Views: 0 Author: Site Editor Publish Time: 2023-04-14 Origin: Site
Lichens are a kind of highly genetically stable biological organisms formed by symbiotic bacteria (ascomycetes or spores) and symbiotic algae (cyanobacteria or green algae) after a long period of biological evolution, also known as lichen-type fungi. Lichens are an important class of organisms in natural ecosystems and widely exist in nature, including plateaus, grasslands, forests, arid deserts, rock surfaces, and even equatorial and polar regions. In taxonomy, lichens are regarded as an independent phylum. Currently, there are 522 genera and more than 13,500 species known. China is very rich in lichen resources, involving 232 genera and 1766 species, of which over 300 lichens are unique to China. The secondary metabolites produced by lichens have strong biological activity. Lichens have a long history of being widely used in folk antibacterial treatment. Because many secondary metabolites produced by lichens have strong antibacterial effects, lichens were officially taken as an important research object for screening antibiotic from 1940 to 1950, following penicillin. In fact, a large number of studies conducted in modern times have further confirmed the antibacterial effect of lichens.
Usnic acid is currently the most important and one of the most widely distributed lichenic acids, also known as lichenic acid. Usnic acid is a powerful furan antibiotic with optical activity. It is found in two forms (+) and (-) in lichens. According to reports, in the 1960s, the former Soviet Union made usnic acid into various dosage forms, which were widely used in the treatment of wounds, burns, chapped and other diseases. Because of its strong antibacterial, radiation resistant, antiseptic and other effects, currently usnic acid has been used in medicine, perfume, cosmetics and other industries, and added as a pure substance to toothpaste, mouthwash, deodorant, sunscreen and weight loss products. In recent years, research on rosinic acid has mostly focused on antibacterial, antiviral, insecticidal, anti-tumor, anti-inflammatory, and other aspects.
1. This product is a broad-spectrum antibiotic, which has a strong inhibitory effect on most Gram-positive bacteria and can also inhibit the growth of Mycobacterium tuberculosis. If used in combination with a small amount of streptomycin, its effect on inhibiting tuberculosis can be greatly enhanced.
2. Pale to golden yellow needle-like crystal, easily soluble in chloroform and glacial acetic acid, insoluble in hot alcohol, tasteless, odorless, non-toxic, non-corrosive, and non-volatile.
1. The scurf of the genus Usnea and the Usnea spp. attached to the bark of coniferous forests such as fir (white pine) and pine are generally called tree moss. Extracts of oak moss and tree moss with benzene or ethanol as solvent. The extract contains a large amount of phenolic acid and ketal compounds. These compounds have relatively large molecular weight, are non-volatile, and have no aroma. These compounds do not contribute much to the aroma of oakmoss and tree moss products. After a series of treatments, one of the above-mentioned by-products, lichenic acid, can be obtained.
2. After the lichen was dried, it was heated and extracted with acetone as solvent. Collect the extract, concentrate it to a small volume, let it stand still, the usnic acid can be crystallized, and the pure product can be obtained after recrystallization.
1. The preparation containing this product has obvious therapeutic effect on cancer patients. Clinically, it has certain curative effect against malaria. It has a certain effect on trauma, burns and skin diseases, cervix inflammation, cleft papilla, and prevention of perineal rupture. In addition, it can also be used as a raw material for the antibiotic "Pyramide".
2. It is used for hemostasis, antibacterial, anti-inflammatory, wound healing, anti-caries, can also remove dental plaque, enhance human immunity, and has a good effect on oral ulcers and vaginitis. Usually used as an additive in toothpaste and cosmetics.
3. Usnic acid, as a cosmetic auxiliary approved by CTFA, is a broad-spectrum antibiotic, which has a strong inhibitory effect on most gram-positive bacteria with a concentration of 50 μ g. Ml-1 can completely inhibit bacterial growth and is used as an efficient preservative in cosmetics. It has a selective inhibitory effect on Streptococcus, the main bacteria that cause oral diseases and dental caries. Usnic acid has curative effect on various skin diseases such as burns, infection, psoriasis and so on.