 in elderly mouse spleen cells. Brewing alcohol mother glucan can promote the production of I1 by peritoneal macrophages in mice. Carboxymethyl Poria polysaccharides, Ganoderma lucidum polysaccharides, Charactylodes macrocephala polysaccharides, and Armillaria polysaccharides can all promote the production of L-1 in mouse peritoneal giant cells.
5. Inducing tumor necrosis factor (TNF): Coriolus versicolor polysaccharide PSK can induce the expression of adhesive peripheral blood cytokine TNF -, which has an inhibitory effect on the growth of tumor cells. Mushroom polysaccharides can promote the release of tumor necrosis factor (TNF) from mouse peritoneal macrophages to regulate the body’s immune function.
6. Activate the reticuloendothelial system (RES): The reticuloendothelial system in organisms has the ability to engulf, remove aging cells, foreign bodies, and pathogens. Honeysuckle fungus and cordyceps polysaccharides can activate the reticuloendothelial system, significantly enhancing its activity in carbon clearance tests and increasing the production of red blood cell antibodies in mice and sheep.
Example of Extraction of Poria Polysaccharides
Poria cocos polysaccharides include two types: water-soluble and alkali soluble, with different extraction processes.
(1) Extraction of water-soluble polysaccharides
Weigh 150g of Poria cocos powder, add an appropriate amount of papain, and extract with 5-fold water. At the beginning of extraction, heat up to 60 ℃ and maintain at 60-70 ℃ for 40 minutes. Then extract in boiling water for 1 hour, centrifuge, and separate the supernatant. Extract the filter residue with 5 times the amount of water, combine the two extracts, concentrate under reduced pressure to 1/10 of the original volume, and use the Severge method to remove protein. Repeat at least 6 times. The clear liquid is then concentrated under reduced pressure, and the polysaccharide is precipitated with three times the amount of ethanol. It is left to stand overnight in the refrigerator and centrifuged to obtain the water-soluble Poria cocos crude polysaccharide.
2) Extraction of alkali soluble polysaccharides
Treat the water extracted Poria cocos residue with dilute alkali (0.5mol/L sodium hydroxide aqueous solution), as shown in the process flowchart.
When extracting, soak the residue of Poria cocos after water extraction in 5 times the amount of alkaline solution for 4 hours. At this time, the solution becomes viscous, and the supernatant is alkaline solution I; Extract the centrifugal residue with three times the amount of alkaline solution again to obtain alkaline solution II. Combine the alkaline solution, filter by suction, neutralize the filtrate with 10% acetic acid to pH 6.0, then add 3 times the amount of 95% ethanol, let it stand overnight at 4 ℃, centrifuge to obtain a precipitate, and after Smith dialysis degradation, wash it successively with distilled water, anhydrous ethanol, acetone, and ether, and vacuum dry to obtain Poria alkaloid soluble crude polysaccharide.
